Chemical profiling and targeted anti-photoaging mechanisms of wild tree peony stem and leaf extracts

Genus Paeonia comprises 34 wild species worldwide, with 9 woody species belonging to the subgenus Moutan endemic to China, which are valued for their ornamental, medicinal, edible, and cosmetic value. However, the secondary metabolite profiles and skin anti-photoaging effects of stems and leaves from these wild tree peonies remain understudied. This study systematically evaluated the secondary metabolite profiles, and anti-skin photoaging effects of stems and leaves from 9 wild tree peonies. Qualitative analysis identified 22 secondary metabolites, with leaves consistently containing more diverse and abundant metabolites than stems. P. delavayi and P. ludlowii stood out for their high total metabolite content. In UVB-irradiated keratinocytes, both P. ludlowii and P. ostii exhibited distinct but potent anti-photoaging effects. P. ostii extract showed superior antioxidant performance by efficiently scavenging reactive oxygen species and activating superoxide dismutase (up to 73.48% enhancement at 3.00 μg/mL), while P. ludlowii extract displayed stronger anti-inflammatory activity by inhibiting tumor necrosis factor-α secretion (up to 66.05% inhibition at 3.00 μg/mL). Both extracts effectively suppressed matrix metalloproteinase-1 production (up to 46.17% reduction by P. ludlowii and 43.61% by P. ostii ), thereby protecting collagen from degradation and exerting anti-wrinkle effects. These findings demonstrate that stems and leaves from wild tree peonies serve as a plentiful source of secondary metabolites with biological activity, possessing powerful antioxidant, anti-inflammatory, and anti-collagenolytic properties. The extracts of Paeonia effectively protect keratinocytes against UVB-induced photoaging, providing a scientific basis for the comprehensive exploitation of wild Paeonia resources and their development as natural anti-photoaging ingredients in cosmetics. • 22 metabolites were identified in 9 wild tree peonies, and leaves were richer in metabolites. • Paeonia ludlowii and P. delavayi showed high metabolite content and strong antioxidant activity. • P. ostii showed stronger antioxidant, P. ludlowii stronger anti-inflammatory activity. • Wild tree peony stems and leaves protect keratinocytes from UVB photoaging.