Mitigation of experimental hepatocellular Carcinoma by Inonotus obliquus Mushroom extract in association with oxidative stress and inflammation signaling

Abstract

Chaga mushroom (Inonotus obliquus) has been a component of folk medicine treating several disorders mainly through its anti-inflammatory and antioxidant properties, yet its effects on liver carcinoma needed elucidation. This study investigated the effect of an aqueous extract of Inonotus obliquus (IOAE) against diethyl-nitrosamine/carbon tetrachloride (DEN/CCl₄) induced HCC in mice and addressed its molecular mechanism. HCC was induced by a single intraperitoneal injection (i.p.) of DEN (1 mg/kg b.w.) followed by CCl₄ (0.2 ml/kg, i.p., twice a week) after six weeks. IOAE (200 mg/kg b.w.) was administered orally after the induction of HCC. Physiological and hematological parameters and biochemical assays for oxidative stress markers were performed. Histopathological and immunohistochemistry for inflammation and apoptosis were performed. DEN/CCl₄ caused a reduction in mice body weight and an increase in the liver weight which was significantly restored by IOAE administration. The tumor incidence of DEN/CCl₄ (100 %) was reduced to about 25 % by IOAE supplementation. DEN/CCl₄ caused alterations in the hematological parameters, serum total protein albumin globulin, A/G ratio, liver function markers (aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase gamma-glutamyl transferase, acid phosphatase and bilirubin) and lipid profile markers that were significantly restored by IOAE administration. Oxidative stress markers (malondialdehyde, superoxide dismutase, catalase, nitric oxide, lactate dehydrogenase, and glutathione-s-transferase) were reduced by DEN/CCl₄ which were significantly restored by IOAE treatment. The liver histopathology alterations caused by DEN/CCl₄ were significantly ameliorated by IOAE treatment. Immunohistochemical studies suggest that AFP, caspase-3, COX-2, and iNOS were chronically overexpressed in DEN/CCl₄-exposed mice which were notably attenuated by IOAE administration. Collectively IOAE was found to suppress tumor incidence by suppressing iNOS-COX-2-dependent inflammation and caspase-3 mediated apoptosis. Chaga mushroom showed remarkable anticancer effects against liver carcinoma through induction of apoptosis and suppression of inflammation.