SCREENING OF PHARMACOLOGICAL AND CYTOTOXIC ACTIVITIES OF FRESH WATER LAKE ISOLATED MICROALGAE CHLORELLA VULGARIS AS-13 AND CHLORELLA PYRENOIDOSA AS-6

Micro Algae are rich sources of biologically active metabolites. Pharmaceutical industries nowadays are focusing on isolation and extraction of primary and secondary metabolites of medicinal importance produced by these organisms. The present investigation is to evaluate phenolic and flavonoid content in methanolic extracts of freshwater algal biomass isolated from Unkal Lake, Dharwad district, Karnataka, India, followed by evaluation of antioxidant and anticancer activities. Determination of total phenol and flavonoid content was followed by the 2,2-diphenyl-1-picrylhydrazyl radicals scavenging, phosphomolybdate and reducing power assay for evaluating antioxidant potency. Among two microalgae, Chlorella vulgaris AS-13 had efficiently high amount of total phenol and flavonoid content. At 1000 μg/ml concentration of extract, Chlorella vulgaris AS-13 and Chlorella pyrenoidosa AS-6 exhibited 105 and 88 % diphenyl-1-picryhydrazyl free radical scavenging activity and 78 and 61% total antioxidant potency respectively. The cytotoxicity of Methanol extract of Chlorella vulgaris AS-13 showed 50% inhibition (IC50) of cells with 92 μg/ml after 72 hours period incubation for MCF7 when compared to HepG2 cell lines. Whereas there was a positive effect of methanolic extract of Chlorella pyrenoidosa AS-6 on MCF7 at 72 hour period of with 87 μg/mL. Thus, both of the microalgae in dietary supplements will be effective mediators in scavenging free radicals and act as antiapoptotic peptides for tumor cells.