Beneficial dose-independent influence of Camellia sinensis supplementation on lipid profile, glycemia, and insulin resistance in an NaCl-induced hypertensive rat model.

ABSTRACT

Green tea extract exerts favorable influence on the lipid profile and insulin resistance in the high-sodium intake arterial hypertension. A high-sodium diet (HSD) was introduced to thirty Wistar rats to create a model of hypertension. Rats were randomized into three groups, 10 animals each. The SK group consumed HSD. The SH2 group consumed HSD with 2 g of green tea extract in kg of diet. The SH4 group was fed HSD with 4 g of green tea extract in kg of diet. After six-week trial blood samples were collected. The serum concentrations of glucose, insulin and lipids were estimated, and insulin sensitivity was calculated using homeostatic model assessment (HOMA). Neither the high-sodium diet nor supplementation with green tea extract had any significant influence on the body mass of the animals in either group. Total cholesterol (TCH) and low-density lipoproteins (LDL) cholesterol serum concentrations were significantly smaller in both supplemented groups than in the SK group. The insulin level in the SH2 rats and HOMA in SH2 and SH4 groups were found to be significantly smaller than in the SK group. There were no differences in glucose concentrations between groups. Within the whole population, statistically significant positive correlations between HOMA and LDL, TCH were found. We conclude that in NaCl-induced hypertensive Wistar rats, supplementation with green tea extract produced a dose-independent beneficial and parallel effect on the lipid profile and insulin resistance.