CYTOTOXICITY, ANTIMICROBIAL AND NEUROPHARMACOLOGICAL EVALUATION OF ETHANOLIC EXTRACT OF PISTIA STRATIOTES L.

Abstract

In phytochemical screening of the ethanolic extract of Pistia stratiotes L. aerial part anthraquinone glycosides, cardiac glycosides, cyanogenetic glycosides, flavonoids, steroids, tannins, carbohydrates were found to be present. The LC₅₀ and LC₉₀ were 1.8µg/ml & 2.07µg/ml respectively in brine shrimp lethality assay. It was to have produced significant zones of inhibition against gram positive Bacillus cereus, B. subtilis, Staphylococcus aureus, gram negative Escherichia coli, Salmonella typhi, Proteus mirabilis and yeast Candida albicans and Rhodotorula rubra, which were comparable with standard antimicrobial drugs tetracycline, vancomicin and nystatin. In acute-toxicity test in mice LD₅₀ was 850mg/kg body weight (i.p). In CNS depressant tests; hole cross, open field, beam walking and thiopental sodium induced sedative test in mice it significantly (p<0.005, p<0.001) decreased the locomotor activity in mice. The extract showed significant (p<0.005, p<0.001) antinociceptive activity when subjected to hot plate, tail immersion and acetic acid-induced writhing tests in mice.