Evaluation of physicochemical parameters, acute and subchronic toxicities, and anti-diabetic activity of Spondias venulosa (Engl.) Mart. ex Engl. leaf extract on alloxan-induced diabetic rats.

Ethnopharmacological Relevance: Spondias venulosa is a medicinal plant whose leaves are popularly used for decades in Northeast Nigeria as a first-choice medicinal plants for the treatment of diabetes. This claim has not been proven scientifically.

Aim Of The Study: The present study was carried out to determine the physicochemical profiles, acute, sub-chronic toxicities, and antidiabetic activity the leaf extract in alloxan-induced diabetic rats.

Materials And Methods: The physicochemical parameters of S. venulosa leaves, acute, subchronic toxicities, and antidiabetic activity in alloxan-induced diabetic rats were determined using standard procedures. All physicochemical parameters were carried out triplicate. Acute and subchronic toxicity studies were carried out following OECD guidelines by administering maximum extract dose of 2000 mg/kg orally to Wistar rats. Subchronic toxicity and antidiabetic studies were carried out in rats of opposite sexes at doses 300, 600, and 1200 mg/kg (orally).

Results: Results obtained showed that the moisture content, water soluble extractive, and organic matter had values of 4.98 ± 1.01, 12.04 ± 1.24 and 1.01 ± 0.01% w/w respectively. The metallic contents of the methanol leaf extract revealed the presence of zinc with value of 12.01 ± 1.01 ppm (normal range:< 100 mg/kg DM) and copper with value of 6.24 ± 2.14 ppm (normal range:< 30 mg/kg DM). Oral median lethal dose (LD) was estimated to be greater than 2000 mg/kg since the extract did not produce any sign of toxicity or death in short term while, subchronic toxicity study showed that there was no significant weight loss in the rats after 28 days of extract administration. All hematology and biochemical parameters showed no elevated values when compared to the control group (p < 0.05). Histopathological examinations of major organs do not show signs of organ damages which indicate that the extract was safe at the doses administered. Oral administration of extract doses for 30 days reduced blood glucose levels in alloxan-induced diabetic rats in dose-dependent manner compared (p < 0.05) to standard drug (Glibenclamide).

Conclusions: Our study showed some physicochemical parameters of S. venulosa leaf which are essential for its identification from closely related species in traditional medicine. The study further showed that S. venulosa methanol leaf extract possessed antidiabetic activity, thus, justifying its use for the treatment of diabetes in Nigeria. However, there is need to identify and investigate the bioactive compound(s) responsible for the activity towards drug discovery.