Protective Effects of Naringenin against UVB Irradiation and Air Pollution-Induced Skin Aging and Pigmentation

Both UVB irradiation and air pollution are major extrinsic factors causing premature aging of the skin, including sagging, wrinkles, and pigmentation spots. Naringenin, a naturally occurring flavanone, found in citrus fruits, and known for its good antioxidant and anti-inflammatory effects, was investigated for protective effects in human skin cells and reconstructed epidermis. The results showed that naringenin inhibits UVB-induced inflammation markers MMP1, MMP3, IL6, and GM-CSF, as well as pollution-induced MMP1 in human skin fibroblasts. Furthermore, naringenin inhibited the pollution-induced expression of the CYP1A1 gene in human skin keratinocytes. In melanocytes and pigmented reconstructed epidermis, naringenin significantly downregulated several genes involved in melanogenesis, such as MITF, MLPH, and MYO5A. Additionally topical treatment with naringenin on pigmented reconstructed epidermis significantly decreased melanin production. In conclusion, this study demonstrates that naringenin could be a valuable ingredient in skincare products, protecting against the detrimental effects of both UVB and pollution on the skin.