EVALUATION OF BIOACTIVE COMPOUNDS, ANTIOXIDANT ACTIVITY, ANTI-ACNE AND ALNAGESIC ACTIVITY OF CHINESE MOTHERWORT (LEONURUS JAPONICUS) DIFFERENT PART EXTRACTS

Leonurus japonicus Houtt. (Lamiaceae), commonly known as Chinese motherwort or Yi-Mu-Cao, has a longstanding history in traditional Asian medicine. This study comparatively evaluated the phytochemical constituents, antioxidant capacity, anti-acne properties, and in–vitro anti-inflammatory activities of hot-water extracts obtained from the aerial parts and roots of L.japonicus cultivated in Northern Thailand. Total phenolic content (TPC) and total flavonoid content (TFC) were determined spectrophotometrically, while antioxidant capacities were evaluated using DPPH and FRAP assays. Antibacterial activity against acne-associated pathogens (Cutibacterium acnes, Staphylococcus aureus, and Staphylococcus epidermidis) was assessed by broth microdilution to determine minimum inhibitory (MIC) and minimum bactericidal (MBC) concentrations. In–vitro anti-inflammatory activity was quantified by measuring prostaglandin E₂ (PGE₂) inhibition in LPS-stimulated RAW 264.7 macrophages via enzyme-linked immunosorbent assay (ELISA). The aerial part extract contained significantly higher TPC (26.35 ± 0.11 mg GAE/g) and TFC (17.89 ± 0.19 mg QE/g) than the root extract (7.40 ± 0.37 mg GAE/g and 5.77 ± 0.14 mg QE/g, respectively; p < 0.001). Correspondingly, aerial extracts exhibited superior DPPH (97.14 ± 0.15 mg TE/g) and FRAP (90.20 ± 0.35 mg TE/g) values. Aerial extracts demonstrated moderate antibacterial activity, inhibiting C. acnes at an MIC of 625.0 µg/mL, and S. aureus and S. epidermidis at 1250.0 µg/mL. Both extracts produced a concentration-dependent suppression of PGE₂ production (0.25–1.50 mg/mL), with the aerial extract achieving 75.8% inhibition at 1.50 mg/mL. These results indicate that aqueous extracts of L.japonicus aerial parts possess noteworthy antioxidant, antibacterial, and PGE₂-suppressing properties in–vitro, corroborating the traditional preference for aerial structures in herbal preparations.