Abstract P038: Dietary Capsaicin May Decrease Blood Pressure Through Enhancing NO With eNOS Activation in 2-Kidney, 1-Clip Hypertensive Rats
Objective: Capsaicin, a component of chili peppers, is reported to have beneficial effects on cardiovascular system through the vasodilative effects. We recently demonstrated the alleviation of blood pressure (BP) elevation by consuming a low concentration of capsaicin diet in 2-kidney, 1-clip (2K1C) hypertensive rats. Since the alleviation was diminished when 2K1C rats took NG-nitro-L-arginine methyl ester, a NO synthase (NOS) inhibitor, during the protocol, we hypothesized that NO has a key role in the effect of capsaicin in 2K1C rats. In this study, we observed eNOS mRNA expression and protein expressions of eNOS and phosphorylated eNOS in 2K1C rats fed a diet containing capsaicin.
Methods: Six-week old male Sprague-Dawley rats were treated with sham operation (SHAM) or clipping the left renal artery (2K1C). One week after the surgery, each group of rats were further divided into 2 groups randomly, which received either a control diet (CTL) or a diet containing 0.006% capsaicin (CAP) for 6 weeks. The systolic BP was measured by a tail-cuff method once per week throughout the protocol. At the end of the protocol, rats were euthanized and the abdominal aortas were collected for extracting mRNA and protein. Then, the expression of eNOS mRNA and protein in aorta was evaluated in each group of rats by real time RT-PCR and Western blotting.
Results: As shown in Table, capsaicin diet alleviated BP elevation in 2K1C rats. After the dietary protocol, eNOS mRNA expression in 2K1C-CAP was significantly higher than in 2K1C-CTL. Although there were no significant differences in eNOS protein expression among four groups, phosphorylated eNOS protein expression in 2K1C-CAP was marginally significantly higher than in 2K1C-CTL. The expression was also significantly higher in 2K1C rats than in SHAM.
Discussion: The present data suggested that dietary capsaicin decreases BP through enhancing NO with activation of eNOS in 2K1C hypertensive rats. It may be a clue for developing a dietary therapy for prevention of hypertension.
Author Disclosures: Y. Segawa: None. H. Hashimoto: None. T. Osera: None. N. Kurihara: B. Research Grant; Modest; This work was supported by JSPS KAKENHI Grant Number 24501014.
- © 2015 by American Heart Association, Inc.