Effect of Resveratrol Administration on Tumor Necrosis factor- alpha (TNF-alpha) Expression and Lymphocyte Cell counts in Endotoxin-induced Uveitis

Abstract

Corticosteroids remain the first-line therapy for uveitis; however, long-term use may lead to glaucoma and cataract. Resveratrol, a polyphenolic compound naturally present in foods such as blueberries, and red grapes has notable anti-inflammatory properties. This study aims to evaluate the effects of resveratrol administration on Tumor Necrosis Factor-α (TNF-α) expression and lymphocyte cell counts in an endotoxin-induced uveitis rat model. Endotoxin-induced uveitis was induced in 30 rats by subcutaneous injection of 200 µg/100 µl  lipopolysaccharide into the plantar surface of the foot. Four hours post-induction, anterior segment examination was performed to confirm signs of uveitis and the animals were divided into five groups of 6 each: negative control with placebo (K1), positive control with 20 µg subconjunctival dexamethasone (K2), subconjunctival resveratrol at doses of 200 µM (K3), 400 µM (K4), and 800 µM (K5). Clinical scoring was conducted at 24 hours post-induction, followed by enucleation to assess lymphocyte count and TNF-α expression. TNF-α expression was significantly lower in the 200 µM resveratrol group compared to the negative control group (p=0.028). Higher doses of resveratrol did not show a significant reduction compared to negative and positive control group in TNF-α expression. Lymphocyte count analysis showed no significant differences among the groups; however, the groups treated with 200, 400, and 800 µM resveratrol exhibited higher lymphocyte counts compared to both negative and positive control groups. This study demonstrates resveratrol's potential in reducing TNF-α-driven inflammation in endotoxin-induced uveitis, with its anti-apoptotic effects possibly contributing to the observed lymphocyte increase within the 24-hour period.