Chronic black tea extract consumption improves endothelial function in ovariectomized rats

Area of Science:

• Cardiovascular Science
• Endocrinology
• Nutritional Science

Background:

• Menopause increases cardiovascular disease risk in women due to estrogen deficiency.
• Estrogen deficiency leads to cardiovascular complications and altered lipid metabolism.
• There is a need for effective interventions for estrogen-deficiency-related cardiovascular issues.

Purpose of the Study:

• To investigate the effects of chronic black tea extract (BT) consumption on cardiovascular function in an ovariectomized (OVX) rat model.
• To assess the impact of BT on lipid metabolism in estrogen-deficient rats.
• To explore BT as a potential dietary supplement for managing menopausal cardiovascular risks.

Main Methods:

• Ovariectomized (OVX) Sprague-Dawley rats were treated with black tea extract (BT) or estrogen (E2) for four weeks.
• Vascular reactivity, serum lipid profiles (cholesterol, triacylglycerol), and estradiol levels were measured.
• Protein levels of NADPH oxidases, reactive oxygen species (ROS), and cyclic guanosine monophosphate (cGMP) were assessed.

Main Results:

• BT and E2 treatments improved endothelium-dependent relaxations and flow-mediated dilation in OVX rats.
• BT/E2 administration restored eNOS phosphorylation, reduced NADPH oxidases, and decreased ROS overproduction.
• Circulating total cholesterol levels were reduced by BT/E2 treatment, and cGMP production was elevated.

Conclusions:

• Chronic black tea extract consumption beneficially impacts endothelial function in estrogen deficiency.
• BT favorably modifies cholesterol profiles, suggesting potential cardiovascular benefits.
• Black tea extract shows promise as a dietary supplement for postmenopausal women's cardiovascular health.