Targeting Skin Aging at Multiple Fronts: Antioxidant, Antielastase, Anticollagenase, and UVB-Protective Effects of <em>Vitex trifolia</em>

Skin aging is driven by oxidative stress, extracellular matrix degradation, and UVB-induced cellular injury. Plant-derived bioactives with multi-targeted protective actions offer promising avenues for cosmeceutical development. This study assessed ethanolic leaf extracts of Vitex trifolia, an Indonesian medicinal plant traditionally used for skin disorders. Phytochemical analysis showed a total phenolic content of 78.52 ± 0.01 mg GAE/g and total flavonoid content of 1.99 ± 0.02 mg QE/g. LC–HRMS profiling identified major metabolites including casticin and several flavonoid and phenolic acid derivatives. Antioxidant assays demonstrated strong radical-scavenging and reducing activities, with IC₅₀ value of 63.47 ± 0.24 (DPPH) and 70.13 ± 1.28 μg/mL (ABTS), and a FRAP value of 36.3 ± 0.18 FeSO₄ eq/100 g. Enzymatic studies confirmed potent collagenase inhibition (IC₅₀=27.94 ± 3.20 μg/mL) and moderate elastase inhibition. In HaCaT keratinocytes, V. trifolia extract remained non-toxic up to 100 μg/mL and exerted cytoprotective activity against UVB-induced damage at 12.5–50 μg/mL. The extract also downregulated UVB-induced MMP-1 and MMP-9 expression up to 42% and 69%, respectively, outperforming ascorbic acid. These findings highlight V. trifolia as a promising natural anti-aging agent with strong antioxidant, protease-inhibitory and photoprotective properties, supporting its potential as safe and effective cosmeceutical ingredient.