The hypotensive effect of the aqueous calyx extract of Hibiscus sabdariffa may occur through the attenuation of Autonomic nervous system activity


This study tested the hypothesis that the hypotensive effect of the aqueous calyx extract of Hibiscus sabdariffa (HS) occurs through autonomic mechanisms that may be associated with a reduction in the double product (DP) of the heart. Experiments were performed in accordance with the Principles of the Declaration of Helsinki. Following ethical approval and informed consent, the Harvard step test (HST) was performed in healthy subjects (n=14) to activate the autonomic nervous system before and after the oral administration of 15mg/kg HS. The blood pressure (BP) and heart rate (HR) responses were measured and DPs and the mean arterial pressure (MAP) were calculated. Results were expressed as mean ±SEM. Paired t-test and one way ANOVA with a posthoc Bonferoni test were used for statistical analyses. P<0.05 was considered significant. HST without HS resulted in a significant rise in MAP, HR and DP (112.6±2.7mmHg, 97.7±2.5/min and 12630.0±642 mmHg.bpm) from the basal values (98.5±2.3mmHg, 76.5±2.0/min and 8730.7±354.9 mmHg.bpm, P<0.001, P<0.01 and P<0.001 respectively). In the presence of HS, HST-induced changes (∆MAP=7.8±1.6mmHg; ∆HR=8.1±1.6/min; ∆DP= 1113.6±103.4 mmHg.bpm) were significantly dampened compared to its absence (∆MAP= 13.3±2.6mmHg; ∆HR=17.0±3.7/min; ∆DP= 3899.3±287.2 mmHg.bpm; P<0.001, P<0.01 and P<0.0001 respectively). The HST-induced increase in BP, HR and DP suggest sympathetic nervous system (SNS) activation and parasympathetic nervous system (PNS) withdrawal associated with an increased cardiac O2 consumption and workload. These were dampened by HS suggesting that its hypotensive effect occurs through the inhibition of SNS activation, PNS withdrawal and an associated reduction in cardiac O2 demand and workload.

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Abubakar SM, Ukeyima MT, Spencer JPE, Lovegrove JA (2019). Acute Effects of Hibiscus sabdariffa Calyces on Postprandial Blood Pressure, Vascular Function, Blood Lipids, Biomarkers of Insulin Resistance and Inflammation in Humans. Nutrients. 11: 341 DOI:10.3390/nu11020341

Adegunloye BJ, Omoniyi JO, Owolabi OA, Ajagbonna OP, Sofola OA, Coker HA (1996). Mechanisms of blood pressure lowering effects of the calyx extract of Hibiscus sabdariffa in rats. Afr J Med Med Sci. 25:235-38

Ajay M, Chai HJ, Mustafa AM, Gilani AH, Mustafa MR (2007). Mechanism of `antihypertensive effect of Hibiscus sabdariffa L. calyces. J Ethnopharmacol. 109:338-93

Ali BH, Wabel NA, Blunden G (2005). Phytochemical, pharmacological and toxicological aspects of Hibiscus sabdariffa L.: a review. Phytother Res. 19:369–75.

Aliyu B, Oyeniyi YJ, Mojiminiyi FBO, Isezuo SA, Alada, ARA (2014). The Aqueous Calyx Extract of Hibiscus sabdariffa Lowers Blood Pressure and Heart Rate via Sympathetic Nervous System Dependent Mechanisms. Niger J Physiol Sci. 29: 131-36

Bell DR, Gochenaur K (2006). Direct vasoactive and vasoprotective properties of anthocyanin- rich extracts. J Appl Physiol. 100: 1164–170

Brouha L, Graybiel A, Heath CW, (1943). The step test: a simple method of measuring physical fitness for hard muscular work in adult man. Rev. Can. Biol. 2:86-92

Carvajal-Zarrabal O, Waliszewski S, Barradas-Dermitz D, Orta-Flores Z, Hayward-Jones P, Nolasco-Hipólito C (2005). The consumption of Hibiscus sabdariffa dried calyx ethanolic extract reduced lipid profile in rats. Plant Foods Hum Nutr. 60:153–159.

