Effects Of Gypenosides (GP) On P38 And P42/p44 Of Photodamage Mouse Skin

Objective:To establish photo-damaged model of Balb/C mice with ultraviolet B (UVB) irradiation. To explore the mechanism of anti-photodamage effect of gypenosides(GP) by studying the effects of GPon p38 mitogen activated protein kinases(p38MAPK) and extra cellular signal-regulated protein kinase (ERK, p42/p44) pathway of associated with UVB irritation.Materials and methods:1. To establish photo-damaged model of Balb/C mice with ultraviolet B (UVB) irradiation and to treat photo-damaged skin by topical treated with 1.5% GP cream.2.The expression levels of p38MAPK protein, phosphorylated p38MAPK protein and p42/44 protein were determined by western blotting of the eight groups. Grouping:the control group, UVB model group, UVB+1.5%GP group, 1.5%GP+UVB group, UVB+vitamine E positive control group, vitamine E+UVB positive control group, UVB+vehicle group, vehicle+UVB group, respectively.Results:1.The expression levels of p38MAPK protein of Balb/C mice in every groups had no significantly changed after UVB irradiation (P>0.05).2.After UVB irradiation the activation of p38 was detectable immediately and the expression levels of pp38MAPK was higher in the UVB model group than in the control group(P<0.01). 3.The pp38MAPK protein in 1.5%GP treated group was lower than that of UVB treated group(P<0.05).The expression level of pp38MAPK were increased in the vitamine E group than that of the control group(P<0.01), while lower than that of UVB treated group(P<0.01), the results were similar to 1.5%GP groups.4.The expression level of pp38MAPK protein of pretreated 1.5% GP cream group were lower than that of pretreated UVB irradiation groups, the effect were similar to vitamine E cream group.5. There were no difference that expression of pp38MAPK protein between vehicle group and UVB group(P>0.05).6. The expression levels of p42/44MAPK protein had no changed among eight groups (P>0.05).Conclusion:1.These data suggest that UVB increased the expression of phosphorylated p38 and induced activation of p38MAPK.2.1.5%GP cream can decrease the expression of pp38MAPK protein in photodamage mouse skin after UVB irradiation, but it have no effect on p38MAPK and p42/44, the effect of vitamine E groups are similar with GP.3. The mechanisms of resistance UVB-induced damages of cream 1.5% GP are possibly related with inhibiting the activity of phosphorylated p38MAPK protein.