Protective Effects of Pear Extract on Skin from In Vitro and In Vivo UVA-Induced Damage

The ancient Chinese medical book "Compendium of Materia Medica" records that pears can relieve symptoms of respiratory-related diseases. Previous research has shown that pear Pyrus Pyrifolia (Burm.f.) Nakai has antioxidant and anti-inflammatory properties. However, the anti-inflammatory, antioxidant, and anti-photoaging protective effects of Pyrus pyrifolia (Burm.f.) Nakai seed components have not been studied. Ultraviolet light (UV) causes skin inflammation, damages the skin barrier, and is an important cause of skin photoaging. Therefore, UV light with a wavelength of 365 nm was used to irradiate HaCaT and mice. Western blot, real-time quantitative polymerase chain reaction, and fluorescence imaging system were used to explore its anti-UVA mechanism. Dialysis membrane and nuclear magnetic resonance were used for the chemical constituent analysis of pear seed water extract (PSWE). We found that PSWE can significantly reduce UVA-induced skin cell death and mitogen-activated protein kinase phosphorylation and can inhibit the mRNA expression of UVA-induced cytokines (including IL-1 beta, IL-6, and TNF-alpha). In addition, PSWE can also reduce the generation of oxidative stress within skin cells. In vivo experimental studies found that PSWE pretreatment effectively reduced transepidermal water loss, inflammation, redness, and dryness in hairless mice. The molecular weight of the active part of pear water extract is approximately 384. Based on the above results, we first found that pear seeds can effectively inhibit oxidative stress and damage caused by UVA. It is a natural extract with antioxidant properties and anti-aging activity that protects skin cells and strengthens the skin barrier.