Toxicological evaluation of the aqueous leaf extract of Moringa oleifera Lam. (Moringaceae)

Ethnopharmacological relevance: The rapid increase in consumption of herbal remedies worldwide has been stimulated by several factors, including the notion that all herbal products are safe and effective. However, over the past decade, several news-catching episodes in developed communities indicated adverse effects, sometimes life-threatening, allegedly arising as a consequence to taking herbal products or traditional medicines from various ethnic groups. Despite the popular use of Moringa oleifera for treating various disorders, there is limited or no scientific data available regarding safety aspects of this remedy, nor are there any documented toxicological studies that can be used to ascertain the safety index of its herbal preparation. Therefore, this present study aimed to carry out extensive toxicological evaluation of the aqueous leaf extract of Moringa oleifera. Materials and Methods: In an acute toxicity test, male Wistar albino mice were orally administered an aqueous extract up to 6400 mg/kg and intraperitoneally up to 2000 mg/kg. A sub-chronic toxicity test was performed by daily administration with the extract at 250, 500 and 1500 mg/kg orally for 60 days. Control rats received distilled water. Sperm quality was analyzed, haematological and biochemical (liver enzymes, urea and creatinine) parameters were determined and a histopathological examination was carried out. Results: The LD50 was estimated to be 1585 mg/kg. The extract did not elicit any significant difference (P >= 0.05) in sperm quality, haematological and biochemical parameters in the treated rats compared to the control. Moreover, there was no significant difference in weight gain of the control and treated animals although there was a dose-dependent reduction in food consumption of the animals treated with 250 to 1500 mg/kg extract. Conclusions: Results obtained in this study suggest that the aqueous leaf extract of Moringa oleifera is relatively safe when administered orally. (C) 2011 Elsevier Ireland Ltd. All rights reserved.