Impact of curcumin on toll‐like receptors

Abstract

Toll‐like receptors (TLRs) have a pivotal role in the activation of innate immune response and inflammation. TLRs can be divided into two subgroups including extracellular TLRs that recognize microbial membrane components (TLR1, 2, 4, 5, 6, and 10), and intracellular TLRs that recognize microbial nucleic acids (TLR3, 7, 8, and 9). Curcumin is a dietary polyphenol from Curcuma longa L. that is reputed to have diverse biological and pharmacological effects. Extensive research has defined the molecular mechanisms through which curcumin mediates its therapeutic effects. One newly defined and important target of curcumin is the TLR, where it exerts an inhibitory effect. In the current study, we focus upon the TLR antagonistic effect of curcumin and curcumin's therapeutic effect as mediated via TLR inhibition. The available evidence indicates that curcumin inhibits the extracellular TLR 2 and 4 and intracellular TLR9 and thereby exerts a therapeutic effect in diseases such as cancer, inflammation, infection, autoimmune, and ischemic disease. Curcumin effectively modulates the TLR response and thereby exerts its potent therapeutic effects.

Curcumin and Intestinal Inflammatory Diseases: Molecular Mechanisms of Protection

“…Treatments abrogating TLR4-dependent signal transduction have been shown to lead to an amelioration of intestinal inflammatory disease [268]. Curcumin has been shown to inhibit both MyD88-dependent and -independent signaling mechanisms [88,269]. Additionally, curcumin can bind to myeloid differentiation protein 2 (MD-2), a protein bound to the extracellular TLR4 domain, thereby suppressing the innate immune response to LPS [270].…”

The effectiveness and safety of curcumin as a complementary therapy in inflammatory bowel disease

“…[ 30 – 32 ] In AP-1 signaling, curcumin can inhibit MAPK, ERK1/2, JNK, and p38, both directly and indirectly, thereby limiting transcription of inflammatory target genes. [ 33 ] We hope this systematic review will provide more reliable evidence in the management of IBD.…”

Beneficial effects of emodin and curcumin supplementation on antioxidant defence response, inflammatory response and intestinal barrier of Pengze crucian carp ( Carassius auratus var. Pengze)

“…Intestinal inflammation is a complex process, and TLR4 signalling pathway plays an important role in the inflammatory process (Płóciennikowska, Hromada-Judycka, Borzęcka, & Kwiatkowska, 2015). Previous studies revealed that emodin and curcumin could attenuate inflammatory responses through directly suppressing TLR4 signalling pathway (Boozari, Butler, & Sahebkar, 2019;Ding et al, 2018;Fu et al, 2014;Zhu et al, 2012).…”