Nigerian Journal of Physiological Sciences
Nigerian Journal of Physiological Sciences (Niger. J. Physiol. Sci.) is a biannual publication of the Physiological Society of Nigeria. It covers diverse areas of research in physiological sciences, publishing reviews in current research areas and original laboratory and clinical research in physiological sciences.
Raw garlic homogenate ameliorates cardiometabolic effect of high caloric intake in Wistar rats
Fructose consumption has tremendously increased due to increased consumption of sweeteners in beverages, and this has been suggested to increase caloric intake. Higher caloric intake had been linked with diverse health consequences such as obesity, diabetes and cardiovascular diseases. Garlic (Allium sativum) has also been reported to be protective against adverse dietary effects. We hypothesized that increased caloric intake via sweetened drinks can cause hemorheologic, haematopoietic, nutritional, and metabolic derangements and that raw garlic homogenate consumption can mitigate these adverse effects. Therefore, we investigated the effects of increased caloric intake via sweetened drink as well as examined the potentials of raw garlic homogenate (RGH) to ameliorate such effects in Wistar rats. Twenty male Wistar rats were randomly divided into four groups (n=5): Control, Fructose (F) given fructose sweetened drink (FSD), Allium Sativum (AS) given raw garlic homogenate (RGH) (250 mg/kg/day) and F+AS given FSD and RGH (250 mg/kg/day) for nine weeks. Energy intake, haematopoiesis, metabolic risk factors, hemorheologic variables, fluid intake, liver enzymes and serum proteins were significantly increased by increased caloric intake via FSD consumption, however, RGH mitigated these effects in treated rats as observed from comparison between groups F and F+AS rats. The findings of this study revealed the fact that sugar sweetened beverages can increase caloric intake tremendously, even in the face of significantly reduced food intake and that RGH can ameliorate the adverse effects induced by high caloric intake in Wistar rats.
Sva prava zadržana (c) 2025 Nigerian Journal of Physiological Sciences https://creativecommons.org/licenses/by/4.0
Methanol Leaf Extract of Azadirachta Indica Attenuates Lead Acetate-Induced Cardiorenal Toxicity in Rats
The toxic effect of lead on heart and kidney tissues has been associated with its ability to cause oxidative stress. Azadirachta indica is a versatile medicinal plant with diverse pharmacological potentials. The ameliorative effect of the methanol extract of Azadirachta indica leaf (MEAI) was studied on male Wistar rats exposed to lead acetate (PbAc). Preliminary assays were carried out to assess the total phenolic, total flavonoid, and total flavonol contents of the extract using quantitative phytochemical assays. Cytotoxicity was tested on Vero cells using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide [MTT] assay. Wistar rats were grouped into control, toxicant, and treated groups and administered distilled water, 0.1/0.2% PbAc, and 0.1/0.2% PbAc + 100/200 mg/kg MEAI respectively. Results showed that the total phenolic content of MEAI was negligible while the flavonoid (300±0.12 mg Quercetin/g) and flavonol (80±0.06 mg Rutin/g) contents were significant. LC50 value of MEAI was 0.05 mg/mL. MEAI significantly (p<0.05) increased weight, reduced blood pressure, and increased blood flow/volume in the treated groups. There was significant (p<0.05) reduction in hydrogen peroxide (H2O2) and significant (p<0.05) increase in Nitric oxide (NO) in some of the treated groups. Histopathology revealed that MEAI reduced the infiltration of inflammatory cells in the heart and kidney tissues of the treated groups when compared to those of the lead-exposed untreated groups. There were variations in the expression of cytochrome C in the heart and kidney tissues of the experimental groups compared with the control. This study demonstrates MEAI as a potential drug candidate in the amelioration of lead acetate-induced cardiorenal toxicity by inhibition of oxidative stress, inflammation and by regulating apoptosis.
A novel gedunin-2-hydroxypropyl-β-cyclodextrin inclusion complex improves anti-nociceptive and anti-inflammatory activities of gedunin in rodents
Gedunin is a bioactive compound, obtained from Entandrophragma angolense (EA), which has limited therapeutic usefulness due to poor aqueous solubility and first-pass effects. Cyclodextrins are cyclic oligosaccharides that form complexes with poorly soluble compounds, thus enhancing their pharmacological activity. In this article, we evaluated the pharmacological activities of gedunin-2-hydroxypropyl-β-cyclodextrin complex (GCD) in rodents. The antinociceptive activity of GCD (50, 100, 200 mg/kg) and Gedunin (50mg/kg) was tested in acetic acid-induced writhing and formalin-induced paw licking in mice. The anti-inflammatory activity was investigated in carrageenan-induced paw oedema and air pouch inflammation models in rats. Leucocytes counts, Tumour Necrosis Factor-alpha (TNF-α) level, nitric oxide, malondialdehyde, reduced glutathione, and myeloperoxidase enzyme activities were assessed in the air pouch exudate. The GCD (200mg/kg) significantly decreased writhing response, reduced licking duration and decreased oedema compared with gedunin and control. Exudate volume and leucocyte count were significantly reduced by GCD (200 mg/kg), it decreased myeloperoxidase activity and inhibited TNF-α release. The carrageenan-induced GSH depletion, increased malondialdehyde and nitrite levels were significantly reversed by GCD (200 mg/kg) relative to gedunin and control. The GCD complex demonstrated significant antinociceptive and anti-inflammatory activities relative to gedunin alone via mechanisms associated with inhibition of oxidative stress and inflammation in rodents
Sva prava zadržana (c) 2022 Nigerian Journal of Physiological Sciences https://creativecommons.org/licenses/by/4.0
Essential Metals in the Brain and the Application of Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry for their Detection
Metals are natural component of the ecosystem present throughout the layers of atmosphere; their abundant expression in the brain indicates their importance in the central nervous system (CNS). Within the brain tissue, their distribution is highly compartmentalized, the pattern of which is determined by their primary roles. Bio-imaging of the brain to reveal spatial distribution of metals within specific regions has provided a unique understanding of brain biochemistry and architecture, linking both the structures and the functions through several metal mediated activities. Bioavailability of essential trace metal is needed for normal brain function. However, disrupted metal homeostasis can influence several biochemical pathways in different fields of metabolism and cause characteristic neurological disorders with a typical disease process usually linked with aberrant metal accumulations. In this review we give a brief overview of roles of key essential metals (Iron, Copper and Zinc) including their molecular mechanisms and bio-distribution in the brain as well as their possible involvement in the pathogenesis of related neurodegenerative diseases. In addition, we also reviewed recent applications of Laser Ablation Inductively Couple Plasma Mass Spectrophotometry (LA-ICP-MS) in the detection of both toxic and essential metal dyshomeostasis in neuroscience research and other related brain diseases
The Effect of Acute Administration of the Aqueous Calyx Extract of Hibiscus sabdariffa on Blood pressure, Heart rate and Double Product of Apparently Healthy Human Subjects during Different Postures
