The powerful potential of amino acid menthyl esters for anti‐inflammatory and anti‐obesity therapies.

Our newly developed menthyl esters of valine and isoleucine exhibit anti‐inflammatory properties beyond those of the well‐known menthol in macrophages stimulated by lipopolysaccharide (LPS) and in a mouse model of colitis induced by sodium dextran sulfate. Unlike menthol, which acts primarily through the cold‐sensitive TRPM8 channel, these menthyl esters displayed unique mechanisms that operate independently of this receptor. They readily penetrated target cells and efficiently suppressed LPS‐stimulated tumour necrosis factor‐alpha (Tnf) expression mediated by liver X receptor (LXR), a key nuclear receptor that regulates intracellular cholesterol and lipid balance. The menthyl esters showed affinity for LXR and enhanced the transcriptional activity through their non‐competitive and potentially synergistic agonistic effect. This effect can be attributed to the crucial involvement of SCD1, an enzyme regulated by LXR, which is central to lipid metabolism and plays a key role in the anti‐inflammatory response. In addition, we discovered that the menthyl esters showed remarkable efficacy in suppressing adipogenesis in 3T3‐L1 adipocytes at the mitotic clonal expansion stage in an LXR‐independent manner as well as in mice subjected to diet‐induced obesity. These multiple capabilities of our compounds establish them as formidable allies in the fight against inflammation and obesity, paving the way for a range of potential therapeutic applications. [ABSTRACT FROM AUTHOR]