Monomelittoside and Dichotomoside D from bark extract of <i>Alstonia scholaris</i> (L.) R. Br. inhibits dental caries pathogen <i>Streptococcus mutans</i>

Dental caries advances to be a significant global health concern, primarily attributed to the virulent actions of <i>Streptococcus mutans</i>. The antibacterial property of the bark extract of <i>Alstonia scholaris</i> was assessed using standard disc diffusion assays, which revealed significant inhibition of <i>S. mutans</i>. Subsequently, we determined the Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) revealed potent antibacterial activity of bark extract against <i>S. mutans</i>, at MIC and MBC values 62.5 and 125 µg/mL, respectively and antibiofilm activity at 125 µg/mL. Furthermore, cytotoxicity assays showed no adverse effects on mammalian cells. Moreover, we employed liquid chromatography-mass spectrometry to identify bioactive compounds in the bark extract and revealed the presence of major active compounds as Monomelittoside and Dichotomoside D effective in targeting the <i>S. mutans</i>. These findings showed that, the promising antibacterial efficacy of Monomelittoside and Dichotomoside D, highlighting their potential as natural therapeutics for combating dental caries.