~ 265 ~ Journal of Pharmacognosy and Phytochemistry 2016; 5(2): 265-269 E-ISSN: 2278-4136 P-ISSN: 2349-8234 JPP 2016; 5(2): 265-269 Received: 26-01-2016 Accepted: 27-02-2016 Mohammed Mozammel Hoque Department of Botany University of Chittagong Chittagong-4331, Bangladesh. Laila Khaleda Department of Genetic Engineering and Biotechnology, University of Chittagong, Chittagong-4331, Bangladesh. Mohammad Al-Forkan Department of Genetic Engineering and Biotechnology, University of Chittagong, Chittagong-4331, Bangladesh. Correspondence: Mohammad Al-Forkan Department of Genetic Engineering and Biotechnology, University of Chittagong, Chittagong-4331, Bangladesh. Evaluation of pharmaceutical properties on microbial activities of some important medicinal orchids of Bangladesh Mohammed Mozammel Hoque, Laila Khaleda, Mohammad Al-Forkan 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. Keywords: Antifungal activity, medicinal orchids, antimicrobial agent 1. Introduction Orchids have been very closely associated with human being since ancient times. It has not only the horticultural value but also good medicinal value. Many orchids play a significant role in traditional system of medicine because they are rich in alkaloids, flavonoids, glycosides, carbohydrates and other photochemical contents [1]. Fifty three orchids, species belonging to 34 genera have various medicinal properties [2] . Acampe papillosa (Lindl.) Lindl. Roots are used in rheumatism [3] to cure rheumatism, sciatica, neuralgia, syphilis, uterine diseases and as tonic. Aerides odorata Lour; Ground fruit was used in Indochina to treat wounds [4] . Extracted juice from the pseudobulbs of Bulbophyllum sp. are use for restoration of adolescence and as tonic [5] [3] , Pholidota pallida Lindl. Leaves and roots were used in bone fracture [5] . The Himalayan squirrel likes to eat the inflorescence [6] . In Indochina this plant is used to bathe depilated infants and to treat menstrual irregularity and also to treat burns and sores [7] . Microorganisms have developed resistant to many antibiotics and this has created immense clinical problems in the treatment of infectious diseases [8] . This situation forced scientists to search for new antimicrobial substance from various sources, such as medicinal plants. Various plant species have been serving as the best natural source of drugs and medicines from the beginning of civilization. Among the different plant derived, secondary metabolites proved to be the most important group of compounds that showed wide range of antibacterial and antifungal agents since none of the available drugs is free from adverse effects and limitation. But medicinal plants possess various remedial properties with worthless materials and it is important to separate those materials from the good ones. Now-a-days, the natural products have been interesting and important sources of biologically active antimicrobial substances and the major sources of new materials which are still left undiscovered. It is evident from various reports that orchids have ingredient to cure various diseases. The present work was undertaken to investigate the pharmaceutical properties on antibacterial and antifungal potentiality of these orchid species which are indigenous to Bangladesh.