Artocarpin isolated from Artocarpus heterophyllus heartwoods alters membrane permeability of Streptococcus mutans

Artocarpin was successfully isolated from the heartwoods of A. heterophyllus. Objectives: The present study was conducted to determine the antimicrobial activity of artocarpin against cariogenic microbial including Streptococcus mutans, Escherichia coli, and Candida albicans. The activity of artocarpin on alteration of the cell membrane was also investigated. Methods: Standard microdilution method was applied to evaluate its antibacterial activity against tested microorganisms. Time-killing test was then performed to verify its antimicrobial effect. In order to know its effect on membrane permeability, bacteriolysis assay was selected, followed by determining loss of 260 nm absorbing material using UV-Vis spectrophotometer. Results: Artocarpin exhibited strong antibacterial against S. mutans with MIC and MBC values of 1.95 and 3.91 μg/mL, respectively. Time-killing curve showed that artocarpin at 2 × MIC (3.9 μg/ mL) and 4 × MIC (7.8 μg/mL) inhibited bacterial growth after 4 h incubation which was comparable to ampicillin as a positive control. Artocarpin 2 × MIC (3.9 μg/mL) and 4 × MIC (7.8 μg/mL) altered membrane permeability of S. mutans after 24 h exposure and led to release 260 nm absorbing material as an indicator of membrane cell damage. Conclusion: This finding indicated that artocarpin has high potency as antibacterial compound against S. mutans by reducing cell membrane permeability.