Inhibitory Effect On Tyrosinase And Anti-oxidant Activity Of Extracts From Leaves Of Shibataea Chinensis Nakai

China is rich in bamboo resources, known as "bamboo Kingdom". Bamboo resources are not fullyexploited. Bamboo extracts are rich in secondary metabolites, such as flavonoids, phenolic acids, aminoacids, proteins and volatile ingredients. It also has anti-oxidation, anti-aging, anti-radiation and othereffects. This study screened out high activity of bamboo species by antioxidant activity and effect ontyrosinase activity in order to promote to utilizate China’s bamboo resources, especially ground bambooresource. For highly active bamboo species, the best condition of extraction effecting on tyrosinase wasstudied, and the effective part of the extraction effecting on tyrosinase was screened. A preliminaryanalysis of its components and its biological activity was studied. The study is not only designed toprovide a scientific basis for the use of bamboo resources, but also provide a reference for thedevelopment of tyrosinase inhibitors. The main results were as follows:(1) The study for the antioxidant and the tyrosinase inhibitory activity of extracts of the6kinds ofbamboo leaves showed that all ectractions had antioxidant and activity on tyrosinase on the sameconcentration. Among the six kinds of bamboo, the extraction from leaves of Shibataea chinensis Nakaishowed the strongest activity on antioxidant and tyrosinase inhibitory, whose IC50values of DPPHradical and IC50values of ABTS radical were32.33μg/mL,5.69μg/mL, respectively. Its iron reductionwas（585.00±1.43）μg/mL and its inhibitory concentration leading to50%enzyme activity lost wasestimated to be5.59mg/mL.(2)When the concentration of the extracts was4mg/mL, in terms of single factor experiments,response surface method was designed to study the best condition of extracting by the value oftyrosinase inhibition. The optimum condition was the ethanol concentration of70%, solid-liquid ratio1:16, extraction temperature80℃, extraction time1h. Under the condition, the tyrosinase inhibitionrate reached the maximum45.35%, that was consistent with the theoretical prediction.(3)The extraction from leaves of Shibataea chinensis Nakai was obtained by using the best condition,and the extract further was gotten with petroleum ether, ethyl acetate and n-butanol. The anti-oxidativeand reducing activities of extracts from leaves of Shibataea chinensis Nakai were investigated by DPPH,ABTS and FRAP. It showed that the ethyl acetate extraction was the best, whose IC50values of DPPHradical and IC50values of ABTS radical were （28.74±0.56）ug/ml、（10.10±0.39）ug/ml, respectively;and its iron reduction was（3886.43±7.14）ug/ml. Except the petroleum part, the ethyl acetate part, then-butanol part and the water part all had some tyrosinase inhibitory activity. Amoung them, the ethylacetate part showed the strongest activity, whose inhibitory concentration leading to50%enzymeactivity lost was3.29mg/mL. And it is a reversible competitive inhibitor for the oxidation of L-dopa,whose inhibitor constants is27.49mg/mL.(4)The effective ingredient of the ethyl acetate part was analyzed by HPLC external standard method.It showed that chlorogenic acid, caffeic acid, iso-orientin, coumaric acid, kaempferol and tricin weredeceted. Chlorogenic acid, caffeic acid, iso-orientin and kaempferol, whose IC50values were5.31μg/mL,6.72μg/mL,11.66μg/mL,7.29μg/mL, respectively, had the ability to scavenging DPPH radicals. Chlorogenic acid, caffeic acid, iso-orientin, coumaric acid and tricin, whose IC50values were1.56μg/mL,4.72μg/mL,7.39μg/mL,1.11μg/mL and4.62μg/mL, had the ability to scavenging ABTSradicals. Chlorogenic acid, caffeic acid and kaempferol, whose FRAP were572.00μg/mL,259.14μg/mLand362.00μg/mL, had stronger iron reduction ability. Chlorogenic acid, caffeic acid, and kaempferolhad the effect on tyrosinase inhibition with IC50values of1.46mg/mL,4.47mg/mL,0.78mg/mL.