| "Fu" tea is a kind of the Chinese dark teas according to the classification of processing method, and belongs to post-fermented tea, the history of which should be dated back to the Ming Dynasty at 1500 A.D. It is indispensible for the highland minority who consume high levels of dietary saturated animal products rather than vegetables and fruits in Western China, such as Sinkiang, Tibet, Inner Mongolia. But their chances of developing metabolic disease is not high, this may be related to their daily drinking lots of Fu brick tea, Fu brick tea may be able to help digest fats, promote the metabolism of lipid. JWFT is produced from the mature leaves of Camellia sinensis, undergoes a special process of fermentation with the fungus Eurotuim cristotium in the areas of Yellow river basin. The detailed manufacture process of the tea has been described as panning, rapid pile fermentation, rolling, drying, softening with steam, piling, tea brick pressing, fungal fermentation, and drying. The "fungal fermentation" phase is critical for forming the typical fungal aroma and taste, and unique phytochemical profile.In this study, we based on GB15193.3-2003 procedures to assessing the acute toxicity of Jing-wei fu tea. And referred to the 2003 Edition of the health food testing and evaluation technical norms regarding function product evaluation method of reducing weight and lipid-lowering, adopt the obesity prevention model, high-fat diet and tea aqueous extract were given at the same time, administration different doses of tea for 4 weeks to analysis the influence of JWFT on serum total cholesterol, triglyceride, LDL-C, hepatic total cholesterol and triglyceride, fecal total cholesterol and triglyceride were determined. Hepatic fatty acid composition and relative expression of lipids metabolism gene in liver were investigated by the GC-MS based lipidomics and RT-PCR analysis. The aim of this paper is to discover the marker fatty acids of high-fat diet fed rats treated with JWFT, elucidate JWFT’s function in regulating lipid metabolism and provide a novel understanding of JWFT’s efficacy on lipid-related disease, especially lipid-lowering and anti-obesity. Research results are as follows:1. Acute toxicity of Jing-wei fu tea14 days acute toxicity test of Jing-wei fu tea, showed Jing-wei fu tea on acute oral LD50 in male mice was 15.163 g/kg,95% trusted limit 13.575～17.036 g/kg.bw; acute oral LD50 in female mice 16.944 g/kg,95% credible limit 15.141～19.072 g/kg.bw. According to the PRC national standard, it is greater than the half lethal dose of non-toxic substances, so Jing-wei fu tea is a non-toxic substance.2. The effect of anti-obesity and lipid-lowering of Jing-wei fu tea.The control group of hyperlipidemic rats gained significantly more weight during the study than those fed a normal chow diet (p<0.05). Within the groups fed the hyperlipidemic diet, the group treated with daily administration of the medium and high dose (1.0,2.0g/kg) of JWFT extract exhibited a remarkably decreasing on body weight and abdominal fat over the course of the study compared with the control-treated hyperlipidemic group (p< 0.05,0.01), and the body weight again were reduced 14.2% and 19.4%, abdominal fat accumulation rate decreased 31.1% and 42.0% respectively。But treatment with low dose of JWFT extract did not exert significant effect on the weight increase in hyperlipidemic rats.Serum levels of total cholesterol (TC) and triglycerides (TG) consistently were much higher in rats fed the hyperlipidemic diet compared with the basal diet group after 28days (p< 0.01). After four weeks treatment of high dose of JWFT extract(2.0g/Kg), levels of TC, TG and LDL-C were significantly lower than the high fat control group (p <0.05)The high fat-diet caused the elevation of hepatic total TG and TC levels. Consumption of JWFT suppressed the increase in hepatic total TG and TC concentrations. TC levels dose-dependently decreased by 15.93%,17.24%,29.56% when treat with 0.5,1.0 and 2.0 g/kg, respectively, of JWFT extract. JWFT also significantly inhabited the increase of hepatic total TG levels in moderate and high doses, and had 42.34%,55.49% reduction respectively compared with HFC. Although, the low dose did not reduce TG level evidently than other two doses, it also had 27.57% reduction.The above results demonstrate that moderate and high dose of JWFT both have potent effect on lowering hepatic total TG and TC levels in hyperlipidemic.3. The relative proportional fatty acid composition of liverJing-wei fu tea can regulate fatty acid metabolism of rat liver, and promote liver fatty acid ratio changed. Hepatic stearoyl-CoA desaturase 1 (SCD1) activity can estimate from the C16:1/C16:0 or C18:1n-9/C18:0 ratios, high dose Jing-wei fu tea can significantly reduce this two group fatty acids proportion. The principal components analysis (PCA) of GC-MS data of fatty acids of liver showed that the fatty acids composition of rat liver of HFC is highly different from NC. After the treatment of JWFT, the profiles of fatty acids of liver were reversed and similar to the normal diet feed rats. It indicate that jing-wei fu tea can normalize the liver fatty acids metabolism of high fat fed rats4. Relative mRNA expression of hepatic lipid metabolism geneCompared with normal control group, hyperlipidemia model group of fatty acids de novo genes relative expression of SCD1, FAS and ACC mRNA were significantly down-regulated, while the CPT-1 gene involved in theβ-oxidation was up-regulated. It shows that animals had the ability to regulate lipid metabolism by "self-adaptive response":increase of exogenous fat breakdown (β-oxidation), reduce endogenous lipid de novo synthesis under high-fat diet condition.After four weeks’Jing-wei fu tea administration, relative expression of rat hepatic SCD1, FAS and ACC mRNA were more significantly down-regulated, and the CPT-1 gene appeared more markedly up-regulated. It indicates that Jing-wei fu tea can enhance the effect of "self-adaptive response" to balace the lipid metabolism. |
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