Cinnamon Modulates Toll-Like Receptors: a New Therapeutic Approach for Diabetes

Diabetes mellitus is a chronic metabolic disease with a high global incidence that can lead to serious and life-threatening conditions. Diabetes mellitus and its related complications are associated with several inflammatory events majorly caused by irregular insulin action. Toll-like receptors are considered to play a pivotal role in this scenario by acting as a mediator of the immune and inflammatory systems and are part of the innate immunity system recognizing pathogens entering the body, categorized as surface or inner receptors. Different toll-like receptors have been identified and each can further activate other inflammatory pathways. They are believed to be responsible for various inflammatory and immune-related disorders such as rheumatoid arthritis, lupus, and sclerosis. Toll-like receptors are capable of activating nuclear factor kappa B and interferons. Cinnamon as a traditional spice has innumerable health benefits due to its characteristics such as antioxidant, anti-inflammatory, anti-microbial, neuroprotective, lipid-lowering, glucose-lowering, and immunomodulatory. It is considered to be advantageous for diabetic patients and can affect the toll-like receptor pathway. Barks of Cinnamomum species, Lauraceae, are rich in aromatic volatile compounds, such as cinnamaldehyde and cinnamic acid; also no serious side effects have been reported for these compounds. In this review, it was examined how cinnamon could impact diabetes and its complications by affecting the toll-like receptor pathways. Cinnamon derivatives can affect toll-like receptor downstream pathways and cytokines such as NF-κB, interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α.