Menthyl salicylate, also known as Max-freeze, is an ester of menthol and salicylic acid, therefore it is a member of the salicylates drug class (NSAIDs). It is used to relieve mild to moderate pain associated with rheumatism, arthritis, neuralgia, sprains, and strains of joints and muscles. The menthol part of the molecule dilates blood vessels while the salicylate portion provides a topical anesthetic and analgesic action on the applied area of the skin/muscle. The salicylate drugs target the prostaglandin G/H synthase-1 (COX-1) and prostaglandin G/H synthase-2 (COX-2) in the cyclooxygenase pathway. The cyclooxygenase pathway begins in the cytosol with phospholipids being converted into arachidonic acid by the action of phospholipase A2. The rest of the pathway occurs on the endoplasmic reticulum membrane, where prostaglandin G/H synthase 1 & 2 convert arachidonic acid into prostaglandin H2. Prostaglandin H2 can either be converted into thromboxane A2 via thromboxane A synthase, prostacyclin/prostaglandin I2 via prostacyclin synthase, or prostaglandin E2 via prostaglandin E synthase. COX-2 is an inducible enzyme, and during inflammation, it is responsible for prostaglandin synthesis. It leads to the formation of prostaglandin E2 which is responsible for contributing to the inflammatory response by activating immune cells and for increasing pain sensation by acting on pain fibers. Menthyl salicylate inhibits the action of COX-1 and COX-2 on the endoplasmic reticulum membrane. This reduces the formation of prostaglandin H2 and therefore, prostaglandin E2 (PGE2). The low concentration of prostaglandin E2 attenuates the effect it has on stimulating immune cells and pain fibers, consequently reducing inflammation and pain. Menthyl salicylate is administered as a topical cream, ointment, patch, gel or liquid.

Menthyl salicylate Pathway References