Cui J, Leuenberger UA, Blaha C, King NC, Sinoway LI (2011). Effect of P2 receptor blockade with pyridoxine on sympathetic response to exercise pressor reflex in humans. J Physiol. 589:685–95

Dalziel JM (1937). The useful of plants of West Tropical Africa. London: The crown agents for the colonies. 52-560.

Furberg CD, Psaty BM, Meyer JV (1995). Nifedipine. Dose-related increase in mortality in patients with coronary heart disease. Circulation. 92: 1326-31.

Guyenet PG (2006). The sympathetic control of blood pressure. Nat Rev Neurosci. 7:335-46

Haji-Faraji M, Haji-Tarkhani A (1999). The effect of sour tea (Hibiscus sabdariffa) onessential hypertension. J Ethnopharmacol. 65:231-36

Hermida RC, Fernández JR, Ayala DE (2001). Circadian Rhythm of Double (Rate-Pressure) Product in Healthy Normotensive Young Subjects. Chronobiology International. 18: 475–89

Herrera-Arellano A, Flores-Rameo S,Chavez-Soto MA, Tortoriello J (2004). Effectiveness and tolerability of standardized extract from Hibiscus sabdariffa in patients with mild to moderate Hypertension. Phytomedicine. 11:375-82

Herrera-Arellano A, Miranda-Sanchez J, Avica-Castro P (2007). Clinical effects produced by a standardized herbal medicinal product of Hibiscus sabdariffa in patients with hypertension. A randomized, double-blind, lisinopril-controlled clinical trial. Planta Medica. 73: 6-12

Hopkins AL, Lamm MG, Funk J, Retenbaugh C (2013). Hibiscus sabdariffa L. in the treatment of hypertension and hyperlipidemia: a comprehensive review of animal and human studies. Fitoterapia. 85:84-94

Izquierdo-Vega JA, Arteaga-Badillo DA, Sánchez-Gutiérrez M, Morales-González JA, Vargas-Mendoza N, Gómez-Aldapa CA, Castro-Rosas J, Delgado-Olivares L, Madrigal-Bujaidar E, Madrigal-Santillán E (2020). Organic Acids from Roselle (Hibiscus sabdariffa L.)-A Brief Review of Its Pharmacological Effects. Biomedicines.8(5):100. doi: 10.3390/biomedicines8050100. PMID: 32354172; PMCID: PMC7277581.

Jackson G, Schwartz J, Kates RE, Winchester M, Harrison DC (1980). Atenolol: Once-daily Cardioselective Beta Blockade for Angina Pectoris. Circulation. 613:555-60

Jaja SI, Kehinde MO, Gbenebitse S, Mojiminiyi FBO, Ogungbemi A (2000). Effect of Vitamin C on Arterial Blood Pressure, Irreversibly Sickled Cells and Osmotic Fragility in Sickle Cell Anemia Subjects. Niger. J. Physiol. Sci. 16 (1-2): 14-18

Kambara H, Kinoshita M, Hirota Y, Kadota K, Sawamura M, Saito T, Kawai C (1984). Effect on Exercise Tolerance and Pharmacokinetics of Conventional and Sustained Release Preparations of Propranolol in Patients with Angina Pectoris: A Double-blind Cross-over Study. Japanese Circulation Journal. 48: 1066-1073

Katz LN, Feinberg H (1958). The relation of cardiac effort to myocardial oxygen consumption and coronary flow. Circ Res. 6: 656–669.

Kitamura K, Jorgensen CR, Gobel FL, Taylor HL, Wang Y (1972). Hemodynamic correlates of myocardial oxygen consumption during upright exercise. J Appl Physiol. 32: 516–522.

