Yashoda Kambar, Vivek M. N, Prashith Kekuda T.R, Raghavendra H. L
Alpinia galanga (L.) Willd belonging to the family Zingiberaceae is widely distributed in tropical areas. The plant is used in food preparation and as medicine. The present study was carried out to determine antimicrobial and radical scavenging effect of leaf and rhizome extract of A. galanga. The powdered leaf and rhizome were extracted by soxhlet extraction using methanol. Antimicrobial activity of extracts was determined by Agar well diffusion assay against 15 clinical isolates of bacteria (from burn, dental caries and urinary tract infection) and two fungi (Candida albicans and Cryptococcus neoformans). Radical scavenging activity of extracts was determined by DPPH free radical scavenging assay. Total phenolic and flavonoid contents were estimated by Folin- Ciocalteau reagent and Aluminium chloride colorimetric estimation method respectively. Rhizome extract was found to possess high inhibitory activity against fungi and clinical isolates of bacteria. Inhibitory activity was marked against burn and dental caries isolates when compared to urinary tract isolates. Overall, Gram positive bacteria showed higher susceptibility to extracts. Among fungi, C. neoformans was inhibited to higher extent. The extracts have shown dose dependent scavenging of free radicals. The rhizome extract (IC50 32.34μg/ml) was more efficient in scavenging free radicals than leaf extract as revealed by low IC50 value. The content of total phenolics and flavonoids were high in rhizome extract when compared to leaf extract. Marked antimicrobial and radical scavenging potential of rhizome extract can be ascribed to high phenolic and flavonoid content. The plant can be used for the development of agents active against pathogenic microbes and radical induced damage.
