The Protective Effects of a Single Dose Myricetin Application on CLP-Induced Rat Sepsis Model by Analyzing Some Immune Mechanisms

In this study, our aim was to investigate the protective effects of myricetin (single dose–100 mg/kg) on CLP-induced rat sepsis model by analyzing some immune mechanisms including inflammation and oxidative stress by different techniques such as Immunohistochemistry, ELISA, tissue biochemistry and Western Blotting. Twenty-eight Wistar albino rats were divided into 4 groups. The pro-inflammatory and anti-inflammatory cytokine levels were measured by ELISA technique. CD68 and Nuclear-Factor-Kappa-B (NF-κB) positivity rates were detected by IHC. Some of oxidative stress parameters were measured by tissue biochemistry, while Toll-lke Receptor-4 (TLR4) expression others were detected by Western blot technique. Sepsis caused a significant increase in all pro-inflammatory cytokine and oxidant levels. Also, it led to an increase in the positivity of CD68 and NF-κB markers as well as the expression levels of TNF-alpha, IL-1-beta, TLR4, Keap-1. However, single dose myricetin application normalized pro-inflammatory cytokine levels, increased anti-oxidant and anti-inflammatory cytokine levels, decreased positivity of CD68 and NF-κB and increased NRF2 and HO-1 expressions. As a conclusion, the beneficial effect of myricetin on lung injury also involved inhibition of TLR4/NF-κB pathway, suppression of proinflammatory cytokines and induction of anti-inflammatory cytokine production, regulation of oxidant and anti-oxidant system parameters, and activating the NRF2/Keap1/HO-1 pathway.