Thymoquinone upregulates TRAIL/TRAILR2 expression and attenuates hepatocellular carcinoma in vivo model.

AIMS

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related mortality worldwide. Indeed, chemotherapeutic drugs-induced systemic toxicity results in suboptimal cancer treatment. Consequently, there is a need for exploring of a safe and effective therapy for cancer patients. This study aimed to evaluate the hepatoprotective effect of thymoquinone (TQ) against thioacetamide (TAA)-induced HCC. Also, we investigated TQ's ability to sensitize cancer cells toward TRAIL/TRAILR2 apoptotic pathway.

MAIN METHODS

Forty male Sprague Dawley rats were divided into 4 groups (n = 10) as follows: control group, CMC group, HCC group and HCC + TQ group. Serum levels of liver function biomarkers and Alpha-Fetoprotein (AFP), as well as hepatic levels of glutathione (GSH) and Alpha-Fetoprotein (MDA) were measured. Transforming growth factor-beta 1 (TGF-β1), TRAILR2, TRAIL, caspase-3, caspase-9, caspase-8 and B cell lymphoma-2 (Bcl-2) mRNA levels were assessed by Quantitative, Real-Time PCR. Fibrosis percentage and necroinflammation were quantified by histopathological examination.

KEY FINDINGS

Our results indicated improvement in liver functions, decrease in AFP level and attenuation of HCC progression in TQ treated rats. TQ upregulated TRAIL/TRAILR2 and subsequently enhanced apoptosis as hinted by caspase-3 upregulation and Bcl-2 downregulation. Also, TQ decreased TGF-β1 gene expression level. Moreover, HCC + TQ group showed significant increase in hepatic GSH level and marked decrease in hepatic MDA level.

SIGNIFICANCE

This study proved that TQ is able to suppress HCC development via decreasing oxidative stress, suppression of TGF-β1 and induction of TRAIL-mediated apoptosis.