Background and objectives: Clitoria ternatea L. (CT) is known as Anchan in Thai. It has been extensively used for food coloring and a traditional herbal medicine in South East Asia. Several studies reported its biological activities including, anti-inflammatory and antioxidant. This study was to investigate whether CT extract could reduce blood pressure, oxidative stress and improve vascular function in two-kidneys, one-clip (2K-1C) hypertensive rats.
Methods: Male Sprague Dawley rats were induced hypertension by clipping the left renal artery. After three weeks of surgery, hypertensive rats were continuously treated with distilled water and CT extract 500 mg/kg while sham-operated group received distilled water for four weeks. After that rats were anesthetized to measure blood pressure, vascular function and oxidative stress biomarkers.
Results: The rats received CT extract 500 mg/kg significantly decreased systolic blood pressure, diastolic blood pressure and mean arterial pressure (p<0.01). Vasorelaxation responses to acetylcholine (ACh) were blunted in 2K-1C hypertensive rats while treated with CT extract 500 mg/kg significantly improved vasorelaxation response to ACh (p<0.01). In addition, CT extract significantly decreased vascular superoxide production in 2K-1C hypertensive rats (p<0.05).
Conclusion: These findings showed that CT extract had an antihypertensive effect, which associated with improving endothelial dysfunction. Its vascular effect is likely to be increased NO bioavailability as a result of reducing superoxide production.