Antimicrobial and in vitro cytotoxic studies of Acampe praemorsa and Aeridis odarata of Orchidaceae

Abstract

This paper aims at studying antimicrobial efficacy and in vitro cytoxic activity of epiphytic orchids namely Acampe praemorsa, Aeridis odorata distributed in Eastern Ghats of Visakhapatnam district. Plants were collected, identified following literature, shade dried and Methanol, ethyl acetate extracts were prepared for the systematic investigation of antimicrobial activity of plant extracts. Antibacterial activity against three gram positive bacteria Bacillus megaterium, Lactobacillus acidophillus and Enterococcus faecalis, three gram negative bacteria Proteus vulgaris, Klebsiella pneumoniae and Escherichia coli was done using Agar well diffusion method, antifungal activity was carried against Candida albicans, Aspergillus flavus by Cpzapak dox agar media, MIC by broth dilution method, zones of inhibition were recorded. Ethyl acetate extracts showed maximum antimicrobial activity against all bacteria and fungi, Aeridis odarata ethyl acetate extract showed highest zone of inhibition 17mm against Lactobacillus acidophilus in bacteria, Ethyl acetate extract of Acampe praemorsa showed highest zone of inhibition 17mm against Candida albicans in fungi, the leaf extracts were tested for its inhibitory effect on HeLa and MCF-7 cell lines were evaluated by the MTT assay and methanolic extract of Aeridis odarata has significant cytotoxicity effect on MCF-7 cell line in concentration range between 5 to 100µg/ml, with IC 50 (µg/ml) value is 26.2. These plants have good antimicrobial activity, further investigation on the phytochemistry of bioactive compounds of these plants would result in discovery of new drugs and further pharmacological investigation of anti-cancer activity of Aeridis odarata should be done.