Resumo
In the present study, acute and subchronic oral toxicity studies of an aqueous extract of a Nigerian Polyherbal Health Tonic (PHT) were investigated in adult Wistar rats of both sexes and weighting between 110 - 200 g. Acute toxicity study was conducted using limit dose test of Up and Down Procedure under computer guided statistical software program (AOT 425 StatPgm). The subchronic toxicity was evaluated in 4 groups of rats made up of six rats/group, administered single, daily oral doses of 10 ml/kg distilled water (DW), 125, 500 and 1500 mg/kg of PHT, respectively, for 90 days. On the 91st day, blood samples for haematological and biochemical assays were collected through cardiac puncture and selected vital organs harvested en bloc for histopathological examination under inhaled anaesthesia. Results showed PHT to be relatively safe on acute toxicity with an estimated LD50 value greater than 5000 mg/kg/oral route. On prolonged exposure, PHT induced initial weight gain in the 1st 6 week followed by significant (P<0.05) dose related weight loss in the latter 6 weeks. The extract also caused significant (P<0.05) dose related elevation of the full blood count parameters, dose unrelated elevation of serum urea, liver enzymes, serum proteins, albumin, total and conjugated bilirubin. On histology, PHT induced dose dependent gastric mucosal denudation, bile ductal lining distortion, diffuse pulmonary interstitial fibrous proliferation and diffuse splenic lymphocytic proliferation. Thus, our results showed that PHT use may be relatively safe on acute exposure but toxic on chronic exposure to high doses, although reversibility of these toxic effects was not studied in the present study.
Keywords: Nigerian polyherbal tea, oral toxicity, haematological and biochemical assays.
Résumé
Dans cette étude, les toxicités acute et sous chronique orale de l’extrait aqueuse du Polyherbale Tonique Nigériane (PHT) étaient investigués chez les Wistar rats adulte males et femelles pesant entre 110 - 200 g. L’étude de la toxicité acute était conduite en utilisant la procédure de dose limitée d’haut et bas sous le guide d’un programme informatique statistique (AOT 425 StatPgm). La toxicité subacute était évalué chez 4 groupes de rats composé de six rats par groupe, administré à la dose de 10 ml/kg par jour (DW), 125, 500 et 1500 mg/kg de PHT, respectivement pour 90 jours. Au 91st jour, Les échantillons de sang pour les analyses hématologiques et biochimiques étaient collectés par puncture cardiaque et des organes vitaux sélectionnés en bloc pour l’examination histopathologique sous anesthésie aspiré. Les résultats montraient le PHT relativement effective en toxicité acute avec la LD50 estimée a la valeur plus élevée que 5000 mg/kg/ route orale. Suivant une exposition prolongée, PHT induisait un gain en poids initial en 1st 6 semaine, suivi significativement par (P<0.05) une dose lié au perte de poids dans les 6 semaines. L’extrait causait aussi significativement (P<0.05) une dose liée a l’élévation des paramètres sanguin, dose non liée à l’élévation de l’urée en sérum , enzymes hépatiques, protéines du sérum, albumine, et la bilirubine totale et conjuguée. En histologie, PHT induisait une dénudation de la mucose gastrique à dose dépendante, distorsion de tube de la bile, une prolifération fibreuse interstitielle diffuse pulmonaire et diffuse splénique lymphocytaire. Ainsi, nos résultats démontraient que l’usage du PHT peut être relativement effective dans l’exposition acute mais toxique à l’exposition chronique aux doses élevées, bien que la réversibilité des effets toxique n’était pas évaluée dans cette étude
Correspondence: Dr. A.A. Adeneye, Department of Pharmacology, Faculty of Basic Medical Sciences, Lagos State University, College of Medicine, Ikeja, Lagos, Nigeria. Email: adeneye2001@yahoo.com
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