ABSTRACT
Aims: Natural products obtained from different types of plants have made an important impact since ancient times throughout Asia. Since wood of Hesperethusa crenulata (Roxb.) Roem has been used traditionally by women in Southeast Asia for protection against sunlight and other harmful environmental factors, present study was aimed to determine antioxidant and antimicrobial properties of water extract of H. crenulata wood. Methodology: Wood was powdered, soaked in water, macerated, extracted fluid was lyophilized and tested for antioxidant and antimicrobial properties following standard techniques. The IC50 values were calculated from regression equations prepared from concentrations of extract and inhibition percent of free radical formation. The extract was screened for antimicrobial action following international guidelines against 44 organisms. Results: In DPPH assay system IC50 value was 344.74 μg/ml, the same for superoxide scavenging assay was 326.13μg/ml, while in hydroxyl radical scavenging system it was 999.85 μg/ml. Among 32 strains of staphylococci 10 strains were inhibited at 25 -50 μg /ml level of the extract, 6 strains at 100 μg /ml, 4 at 200 μg /ml and the remaining 12 strains were resistant. Strains of Bacillus spp and Vibrio vulnificus were rather sensitive to the extract, while E. coli and Pseudomonas aeruginosa were resistant. Thus the extract was inhibitory for bacteria known to invade human skin. Conclusions: The distinctly beneficial properties of the wood of H. crenulata indicate its usefulness as a highly active agent for the protection of skin against invasion by microorganisms and free radicals including those that may come from the sunlight.