Thymol, a Dietary Monoterpene, Abrogates Hexachlorobenzene-Induced Hepatic Dysfunction Via Different Mechanisms

Thymol (2-isopropyl-5-methyl-phenol) is a natural monoterpene phenolic antioxidant that has anti-inflammatory and anti-apoptotic potentials in experimental studies. Literatures are scarce on effects of hexachlorobenzene-induced hepatic damage. Therefore, this study investigated the ameliorating potential of thymol (THY) on hexachlorobenzene (HCB)-induced hepatic damage as well as the effects on the antioxidant status, polyamine catabolism, inflammatory and apoptotic processes. Thirty-two adult male rats were daily treated orally by gavage for 25 days and allocated into four groups; control group received corn oil, HCB alone group (15 mg/kg b.wt), THY-treated group (100 mg/kg b.wt) and HCB + THY-treated group. The results showed that HCB significantly reduced the body weight with concurrent increase in relative liver weight accompanied by widespread histological aberrations. Furthermore, HCB-treated rats revealed increases in hepatic putrescine oxidase, spermine oxidase, and myeloperoxidase activities, tumor necrosis-α and interleukin-1β levels, caspase-3 activity, induced oxidative damage as evidenced by elevated malondialdehyde (MDA) levels and significant reduction in antioxidant enzyme activities and reduced glutathione (GSH). However, co-administration of THY with HBC abated the hepatic damage by preventing the generation and release of reactive oxygen species, improving the antioxidant system, down-regulated polyamine catabolism, inflammatory and apoptotic responses. The findings of this study revealed that HCB acts as a hepatotoxicant and thymol might be a possible future therapeutic agent for HCB-induced hepatic damage.