Modulation of endothelin B receptor in spontaneous hypertensive rats treated with Piper sarmentosum

Abstract

Systemic arterial hypertension (HTN (is the most common risk factor of cardiovascular diseases (CVD). World health organization (WHO) in 2013 estimated that 7.5 million deaths per year worldwide occurred due to HTN. Piper sarmentosum (PS) is a herbal plant that has been widely used as cuisine and in the treatment of diseases including HTN. It is well known for its high antioxidants compounds. Previous studies with PS have shown its ability to reduce blood pressure (BP) in spontaneous hypertensive rats (SHR). However, the mechanism is as yet unclear especially at receptor level. The aim of this research is to study the modulatory mechanism of PS on endothelin receptor type B (ETBR) and its effect on oxidative stress to reduce BP in SHR. The PS leaves were extracted with distilled water and freeze-dried. The rats were divided into four different groups (n=6); group C (negative control), group K (PS leaves aqueous extract (PSAE) 500mg/kg/day), group P (perindopril 3mg/kg/day) and group M (PSAE 250mg/kg/day + 1.5mg/kg/day perindopril). The arterial BP were weekly measured and recorded using the tail-cuff technique for 28 consecutive days. Serum malondialdehyde (MDA) was determined pre and post treatment. ETBR expression in rat’s arterioles kidney were assessed through immunohistochemistry (IHC). The PSAE showed a significant lowering effect of BP and a decrease in serum MDA level. It also shows an upregulation of ETBR in SHR compared to the control group. In conclusion PSAE decreases the oxidative stress and upregulates ETBR of SHR arterioles thus ameliorating the BP.