Phytochemical Investigation of Insulin Plant ( Costus pictus )

Insulin plant (Costus pictus) is one of the folk medicines used for the treatment for Diabetes mellitus. This plant belongs to Costaceae family, which has been separated from Zingiberaceae on the basis of the presence of spirally arranged leaves and rhizomes being free from aromatic essential oils. The plant commonly known as spiral ginger is originated in Mexico and is found to have antidiabetic properties. Dichloromethane and methanol extracts of the plants belonging to Zingiberaceae, from Alpinia, Costus and Zingiber genera were found to be antibacterial, while methanolic extract of Costus discolour exhibited potent antifungal activity against Aspergillus ochraceous (MIC-15.6 μ/disc). All these extracts showed antioxidant activity comparable or higher than that of α-tocopherol. The methanolic extract of the leaves of the insulin plant showed no toxicity in both acute and sub acute toxicity studies conducted in mice and rats, respectively. Since this is a newly identified medicinal plant not much work are reported on its phytochemical studies. Hence this plant is selected for the phytochemical investigation.