Influence of Allium sativum extract on the hypoglycemic activity of glibenclamide: an approach to possible herb-drug interaction.

Background: The use of herbs with allopathic medicines increases the possibility of herb-drug interaction, which may either be beneficial or harmful. Therefore, the present study was undertaken to determine the interaction of glibenclamide, a sulfonylurea, with the aqueous extract of garlic (Allium sativum), an herb used widely as an antidiabetic agent.

Methods: The interaction was evaluated by an acute study, chronic study, oral glucose tolerance test, and body weight estimation in streptozotocin-induced diabetic rats. Glibenclamide was given orally at two different doses of 0.25 and 0.5 mg/kg, and A. sativum extract (ASE) was administered at the dose of 500 mg/kg. Blood glucose level and body weight estimation were carried out at various intervals.

Results: The hypoglycemic effect observed with combinations of glibenclamide and ASE was greater than either of the drug given alone. Combined treatments of glibenclamide and ASE resulted in higher increase in body weight than alone treatments.

Conclusions: We conclude that ASE shows a synergistic effect with glibenclamide. This could be important in reducing the dose of glibenclamide to achieve an enhanced therapeutic effect with minimal side effects.