Synergistic Antimicrobial Effects of Different Ratio Combination of Smilax myosotiflora, Persicaria odorata and Syzygium aromaticum with antibiotics
Antibiotic resistance to infectious microbe has become a major threat to clinical treatment. In order to control the misuse of antibiotics, an alternative antimicrobial agent is crucially needed to cater to this issue. This study was carried out to assess the efficacy of antibacterial and antifungal activities of all single or combination extracts of Smilax myosotiflora (SM), Persicaria odorata (PO) and Syzygium aromaticum (SA) with standard antibiotics (gentamicin or ketoconazole) as the positive controls. All plant extracts were prepared using methanol extraction procedure. Antibacterial activities of the crude extracts were determined by agar well diffusion method. The mixed extracts were prepared by adding 25µg/µl concentration of each crude extract based on the volume ratio of 1:1, 1:2, 2:1, 1:1:1, 1:1:2, 1:2:1 and 2:1:1. Single extracts of SM, PO and SA demonstrated positive effects on the growth of Bacillus subtilis, Salmonella typhi, and Candida albicans. All crude extracts displayed increased diameter of inhibition zones when combined with positive controls. Findings of this study suggested that the synergism activity is present, and extracts do not react antagonistically with antibiotics.