In vitro antibacterial, cytotoxic and antioxidant activities of plant Nephelium longan.

The petroleum ether, chloroform and ethyl acetate fractions of ethanol extract of leaf and stem from the plant Nephelium longan (Fam-Sapindaceae) was subjected to antioxidant, antibacterial and cytotoxic activity. All the fractions showed potent antioxidant activity, of which the ethyl acetate and chloroform fraction of leaf demonstrated the strongest antioxidant activity with the IC50 value of 44.28 and 44.31 microg mL(-1), respectively. The petroleum ether extracts (500 microg disc(-1)) of leaf and stem of N. longan almost showed no activity against the tested pathogenic organisms except Escherichia coli. On the other hand, chloroform crude extracts of leaf and stem (500 microg disc(-1)) showed excellent antibacterial activity with the average zone of inhibition of 13-21 mm among the tested bacteria. Besides this, ethyl acetate crude extracts showed good activity against the growth of Sarcina lutea (20 mm), Vibrio mimicus (18 mm), Salmonella typhi (18 mm), E. coli (17 mm) and Staphylococcus aureus (14 mm). However, in the brine shrimp lethality bioassay, all the crude extracts of leaf and stem possessed considerable cytotoxic activity. It was evident that, the chloroform and ethyl acetate extracts of leaf and stem have significant cytotoxic potentials with the LC50 value of 8.802, 9.587, 9.248 and 10.45 microg mL(-1), respectively. Both the stem and leaf of the experimental plant have considerable antibacterial, cytotoxic and antioxidant properties which indicates that the plant have potent bioactive principles.