Antibacterial and Radical Scavenging Activity of Selected Orchids of Karnataka, India
The present study was carried out to determine antibacterial and radical scavenging activity of extract of four epiphytic orchids (Orchidaceae family) namely Luisia zeylanica Lindl., Pholidota pallida Lindl., Dendrobium nutantiflorum A. D. Hawkes and A. H. Heller and Coelogyne breviscapa Lindl collected at different places of Western Ghats of Karnataka, India. Antibacterial and radical scavenging activity of orchid extracts was determined by Agar well diffusion and DPPH free radical scavenging activity respectively. The total phenolic content was estimated by Folin-Ciocalteau reagent method. All orchid extracts inhibited test bacteria. Marked antibacterial activity was observed in case of C. breviscapa. Extract of L. zeyianica exhibited stronger radical scavenging activity when compared to other orchid extracts. The phenolic content was highest in L. zeylanica. A direct correlation was observed between phenolic content and radical scavenging effect of orchid extracts. These orchids appear to be promising sources of bioactive agents which can be exploited for treatment of several kinds of ailments.