The aqueous calyx extract of Hibiscus sabdariffa (HS) is widely consumed as a beverage in Northern Nigeria and other parts of the world. HS has been reported to lower blood pressure (BP) in animals and man. However, not much is known about the effect of HS on BP in different postures. We tested the hypothesis that HS may lower BP, heart rate (HR) and heart rate-pressure product or double product (DP) by attenuating the discharge of the autonomic nervous system in different postures. Experiments were performed in accordance with the Principles of the Declaration of Helsinki. Following ethical approval and informed consent, BP and HR were measured in different postures (supine, sitting and standing) in apparently healthy human subjects (n=20) before and after (+HS) the oral administration of 15mg/Kg HS. Mean arterial pressure (MAP; taken as representative BP) and DP were calculated. Results are expressed as mean ±SEM. Paired t test and ANOVA with a post hoc Bonferroni test were used for statistical analyses. P<0.05 was considered significant. In the supine position MAP, HR and DP were significantly (P<0.0001 each) reduced in the presence of HS (85.6±1.7mmHg, 72.1±1.1/min and 8716±320mmHg.bpm) compared to its absence (89.6±2.0mmHg, 73.7±1.6/min and 8921±444mmHg.bpm). Similar trends were observed in the sitting position in the presence of HS (85.4±2.7mmHg, 73.7±1.8/min and 9098±345mmHg.bpm vs its absence: 91.4±2.3mmHg, 77.1±1.9/min and 9388±478mmHg.bpm; P<0.0001, P<0.0001 and P=0.007 respectively) and in the standing position (+HS: 89.3±2.0mmHg, 78.1±1.8/min and 10164±230mmHg.bpm vs its absence: 94.3±2.1mmHg, 81.8±2.3/min and 10742±268mmHg.bpm; P<0.0001, P<0.0001 and P=0.007 respectively). In the absence of HS, HR and DP were significantly higher in the standing posture (81.8±2.3/min, 10742±268mmHg.bpm) compared to the sitting (77.1±1.9/min, 9388±478mmHg.bpm; P<0.05 and P<0.0001 respectively) and the supine (73.7±1.6/min, 8921±444mmHg.bpm; P<0.001 each) postures while the BP remained similar. A similar trend was observed across the three postures in the presence of HS although the parameters were significantly lower. It is concluded that HS lowered BP, HR and DP by modulating autonomic mechanisms through the inhibition of both parasympathetic withdrawal and sympathetic nervous system discharge across the postures. Also the standing posture is associated more with a higher sympathetic nervous system discharge and a higher cardiac oxygen demand and workload than the sitting and supine postures in the absence or presence of HS.
Effect of Angiotensin receptor blockade on Plasma Osmolality and Neurohumoral Responses to High Environmental Temperature in Rats Fed a High Salt Diet
Plasma osmolality (pOsmol) and neurohumoral signals play important roles in the pathophysiology of cardiovascular diseases. Our study investigated the effect of high environmental temperature (HET) on neurohumoral responses and pOsmol in rats fed a high salt diet (HSD), with and without angiotensin II receptor blockade (ARB), using telmisartan. Fifty-six male 8-week old Sprague-Dawley rats (95-110g) were randomly assigned into seven groups of 8 rats. These included control rats (I) fed with 0.3% NaCl diet (normal diet, ND); salt-loaded rats (II) fed with 8% NaCl (high salt) diet; ND rats (III) exposed to HET (38.5±0.5oC ) 4 hours daily per week; rats (IV) fed with 8% NaCl diet and exposed to HET daily. Others included rats (V) fed with 8% NaCl diet and treated with telmisartan (30mg/kg); ND rats (VI) exposed to HET and treated with telmisartan; rats (VI) fed with 8% NaCl diet, exposed to HET and treated with telmisartan. Plasma angiotensin II, aldosterone, vasopressin and norepinephrine (NE) concentrations were determined by ELISA technique; pOsmol from plasma K+, Na+ and Urea. HSD combined with HET in rats synergistically increased pOsmol (P<0.001) with an associated non-synergistic rise in fluid intake (P<0.001), fluid balance (P<0.001), plasma angiotensin II (P<0.01) and aldosterone (P<0.05), NE (P<0.001) and vasopressin (P<0.05) concentrations compared to control. Telmisartan did not alter pOsmol in all the treated-rats, but normalized fluid intake levels and plasma vasopressin in the rats exposed to either HSD or HEt alone. Prolonged exposure of rats to hot environment exacerbated the effect of excess dietary salt on pOsmol, with no effect on angiotensin II-mediated neurohumoral responses
Sva prava zadržana (c) 2021 Nigerian Journal of Physiological Sciences https://creativecommons.org/licenses/by/4.0
Physiological Changes in Serum Calcium, Phosphate, Vitamin D, Parathyroid Hormone and Calcitonin During Pregnancy and Lactation in Randomised Population of Zaria Women
Pregnancy and lactation are usual but stressful physiological conditions accompanied by changes in calcium and phosphate metabolism and their regulatory hormones which may lead to calcium-related disorders in pregnant women. This study aimed to evaluate the changes in serum levels of calcium, phosphate, vitamin D and their regulatory hormones in pregnant and lactating women in Zaria, Nigeria. A cross‑sectional descriptive study was conducted at Ahmadu Bello University Teaching Hospital, Zaria for three (3) months. Blood samples were collected, anthropometric measurements (weight, height and body mass index) of 179 women were taken. Serum calcium, phosphate, vitamin D, parathyroid hormone and calcitonin were determined using standard methods. Data were presented as mean ± SD, analysis was performed using one-way ANOVA and Pearson’s correlation analysis. Values were considered significant at p ≤ 0.05. There was a significant decrease in serum calcium concentration (p < 0.01) during the third trimester of pregnancy and lactation. An increase in serum concentration of vitamin D, parathyroid hormone, and calcitonin in the 2nd trimester and a decrease during the third trimester and lactation although not statistically significant when compared with the control. There was a negative correlation between serum calcium concentration and gestational age (r = 0.255) while no correlation between gestational age and serum phosphate concentration. Changes in serum calcium, vitamin D, parathyroid hormone and calcitonin during pregnancy and lactation has been demonstrated suggesting a relationship between calcium metabolism and these hormones at some stages of pregnancy
Age-Dependent Effects of Copper Toxicity on Connective Tissue Structural Stability in Wistar Rats Skin
Over the last three decades, there has been increasing global concern over the public health impacts attributed to direct and indirect environmental pollution, in particular, the global burden of disease. The World Health Organization estimates that, about a quarter of the diseases facing mankind today occur due to prolonged exposure to environmental pollution; the health of 200 million people in lower-income countries is at risk from toxins such as lead and copper or mercury, more than from AIDS, tuberculosis and malaria combined and that, nearly a quarter of deaths in developing countries including Nigeria and Ghana, are linked to pollution. The purpose of the study was to investigate the effects of the ingestion of large dose of copper on the structural stability of collagen molecules, as well as reveal age-dependent differences in the phenomena. The content of de novo synthesized collagen was determined by hydroxyproline concentration using Stegmann-Staeder’s method as modified by Utevskaya and Persky; the nature of intra- and inter-molecular covalent cross-links in collagen matrix was estimated by electrophoretic separation of products of partial thermal denaturation of collagen in polyacrylamide gel. There was intensification of synthesis over degradation in young rats, and that administration of copper led to a decrease in collagen solubility. Effects of copper on the structural stability of collagen appeared mostly in young rats.
