Study On Scavenging Activity Of Free Radicals And Proliferation Of Preadipocytes From Qingzhuan Tea

Qingzhuan Tea belongs to the kind of dark tea, which is mainly made in HuBei XianNing, Qingzhuan Tea is made of Laoqing tea under the process of pile-fermentation and repression, it has a long history over 100 years and plays an importment role as a natural beverage during the daily life of the northwestern people such as inner Mongolia. According to the results of animal experiment, Qingzhuan Tea showed the ability of reducing weight, antilipid and antioxidation, according to the study of enzymology, Qingzhuan Tea could inhibit the activity of lipase and amylase. In order to explain the mechanism of anti-obesity and anti-lipid of Qingzhuan Tea further, this article studied the major active components of fractions extracted with different polar solvents and elutions from ethyl acetate fraction and n-butanol faction separated by Selphadex LH-20 column chromatography from Qingzhuan tea and their scavenging activity of free radicals. Then, The effect on the proliferation of preadipocytes from Qingzhuan Tea of different polar solvents was measured to supply theory evidence for the mechanism of anti-obesity.1 Study on the active compontents and Scavenging activity to free radicals of different fractions of Qingzhuan TeaThe content of the Tea polyphenol and Gallic acid were measured by use of colorimetry and HPLC, results showed that tea polyphenol and GA in ethyl acetate fiaction and n-butanol fiaction were much more than that in the other fractions,meanwhile, the content of tea pigment was tested by reference to the system analysis method, the results were as follows, the content of Theaflavins in all fractions was low, Thearubigins in n-butanol fiaction and Theabrownine in precipitation were the highestThe Scavening activity of different fractions of Qingzhuan tea to·OH, O2-·and DPPH were studied by the method of deoxyribose, xanthine oxidase and spectrophotometry. Results showed that ethyl acetate fraction and n-butanol fraction had good activity of scavenging free radicasl The 50% inhibition concentration of ethyl acetate fraction and n-butanol fraction were 6.585μg/mL and 17.334μg/mL, As to the scavenging activity of O2-·, the precipitation fraction performed best whose 50% inhibition concentration was 2.512 mg/mL, then followed the ethyl acetate fraction and n-butanol fraction. The scavenging activity of the ethyl acetate fraction and n-butanol fraction to·OH performed differently which showed that the inhibition rate firstly inscrsed but filled down finally, the inhibition rates of the other fractions were increasing along with the raise of their concentration.2 Scavenging activity to free radicals of elutions from ethyl acetate fraction and n-butanol fractionThe Scavenging activity of elutions from ethyl acetate fraction and n-butanol fraction was studied by the method of xanthine oxidase and spectrophotometry, Results demonstrated that 50% acetone elutions and 10% methanol elutions from ethyl acetate fractionbehavedbetter, their IC50 to DPPH were 4.545μg/mL and 7.076μg/mL, as to the O2-·, their IC50 were 4.997mg/mL and 4.703mg/mL. The Scavenging activity to DPPH and O2-·of 10% methanol elutions from n-butanol performed best, but compared to the elutions from ethyl acetate fraction,The Scavenging activity of elutions from n-butanol performed worse.According to the data of HPLC and LC-MS, the content of Gallic acid and EGC in 10 % methanol elutions from ethyl acetate fraction was 198.205 mg/g and 163.026 mg/g which ranked first compared to other elutions, the content of ECG and EGCG in 50% acetone elutions were the highest which were 111.141 mg/g and 222.902 mg/g, their were few catehins in the other elutions. The Gallic acid content of 10% methanol elutions from n-butanol was higher than other elutions, the content of total catechin in water elution ranked first which was 64.731 mg/g, and the kind of catechins were ester type catechins, the content of n-butanol fraction were GA,Theaflavins, polymer of pronathocyanidin and double gallate.3 Effect on the proliferation of preadipocytes of different fractions from Qingzhuan TeaThe toxicrty on the 3T3-L1 preadipocytes of different fractions from Qingzhuan Tea was measured by the metnod of LDH kit, the result showed that there was no toxicity under the concentration of 100-500μg/mL.According to the MTT assay, the ethyl acetate fraction suppressed the proliferation of preadipocytes most prominently.