Natural biomedical metabolites procured from marine sources have been the sole source of recent research. The antimicrobial resistance to human infections has made a mounting need for novel natural antibiotics. Much explored marine invertebrates largely the echinoderms (sea stars) tend to pose a natural innate mechanism to safeguard them against predators. The sea star secretes antimicrobial peptides which are naturally occurring secondary metabolites that possess a broad spectrum of antimicrobial susceptibility against bacteria, fungi, and viruses. The present study centers on the aspects of isolation and evaluation of active bioactive metabolite from the echinoderm Stellaster equestris from the Chennai coast. The whole body was utilized for the extraction using non-polar to polar solvents. The active crude extracts were investigated by qualitative assay for their chemical composition and were purified by column chromatography. The purity of the compound was further analyzed and checked for purity and quantified by the High-pressure liquid chromatography. The defined concentration of the isolated and purified compound from sea star Stellaster equestris (50,100, 150, 200, 250 and 300µg/ml) were subjected for antimicrobial sensitivity by well diffusion method and Tube dilution method. The outcome of the present study indicated the active crude extract from the sea star Stellaster equestris was rich in sterols. The evaluation of antimicrobial susceptibility by tube dilution and well diffusion assay indicated that the isolated purified compound from the sea star Stellaster equestris was reported to be evident for all the above-mentioned concentrations by a marked zone of clearance. A dose-dependent increase was observed in the tube dilution method. Therefore compounds possess antimicrobial activity and can be further subjected for developing the compound as a potent antimicrobial drug.

Background: Ocean acts as a wealthy resource of biological diversity producing prospective novel metabolites from the organisms present in the environment. Novel bioactive compounds from Echinoderms mainly from sea stars have been extensively studied procuring rich diverse compounds which exhibits in vitro cytotoxicity comparable to or better than those of the potent anticancer drug. These sea stars which reside in the benthic region serves as their habitat and they are therefore predators and persistently being attacked by various organisms subsequently they acclimatize the survival approach to defend themselves from the external pathogens. Since these metabolites are obscured as a metabolic product during their endurance an initial evaluation of these compounds is necessary to assess human risk. Objectives: The present study focuses in vitro toxicity evaluation of isolated sterol like isolate from echinoderm sea star Stellaster equestris by incorporating hemolytic, chromosomal aberration assay and the cell viability tryphan blue exclusion assay against human peripheral blood. Methods: The in vitro toxicity evaluation was studied against the human peripheral blood collected from the healthy donors with the defined concentration of the sterol like compound from the sea star Stellaster equestris. The hemolytic, cell viability trypan blue exclusion method and chromosomal aberration assay were performed to check the hemolytic, mutagenic and genotoxic effect against the lymphocytes and the red blood cells. Results and Discussion: The result suggested that the hemolytic assay and the cell viability assay even in a dose dependent manner were non-hemolytic and percentage of the viability was not affected due to the exposure of the compound. The absence of genotoxicity was evident for the chromosomal aberration assay indicated that the isolated compound from the sea star Stellaster equestris might be considered as effective novel compound.

Marine invertebrates specifically echinoderms have been the subject of researchers in recent times. Quite a few metabolites have been elucidated from echinoderms which have gained a demand in the fields of pharmacology and pharmaceutics. The sea star which belongs to the Echinoderms produces unique natural products which have gained a demand in the fields of medicine The aim of this review is to provide current analysis on varied species of starfish and its bioactive compounds possessing cytotoxic, hemolytic, antibacterial, antifungal, antiparasitic, itcthyotoxic and antifouling activity. The major compounds isolated from marine sea stars include steroids, steroidal glycosides, anthraquinones, alkaloids, phospholipids and peptides.