Effects of Ruzu, a Polyherbal Mixture, on Neurobehaviour and Expression of Serotonin and Dopamine Transporters in Rats
There is increased possibility that combined herbal constituents may interact to increase toxicity and lower efficacy. Ruzu herbal bitters (RHB) is a blend of extracts from Curculigo pilosa, Uvaria chamae, and Citrullus colocynthis, each of which has been shown to possess important bio-effects. There is anecdotal evidence for efficacy of RHB in neurological disorders; however, there are no data on possible neurotoxic effects of RHB. Using behavioural, biochemical and molecular indices as surrogates of neurotoxicity, this study therefore evaluated the nervous system effects of RHB. Twenty male Wistar rats were divided into two groups – a control group and RHB group (n=10). RHB (0.5ml/kg) was administered to the RHB group twice daily while control group took water (0.5ml/kg). Treatments lasted 6 weeks after which behavioural tests were carried out. Animals were subsequently sacrificed and the expression of serotonin transporter (SERT) and dopamine transporter (DAT) was determined in the striatum by immunofluorescence while specific activities of catalase, alkaline phosphatase and gamma glutamyltransferase were determined. In the elevated plus maze and light and dark box tests which are models of anxiety, animals treated with RHB showed significant anxiety compared to control. They also showed impaired locomotor activity in the open field and wire hang tests. The activity of catalase was significantly increased in the brain of the RHB treated rats while an increase in the expression of both DAT and SERT was observed in the striatum
Changes in Serum Electrolytes, Urea and Creatinine in Nicotiana tabacum-treated Rats
Tobacco, which is a product of Nicotiana tabacum, has nicotine as its principal phytochemical. Nicotine has been reported to be an addictive drug and the leading cause of tobacco addiction worldwide with consequent renal implications. Therefore, this study was conducted to investigate the effect of the aqueous extract of Nicotiana. tabacum on serum electrolytes, urea and creatinine levels as indices of renal function in male rats. A total of 18 male wistar rats weighing 140-230g were used for this study. The animals were randomly divided into three groups (A, B and C), containing 6 rats each. Group A served as control while Group B and C were orally administered sublethal doses of 20 and 30 mg/kg body weight of the Nicotiana. tabacum extract respectively once per day for three weeks. At the end of the experimental period, all the animals were sacrificed. Blood samples were collected for biochemical assay. The results showed a significant increase (p<0.05) in the serum concentration of sodium, potassium and urea levels of rats treated with the extract when compared with the control. However, serum concentrations of chloride, bicarbonate and creatinine showed no significant appreciable differences between the treated groups and the control group (p<0.05). In conclusion, the study showed that aqueous extract of Nicotiana tabacum is associated with renal dysfunction with consequent hypernatremia and hyperkalemia, and may also suggest impaired urea clearance by the kidneys in male wistar rats.
Skull Shape Variations in the Eidolon helvum (African Fruit Bat) Based on Geographical Location
The shape and size of a skull provides insight into the age, breed and gender of the animal. Skull shape variations have been reported in different animals, with some theories linking these variations to evolution and/or migration. This study assessed the variations observed in the skull shape, size and gross morphometrics of two groups of the Eidolon helvum obtained from two geographical regions in Nigeria (south and north). All skulls were rostro-caudally elongated, having a dolichocephalic appearance. The skulls from the north had a distinct dome shape, with a more prominent zygomatic process, absence of a ‘diastema’ and an extra upper molar, while the southern skulls showed a more dorsally flattened skull and a less prominent zygomatic process. The shape of the sagittal crest was different in the two groups, while there was the presence of an accessory infraorbital foramen in some of the southern skulls. The southern skulls lacked the palatine foramen. The lacrimal foramen was observed to be more caudally placed in the southern skulls. Values for most linear measurements were higher in the northern skulls, although statistically significant difference was not present in all. The value for the neurocranial volume was considerably higher in the northern skulls (4.41 ± 0.28 mls) relative to the southern skulls (2.0 ± 0.27 mls). Statistically significant differences were not observed between males and females (within regions). Data obtained from this study may find application in evolution and migration studies, wildlife medicine and surgery and comparative and forensic anatomy.
