Phytochemical composition, in vitro antioxidant and alpha amylase inhibitory properties of Celosia leptostachya

Plant based phytoconstituents of great importance in the development of drugs and treatment of several health diseases.In this study, the phytochemical constituents of ethanol extract of Celosia leptostachya leaves, invitro antioxidant and alpha amylase inhibitory properties were investigated. Gas chromatography-mass spectrum analysis was used to identify varying percentage composition of phytochemical constituents in the extract. In vitro models were used to evaluate the ability of varying concentrations of the ethanol extracts to exhibit antioxidant activity by free radical scavenging using nitric oxide (NO) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. Major constituents are cis-3-Butyl-4-vinyl-cyclo pentene n-Hexadecanoic acid, 9,12-Octadecadienoic acid (Z,Z) , Bicyclo[2.2.1]heptane, 7,7-dimethyl-2-methylene, octadecanoic acid (7.47%), arachidonic acid and 9-octadecenoic acid (E) (5.40%). Many of the constituents are also representative compounds belonging to fatty acid esters and volatile oils. Invitro antioxidant studies using DPPH and NO radical scavenging activity indicated that the extract exhibited > 50% inhibition at concentrations of 500 µg/ml and 600 µg/ml. IC50 values obtained for the extracts indicated strong antioxidant activity. Alpha amylase inhibition showed that increase in concentration of the extract exhibited a corresponding increase in percentage inhibition of the enzyme similar to acarbose used as standard. The kinetic studies under inhibitory conditions showed a decrease in Km and Vmax from slope and noncompetitive. Thus, it can be deduced that ethanol extract of Celosia leptostachya leaves contained essential phytochemical components that can be explored for broad spectrum bioactivity, pharmacological and nutritional applications. The inhibition mechanism is noncompetitive and can be utilized as strategy in control and treatment of hyperglycemia.