Preparation of pueraria hypotensive tea by fermentation and its hypertensive effect on spontaneously hypertensive rats

Abstract

Objective: This study aimed to obtain a novel fermented green tea with high ACE-inhibitory activity by Eurotium cristatum and to investigate its acute hypotensive effects on spontaneously hypertensive rats （SHR）. Methods: The effects of pueraria addition, water content of substrate and spore suspension on ACE-inhibitory activity in vitro were investigated, and the fermentation process was optimized by orthogonal design experiment. The fermented tea solution was prepared by water extraction method, and SHR model was selected to study the hypotensive effect of fermented tea. Results: The optimal fermentation process for fermented tea was as follows: adding 2 g pueraria into 20 g green tea matrix, controlling the water content of the matrix to 20%, inoculatin 5% suspension of E. cristatum. Compared with the control group, different doses of fermented tea had lowering effects on blood pressure in SHR within 24 h. Conclusion: The acute hypotensive effect of the daily dose of 300~600 mg/kg was the most significant, which could lower the blood pressure of SHR in a short period of time.

Keywords

• eurotium cristatum
• pueraria
• green tea
• angiotensin-converting enzyme
• spontaneously hypertensive rats