Hypoglycemic, Hypolipidemic and Antioxidant Potentials of Ethanolic Stem Bark Extract of Anacardium occidentale in Streptozotocin-Induced Diabetic Rats
Diabetes mellitus is one of the most widespread diseases affecting the world’s population causing substantial morbidity, mortality and long-term complications. This study was designed to investigate possible hypoglycemic, hypolipidemic and antioxidant effect of ethanolic stem bark extract of Anacardium occidentale in streptozotocin (STZ)-induced diabetic rats. Twenty-eight STZ (60 mg/kg body weight)-induced diabetic, male albino rats were randomly distributed into Groups II-V (7 rats each) and orally administered with water, metformin (14.2 mg/kg), 200 mg/kg Anacardium occidentale extract and 400 mg/kg Anacardium occidentale extract respectively daily for 15 days. Group I rats were untreated with STZ and serves as control all under the same sham handling. Blood samples were taken for measurement of fasting blood glucose (FBG) and lipid profile. Liver and kidney tissue samples were taken for determination of glycemic indices (glucose and glycogen), as well as redox status markers such as malondialdehyde (MDA), total glutathione (GSH), activities of superoxide dismutase (SOD) and glutathione-s-transferase (GST). Results showed that treatment with 200 and 400 mg/kg Anacardium occidentale stem bark extract reversed hyperglycemia and hyperlipidemia induced by STZ similar to what was observed with the standard drug, metformin. Similarly, both extract concentration produced a significant reduction in MDA while the activity of SOD and GST, as well as concentration of GSH were elevated. This study suggested that ethanolic stem bark extract of Anacardium occidentale at 200 and 400 mg/kg can ameliorate diabetes and its associated complications via its hypoglycemic, hypolipidemic, antioxidant and free radical scavenging properties
Ethanolic extract of Camellia sinensise licited hypoglycemic but lacked antimalarial properties in Plasmodium berghei-infected diabetic mice
The in vivo antimalarial and antidiabetic activity of extract of Camellia sinensis (ECS) in alloxan-induced diabetic and Plasmodium berghei-infected mice were investigated. Eighty-four BALB/c mice divided into sets 1 & 2 infected with P. berghei and 2 & 3 injected with alloxan received either distilled water, ECS (300mg/kg), Chloroquine (CQ-10mg/kg) or Metformin (250mg/kg). Results showed significant increases (p<0.05) in percentage parasitaemia of P. berghei-infected mice treated with ECS and P. berghei-diabetic mice. Furthermore, ECS significantly decreased (p<0.05) blood glucose and PCV in diabetic and P. berghei-diabetic mice. ECS regenerated pancreatic islet cells in P. berghei-infected-diabetes but lacked appreciable antimalarial activity
Angiotensin converting enzyme inhibitor captopril prevents neuronal overexpression of amyloid-beta and alpha-synuclein in Drosophila melanogaster genetic models of neurodegenerative diseases
Background: Parkinson disease (PD) and Alzheimer’s disease (AD) are progressive neurodegenerative disorders characterized by loss of selective neurons in discreet part of the brain. The peptide angiotensin II (Ang II) plays significant role in hippocampal and striatal neurons degeneration through the generation of reactive oxygen species. Blockade of the angiotensin converting enzyme or ATI receptors provides protection in animal models of neurodegenerative diseases. In the present study, the neuroprotective effect of captopril was investigated in Drosophila melanogaster model using the UAS-GAL4 system to express the synuclein and Aβ42 peptide in the flies’ neurons. Methods: The disease causing human Aβ42 peptide or α-syn was expressed pan-neuronally (elav-GAL4) or dopamine neuron (DDC-GAL4) using the UAS-GAL4 system. Flies were either grown in food media with or without captopril (1, 5, or 10µM). This was followed by fecundity, larva motility, negative geotaxis assay (climbing) and lifespan as a measure of neurodegeneration. Results: Elav-Gal4<Aβ or DDC-GAL4<α-syn flies displayed significant decrease in larva motility when compared with normal control (w1118) which was reversed by the supplementation of the media with captopril (5 or 10 mM) indicative of neuroprotection. Interestingly, supplementation of flies’ media with captopril improved climbing activity in Elav-Gal4<Aβ or DDC-GAL4<α-syn flies when compared with vehicle treated only. Moreover, flies grown on captopril caused no significant change in lifespan. Conclusion: Findings from this study confirmed the neuroprotective action of captopril in genetic or familial forms of neurodegeneration.
Teratogenic Effect of Aqueous Leaf Extract of Aspilia africana on The Dentate Gyrus of Wistar Rat Fetuses
Aspilia africana is an herbal plant widespread in Africa used for medicinal purposes and also used by pregnant women for health related issues. This study was aimed at investigating the teratogenic effect of aqueous leaf extract of Aspilia africana on the dentate gyrus of albino wistar rat fetuses. Twenty (20) female adult rats weighing between 190-205g were used for this study. The rats were divided into four groups; control, low dose, medium dose and high dose with each group containing five rats. Pregnancy was induced by caging the female rats with sexually matured males. The presence of vaginal plug and tail structure in the vaginal smear the following morning confirmed coition, and it was regarded as day 0 of pregnancy. The control group was given distilled water. The low dose, medium dose, and the high dose groups received 750mg/kg, 1000mg/kg, and 1250mg/kg body weight of aqueous leaf extract of Aspilia africana through an orogastric tube from day 7-11 of gestation. On the 20th day of gestation, the animals were sacrificed using chloroform-inhalation method. Their fetuses were harvested via uterectomy, the brain was excised and fixed in 10% buffered formalin, and then routine histological processes were carried out. Staining was done using Haematoxylin and Eosin method. Histological observation of the dentate gyri of experimental groups revealed marked distortion, reduction of the polymorphic layer, hyperplasia and hypertrophy of cells in the molecular and granular layer especially in the high dose group whose mothers received 1250mg/kg of the extracts. The result suggests high doses of aqueous leaf extract of Aspilia africana may be teratogenic to the dentate gyrus of Wistar rat fetuses.
Gestational Nutrition as a Predisposing Factor to Obesity Onset in Offspring: Role for Involvement of Epigenetic Mechanism
Maternal lifestyle has been implicated as a predisposing factor in the development of metabolic disorders in adulthood. This lifestyle includes the immediate environment, physical activity and nutrition. Maternal nutrition has direct influence on the developmental programming through biochemical alterations and can lead to modifications in the fetal genome through epigenetic mechanisms. Imbalance in basic micro or macro nutrients due to famine or food deficiency during delicate gestational periods can lead to onset of metabolic syndrome including obesity. A major example is the Dutch famine which led to a serious metabolic disorder in adulthood of affected infants. Notably due to gene variants, individualized responses to nutritional deficiencies are unconventional, therefore intensifying the need to study nutritional genomics during fetal programming. Epigenetic mechanisms can cause hereditary changes without changing the DNA sequence; the major mechanisms include small non-coding RNAs, histone modifications and most stable of all is DNA methylation. The significance association between obesity and DNA methylation is through regulation of genes implicated in lipid and glucose metabolism either directly or indirectly by hypomethylation or hypermethylation. Examples include CPT1A, APOA2, ADRB3 and POMC. Any maternal exposure to malnutrition or overnutrition that can affect genes regulating major metabolic pathways in the fetus, will eventually cause underlying changes that can predispose or cause the onset of metabolic disorder in adulthood. In this review, we examined the interaction between nutrition during gestation and epigenetic programming of metabolic syndrome.
