IN VITRO EVALUATION OF PHYTOCHEMICAL, ANTIMICROBIAL AND ANTIOXIDANT ACTIVITY OF CALYCES OF ROSELLE (HIBISCUS SABDARIFFA L.)

Diversity of plants has attracted a great deal of research interest in search of natural antioxidants and antimicrobials. Many natural substances having anti-oxidant and anti-microbial properties have been used in health foods for medicinal and preservative purposes Fleshy calyces ofHibiscus sabdariffa L. of family Malvaceae including the fleshy calyces were tested positive for presence of phytochemicals like Phenols, tannin, flavonoids,  alkaloids, saponin, anthraquinone, triterpenoids and steroids etc. Both Petroleum ether extract and ethanol extract had shown similar antimicrobial activities. Petroleum ether extract was very effective against bacteria like Klebsiella pneumoniae, Staphylococcus aureus, Bacillus cereus and Lactobacillus brevis. But ethanol extract showed moderate antimicrobial activities against Staphylococcus aureus, Escherichia coli and Bacillus cereus.  Antioxidants like phenolics and flavonoid content of roselle was found to be high. Petroleum ether extract also showed better antioxidant activity by scavenging DPPH free radical. This plant has the prospect of being a source of new clinically efficient antimicrobial or antioxidant compounds.