Antibacterial Efficacy of Garcinia mangostana Extracts Against Multidrug-Resistant and Clinically Significant Bacterial Pathogens.

&lt;b&gt;Background and Objective:&lt;/b&gt; &lt;i&gt;Garcinia mangostana&lt;/i&gt;, commonly known as mangosteen, is rich in bioactive compounds, particularly xanthones such as α-mangostin, which have exhibited potent antibacterial activity against a range of pathogenic bacteria in numerous &lt;i&gt;in vitro&lt;/i&gt; studies. This research aimed to assess the antibacterial activity of &lt;i&gt;G. mangostana&lt;/i&gt; extracts against eight clinically significant human pathogenic bacteria. &lt;b&gt;Materials and Methods:&lt;/b&gt; Powdered &lt;i&gt;G. mangostana&lt;/i&gt; was subjected to solvent extraction using ethanol, dichloromethane and hexane. The resulting extracts were evaluated for their antibacterial activity by determining the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against eight clinically relevant human pathogenic bacteria using the microbroth dilution method. The MIC and MBC data were analyzed using ANOVA under a CRD with three replicates and means were compared using DMRT at p<0.05 in SPSS v28. &lt;b&gt;Results:&lt;/b&gt; The lowest MIC value of 0.049 mg/mL was observed for the ethanol, dichloromethane and hexane extracts against &lt;i&gt;Pseudomonas aeruginosa&lt;/i&gt; TISTR 2370. Correspondingly, the lowest MBC values, at <0.049 mg/mL, were also recorded for these extracts against the same bacterial strain. &lt;b&gt;Conclusion:&lt;/b&gt; This study is the first to report the antibacterial efficacy of &lt;i&gt;G. mangostana&lt;/i&gt; against antibiotic-resistant bacteria, including colistin-resistant &lt;i&gt;P. aeruginosa&lt;/i&gt;, carbapenem-resistant Enterobacteriaceae, multidrug-resistant &lt;i&gt;Klebsiella pneumoniae&lt;/i&gt; and &lt;i&gt;Acinetobacter baumannii&lt;/i&gt;. These findings are significant and hold promise for the development of novel antibiotic agents for the treatment of infections caused by these clinically challenging pathogens.