Glycated Haemogloin, Fasting Plasma Glucose, Plasminogen Activator Inhibitor Type-1, and Soluble Thrombomodulin Levels in Patients with Type 2 Diabetes Mellitus
Diabetes mellitus has become increasingly prevalent over the years. The chronic hyperglycaemia of diabetes is associated with long-term damage, dysfunctions, and failure of different organs suggesting that the most effective tool to prevent complications is the effective control of hyperglycaemia itself. The study is set to determine the effect of glycemic control on plasminogen activator inhibitor type 1 (PAI-1), soluble thrombomodulin (STM) alongside fasting plasma glucose (FPG) and glycated hemoglobin (HbA1c) among type 2 diabetic subjects. One hundred diabetic subjects accessing care at the University of Calabar Teaching Hospital Calabar and 100 non –diabetics that served as controls were enrolled. Blood samples from participants were analyzed for FPG, HbA1c, PAI-1 and STM by standard methods. The result shows 74% of the diabetic to be females. Half of the diabetics were managed on only oral anti-diabetic drugs while the remaining half were either on insulin injection or a combination of oral and insulin injection. Poor glycemic control was observed in 56% of the studied subjects. The mean age of 54.69 ± 9.94 years for the diabetics was comparable to the age-matched controls (p=.097). Diabetics showed significantly higher FPG, HbA1c, PAI-1and STM (P=0.001) compared to control values. Correlations between STM, PAI 1 and glycated hemoglobin (figures 2 p=0.001, p =0.001) and STM, PAI-1 and FPG revealed significantly robust association (p=0.001, p=0.001). The study concludes that there is poor glycemic control among the treated diabetic subjects with PAI-1 and STM showing a very strong positive correlation with HbA1c than FPG.
Hippocampal Astrogliotic Reduction in Scopolamine Hydrobromide-Induced Alzheimer’s Type Cognitive Dysfunction Wistar Rats Following Administration of Aqueous Extract of Telfairia Occidentalis (pumpkin) seeds.
Astrocytes are small star-shaped glial cells that maintain normal human brain physiology including secretion of several active compounds and the formation of blood brain barrier. Reactive astrocytes support regenerating axons and also, actuate some genes responsible for the induction of synapse formation. In this study, the effect of aqueous extract of Telfairia occidentalis seeds on hippocampal astrogliosis was probed using scopolamine-induced Alzheimer’s type cognitive dysfunction Wistar rats. Thirty Wistar rats weighed between 180-200g were randomly grouped into five designated A, B, C, D and E. Each group contained six rats. Alzheimer’s type cognitive dysfunction was induced in groups B to E by administering intraperitoneally, 1 mg/kg body weight of scopolamine for seven days before Donepezil and the aqueous extract of Telfairia occidentalis seeds for fourteen days. Twenty-four hours after the last administration, the animals were sacrificed; their brain tissues perfused and stained with glial fibrillary acidic protein (GFAP) dye. Results revealed prominently stained astrocytes with their processes intact (group A). Some densely stained numerous astrogliosis with hypertrophied fibres were noticed in group B. Group C demonstrated prominent astrocytes with hypertrophied fibres, group D, moderately stained astrogliosis with hypertrophied fibres while group E showed numerous astrocytes with prominent nuclei and hypertrophied fibres. In conclusion, there was reduced hippocampal astrogliosis mostly in group D treated with Telfairia occidentalis which may neutralize oxidative stress and enhanced learning and memory in the Wistar rats of the present study.
Ficus vogelii methanol leaf extract ameliorates inflammation and arthritis by modulating osmotic fragility in C57BL/6J mice
The study evaluated the membrane-stabilizing potentials in red blood cells and anti-inflammatory properties in C57BL/6J mice of the methanol leaf extract of Ficus vogelii. Animals were treated orally with different doses of the extract (50, 100, 200 mg/kg) for 30 days and their blood was measured for membrane stability at different saline concentrations. Diclofenac (12.5 mg/kg) or Indomethacin (10 mg/kg) was used as standard in the anti-inflammatory studies. The mean corpuscular fragility (MCF) values and their corresponding percentage stabilization increased significantly (p≤0.05) in the treatment groups compared to the negative control. Treatment of mice with 50, 100 and 200 mg/kg of the extract significantly (p≤0.05) inhibited carrageenan-induced paw oedema in mice. The highest dose (200 mg/kg) showed lower anti-inflammatory activity compared to Diclofenac (12.5 mg/kg). Daily administration of the extract significantly (p≤0.05) suppressed adjuvant-induced paw arthritis by day 15 and 30 post arthritis induction. Ficus vogelii extract inhibited granuloma formation significantly. The anti-inflammatory effects of methanol leaf extract of Ficus vogelii on granuloma formation were comparable to that of Indomethacin (10 mg/kg). In summary, this study showed that the methanol leaf extract of Ficus vogelii possessed membrane-stabilizing potentials and anti-inflammatory properties, therefore, providing further proof that the leaves contain an active compound with potent anti-inflammatory activity
Aquoeus Extracts of Daucus Carota (Linn) Protected the Postnatal Developing Cerebellum of Wistar Rats Against Arsenic-Induced Oxidative Stress
The neuroprotective effects of the aqueous extract of Daucus carota (Dc) tuber against arsenic-induced oxidative damage on the developing cerebellum of Wistar rats were studied. Twenty-five pregnant rats (110-200g) were divided into five groups (n=5) – control received distilled water; Arsenic (As); Dc (200mg/kg); Dc (200mg/kg) +As; Vitamin C (Vc) (100mg/kg) +As. The pregnant rats in all the groups were treated orally from the first day of pregnancy to postnatal day 21. The Dc extract and Vc were administered one hour before the administration of As. Body weight of the pups on days 1, 7, 14, 21 and 28 were recorded, while neurobehavioural (forelimb grip strength and negative geotaxis) tests were done on day 21 pups. The rats were sacrificed and cerebellar tissues were collected for oxidative stress, histological (H and E), and immunohistochemical studies. Decreased forelimb grip strength, increased lipid peroxidation and decreased glutathione, glutathione peroxidase, catalase and superoxide dismutase was observed in the As group compared with the control and other treated groups. Histologically, the cerebellar cortex of the As pups showed persistent external granular layer (EGL) on postnatal day 21, reduced thickness of the molecular layer (ML) on postnatal day 28, pyknotic and depleted Purkinje cells compared with the control and other treated rats. Immunohistochemical evaluations of the cerebellar cortex showed astroliosis in the As-treated group on day 21 pups compared with the control and other treated groups. Aqueous extracts of Daucus carota and Vitamin C reversed the toxicity caused by arsenic. From the results of the study, arsenic-induced oxidative stress with morphological alterations in the perinatal developing rat cerebellum. Extracts of Daucus carota exhibited antioxidant activity as such may be a potential neuroprotective agent.
