Conclusion
In this study, it was found that the extraction temperature had a huge
effect on the bioactive components of S. cusia . Indoxyl formed in
this extraction process inhibited cell growth and metabolism by
disrupting EM formation and altering intracellular redox, and its
inhibitory effect was much higher than the traditionally recognized
bioactives in banlangen, such as indigo and indirubin. Moreover, the
precursor of indoxyl, indican, did not have any antimicrobial activity.
Simulating the hydrolysis of indican by β-glucosidase in plants, a novel
antibacterial mode with indican could be formed, improving the medicinal
properties of antimicrobial agents.