Phytochemical analysis and antimicrobial screening of selected medicinal herbs used in Malaysian diet

Drug development to combat infectious disease has gain popularity in many researches at present time. The undesirable side effects of certain antibiotics and the emergence of previously uncommon infections have forced scientists to look for new antimicrobial substances from various sources like medicinal plants. Antimicrobial screening and phytochemical analysis was done for seven different plant spcies including Cymbopogon citratus (Lemon grass), Citrus hystrix (Kaffir lime leaf), Pandanus amaryllifolius (Pandan), Murraya koenigii (Curry leaf), Allium ascalonicum (Spring onion), Apium graveolens (Celery) and Mentha spicata (Pudina) ethanolic extract were analyzed initially. Disc diffusion assay was done by using four different bacterial strain, Staphylococcus aereus, Escherichia coli, Shigella sonnei and Salmonella choleraciuis. Further investigation including Minimum Inhibitory Concentration (MIC) and Thin Layer Chromatography (TLC) was determined for positive sample in antimicrobial screening, Phytochemical analysis indicated that glycoside was present in ethanolic extract of A graveolens and M spicata while flavonoid was present only in C,citratus. Tannins and saponins were present in P. amaryllifoluis, M koenigii, C. hystrix and Aascalonicum while A graveolens only had tannins. Presence of anthroquinone was detected only in ethanolic extract of C.citratus. The antimicrobial screening results of ethanolic extract of C.citratus inhibited growth of only S.aereus bacterial strain with an inhibition zone of 0.87±0,12cm while the other plants did not show any antimicrobial activity, Ethanolic extract of six other samples showed negative effect on all four strains of bacteria. The MIC value of S.aereus against C. citratus is 12.5mg/ml. Hence, C. citratus has potential antimicrobial activity which can be further studied for active compound.