SEX-SPECIFIC SUB-ACUTE TOXICITY AND IMMUNOMODULATORY PROFILE OF A NIGERIAN POLYHERBAL SUPPLEMENT (NAPHERBS) IN ALBINO WISTAR RATS
NaPherbs, a Nigerian-based polyherbal supplement compounded with Moringa oleifera, Vernonia amygdalina, Garcinia kola, etc. is consumed locally as an immune-boosting nutraceutical. In this study, we investigated its preliminary immune-boosting mechanisms and sub-acute toxicity profile in both male and female albino Wistar rats. A total of 40 Wistar rats (20 males and 20 females) were randomly allotted to 5 experimental groups (n=8, 4 males and 4 females); control, 125, 250, 500 and 1000 mg/kg/day of NaPherbs for 30 consecutive days. The animals were anesthetized, and cardiac puncture was used to obtain serum for biochemical assays such as the serum lipid profile, immunoglobulins concentration, proinflammatory cytokines’ concentration and liver function enzymes; and whole blood for hematological assessment. In vivo antioxidant assays were carried out also on the liver homogenates, while the liver and kidneys were examined histologically in both male and female animals. There was a dose-dependent increase in the neutrophil: leucocyte ratio in the female animals. This has been linked to physiological stress, underlying disease condition and most recently a risk factor for early onset chronic kidney disease (CKD). NaPherbs did not pose any major cardiovascular risk across the groups, and there seemed to be some level of cardioprotection judging from the reduction in low-density lipoprotein cholesterol (LDL-c), triglyceride (TG) and total cholesterol (TC) observed in both sexes. The antioxidant indices assayed for were not significantly (P<0.05) affected by NaPherbs treatment, except for the catalase enzyme which was significantly increased in the female animals. As a purported immune-boosting supplement, we carried out a preliminary investigation on its effect on pro-inflammatory cytokines and immunoglobulins. NaPherbs did not significantly (P<0.05) alter these indices. Histological examination of the liver and kidneys showed that NaPherbs did not cause any major deleterious effect to these organs, except for mild infiltration of the sinusoids with inflammatory cells in the hepatocyte. NaPherbs showed a consistent profile of safety across the animals and doses considered in this study. However, further immunologic assays must be explored to validate its immune boosting claims and more specific toxicity assays must be employed to focus more on neurotoxicity, nephrotoxicity and gonadotoxicity in both sexes.
SODIUM ACETATE ATTENUATES FRUCTOSE-INDUCED MITOCHONDRIAL DYSFUNCTION AND CARDIOMETABOLIC DISORDERS IN PREGNANT WISTAR RATS
Cardiometabolic disorder is a leading cause of mortality, and mitochondrial dysfunction plays a significant role in its pathophysiology. The mechanisms by which acetate improves fructose-induced cardiometabolic disturbances in pregnancy remain unclear. This study aimed at investigating the role of acetate in modulating the fructose-induced cardiometabolic risks in pregnancy. Thirty-six female Wistar rats (120-150g) were divided into six groups, n=6. A total of 18 rats were made pregnant and 18 non-pregnant. The groups consisted of control (C), fructose (F), and fructose-acetate (FA). The FA group received 10% (w/v) fructose plus sodium acetate (200mg/kg) and distilled water. After three weeks, animals were anesthetized with ketamine (90mg/kg) and xylazine (10mg/kg). Blood and tissue homogenates were analyzed, and data were expressed as mean ± SEM, with significant difference accepted at p < 0.05. Compared to control, fasting blood sugar (FBS), triglyceride-glucose index (TyG), circulatory free fatty acids (FFA), uric acid (UA), malondialdehyde (MDA), and lactate dehydrogenase (LDH) were significantly higher in fructose-treated pregnant rats, and non-pregnant rats. In contrast, high-density lipoprotein-cholesterol (HDL), pyruvate dehydrogenase (PDH), and cardiac aconitase activities were significantly lower in both non-pregnant and pregnant rats, with a more profound effect seen in pregnant rats. Meanwhile, pregnancy significantly exacerbated the fructose-induced alteration in UA, FFA, TG, HDL and MDA. Fructose-induced cardiometabolic alterations were mitigated by acetate irrespective of the gestational status. Acetate restores mitochondrial oxidative capacity in pregnancy, making it a potential therapeutic agent for improving mitochondrial metabolic activities in debilitating gestational cardiac disorders.
Comparative study on effects of Cymbopogon citratus (DC.) Stapf and Mangifera indica (L.) on sperm indices of male albino rats
ABSTRACT: The effects of various doses of Cymbopogon citratus (DC.) Stapf and Mangifera indica (L.) ethanolic leaf extract was investigated on fertility of male albino rats. Twenty-five (25) adult male rats were randomly grouped into five (5) cages (n=5). Control rats were given distilled water while experimental groups were daily administered ethanol leaf extract of C. citratus and M. indica through oral gavage at 150 and 300 mg/kg body weight, respectively; for 21 days. After the 21st day of post exposure (PE), experimental animals were sacrificed and their testes extracted and fixed. Sperm count, sperm morphology and sperm motility were assessed. C. citratus extract significantly increased mean sperm count of the treated rats at both 150 mg/kg body weight (272.00±7.47x106/ml) and 300 mg/kg body weight (297.00±3.62) groups, compared to those of M. indica extract (113.20±12.51x106/ml) and (27.60±3.67x106/ml) for 150 and 300 mg/kg body weight, respectively. Also, C. citratus produced a reduction in abnormal sperm morphology (15.20±1.77%) and (17.00±2.00%) for 300 and 150 mg/kg body weight, respectively; compared to M. indica extract (64.00±1.87%) and (51.00±3.32%) for 300 and 150 mg/kg body weight, respectively. M. indica significantly (p<0.05) reduced sperm motility while increasing sperm morphology indices of rats in all doses. However, C. citratus extract produced significant increase in sperm motility and a corresponding decrease in sperm morphology across the dose groups compared to M. indica extract. C. citratus boosted sperm count while M. indica decreased sperm count. The findings in this research indicated that C. citratus may influence fertility by stimulating sperm count production than M. indica, compared with control, and this effect is dose-dependent. Keywords: Cymbopogon citratus, Mangifera indica, human fertility control, contraceptives, family planning, sperm indices.
