Antimicrobial, anticancer, antidiabetic, antineurodegenerative, and antirheumatic activities of thymol: clarification of mechanisms

Thymol is monoterpenic phenol with a wide range of therapeutic properties. Various pharmacological properties including antimicrobial, antineoplastic, anti-inflammatory, antidiabetic, antirheumatic, and antineurodegenerative have been found for this metabolite. The severity of peripheral nerve dysfunction in diabetes mellitus can be ameliorated by thymol treatment via decreasing tumor necrosis factor-α (TNF- α) and nitric oxide levels. In the case of the anticancer mechanism, thymol can increase the expression of the tumor suppressor of p53, Bcl-2-associated X protein (Bax), and apoptosis. Moreover, in this review, three main neurodegenerative diseases of Alzheimer’s disease (AD), multiple sclerosis (MS), and Parkinson’s disease (PD) have been discussed with respect to antineurodegenerative activities of thymol. Recent studies show that novel formulations of thymol in the nanoscale can improve therapeutic activities such as thymol release in vitro and in vivo. Antimicrobial and antioxidant activities of thymol against both Gram-negative and Gram-positive bacteria can be augmented by various nanoformulations. Therefore, we have tried to discuss the advantages and disadvantages of micro and nanoformulations of this bioactive material according to recent investigations.