Lycium barbarum polysaccharide promotes proliferation of human melanocytes via activating the Nrf2/p62 signaling pathway by inducing autophagy in vitro

Abstract

Vitiligo is a skin disease characterized by lack of functional melanocytes. Lycium barbarum polysaccharide (LBP) has been demonstrated to preserve keratinocytes and fibroblasts against oxidative stress. This study aimed to explore the efficacy and underlying mechanisms of LBP on autophagy in H 2 O 2 -damaged human melanocytes. Cellular viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoli um bromide assay and annexin V-fluorescein isothiocyanate/propidium iodide double staining. Reverse transcription-polymerase chain reaction, western blotting and electron microscopy were performed to detect autophagy. The protein expression level of Nrf2 and p62 were assessed by western blotting. Plasmid transfection and lentiviral infection were used to overexpress and silence Nrf2 in PIG1 cells. LBP promoted the proliferation and inhibited apoptosis of H 2 O 2 -damaged PIG1 cells. LBP increased the proliferation of H 2 O 2 -damaged PIG1 cells via induction of autophagy, and Nrf2shRNA experiment confirmed that LBP activated the Nrf2/p62 signal pathway. These results suggest that LBP may be used for the treatment of vitiligo. Practical applicationsGoji berry is the mature and dried fruit of Lycium barbarum L., which is a common food with a long history in China, as well as a Traditional Chinese Medicine. Our previous research found that LBP could activated the Nrf2/ARE pathway in an ultraviolet (UV)-induced photodamage model of keratinocytes, and increase the levels of phase II detoxification and antioxidant enzymes. We firstly confirmed the anti-vitiligo effects of L. barbarum polysaccharide (LBP) by inducing autophagy and promoted proliferation of human melanocytes, and LBP induced autophagy via activating the Nrf2/p62 signaling pathway in this study. These results proved that LBP can be an effective therapy for vitiligo treatment.

Lycium barbarum polysaccharide inhibits blue‐light‐induced skin oxidative damage with the involvement of mitophagy

“…Previous studies have shown that LBP has a great potential in the treatment of various physiological and pathological processes. 51,52 LBP is composed of a complex mixture of polysaccharides and proteoglycans. Its main constituents include arabinose, glucose, galactose, mannose, rhamnose, xylose, and galacturonic acid.…”

“…Previous studies have shown that LBP has a great potential in the treatment of various physiological and pathological processes 51,52 . LBP is composed of a complex mixture of polysaccharides and proteoglycans.…”

NRF2 in the Epidermal Pigmentary System

“…Several compounds can protect melanocytes against oxidative stress through NRF2 activation (Table 1). Melatonin and its metabolites (6-hydroxymelatonin, N1-acetyl-N2-formyl-5-methoxykynuramine, N-acetylserotonin, and 5-methoxytryptamine) [101], vitamins (folic acid [102], methylcobalamin [103], and vitamin D [104]), natural compounds (4-octyl itaconate [105], ginsenoside Rk1 [106], Cistanche deserticola polysaccharides [107], glycyrrhizin [108], Lycium barbarum polysaccharides [109], paeoniflorin [110], 6-shogaol [111], paeonol [112], afzelin [113], apigenin [114], baicalein [115], vitexin [116], and berberine [117]), and therapeutic agents (aspirin [118], dimethyl fumarate [DMF] [94], simvastatin [29], molecular hydrogen [52], and cold atmospheric plasma [119]) are shown to protect melanocytes against oxidative damage caused by H 2 O 2 , UVB, or MBEH. DMF is the methyl ester of fumaric acid and is one of the most successful NRF2 activators.…”