Preparation and Evaluation of Antidiabetic Activity of Allium cepa-Phospholipid Complex (Phytosome) in Streptozotocin Induced Diabetic Rats

Purpose: A phytoformulation, Allium cepa-phospholipid complex (ACP) was prepared, characterized and evaluated for its antidiabetic activity in Streptozotocin (STZ) induced rats. Methodology: ACP was prepared and characterized by SEM, DSC and FT-IR. It was then screened for in vitro free radical scavenging, antidiabetic activity (50 mg/kg and 100 mg/kg, p.o.) in normoglycemic and STZ induced diabetic animals. Concentration of quercetin in ACP was estimated in serum by HPLC. Findings: SEM data showed that ACP has irregular size vesicles consisting of HSPC and ACE intercalated in the lipid layer. ACP showed one endothermal peak in DSC studies. ACP showed good in vitro antioxidant activity. In OGTT, treatment with ACE (Allium cepa extract), ACP and glibenclamide significantly improved the glucose tolerance in normal animals. In STZ induced diabetic rats, a single dose of ACE and ACP treatment exhibited reduction in SG levels at different time intervals compared to basal levels. Administration of both the doses of ACE and ACP for fifteen days exhibited greater percentage reduction in glycemia and restored to near normal value of all tested lipid parameters. Higher serum concentration of quercetin was observed for ACP in bioavailability studies as compared to ACE. Conclusion: ACP has shown significant antioxidant, antidiabetic activity and hypolipidemic activity in STZ induced rats as compared to ACE at the dose studied.