Anti-acne potential of ethanolic extract of <i>Melastoma malabathricum</i> fruits and flowers

Abstract Acne vulgaris affects individuals of all ages and genders worldwide. Current treatment of acne is problematic due to antibiotic resistance. This study aims to identify the anti-acne phytoconstituents present in Melastoma malabathricum fruits and flowers using spectrophotometry and chromatography analysis. The study also seeks to determine the anti-acne activity of M. malabathricum by agar disc diffusion and 96-well microplate assay. The EMMFR and EMMFL were profiled using GC–MS for screening major phytoconstituents and using HP–LC for identifying the quercetin level. Using HPLC as quercetin level as a common compound contains in Melastoma genus. Agar disc diffusion and Resazurin Microplate Assay (REMA) were employed to determine their anti-acne activity. The experimental data reveals that fatty acids constitute the predominant class in the EMMFR and EMMFL. The following constituents were identified and profiled for their potential anti-acne activity: n-Hexadecanoic acid, 9-Octadecenoic acid, Octadecanoic acid, 17-Octadecynoic acid, 9,12-Octadecadienoic acid, Palmitoleic acid, Oleic acid, Undec-10-ynoic acid, 1,3-Propanediol, and Propanoic acid. However, quercetin was not quantified in either of the extracts. The EMMFL displayed the largest inhibition zone (23.67 ± 1.15 mm) while EMMFR showed the inhibition zone (17.00 ± 2.00 mm). Both EMMFR and EMMFL displayed the same MIC value (7.81 mg/mL). Meanwhile, EMMFL showed a strong ability to reduce bacterial cells with MBC value tested (62.50 mg/mL) in contrast to EMMFR (500.00 mg/mL). In conclusion, Melastoma malabathricum possesses strong potential in anti-acne activity. This finding helps in exploring the development of plant-based therapies for acne treatment, addressing challenges associated with prolonged antibiotic use while also maximizing the economic value of the understudied M. malabathricum .