317IMMUNOMODULATORY EFFECTS OF WITHANIA SOMNIFERA AND TERMINALIA CHEBULA EXTRACTS, TLR4- INVOLVMENT AND TNF-A INHIBITION IN INVITRO STUDIESChronic diseases often involve inflammation and immune system imbalances. Toll-like receptors (TLRs) modulate immune responses by recognizing microbial structures and biochemicals like free fatty acids, influencing cytokine secretion and immune responses. In diseases like hypertriglyceridemia and type 2 diabetes mellitus (DMII), TLRs contribute to inflammation and insulin resistance through TNF-? release. Modulating TLR function can alter disease progression. This study explores the immunomodulatory mechanisms of two Ayurvedic herbs, Withania somnifera (WS) and Terminalia chebula (TC), known for their therapeutic efficacy but unclear mechanisms. We hypothesized that these herbs might interact with TLRs, influencing TNF-? and NF-?B activity. Using in vitro assays, WS and TC were evaluated for their effects on TNF-? inhibition and cytoprotection against rhTNF-?-induced cytotoxicity. WS's active constituent, Withaferin A, downregulates Akt phosphorylation and NF-?B, inducing apoptosis in U937 cells and inhibiting cell adhesion molecules. Chebulagic acid from TC inhibits LPS-induced inflammation in mouse macrophages by suppressing NF-?B and MAPK phosphorylation. Despite differing effects on MAPK, both compounds downregulate NF-?B. Our results demonstrate that standardized extracts of WS and TC effectively inhibit TNF-? in U937 cells and provide dose-independent cytoprotection against rhTNF-?-induced cytotoxicity in L929 cells. These findings suggest TLR4 antagonism as the underlying mechanism. Given the involvement of TLRs in DMII and rheumatoid arthritis, this study highlights the potential of WS and TC as immunomodulatory agents targeting TLR pathways. Further research is warranted to pinpoint their exact role in TLR4- MyD88-NF-?B signaling and their broader therapeutic implicationsappharma12@gmail.comResearch1412024Withania somnifera, Terminalia chebula, TLR4, Immunomodulation, Chronic diseaseAkila C. R, Sravani B, Sathwika Reddy K2Laxmi Prasanna B, Niharika D, Neeraja E1Professor, Department of Pharmacology, KLR Pharmacy College, Palwancha, Telangana 507115, India. 2 KLR Pharmacy College, Palwancha, Telangana 507115, India