Perception of 1 st year MBBS students regarding model making as a learning method: Fostering Creativity, Teamwork, and Conceptual Understanding in Physiology
Background: Active learning strategies are increasingly emphasized in medical education to enhance engagement, understanding, and higher-order cognitive skills. Model-making competitions represent a creative, student-centered approach that encourages conceptual clarity, innovation, and teamwork in physiology education. Aim: To explore undergraduate medical students’ perceptions of model-making competitions as an active learning strategy in physiology, focusing on conceptual understanding, creativity, and teamwork. Methods: A model-making competition was organized for 150 first-year MBBS students, divided into 30 self-formed teams. Each team prepared a model on a physiology topic of their choice over one month, with faculty guidance available as needed. Completed models were exhibited and evaluated by senior faculties using a structured rubric. Following the event, students completed a structured feedback questionnaire assessing perceptions of the activity. Results: Of 150 participants, 128 (85.3%) provided feedback. Overall experience was rated Excellent (53.9%) or Good (44.5%). A majority (97%) reported improved conceptual understanding, while 95% agreed the activity fostered creativity. Teamwork was rated Excellent by 50% and Good by 39%. Most students (95%) felt preparation time was adequate, 69% expressed willingness to participate again, and 90% reported being motivated to explore physiology concepts further. Conclusion: Model-making competitions were perceived as highly effective in enhancing conceptual understanding, fostering creativity, and promoting teamwork. These findings support the integration of model-making into physiology curriculam as an engaging and practical student-centered teaching–learning strategy. Keywords: Model-making competition, Active learning, Physiology education, Medical students, Conceptual understanding, Student perceptions.
Cardio-respiratory and haematological indices in factory workers exposed to cement dust
The Nigerian cement industry, which produces 58.9 million metric tonnes annually, creates occupational health risks for workers who regularly encounter cement dust containing fine particulates with crystalline silica and heavy metals. This study aims to investigate the effect of cement dust on cardio-respiratory and haematological indices in exposed factory workers. The research design utilized a cross-sectional approach on 111 participants (60 cement factory workers (53 male, 7 female) who had at least three years of exposure and 51 control subjects (44 male, 7 female), matched by demographic characteristics and unexposed to cement dust. Pulmonary function was assessed via spirometry, cardiovascular health was evaluated using electrocardiography and measurement of blood pressure by a digital sphygmomanometer, and a haematological analysis (full blood count) was carried out using standard methods. The study data demonstrated that exposed workers experienced significant decreases in forced vital capacity (FVC), forced expiratory volume in one second (FEV1), Forced Expiratory Flow at 75% of FVC (FEF75), and peak expiratory flow, which point towards restrictive pulmonary damage. The cardiovascular evaluations revealed elevated systolic blood pressure, along with prolonged QTc intervals and reduced T-wave amplitudes. Simultaneously, the haematological assessments revealed increased red cell distribution width and changes in white blood cell counts. The results demonstrate the occupational risk factors (marked declines in lung function, disruptions in cardiac indices, and haematological abnormalities) associated with cement dust contact, highlighting the necessity for stronger industrial regulations with protective measures
Protective Effects of Kolaviron against Phenylhydrazine-Induced Hepatotoxicity, Genotoxicity, and Splenic Pathology in Wistar Rats
Phenylhydrazine (PHZ) triggers oxidative stress through the generation of reactive oxygen species and lipid peroxidation, resulting in organ and DNA damage. Kolaviron (KV), a biflavonoid complex extracted from Garcinia kola seeds, has shown properties that combat oxidative stress and protect cells. Aim was to evaluate the protective effects of kolaviron against phenylhydrazine-induced hepatotoxicity, splenic pathology, and genotoxicity in Wistar rats. Twenty-eight male rats were divided into four groups: Control (distilled water), PHZ (40 mg/kg intraperitoneally for 3 days), PHZ+KV (PHZ at 40 mg/kg+KV at 100 mg/kg orally for 14 days), and KV alone (100 mg/kg orally for 14 days). Hepatotoxicity, splenic pathology, and genotoxicity were assessed via biochemical analyses, oxidative stress markers, antioxidant parameters, histopathology, and micronucleus testing in bone marrow cells. Results showed PHZ significantly elevated liver enzymes (p<0.05), increased malondialdehyde levels, decreased antioxidant enzymes, and caused periportal fibrosis. Treatment with KV normalized these liver parameters and mitigated histopathological damage. In the spleen, PHZ induced lymphoid follicular hyperplasia, whereas in the PHZ+KV group, we observed lymphoid follicular necrosis; nonetheless, splenic oxidative stress and antioxidant levels remained similar across all groups. For genotoxicity, PHZ significantly increased micronucleated polychromatic erythrocytes and reduced the polychromatic erythrocytes/normochromatic erythrocytes ratio (p<0.05), while KV treatment restored these to near-control levels. Kolaviron showed significant hepatoprotective and genoprotective effects against PHZ-induced toxicity, primarily through modulation of oxidative stress parameters, though its impact on splenic pathology was weak. Further research should investigate the best dosing regimens and molecular mechanisms underlying KV's protective effects against oxidative damage. Keywords: Kolaviron, Phenylhydrazine, Hepatotoxicity, Genotoxicity, Oxidative stress, splenic pathology
TRADITIONAL APPROCHES TO TREATING ERECTILE DYSFUNCTION IN AFRICA
Summary: Erectile dysfunction (ED) is an increasingly prevalent global health issue. Although FDA-approved medications like sildenafil are available, their use is often accompanied by undesirable side effects. Consequently, there is growing interest in traditional medicine as an alternative treatment option. This review provides a detailed mechanistic analysis of key African medicinal plants utilized for managing erectile dysfunction. Relevant literature was obtained from authoritative scientific databases, including PubMed, Scopus, Web of Science, and Google Scholar. Search terms such as "erectile dysfunction," "African medicinal plants," "traditional medicine," and "mechanisms of action" were used to identify pertinent studies. A systematic review was conducted to evaluate research on African medicinal plants with reported efficacy in ED treatment. Studies were selected based on scientific rigor, pharmacological investigations, and mechanistic insights into their bioactive compounds and therapeutic pathways. Several African medicinal plants have demonstrated potential in treating ED through mechanisms such as boosting nitric oxide synthesis, modulating enzymatic pathways (e.g., phosphodiesterase-5 inhibition), and enhancing blood circulation. While existing studies highlight their effectiveness, there is still limited understanding of their precise molecular mechanisms and possible adverse effects. African medicinal plants offer a promising alternative for ED management. However, further research, including mechanistic studies and clinical trials, is essential to establish their safety, efficacy, and pharmacokinetics. This review emphasizes the importance of integrating traditional medicine into ED treatment strategies. Keywords: Erectile dysfunction, Medcinal plants, Herbal remedies, Traditional medicine.
