Antidiabetic activity of alkaloids of Aerva lanata roots on streptozotocin-nicotinamide induced type-II diabetes in rats.

CONTEXT: The roots of Aerva lanata Linn. (Amaranthaceae) (AL) are employed traditionally as an antihyperglycaemic in the Ayurvedic system of medicine.

OBJECTIVE: The present investigation is focus for identification and isolation of the bioactive compound from methanol roots extract of AL against streptozocin-nicotinamide induced elevated serum glucose level in rats.

MATERIALS AND METHODS: The methanol extract of the roots was fractionated using different solvents. The partially purified alkaloid basified toluene fraction (PPABTF) showed the presence of alkaloids. The fraction (10 and 20 mg/kg) was tested for oral glucose tolerance test (OGTT) and in non-insulin-dependent diabetes mellitus (NIDDM)-induced elevated serum glucose level in rats. The fraction was also subjected to high performance thin layer chromatography (HPTLC) for the determination of content of individual alkaloids.

RESULTS: Single oral administration of PPABTF (10 and 20 mg/kg) after 20 h caused a significant (p < 0.01) reduction in the serum glucose level (mg/dl). On other hand, PPABTF normalised plasma glucose levels after 2 weeks of repeated oral administration in diabetic rats (p < 0.01). HPTLC analysis on PPABTF showed the presence of three known alkaloids. The fraction was further subjected to column chromatography and the compounds identified by ultraviolet, infrared, mass spectroscopy and nuclear magnetic resonance, as canthin-6-one derivatives.

CONCLUSION AND DISCUSSION: The PPABTF in the dose of 20 mg/kg showed significant effects on streptozotocin-nicotinamide induced type-II NIDDM in rats. The activity may be due to the presence of alkaloids like canthin-6-one derivatives.