Anti-hyperglycaemic and Mode of Action of Thaumatococcus danielli (BENN.) BENTH Ethanol Leave Extract in Streptozotocin-induced Diabetic Rats

Abstract

Thaumatococcus danielli (Benn.) Benth, a member of the Maranthaceae family has continued to be of immense benefit to the people in the tropics especially in Nigeria. The leaf is widely used among the “Yoruba’s” as a wrapping leaf and for the management of diabetes mellitus. Aim: This study, evaluated the anti-diabetic and possible mode of action(s) of ethanol leaves extract of Thaumatococcus danielli using in vivo and in vitro approach. Methods: Diabetes was induced in Albino rats by administration of Streptozotocin (65 mg/kg/b.wt, i.p). The ethanol leave extract of Thaumatococcus danielli (at a dose of 250 mg/kg and 500 mg/kg body weight was administered at single dose per day to diabetes induced rats for a period of 14 days. The possible mode of action of extract was assessed through in vitro inhibitory effect on alpha amylase, non-enzymatic glycosylation of haemoglobin and glucose uptake in yeast cell. Results: The results showed that the plant extracts demonstrated dose and time dependent reduction in blood glucose. The extract at 250 mg/kg /b.wt and 500 mg/kg/b.wt caused a significant percentage reduction (35.00%/42.04% and 42.16%/60.43%) in blood glucose when compared with the group treated with (25 mg/kg/b.wt) of the standard drug (30.51/40.88%) and the diabetic control (10.46%/-13.67%) on day 7 and day 14 respectively. Although, the extract demonstrated significant (p<0.05) dose dependent inhibitory effect on alpha amylase with an IC50 of 837.97 µg/ml, its activity was significantly (P<0.05) lower than the standard Acarbose. Conversely, the extract showed stronger inhibition of non-enzymatic glycosylation of haemoglobin (87.51%) and enhance glucose uptake in yeast cells by 85.56% when compared with the standard drug Trolax and Metronidazole respectively. Conclusion: The results of this study revealed that Thaumatococcus danielli (Benth) leaves contain anti-hyperglycaemic agent (s) and its possible mode of action is by promoting glucose uptake, inhibition of non-enzymatic glycosylation of haemoglobin and alpha amylase activity.