Oxidized tea polyphenols prevent lipid accumulation in liver and visceral white adipose tissue in rats.
BACKGROUND
Tea polyphenols are the prominent component in tea. After the fermentation process, tea polyphenols are oxidized by polyphenol oxidase to form oxidized tea polyphenols (OTPs). OTPs contain a significant amount of hydrophobic phenyl groups that can bind with non-aqueous materials. Here, we determined whether OTPs can bind with lipids and reduce fat uptake and assessed the effect of OTPs on decreasing obesity and alleviating hyperlipidaemia and other metabolic syndromes.


METHODS
Rats were divided into three groups: control, high-fat diet (HFD) and OTP groups. The control and HFD groups were fed a chow diet and a high-fat diet, respectively, for 12 weeks; the OTP group was fed a high-fat diet for 6 weeks and then a high-fat diet containing 2 % OTP for 6 weeks. The serum and excrement triglyceride (TAG) and total cholesterol (CHOL) concentrations were determined, and liver tissue and white adipose tissue were collected to detect the expression levels of genes involved in lipid metabolism.


RESULTS
Our results revealed that OTPs failed to decrease the serum concentrations of TAG and CHOL. OTPs alleviated the accumulation of lipids in the liver tissue and changed the expression levels of the regulators of lipid metabolism, i.e., peroxisome proliferation-activated receptors (ppars), compared with the rats fed a high-fat diet alone. We also observed a significantly decreased reduction of weight in the visceral white adipose, enhanced regulation of fatty acid β-oxidation by PPARα and enhanced biosynthesis of mitochondria in the visceral white adipose of the OTP rats compared with the HFD rats. Additionally, OTPs promoted the excretion of lipids.


CONCLUSIONS
Our results suggest that OTPs alleviate the accumulation of lipids in liver and visceral white adipose tissue and promote lipid excretion in rats in vivo.
Key Laboratory of Puer Tea Science, Ministry of Education, Yunnan Agricultural University, Kunming, 650201, China.|Yunnan Research Center for Tea Processing, Yunnan Agricultural University, Kunming, 650201, China.|Yunnan Station of Tea Resource and Processing, Ministry of Agriculture, Kunming, 650201, China.
Sumin
S
Wang
Key Laboratory of Puer Tea Science, Ministry of Education, Yunnan Agricultural University, Kunming, 650201, China.|Yunnan Research Center for Tea Processing, Yunnan Agricultural University, Kunming, 650201, China.|Yunnan Station of Tea Resource and Processing, Ministry of Agriculture, Kunming, 650201, China.
Yewei
Y
Huang
Key Laboratory of Puer Tea Science, Ministry of Education, Yunnan Agricultural University, Kunming, 650201, China.|Yunnan Research Center for Tea Processing, Yunnan Agricultural University, Kunming, 650201, China.|Yunnan Station of Tea Resource and Processing, Ministry of Agriculture, Kunming, 650201, China.
Huanhuan
H
Xu
Key Laboratory of Puer Tea Science, Ministry of Education, Yunnan Agricultural University, Kunming, 650201, China.|Yunnan Research Center for Tea Processing, Yunnan Agricultural University, Kunming, 650201, China.|Yunnan Station of Tea Resource and Processing, Ministry of Agriculture, Kunming, 650201, China.
Qiangqiang
Q
Zhu
Key Laboratory of Puer Tea Science, Ministry of Education, Yunnan Agricultural University, Kunming, 650201, China.|Yunnan Research Center for Tea Processing, Yunnan Agricultural University, Kunming, 650201, China.|Yunnan Station of Tea Resource and Processing, Ministry of Agriculture, Kunming, 650201, China.
Hao
H
Lu
Key Laboratory of Puer Tea Science, Ministry of Education, Yunnan Agricultural University, Kunming, 650201, China.|Yunnan Research Center for Tea Processing, Yunnan Agricultural University, Kunming, 650201, China.|Yunnan Station of Tea Resource and Processing, Ministry of Agriculture, Kunming, 650201, China.
Mengmeng
M
Zhang
Department of Life Science, Yunnan University, Kunming, 650091, China.
Shumei
S
Hao
Key Laboratory of Puer Tea Science, Ministry of Education, Yunnan Agricultural University, Kunming, 650201, China.|Yunnan Research Center for Tea Processing, Yunnan Agricultural University, Kunming, 650201, China.|Yunnan Station of Tea Resource and Processing, Ministry of Agriculture, Kunming, 650201, China.
Chongye
C
Fang
Key Laboratory of Puer Tea Science, Ministry of Education, Yunnan Agricultural University, Kunming, 650201, China.|Yunnan Research Center for Tea Processing, Yunnan Agricultural University, Kunming, 650201, China.|Yunnan Station of Tea Resource and Processing, Ministry of Agriculture, Kunming, 650201, China.
Dongying
D
Zhang
Key Laboratory of Puer Tea Science, Ministry of Education, Yunnan Agricultural University, Kunming, 650201, China. wuxiaoyun79@gmail.com.|Yunnan Research Center for Tea Processing, Yunnan Agricultural University, Kunming, 650201, China. wuxiaoyun79@gmail.com.|Yunnan Station of Tea Resource and Processing, Ministry of Agriculture, Kunming, 650201, China. wuxiaoyun79@gmail.com.
Xiaoyun
X
Wu
Key Laboratory of Puer Tea Science, Ministry of Education, Yunnan Agricultural University, Kunming, 650201, China. wangxuanjun@gmail.com.|Yunnan Research Center for Tea Processing, Yunnan Agricultural University, Kunming, 650201, China. wangxuanjun@gmail.com.|Yunnan Station of Tea Resource and Processing, Ministry of Agriculture, Kunming, 650201, China. wangxuanjun@gmail.com.|State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, 650201, China. wangxuanjun@gmail.com.
Xuanjun
X
Wang
Key Laboratory of Puer Tea Science, Ministry of Education, Yunnan Agricultural University, Kunming, 650201, China. shengj@ynau.edu.cn.|Yunnan Research Center for Tea Processing, Yunnan Agricultural University, Kunming, 650201, China. shengj@ynau.edu.cn.|Yunnan Station of Tea Resource and Processing, Ministry of Agriculture, Kunming, 650201, China. shengj@ynau.edu.cn.|State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, 650201, China. shengj@ynau.edu.cn.
Jun
J
Sheng
D000818:Animals; D015415:Biomarkers / Q000097:blood; D002784:Cholesterol / Q000097:blood; D059305:Diet, High-Fat / Q000009:adverse effects; D004195:Disease Models, Animal; D005243:Feces / Q000737:chemistry; D006949:Hyperlipidemias / Q000097:blood / Q000188:drug therapy; D050152:Intra-Abdominal Fat / Q000187:drug effects* / Q000378:metabolism; D050356:Lipid Metabolism / Q000187:drug effects*; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D009765:Obesity / Q000097:blood / Q000188:drug therapy; D009929:Organ Size / Q000187:drug effects; D059808:Polyphenols / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013662:Tea / Q000737:chemistry*; D014280:Triglycerides / Q000097:blood
D015415:Biomarkers; D059808:Polyphenols; D013662:Tea; D014280:Triglycerides; D002784:Cholesterol
Lipolysis; Liver lipid accumulation; Oxidized tea polyphenols; Visceral white adipose; ppars