ABSTRACT:Microalgae have been widely used as novel source of bioactive substances. These substances exhibit various biological actions including, antioxidant, antimicrobial, antiviral, antitumoral, antiinflammatory and anti-allergy effects. In the present investigation algal biomass in methanol extracts of chlorophyceae member of three micro algae of Chlorella vulgaris, Desmococcus olivaceous and Chlorococcum humicola was screened. The antioxidant property of the methanolic extracts of these green microalgae was evaluated by measuring the free radical scavenging activity by DPPH assay method. The algal extracts were then evaluated for their suppressive effect on tumor cell growth (MCF7) by using MTT assay and further analysed using GC-MS to determine the profile of specific molecules or compounds. Antioxidant activities of the microalgal methanol extracts were studied by their ability to scavenge DPPH at various concentrations. The DPPH radical scavenging activity was found to be higher in Chlorella vulgaris (RSA 53.96%) at a concentration 20μg compared to standard ascorbic acid (RSA 59.42%). Anticancer property of the methanol extracts of Chlorella vulgaris, Desmococcus olivaceous and Chlorococcum humicola in MCF7 breast cancer cell was studied. In this assay the micro algal Chlorella vulgaris inhibited the growth of tumor cells (MCF7) when compared to Desmococcus olivaceous. GC-MS analysis of methanol extracts of Chlorococcum humicola showed the presence of five compounds which are reported to be involved in antioxidant and anticancer properties.
INTRODUCTION:Microalgae produce metabolites in order to survive under varying conditions of salinity, temperature, pressure etc. These metabolites are usually secondary, which could be carbohydrate, or proteins or enzymes or pigments or antibiotics or even toxic compounds.