Antioxidant activity and whitening effect of vitamin C and superoxide dismutase from <i>Rosa roxburghii</i> Tratt

Abstract With growing concerns about the negative impact of environmental pollution on skin health, there is an increasing demand for natural active ingredients to combat free radicals and excessive melanin production. In this context, Rosa roxburghii Tratt (RR) has emerged as a potential source of skin-lightening compounds. Vitamin C (Vc) and superoxide dismutase (SOD)-rich extracts were extracted from RR, namely RRVC and RRSOD, using macroporous resin column chromatography and graded ammonium sulfate precipitation. The antioxidant and skin-lightening effects of these extracts were evaluated. RRVC and RRSOD showed strong inhibitory activity against various radicals and tyrosinase. When formulated together, their antioxidant and skin-lightening abilities were significantly enhanced, with the optimal ratio of RRVC and RRSOD (RRVS) of 5:32. In vivo studies on C57BL/6J mice revealed that these two extracts and their formulations effectively lowered oxidative stress levels in a model of d-galactose-induced aging in mice. Furthermore, they inhibited melanogenesis and tyrosinase activity in B16 cells and reduced ultraviolet-radiation-induced melanin deposition in mouse ears. The combination of RRVC and RRSOD had a more potent melanin-scavenging effect compared with the individual extracts. These findings suggest that RRVC and RRSOD, especially when combined at the optimal ratio, can whiten skin, increasing the value of RR products and offering natural alternatives for skin lightening.