Evaluation of pharmaceutical properties on microbial activities of some important medicinal orchids of Bangladesh

Abstract

Three species of medicinal Orchid plants namely; Acampe papillosa, Aerides odoratum and Pholidota pallida were extracted with ethanol, chloroform, petroleum ether and methanolic extract assayed for antimicrobial activity against five bacterial strains namely: Bacillus subtilis, Staphylococcus aureus, Salmonella typhi, Shigella dysenteriae and INABA-ET (Vibrio). Aqueous extracts of the plant also screened for their antifungal activity against six phytopathogenic fungi such as Alternaria alternata (Fr.) Kedissler., Botryodiplodia theobromae Pat., Colletotrichum corchori Ikata (Yoshida), Curvularia lunata (Wakker) Boedijin, Fusarium equiseti (Corda) Sacc., Macrophomina phaseolina (Maubl) Ashby. Here, extracts showed varied degree of activity against the bacterial and fungal strains. Three, extracts showed broad-spectrum antibacterial activity against all the test organisms and among them Aerides odorata Lour. And Pholidota pallida Lindl. Showed prominent antibacterial activity. The highest inhibition was recorded with Aerides odorata Lour. And Pholidota pallida Lindl. Against Salmonella typhi (37.5mm) and Bacillus subtilis showed wide reange of antifungal activity with remarkable inhibition against all the tested phytopathogenic fungi. The highest antifungal activity was recorded with the plant extract of Aerides dratum Lour. Against Colletotrichum corchori (57.14%) followed by Alternaria alternata (57.14%). The present study indicates the antibacterial and antifungal properties in the crude extract of three orchid plants. So, the plants can be used as a novel antimicrobial agent