A new product of multi-plant extracts improved skin photoaging: An oral intake in vivo study

Background: Besides the topical application of cosmetics, nutraceuticals represent a promising strategy for preventing skin photoaging and skin cancers. Methods: To determine the effect of a new multi-plant extracts product containing Cucumis melo extract, acerola extract, olive fruit, aloe vera gel, grape seed extract, and lycopene, a randomized, placebo-controlled, double-blind clinical trial and an ultraviolet (UV)-induced murine photoaging model were deployed. 55 healthy subjects aged 45-60 were enrolled and randomized to take the product or placebo orally for 12 weeks. Skin aging and whitening indexes were measured with non-invasive techniques. 90 Balb/c mice aged 7-8 weeks were randomly divided into six groups: normal, UV, UV+vehicle, UV+different doses of the product (0.500 g/kg.BW, 0.250 g/kg.BW, 0.125 g/kg.BW, respectively). Except the normal group, mid-dorsal regions were irradiated with UVA+UVB for 8 weeks. Factors of oxidative stress, tyrosinase, and histological analysis of the mid-dorsal skin were determined. Results: In the clinical trial, the TEWL, hydration, sebum, elasticity, and the L*, a*, melanin index change from baseline, ITA degrees were significantly improved in the experiment group. In the animal experiment, compared to the UV+vehicle group, UV+high dose group showed significantly lower malondialdehyde (MDA) and tyrosinase, but higher superoxide dismutase (SOD), total antioxidant capacity (T-AOC), and glutathione peroxidase (GSH-Px). The UV+moderate dose group showed significant improvement of MDA and GSH-Px, and the UV+low dose group only showed improvement of GSH-Px. Histological photoaging manifestations were attenuated in the UV+high and moderate dose groups. Conclusions: The multi-plant extracts product improved skin photoaging possibly via antioxidant and anti-tyrosinase ways.