Sci. Signal., 10 August 2010
Physiology Spicy Diet to Reduce Hypertension
Nancy R. Gough
Science Signaling, AAAS, Washington, DC 20005, USA
The chemical in chili peppers that makes them taste hot is called capsaicin, and it activates a cation channel of the transient receptor potential family called TRPV1, allowing calcium ions to flow into cells. The TRPV1-mediated action of capsaicin in sensory neurons causes pain, and local application to skin causes analgesia through desensitization of sensory nerves (see Sessa). Now Yang et al. provide evidence that dietary capsaicin may reduce blood pressure if made a constant part of the diet. First the authors confirmed that TRPV1 was present in arterial endothelial cells in mice; then they confirmed that capsaicin activated the channel to cause an increase in intracellular calcium concentration in these cells. Acute exposure of isolated mouse endothelial cells to capsaicin triggered an increase in the amount of phosphorylated endothelial nitric oxide synthase (eNOS), protein kinase A (PKA) activity, and NO production. These responses were not observed in endothelial cells from TRPV1-deficient mice and were blocked by pharmacological inhibition of the TRPV1 channel, NOS, or PKA, or by calcium chelation. Examination of mesenteric arteries from mice fed a capsaicin-supplemented diet for several months revealed an increase in the abundance of TRPV1 and phosphorylated eNOS and PKA. Additionally, 6-month dietary consumption of capsaicin increased the relaxation response of isolated mouse mesenteric arteries to acetylcholine. Spontaneously hypertensive rats exhibited a reduction in blood pressure that was significant after 5 months; mesenteric arteries from these animals had increased amounts of TRPV1, phosphorylated PKA, and phosphorylated eNOS; and circulating metabolites of NO were increased relative to untreated mice fed a normal diet. How much of capsaicins effects on blood pressure are due to a direct effect on the vasculature and how much are mediated through effects on the nervous system remains to be determined, but these results suggest that targeting TRPV1 may be beneficial for the treatment of hypertension.
D. Yang, Z. Luo, S. Ma, W. T. Wong, L. Ma, J. Zhong, H. He, Z. Zhao, T. Cao, Z. Yan, D. Liu, W. J. Arendshorst, Y. Huang. M. Tepel, Z. Zhu, Activation of TRPV1 by dietary capsaicin improves endothelium-dependent vasorelaxation and prevents hypertension.Cell Metab. 12, 130–141 (2010). [PubMed]
W. C. Sessa, A new way to lower blood pressure: Pass the chili peppers please! Cell Metab. 12, 109–110 (2010). [PubMed]
Citation: N. R. Gough, Spicy Diet to Reduce Hypertension. Sci. Signal. 3, ec241 (2010).
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