The Mechanism Of Naringin Protection The Skin Keratinocytes From UVB Damage

With the development of society and economy, people living level requirements are also getting higher and higher. But with the continuous changes of the environment and the atmosphere ozone layer becoming thinner, more and more ultraviolet radiation exposure to the ground brings increasing damage to the human skin. One of effective means to prevent skin sunburn is using sunscreen,therefore,we are committed to find a monomer plant which has sunburn protection effect. The structure of the flavonoids determines its effect of ultraviolet absorption, at the same time flavonoids also have the oxidation resistance and inhibit free radical activate various signal pathway.The purpose of this study was to clarify the mechanism of naringin protection the skin keratinocytes from UVB-induced damage. Experimental methods:we first established sunshine-proof drug screening system, screened one drug with the most evident property of sun-protecting effect from dozens of candidate plant monomer.Next.we conformed the molecular mechanism of the sunscreen effect in cell and animal level using flow cytometry, RT-PCR, Western, blot, histological, immunohisto chemical methods.We choose the most effective drug, namely naringin.Naringin is one flavonoid compound which we screen out, naringin has many physiological and pathological effects, such as anti-inflammatory reaction, scavenging free radicals,oxidation resistance and inhibiting apoptosis and tumor growthThe sunscreen effection of naringin has not been reported at present,so we explored the effection of naringin against UVB irradiation and its related molecular mechanism in cell and animal leveLCell experimental results showed:naringin can decrease the expression of UVB-induced ROS in HaCat cell; inhibit the UVB-induced apoptosis of HaCat cell;inhibit the inflammatory reaction of HaCat.The animal experimental results show that UVB irradiation can result in the skin damage of the nude mouse,such as erythema, molting.Meanwhile,the nude mice skin epidermal wound thickening.And naringin can protect the UVB-induced skin damage of the nude mouse and inhibit the increase expression of COX-2.UVB irradiation treatment could activate MAPK and NF-κB signal pathway.Study on the molecular mechanism showed that naringin could inhibit the phosphorylation of ERK,JNK,P38,meanwhile naringin pretreatment could inhibit of P65 into the nucleus.Therefore,naringin could protect HaCat cells from UVB damage by inhibiting apotosis,inflammation and oxidative damage.The molecular mechanism of naringin may be by inhibiting the activation of MAPK and NF-κB signal pathway.This paper provides theoretical and experimental basis for naringin used as sunscreen cosmetics in the future.