Umar Muhd Sani*
Chemistry Department, Nigeria Police Academy, P.M.B. 3474, Wudil, Kano State
A number of plants products among which the protein-rich Cucurbitaceae seeds are commonly used in traditional medicine with increasing acclaimed efficacy against diabetes mellitus. In this study the anti-diabetic effect of ethanol and petroleum ether extracts of Citrullus lanatus (watermelon) rind in alloxan-induced diabetic mice have been investigated. Phytochemical screening of the petroleum ether and ethanol extracts of the rind was carried out and diabetes was induced in mice by the injection of 150 mg/kg (i.p.) of alloxan monohydrate freshly dissolved in physiological saline. Doses (150, 200 and 250 mg/kg) of the extracts were administered each to a group of five diabetic mice in the study. The activity was compared with reference standard glibenclamide (2 mg/kg) and negative control of physiological saline. Treatment of the alloxan-induced diabetic mice with the extracts of Citrullus lanatus rind decreased the raised blood glucose levels significantly (P<0.05) in a dose-dependent manner (with ethanol extract more effective than the petroleum ether extract). Results of phytochemical screening of the rind extracts have indicated the presence of steroids, terpenoids, saponins, tannins, alkaloids, reducing sugar, flavonoids, and anthraquinones. The results revealed that both extracts of the rind of this plant have anti-diabetic potential. Results have also shown that the ethanol extract was more potent than the petroleum ether extract which is in agreement with the reported claim that ethanol extract in combination with diet supplement has significant antidiabetic activity in albino mice. Moreover, the classes of phytochemicals observed in this plant extracts have previously been observed to contribute to hyperglycemic effects.
Keywords: Alloxan monohydrate, Citrullus lanatus, diabetes mellitus, rind, glibenclamide, albino mice.