Phytochemicals as Modulators of Toll-Like Receptors: An Immunopharmacological Perspective

Toll-like receptors (TLRs) are molecular receptors that can “sense” potential foreign antigens to protect the host. Crosstalk between exogenous and endogenous threats with intercellular molecular receptors plays a pivotal role in maintaining the immunological functions of the host. Due to the increased risk of chronic illness and increasing rate of infectious diseases, the immune system has become a significant target of toxicity due to the application of chemotherapeutics. Pathogenic resistance and the adverse side effects of chemotherapeutics can be modulated using phytochemicals. Since ancient times, medicinal plants have been in use as therapeutics due to their immunomodulatory properties. They exhibited anti-inflammatory, antimicrobial, antifilarial, and anticancer actions to ameliorate the cytotoxic effects of chronic illness. They have the ability to interact with molecular receptors like Toll-like receptors (TLRs) and hitherto, studies have shown the use of phytochemicals as a modulator of TLR signaling to revert back immunopathological consequences rising from pathogen and endogenous threats. Herein, in this book chapter, we have discussed about phytochemicals as natural immunomodulators of Toll-like receptors.