Panax ginseng Meyer prevents radiation-induced liver injury via modulation of oxidative stress and apoptosis

BACKGROUND: Radiotherapy is one of the most important modalities in cancer treatment; however, normal tissue damage is a serious concern. Drug development for the protection or reduction of normal tissue damage is therefore a clinical issue. Herein, we evaluated the protective properties of Panax ginseng Meyer and its corresponding mechanisms. METHODS: C56BL/6 mice were orally pretreated with P. ginseng water extract (PGE; 25 mg/kg, 50 mg/kg, or 100 mg/kg) or intraperitoneally injected melatonin (20 mg/kg) for 4 d consecutively, then exposed to 15-Gy X-ray radiation 1 h after the last administration. After 10 d of irradiation, the biological properties of hematoxicity, fat accumulation, histopathology, oxidative stress, antioxidant activity, pro-inflammatory cytokines, and apoptosis signals were examined in the hepatic tissue. RESULTS: The irradiation markedly induced myelosuppression as determined by hematological analysis of the peripheral blood. Steatohepatitis was induced by X-ray irradiations, whereas pretreatment with PGE significantly attenuated it. Oxidative stress was drastically increased, whereas antioxidant components were depleted by irradiation. Irradiation also notably increased serum liver enzymes and hepatic protein levels of pro-inflammatory cytokines. Those alterations were markedly normalized by pretreatment with PGE. The degree of irradiation-induced hepatic tissue apoptosis was also attenuated by pretreatment with PGE, which was evidenced by a terminal deoxynucleotidyl transferase 2′-deoxyuridine 5′-triphosphate nick-end labeling assay, western blotting, and gene expressions analysis, particularly of apoptotic molecules. CONCLUSION: We suggest that PGE could be applicable for use against radiation-induced liver injury, and its corresponding mechanisms involve the modulation of oxidative stress, inflammatory reactions, and apoptosis.