GTP, which contains EGCG and catechin, has been shown to be beneficial in preventing heart disease, but the "underlying molecular mechanisms of these effects" are still unclear.
As such, the study sought to explore how GTP treatment affects lipid metabolism, as well as autophagy regulation in the vessel wall, in male mice on a high-fat diet.
The study used 30 eight-week-old male mice and divided them into one control group and one high-fat diet group.
Reversing the effects
After 15 weeks, the mice that had been on the high-fat diet had gained weight, and displayed "atherosclerosis formation and lipid metabolism disorders, as well as reduced autophagy expression in the vessel wall".
However, GTP treatment was found to alleviate the lipid metabolism disorders and increase the protein expression of autophagy markers in the aortae of the high-fat diet mice.
The study added that green tea has a "protective effect on vascular endothelial cell-induced LDL oxidation", as seen in the reduction of the GTP-treated mice’s oxidised serum LDL levels, which "evidence indicates...participate in the induction and the further development of atherosclerosis".
Spilling the tea
Green tea has been touted as having multiple health benefits, including countering obesity, fatigue, diabetes, and cognitive decline.
Its anti-inflammatory, anti-diabetic and anti-fatigue properties are often extensively researched; recently, EGCG, a component of GTP, was said to be useful in reducing obesity and improving cognitive function.
The study said that long-term GTP intake significantly alleviates lipid metabolism disorders brought on by a high-fat diet, and may even help to prevent such disorders altogether.
Additionally, the functions of GTP are multi-factorial, as it reduces lipid droplets in endothelial cells, decreases white adipose tissue, and regulates lipid metabolism disorders in the liver.
The study concluded that "GTP supplementation showed marked suppression of atherogenesis through improved lipid metabolism, as well as through a direct impact on oxidised LDL and autophagy flux in the vessel wall".
Source: PLOS ONE
“Green tea polyphenol treatment attenuates atherosclerosis in high-fat diet-fed apolipoprotein E-knockout mice via alleviating dyslipidemia and up-regulating autophagy”
Authors: Shibin Ding, et al.