Effects of thymoquinone (TQ) on liver damage induced trichloroethylene (TCE) and heat shock protein (HSP) 70 immunreactivity

Effects of Thymoquinone (TQ) on Liver Damage Induced Trichloroethylene (TCE) and Heat Shock Protein (HSP) 70 Immunreactivity Trichloroethylene is widely used industrial chemical and a common environmental contaminant. It was found that thymoquinone had protective effects on organ injuries caused by various toxic agents. HSP70 is one of the early markers of hepatocarcinogenezis in cirrhotic liver disease and its expression levels increases in the organism in stress conditions. The aim of this study was to investigate the possible protective effects of thymoquinone on the liver damage induced trichloroethylene exposure and examination on the changes of HSP 70 immunreactivity. For this purpose, 25 male Wistar-Albino rats were used. The experimental period was determined as 3 weeks. The rats were divided into 5 groups. Group I: control group. Rats in Grup II were treated 1000mg/kg/day trichlorethylene. Rats in Grup III were treated trichlorethylene 1000mg/kg/day with 50mg/kg/day thymoquinone. Rats in Group IV were treated 50mg/kg/day thymoquinone. Rats in Group V were treated 1ml/day dimethyl sulfoxide. All treatments were given by intragastric gavage technique. At the end of 3 weeks treatment, rats were anesthetized with xylazine and ketamine and sacrificed by cervical decapitation. Removed liver tissues was fixed in 10% formaldehyde solution, dehydrated in ethanol series and embedded in paraffin. 5μm thick sections, some of them, were stained with Hematoxyline and Eosin, Masson's trichrome and Periodic Acid Schiff techniques. The remaining sections were used to determine the 4 immunreactivity of HSP70. Tissue sections were examined in photomicroscope and photographed. Differences of HSP70 immünreactivity between groups were determined by statistical analysis. Light microscopic investigation showed that trichloroethylene caused to vascular congestion, necrosis, inflammation, sinusoidal dilatation in the liver and significant increases in immunreactivity of HSP70. The statistical analyzes seem to support our findings including differances between the groups of prevalence of HSP70 immune reactivity. It was detected that thymoquinone relatively decreases trichloroethylene induced structural changes. As a result, in this study, it was found that long-term recurrent exposure to high doses of trichloroethylene may be highly toxic for liver. This influence of trichloroethylene exposure was confirmed by increased immunreactivity of HSP70. In this context, it is emerged for the necessity of taking protective precautions for both environmental contamination and professional groups faced by potential hazards of trichloroethylene. Keywords: Thymoquinone, trichloroethylene, HSP 70, liver, immunohistochemistry