Bioactive Compounds in Propolis from Wallacetrigona incisa and Their Application as Antibacterial Agent: In vitro and Molecular Docking Approach

Propolis, an extremely sticky and resinous substance collected by honeybees, has been widely used as a health food, antioxidant, and antimicrobial. Utilization of propolis as nutraceutical depends on the bioactive compounds contained therein. The plant source, type of bees, and region of honeybees are the main factors affecting the chemical composition of the bioactive compounds in propolis. This study aims to determine the bioactive compounds in propolis from Wallacetrigona incisa using LC-MS/MS and to analyze their antibacterial activity by in vitro and molecular docking approach. A series of propolis with different concentration (5, 7.5, 10, 20, 30, and 100 % w/v) were tested against five bacteria (P. acnes, S. aureus, S. epidermidis, B. subtilis, and E. coli) using disk diffusion method. The inhibition mechanism against the bacteria was studied by molecular docking approach. For the LC-MS/MS analysis, seven bioactive compounds were detected in the propolis from W. incisa: ganoderic acid R, mulberranol, schizandrin A (deoxyschizandrin), neoquassin, octahydrocurcumin, isorhamnetin, and 2-methoxyanofinic acid. Moreover, for the antibacterial activity, propolis has strong inhibition at concentration of 30% and 100%, and better efficacy on Gram-positive bacterial species (S. epidermidis, B. subtilis, S. aureus, P. acnes) than gram-negative bacterial (E. coli). Ganoderic acid R and mulberranol were found to be the most potential bioactive compounds of the propolis as antibacterial agents due to their good performance in interacting with target proteins of bacteria.