Attenuation of Toll-Like Receptor Expression and Function in Latent Tuberculosis by Coexistent Filarial Infection with Restoration Following Antifilarial Chemotherapy

Mycobacterium tuberculosis (Mtb) and filarial coinfection is highly prevalent, and the presence of filarial infections may regulate the Toll-like receptor (TLR)-dependent immune response needed to control Mtb infection. By analyzing the baseline and mycobacterial antigen–stimulated expression of TLR1, 2, 4, and 9 (in individuals with latent tuberculosis [TB] with or without filarial infection), we were able to demonstrate that filarial infection, coincident with Mtb, significantly diminishes both baseline and Mtb antigen-specific TLR2 and TLR9 expression. In addition, pro-inflammatory cytokine responses to TLR2 and 9 ligands are significantly diminished in filaria/TB-coinfected individuals. Definitive treatment of lymphatic filariasis significantly restores the pro-inflammatory cytokine responses in individuals with latent TB. Coincident filarial infection exerted a profound inhibitory effect on protective mycobacteria-specific TLR-mediated immune responses in latent tuberculosis and suggests a novel mechanism by which concomitant filarial infections predispose to the development of active tuberculosis in humans

Antioxidant Effect of Caffeic Acid on Oxytetracycline Induced Lipid Peroxidation in Albino Rats

Caffeic acid is a well-known phenolic compound widely present in plant kingdom. The aim of this study was to investigate the possible protective effect of caffeic acid (CA) against oxytetracycline (OXT) induced hepatotoxicity in male Albino Wistar rats. A total of 30 rats weighing 150–170 g were randomly divided into five groups of six rats in each group. Oral administration of OXT (200 mg/kg body weight/day) for 15 days produced hepatic damage as manifested by a significant increase in serum hepatic markers namely aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), bilirubin and increased plasma and hepatic lipid peroxidation indices (TBARS and hydroperoxide). The present finding shows that the levels of enzymatic antioxidants namely superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were significantly decreased in OXT intoxicated rats. Upon oral administration of caffeic acid (40 mg/kg body weight/day) there were decreased hepatic marker activities, bilirubin and lipid peroxidation and increased enzymatic antioxidants in OXT + Caffeic acid group compared to Normal + OXT group(P < 0.05). Our study suggests that caffeic acid has antioxidant property and hepatoprotective ability against OXT induced toxicity