Leung T, Kuo C, Lee C, Kan N, Hou C (2013). Physiological Effects of Bioceramic Material: Harvard Step, Resting Metabolic Rate and treadmill running assessment. Chinese J Physiol. 56: 334-340

Mckay DL, Chen CYO, Saltzman E, Blumberg JB (2010). Hibiscus sabdariffa L tea (tisane) lowers blood pressure in Pre hypertensive and mildly hypertensive adults. J Nutr. 2010; 140: 298-303

Mitchell JH. (1990). Wolffe memorial lecture. Neural control of the circulation during exercise. Med Sci Sports Exerc. 22: 141–154

Mojiminiyi FBO, Adegunloye BJ, Egbeniyi YA, Okolo RU (2000). An investigation of the diuretic effect of an aqueous extract of the petals of Hibiscus sabdariffa. JMedicine Medical Sci. 2:77-80

Mojiminiyi FBO, Audu Z, Etuk EU, Ajagbonna OP (2012). Attenuation of salt-induced hypertension by aqueous calyx extract of Hibiscus Sabdariffa. Niger J Physiol Sci. 27: 195 –200

Mojiminiyi FB, Dikko M, Muhammad BY, Ojobor PD, Ajagbonna OP, Okolo RU, Igbokwe UV, Mojiminiyi UE, Fagbemi MA, Bello SO, Anga TJ(2007). Antihypertensive effect of an aqueous extract of the calyx of Hibiscus sabdariffa. Fitoterapia 78: 292-297.

Murphy MN, Mizuno M, Mitchell JH, Smith SA (2011). Cardiovascular regulation by skeletal muscle reflexes in health and disease. Am J Physiol Heart Circ Physiol. 301: 1191-1204

Ochani PC, D'Mello P (2009). Antioxidant and antihyperlipidemic activity of Hibiscus sabdariffa Linn. leaves and calyces extracts in rats. Indian J Exp Biol. 47:276–282.

Odigie IP, Ettarh RR, Adigun SA (2003). Chronic administration of aqueous extract of Hibiscus sabdariffa attenuates hypertension and reverses cardiac hypertrophy in 2K-1C hypertensive rats. J Ethnopharmacol. 86:181-185

Ojeda D, Jimenez-Ferrer E, Zamilpa A, Herrera-Arellano A, Tortoriello J, Alvarez L (2010). Inhibition of angiotensin converting enzyme (ACE) activity by the anthocyanins delphinidin and cyanidin-3-O-sambubiosides form Hibiscus sabdariffa. J Ethnopharmacol. 127:7-10

Onyenekwe PC, Ajani EO, Ameh DA, Gamaniel KS (1999). Antihypertensive effect of roselle (Hibiscus sabdariffa) calyx infusion in spontaneously hypertensive rats and comparison of its toxicity with that in Wistar rats. Cell Biochemistry and Function: Cellular biochemistry and its modulation by active agentsor disease, 17: 199-206.

Pardeshi AM, Kirtikar SN (2016). Comparison of Anthropometric Parameters and Blood Pressure Changes in Response to Physical Stress Test in Normotensive Subjects with or Without Family History of Hypertension. Indian J Physiol Pharmacol. 60: 208–212

Parichatikanond W, Pinthong D, Mangmool S (2012). Blockade of the renin-angiotensin system with delphinidin, cyanin, and quercetin. Planta Med. 78: 1626–1632.

Portillo-Torres, L.A., Bernardino-Nicanor, A., Gómez-Aldapa, C.A., González-Montiel, S., Rangel-Vargas, E., Villagómez-Ibarra, J.R., González-Cruz, L., Cortés-López, H., Castro-Rosas, J., (2019). Hibiscus acid and chromatographic fractions from Hibiscus sabdariffa calyces: Antimicrobial activity against multidrug-resistant pathogenic bacteria. Antibiotics, 8: 218. DOI:10.3390/antibiotics8040218. PMID: 31718033; PMCID: PMC6963829.

Smith S A, Mitchell J H, Garry M G (2006). The mammalian exercise pressor reflex in health and disease. Exp Physiol. 91: 89–102

Vendrame S, Klimis-Zacas D (2019). Potential Factors Influencing the Effects of Anthocyanins on Blood Pressure Regulation in Humans: A Review. Nutrients. 11: 1431. DOI: 10.3390/nu11061431. PMID: 31242638; PMCID: PMC6628116.

Wang H, Cao G, Prior RL (1997). The oxygen radical absorbing capacity of anthocyanins. J Agric Food Chem. 45:304-309

Wood DL, Sheps SG, Elveback LR, Schirger A (1984). Cold pressor test as a predictor of hypertension. Hypertension. 6:301-306

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