Understanding Tea and Vascular Function

Abstract

Consumption of tea has been associated with reduced cardiovascular risk (CVD). Epidemiological and clinical studies have demonstrated that tea intervention may improve vascular function by enhancing nitric oxide bioavailability. Majority of the mechanistic studies indicate endothelium dependent nitric oxide (NO) pathway to contribute towards the observed benefit. However, recent evidence suggests that endothelium independent pathway may also contribute equally towards the benefit. In this study, we aimed to prioritize various biomarkers clinically influencing vascular function based on literature evidences and developed in vitro bioassays to determine their modulation in response to tea/tea ingredients. Nitric oxide enhancement, Angiotensin-converting enzyme inhibition, Endothelin-1inhibition and Reactive Oxygen Species were selected as potential biomarkers. We observed that gallated catechins majorly contribute towards Nitric oxide potentiating effects and Endothelin-1 inhibition in green tea, while in black tea it was majorly influenced by theaflavins. Additionally, we found for the first time that only theaflavins majorly contribute towards Angiotensin-converting enzyme inhibition, while the effect of catechins were less evident. Thus, targeting multiple pathways influencing vascular function could provide valuable clues for the prevention or treatment of cardiovascular diseases.