Dietary Menthol Attenuates Inflammation and Cardiac Remodeling After Myocardial Infarction via the Transient Receptor Potential Melastatin 8

BACKGROUND Transient receptor potential melastatin subtype 8 (TRPM8) is a coldsensing cation channel, mainly localized in the sensory neurons, which can be activated by menthol, a compound with a naturally cold sensation in mint. However, the effect of TRPM8 activation in inflammation and cardiac remodeling after myocardial infarction (MI) is not well defined. METHODS TRPM8 knockout (KO) mice (TRPM8(-/-)) and their wild-type littermates, aged 8 weeks, were randomly divided into sham and MI groups and were fed with chow or chow plus menthol. RESULTS Dietary menthol significantly attenuated MI injury, evidenced by decreased survival rates and plasma cardiac troponion I levels, reduced infarct size and cardiomyocytes, declined collagen deposition, and rescued cardiac function and hemodynamics. However, these effects of menthol disappeared when mice were lacking TRPM8. Furthermore, feeding of menthol ameliorated elevated expression of inflammatory cytokines and chemokines, and aggravated inflammation infiltration in the MI mice but not in TRPM8 fmice. In addition, menthol treatment increased the release of calcitonin gene-related peptide (CGRP), which were absent in TRPM8(-/-) mice. CONCLUSIONS In conclusion, our results suggest that dietary menthol can protect against inflammation and cardiac remodeling after MI through activation of TRPM8.