Antimicrobial activity of different part of plant extracts of wild yam (Dioscorea hispida Dennst)

Traditionally, the use of plants and herbs can give the significant benefits for the healing process to cure for the human disease. There are some of the yam species that known as intoxicating yam species that grows well in Malaysia included Ubi Gadong (Dioscorea hispida Dennst). Thus, these plants usually will be ignored their existence due to the reason toxicity of the yam. There was three part of D. hispida plant involved which are tuber, peel and leaf which were extracted by the hot continuous percolation method by using Soxhiet apparatus with the different solvent which were ethanol and hexane. Antimicrobial activities of solvent extracts were tested by using Kirby-Bauer disc diffusion test. All the extracts were tested for antimicrobial efficiency against Escherichia coil P511 and Staphylococcus aureus and were compared by using control positive and control negative which are commercial antibiotic (Gentamicin) and solvents. The different concentration of extract dilution has been used which are 125 µl/mL, 250 µl/mL, 500 µl/mL and 1000 µl/mL to test their efficiency. For tuber part, the hexane of tuber extract was displayed the maximum value of inhibition zone, 9.00±0.50b against S. aureus at 500 µl/ml and 1000 µl/ml. While, for peel extract, the ethanol of peel extract was showed the maximum inhibition zone with the value of 8.17±0.76b against S. aureus at the concentration of 500 µl/ml. For the leaf part, both of the solvents showed the highest value of inhibition zone with the 9.33±0.58b against S. aureus and E. coli at the lowest concentration, 125 µl/m1 and 250 µl/ml respectively. The result of this study has displayed that the leaf extracts of D. hispida dennst exhibited higher antimicrobial activity followed by tuber and the last was peel extract. Lastly, this study was found out that the hexane extract has more potential for antimicrobial activity compare with ethanol.