Ultraviolet B (UVB) irradiation plays a key role in skin damage, which induces oxidative and inflammatory damages, thereby causing photoaging or photocarcinogenesis. Lycium barbarum polysaccharide (LBP), the most biologically active fraction of wolfberry, possesses significant antioxidative and anti-inflammatory effects on multiple tissues. In the present study, the photoprotective effects and potential underlying molecular mechanisms of LBP against UVB-induced photo-damage were investigated in immortalized human keratinocytes (HaCaT cells). The data indicated that pretreatment with LBP significantly attenuated UVB-induced decrease in cell viability, increase in ROS production and DNA damage. LBP also significantly suppressed UVB-induced p38 MAPK activation, and subsequently reversed caspase-3 activation and MMP-9 expression. Notably, LBP was found to induce Nrf2 nuclear translocation and increase the expression of Nrf2-dependent ARE target genes. Furthermore, the protective effects of LBP were abolished by siRNA-mediated Nrf2 silencing. These results showed that the antioxidant LBP could partially protect against UVB irradiation-induced photo-damage through activation of Nrf2/ARE pathway, thereby scavenging ROS and reducing DNA damage, and subsequently suppressing UVB-induced p38 MAP pathway. Thus, LBP can be potentially used for skincare against oxidative damage from environmental insults.

BackgroundLycium barbarum polysaccharide (LBP) is considered an antioxidant agent. NF-E2-related factor-2 (Nrf2) is an important regulator for protection against UV damage. In this study, we verified the performance of LBP and the correlation between LBP and Nrf2.MethodsHSF cells were treated with LBP to determine dose and time dependencies. An antioxidant response element (ARE) reporter was designed to monitor the activity of the Nrf2 antioxidant pathway.ResultsFor HSF cells, the optimal LBP treatment was 300 μg/ml for 3 h. The ARE-reporter assay showed that LBP could increase the robustness of p-Nrf2. Treatments with genistein and LY294002 reduced of nuclear p-Nrf2 after 24 h. LBP increased the level of nuclear Nrf2, which functions by both phosphorylation and nuclear translocation. Silencing Nrf2 led to increased reactive oxygen species (ROS) levels, lower cell viability, and decreased superoxide dismutase (SOD) and glutathione peroxidase (GSP-PX) levels. This induced a higher level of lipid peroxide (LPO). However, LBP could decrease the levels of ROS and LPO and enhance the levels of SOD and GSP-PX.ConclusionLBP protects HSF cells against UV damage via the regulation of Nrf2.

The present study indicated that Pter effectively protected against UVB-induced photodamage by increasing endogenous defense mechanisms, scavenging UVB-induced ROS, and aiding in damaged DNA repair through a PI3K-dependent activation of Nrf2/ARE pathway.

Background: Melasma is considered as a type of acquired facial pigmentary disorder that is challenging to treat. Low-fluence 1064 nm Q-switched Nd: YAG laser (LQSNY) has clinical benefits against melasma; however, there are some disputes.Objective: To explore these contentious views, we conducted a meta-analysis and systematic review to evaluate the efficacy and safety of LQSNY monotherapy and combined therapy for the treatment of melasma. Methods:The PubMed, Embase, Cochrane Library, and Web of Science databases were searched for relevant articles from inception to July 2021. The resulting data were analyzed using the Review Manager 5.3 software. Results:Twelve eligible studies comprising 358 patients were included. No significant differences in melasma area and severity index (MASI) were observed between the LQSNY and drug groups (mean difference (MD):−0.26, 95% confidence interval (CI):−1.16-0.64, p = 0.57). We found that combination therapy with LQSNY and drugs had a greater MASI improvement compared with LQSNY therapy alone (MD: 1.78, 95% CI 0.93-2.63, p < 0.0001); nevertheless, no statistically significant results were found in melanin index (MI) and self-assessment. The melasma improvement was similar when using LQSNY alone and LQSNY combined with other lasers in terms of RMASI (MD 0.05, 95% CI:−0.61, 0.70, p = 0.56). Compared with intense pulsed light (IPL) alone, LQSNY with IPL provided an added benefit for melasma severity (MD:3.23, 95% CI:0.65-5.81, p = 0.01). Conclusion:Low-fluence 1064 nm Q-switched Nd: YAG laser can be applied as an alternative treatment for drug intolerance. Combination therapy with LQSNY and drugs or other lasers may have pleasantly surprising efficacy, but numerous studies are still needed to verify this.

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.