Antioxidant, Antibacterial and Cytotoxic Activity of the Methanol Extract of

The antioxidant, antibacterial and cytotoxic properties of methanol extract of Urtica crenulata (syn: Laportea crenulata Gaud) stem has been investigated in the present study. The antioxidant and cytotoxic activity of the Urtica crenulata methanol extract were assessed by DPPH free radical scavenging method and brine shrimp lethality bioassay method, respectively. The antibacterial activity of the plant extract (500 μg/disc) was also carried out by disc diffusion technique. Stem extract showed DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging effect compared with ascorbic acid. IC50 value of ascorbic acid and stem extract was found 14.72 μg/ml and 1468.9 μg/ml, respectively. In antibacterial experiment, Urtica crenulata stem extract showed 8, 14 and 10 mm of diameter of zone inhibition against Salmonella typhi, Shigella flexneri and Shigella sonnei, respectively and 9 and 8 mm of diameter of zone inhibition against Bacillus subtilis and Bacillus cereus but no activity was observed against Staphylococcus aureus. In brine shrimp lethality assay, the LC50 value of the extract was found 104.0 μg/ml, which indicates that the extract has high cytoxic effect. The present study demonstrates that methanol extract of Urtica crenulata stem has significant cytotoxic effect. The extract also showed some moderate antibacterial and minimum significant antioxidant effects