Antidiabetic activity of root tubers of Asparagus gonoclados Baker in streptozotocin induced diabetic rats

Asparagus gonoclados Baker is a traditional folk remedy used for diabetes, diuretic, galactogogue, gastric ulcer activities etc.The present investigation was intended to evaluate the beneficial effect of the A.gonoclados (Lilliaceae) root tubers against diabetes mellitus.Different solvent extracts of root tubers of A. gonoclados were used to study the antihyperglycemic activity in streptozotocin (45 mg/kg.wt) induced diabetic rats. Oral glucose tolerance test was performed in diabetic and normal rats treated with A.gonoclados. Total phenolic content (TPC), total flavanoid content (TFC) and total steroidal saponins content (TSSC) were measured in different solvent extracts. Following bioassay guided fractionation method antihyperglycemic active fraction of A. gonoclados (AGAF) was isolated from the ethanol extract (AGEE) by silica gel column chromatography. We further tested relationship between insulin stimulation effect and the influence of active fraction on K+-ATP and Ca2+ channels opening in normal and diabetic rats. The characterization of AGAF was carried out by LC-ESI-MS/MS.Among the different solvent extracts, the ethanol extract (AGEE) at a dose of 500 mg/kg b.wt has produced maximum (67%) reduction in fasting blood glucose levels (FBG) in diabetic treated rats after 6 h of oral administration when compared to the standard drug glibenclamide (40%). AGEE also showed dose-dependent inhibitory effect on the activities of α-glucosidase (74.73%) and α-amylase (76.47%), which is comparable to the activity of standard drug acarbose (88.42%). AGEE was found to have the richest quantity of TPCs (138.4 ± 0.39 μg/mg gallic acid equivalents), TFCs (64.8 ± 0.54 μg/mg quercetin equivalents) and TSSCs (12.9 ± 0.11μg/mg sarasapogenin equivalents). We identified 8 potential antihyperglycemic compounds in AGAF by LC-ESI-MS/MS analysis.From our current study we confirm that A. gonoclados root tubers have potent antihyperglycemic activity and it can be a unique drug/formulation for the management of diabetes mellitus.