Bridging ethnomedicine and evidence-based therapy: Phytochemical characterization and bioactivity profiling of Tetradenia riparia and Maesa lanceolata for skin health management.

Medicinal plants represent a valuable source of bioactive secondary metabolites with therapeutic potential for treating skin disorders. Tetradenia riparia and Maesa lanceolata have been traditionally used for wound healing , skin infections and as anti-inflammatory , yet systematic validation of their bioactive compounds and mechanisms of action remains limited.This study aimed to extract, isolate, and characterize bioactive secondary metabolites from T. riparia and M. lanceolata, and comprehensively evaluate their wound healing, antimicrobial, antioxidant, cytoprotective, and anti-inflammatory properties using human keratinocytes (HaCaT cells) and relevant microbial pathogens. T. riparia leaves underwent dichloromethane extraction followed by column chromatography, yielding ten fractions characterized by TLC, LC-MS, and ¹H NMR. M. lanceolata methanol extract was fractionated using preparative HPLC, producing three distinct fractions (F1, F2-Big, F3-Tail). Phytochemical quantification included total phenolics (Folin-Ciocâlteu), triterpenoids (vanillin-sulfuric acid), and flavonoids (spectrophotometry). Bioactivity assessments included: ABTS antioxidant assay, MTT cell viability under UV and TNF-α stress, scratch wound healing assay, antimicrobial testing (MIC, IC₉₀, MBIC) against MRSA, Streptococcus mutans, Candida spp., and Malassezia pachydermatis, and RT-qPCR analysis of pro-inflammatory cytokines (IL-1α, IL-1β, IL-6).LC-MS and ¹H NMR identified umuravumbolide (F3) and 8(14),15-sandaracopimaradiene-7α,18-diol (F9) from T. riparia. T. riparia fractions exhibited high terpenoid content (88-100% β-sitosterol equivalents), while M. lanceolata fractions were rich in phenolics (19.9-30.2% GAE) and flavonoids (41.17% w/w). M. lanceolata demonstrated superior antioxidant capacity (1627-1905 µM VEAC, 61.7-73.5% inhibition) compared to T. riparia (214-354 µM VEAC, 1.6-7.6% inhibition).Both plants showed significant wound healing activity: T. riparia F9 achieved 80% closure at 48h (10 µg/mL), while M. lanceolata crude extract and tail fraction achieved 81.3-81.8% closure at the same concentration and timepoint. T. riparia aqueous crude extract demonstrated comparable efficacy (81.3% closure). For antimicrobial activity, T. riparia F9 exhibited potent activity against M. pachydermatis (MIC: 15.6 µg/mL), S. mutans (15.6 µg/mL), and MRSA (31.2 µg/mL), comparable or superior to standard antibiotics. F9 also demonstrated robust antibiofilm efficacy against MRSA (MBIC: 55.5 µg/mL) and C. albicans (31.6 µg/mL). M. lanceolata showed distinct antimicrobial profiles: the tail fraction exhibited strong antifungal activity against C. albicans (MIC: 47.9-62.5 µg/mL) and C. glabrata (35.9-58.6 µg/mL), while the big fraction was most effective against MRSA (MIC: 312 µg/mL, IC₉₀: 113.6 µg/mL) and S. mutans (MIC: 625 µg/mL, IC₉₀: 177.8 µg/mL). The crude extract of M. lanceolata showed moderate activity against M. pachydermatis (MIC: 125 µg/mL). RT-qPCR analysis revealed distinct anti-inflammatory profiles: T. riparia F9 significantly downregulated IL-1β, IL-1α, and IL-6 expression in TNF-α-stimulated keratinocytes (p<0.05), while umuravumbolide (F3) selectively inhibited IL-1β. M. lanceolata crude methanolic extract at 100 ng/mL effectively suppressed all three pro-inflammatory cytokines (p<0.05), with dose-dependent modulation observed at 50 ng/mL (selective IL-6 inhibition) and 500 ng/mL (trend toward reduction).This study provides systematic validation of the ethnomedicinal use of both T. riparia and M. lanceolata for skin disorders. T. riparia demonstrated exceptional antimicrobial and antibiofilm activity primarily through terpenoid compounds, while M. lanceolata exhibited superior antioxidant capacity and broad anti-inflammatory effects through its polyphenolic constituents. Both plants showed comparable wound healing efficacy. The complementary bioactivity profiles suggest potential for combination therapies or targeted applications: T. riparia for antimicrobial and antibiofilm treatment, and M. lanceolata for antioxidant and anti-inflammatory management of skin conditions. These findings establish both plants as promising sources for developing novel topical therapeutics, warranting further preclinical and clinical investigation.