The study, published in Food Science and Human Wellness, investigated the potential of the polyphenol and theabrownin-rich fermented tea to protect the liver after previous studies linked the tea to a raft of health benefits.
Led by Jing Jing Su from the college of biotechnology and food science at Tianjin University of Commerce in China, the team reported that Pu-erh extracts showed a strong protection against hepatic damage induced by oxidative stress and a high fat diet.
“Pu-erh tea can be used as a potential healthy drink for prevention and/or treatment of fatty liver disease and many diseases associated with oxidative stress,” suggested Jing and colleagues.
Indeed, the Chinese team noted that in addition to acting to protect the liver through its antioxidant system, the Pu-erh extracts are also suggested to have important effect on regulating glucose level by enhancing glycogen synthesis and pyruvate kinase (PK) activity, “and thus prevent people from liver disease.”
Pu-erh is a variety of fermented tea produced in Yunnan province. Production involves the microbial fermentation and oxidation of the tea leaves after they have been dried and rolled.
Rat data
In the current study, Jing and colleagues assigned 50 rats in to five groups (10 rats per group) to assess the effect of the Pu-erh tea extract on metabolic measures in rats feb both a normal and high-fat diet.
The five groups were: a normal-feed control group, a high-fat feed control group, plus three groups fed a high fat diet plus three different doses of Pu-erh extract (0.45 g/kg BW for low-dose group, 0.90 g/kg BW for middle-dose group, and 1.35 g/kg BW for high-dose group).
Jing et al measured the body weight of the rats once per day. In addition, levels of malondialdehyde (MDA) and glucose (Glu) and the activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), nitric oxide synthase (NOS), and pyruvate kinase (PK) in serum were determined.
“Furthermore, the hepatic glycogen level (HGL) and the activities of hepatic total superoxide dismutase (T-SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) were also measured after continuous administration for 12 weeks,” said the authors.
After the trial, they found that the Pu-erh extract led to decreases in body weight, fat index, MDA and NOS levels. They suggested that these were linked to increases in hepatic T-SOD, CAT and GSH-Px activities,
Furthermore, it was found that the extracts increased production of hepatic glycogen and the activity of PK, and reduced glucose levels, thus potentially protecting the liver from the diseases associated with type II diabetes.
Source: Food Science and Human Wellness
Published online ahead of print, doi: 10.1016/j.fshw.2016.09.002
“Reducing oxidative stress and hepatoprotective effect of the water extracts from Pu-erh tea on rats fed with high-fat diet”
Authors: Jing Jing Su, et al