Interplay Between Depression, Anxiety, and Working Memory among Students in College of Medical Sciences Ahmadu Bello University Zaria Nigeria
University life presents a mix of academic and social challenges that often contribute to stress and mental health issues. Chronic stress, particularly in university students, is a well-known risk factor for depression and anxiety, which can lead to cognitive impairments such as deficits in working memory. This study explored the prevalence of depression and anxiety among students at the College of Medical Sciences, Ahmadu Bello University, Zaria, Nigeria, and examined their impact on working memory. A cross-sectional approach was used, involving undergraduate students from different levels and departments within the college. Participants completed the Beck Depression Inventory (BDI) and Generalized Anxiety Disorder-7 (GAD-7) scale to assess symptoms of depression and anxiety, while the 2-back task evaluated working memory performance. Findings revealed a high prevalence of depressive (47.84%) and anxiety (65.12%) symptoms among students. However, no significant relationship was found between these symptoms and working memory performance (p > 0.05). Notably, students experiencing anxiety were 12 times more likely to develop depression, highlighting the strong co-occurrence of these conditions (p = 0.00). Age did not significantly influence these outcomes. These results emphasize the urgent need for increased mental health awareness and accessible support services for university students to reduce the impact of depression and anxiety on academic performance and overall well-being.
Zinc Supplementation Reverses Lead-Induced Anxiety-Like Behaviour and Social Deficits in Male Wistar Rats
Lead is a highly pervasive environmental toxin that exerts harmful effects on the body systems, especially the nervous system. Zinc is an essential trace element that has been found in eukaryotic cells. Lead has a serious neurotoxic effect via mechanisms such as disruption of the antioxidant defense system and activation of inflammatory mediators (Ramírez Ortega et al., 2021; Virgolini & Aschner, 2021). Despite the extensive knowledge on the neurotoxic effects of lead, effective interventions in mitigating its effects are limited. This study aims to assess the effects of zinc supplementation on lead-induced neurotoxicity in male Wistar rats. Twenty-one male Wistar rats were randomly assigned to three groups with seven rats in each group. Group I served as the control; group II, the lead-treated group, received 0.5% of lead in drinking water for 4 weeks; group III, Pb + Zn group, received 0.5% of lead in drinking water and 25 mg/kg of Zinc supplement by oral gavage for 4 weeks. Behavioral assessments were conducted using the Open Field Test (OFT), Elevated Plus Maze (EPM), and three-chamber sociability test to evaluate anxiety and social behavior. Biochemical and hematological analyses were performed to determine the serum levels of proinflammatory cytokines (IL-1β and TNF-α), total antioxidant capacity (TAC), hematological indices, and electrolytes. The results revealed a significant increase in anxiety and a decrease in social behavior in the Pb-only group. Biochemically, there was a marked elevation in IL-1β and TNF-α, with a significant reduction in TAC in these rats. No marked changes were, however, observed in the serum electrolyte levels across all experimental groups. Contrastingly, zinc supplementation effectively ameliorated these effects. Rats in the Pb + Zn group demonstrated improved neurobehavioral outcomes, decreased levels of pro-inflammatory cytokines, restored antioxidant capacity, and increased Neutrophil to Lymphocytes Ratio (NLR). These findings suggest that zinc confers neuroprotective effects against lead-induced neurotoxicity, likely by modulating oxidative stress and suppressing inflammatory and neuroimmune responses.
Intranasal Dexamethasone Selectively Impairs Exploratory and Learning Behaviour While Sparing Peripheral Metabolic and Oxidative Homeostasis in Adult Mice
Dexamethasone (Dex) is a potent synthetic glucocorticoid with broad clinical applications, but systemic administration often leads to metabolic disturbances and cognitive side effects. Intranasal Dex has potential to deliver glucocorticoids directly to the brain, minimizing systemic side effects associated with traditional administration. However, its comprehensive effects on metabolic, behavioural, and neurochemical endpoints after repeated dosing remain unclear. Adult male mice were randomly assigned to four groups: control (saline) and dexamethasone (Dex) doses of 5, 15, or 50 μg/kg administered intranasally once daily for seven days. Peripheral measures included body weight, fasting blood glucose, glucose tolerance test (GTT), fasting serum and brain insulin levels, HOMA‑IR, and serum corticosterone via ELISA. Behavioural assays comprised the Morris Water Maze, Elevated Plus Maze, Open Field Test, and Novel Object Recognition Test. Brain homogenates were analysed for oxidative stress markers (superoxide dismutase, glutathione), cholinergic activity (acetylcholinesterase), and trace minerals (Zn, Fe, Ca). Intranasal Dex did not affect body weight, glycaemic control, insulin sensitivity, or corticosterone levels. Dose‑dependent declines in locomotor exploration and spontaneous alternation were observed, alongside increased escape latencies during spatial learning without altering memory retention or novel object recognition. Oxidative stress markers and global Zn, Fe, and Ca remained stable; however, acetylcholinesterase activity trended downward and variability in Fe and Ca emerged at higher doses. Seven-day intranasal Dex selectively impairs exploratory behaviour and learning acquisition through central glucocorticoid receptor–mediated synaptic and cholinergic modulation, while preserving peripheral metabolic and oxidative balance.