Objective: The present study represents the effect of the extracts of A. sativum bulbs growing in Sudan on glucose reuptake by rats hemidiaphgrams, and; to investigate the anti-hyperglycemic effect of the extracts on glucose-loaded Wistar albino rat. Methods: A. sativum bulbs were powdered and extracted continuously by Soxhlet apparatus using 96% ethanol to obtain the total crude ethanolic extract. The extracts with increasing polarity were successively prepared with petroleum ether, chloroform, ethyl acetate, and methanol using the Soxhlet apparatus. The extracts were screened for their phytochemical constituents. Their anti-hyperglycemic effect was evaluated in vitro on glucose reuptake; by using isolated rats hemi-diaphgrams after loading the fasting rats with glucose and; in vivo by investigate the anti-hyperglycemic effect of the extracts on glucose-loaded Wistar albino rat. Their effects were compared to control rats administered with the vehicle and to a standard group administered with Metformin standard drug. Results: The result revealed the presence of flavonoids, alkaloids, terpenoids, tannins and saponins. The in vitro anti-hyperglycemic results showed that, the glucose reuptake by isolated hemi-diaphragm was found to be 10.01 mg/g regarding the control group. Whereas, the glucose reuptake by hemi-diaphragm treated with Metformin, crude ethanolic extract, petroleum ether extract, chloroform extract, ethyl acetate extract and methanolic extract was found to be 17, 11.39, 24.11, 19.07, 15.66, 12.71 mg/g respectively. The in vivo anti-hyperglycemic effect of the petroleum ether extract with the highest in vitro activity revealed lowering of blood glucose level on glucose-loaded rat with 25 and 60 mg/dL after two and four hours of loaded respectively when treated with 200mg/kg of the extract. Regarding the high dose of 400mg/kg lowering of blood glucose level was found to be 30 and 53 mg/dL after two and four hours of loaded respectively. Whereas, the lowering in the blood glucose level of the rats treated with Metformin drug was found to be 23 and 48 mg/dL after two and four hours respectively. GC-MS analysis of the petroleum ether extract, with highest anti-hyperglycemic activity showed the presence of Methyl linolate (42.75%), Hexadecanoic acid, methyl ester (10.54%), Methyl α-linolenate (8.36%), Dotriacontane (6.83), Tetrapentacontane (6.33), Methyl 18-methylnonadecanoate (4.8), Phenol,2,2’-methylenebis[6-(1,1-dimethylethyl)-4-methyl] (3.25), Methyl 20-methyl-heneicosanoate (2.70), Pentatriacontane (2.13) and many other minor compounds. The most of these compounds are well known for their anti-diabetic Activity. Conclusions: The study conclude the significant anti-hyperglycemic effect of A. sativum bulb extracts. In addition to the petroleum ether extract was found to posses anti-hyperglycemic activity more than the other extracts and Metformin standard drug.
