Skin resistance to UVB-induced oxidative stress and hyperpigmentation by the topical use of Lactobacillus helveticus NS8-fermented milk supernatant

AimsIn this study, we investigated the preventive properties of the supernatant of Lactobacillushelveticus NS8-fermented milk (NS8-FS) against UV light-induced skin oxidative damage and hyperpigmentation.Methods and ResultsNS8-FS exhibited significant radical scavenging activity in tests with ABST(+) and DPPH scavenging methods, and as well strongly inhibited 3-morpholinosydnonimine (Sin-1)-induced ROS generation in HaCat keratinocytes. Unexpectedly, NS8-FS was found to inhibit melanin production in B16F10 melanoma cells and to exhibit inhibitory effects both to the enzymatic activity of tyrosinase (TYR) and the expression of proteins required for melanin synthesis. In SKH-1 hairless mice, topical application of NS8-FS alleviated UVB-induced skin photodamage, including the improvement of the appearance of epidermal thickness, transepidennal water loss and lipid peroxidation levels. In the tanning guinea pig model, the whitening effect of NS8-FS was demonstrated using Masson-Fontana staining and TYR staining. Furthermore, NS8-FS was shown to stimulate the nuclear translocation and activation of the Nrf2 protein, along with recovery of antioxidant enzyme activities.ConclusionNS8-FS exhibits the protective capacities against UV light-induced skin oxidative damage and hyperpigmentation.Significance and Impact of the StudyOur findings indicate the potential of cell-free fermented products of lactic acid bacteria in topical photoprotection.

目的 在本研究中，我们研究了瑞士乳杆菌NS8发酵乳上清液（NS8 - FS）对紫外线诱导的皮肤氧化损伤和色素沉着过度的预防特性。 方法与结果 在ABTS（+）和DPPH清除法测试中，NS8 - FS表现出显著的自由基清除活性，并且强烈抑制了在HaCaT角质形成细胞中由3 - 吗啉代斯德酮亚胺（Sin - 1）诱导的活性氧（ROS）产生。出乎意料的是，发现NS8 - FS抑制B16F10黑色素瘤细胞中的黑色素生成，并且对酪氨酸酶（TYR）的酶活性以及黑色素合成所需蛋白质的表达均表现出抑制作用。在SKH - 1无毛小鼠中，局部应用NS8 - FS减轻了UVB诱导的皮肤光损伤，包括改善表皮厚度、经表皮水分流失和脂质过氧化水平。在豚鼠晒黑模型中，通过Masson - Fontana染色和TYR染色证明了NS8 - FS的美白效果。此外，NS8 - FS被证明可刺激Nrf2蛋白的核转位和激活，以及恢复抗氧化酶活性。 结论 NS8 - FS对紫外线诱导的皮肤氧化损伤和色素沉着过度具有保护能力。 研究的意义和影响 我们的研究结果表明乳酸菌无细胞发酵产物在局部光保护方面具有潜力。