Radioprotective effect of silymarin against radiation induced hepatotoxicity

• Published in: Pharmacological research Vol. 45; no. 6; pp. 447 - 454
• Main Authors: Ramadan, Laila A., Roushdy, Hamed M., Abu Senna, Gamal M., Amin, Nour E., El-Deshw, Ola A.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.06.2002
• Subjects: Administration, Oral; Alkaline Phosphatase - metabolism; Animals; Gamma Rays; Glutathione Peroxidase - metabolism; Glutathione Reductase - metabolism; Injections, Intravenous; irradiation, silymarin, hepatotoxicity; Liver - drug effects; Liver - enzymology; Liver - radiation effects; Male; Radiation Injuries, Experimental - enzymology; Radiation Injuries, Experimental - prevention & control; Radiation-Protective Agents - administration & dosage; Radiation-Protective Agents - therapeutic use; Rats; Rats, Wistar; Silymarin - administration & dosage; Silymarin - therapeutic use; Whole-Body Irradiation; irradiation, silymarin, hepatotoxicity
• ISSN: 1043-6618; 1096-1186
• DOI: 10.1006/phrs.2002.0990

The radioprotective effect of silymarin using different modes of treatment against radiation (3 or 6 Gy) induced hepatotoxicity 1, 3 and 7 days post-irradiation was studied. Whole-body gamma-irradiation revealed an increase in serum alkaline phosphatase (AP) activity as well as liver glutathione reductase (GR) and glutathione peroxidase (GSH-PX) activities on the first post-exposure day with respect to the control value. However, 3 days after radiation exposure, these parameters showed a significant decrease below the control level which persisted till the end of the experimental time except for serum AP activity that showed another increase on the seventh post-exposure day at 3 Gy dose of radiation. A gradual increase in serum alanine and aspartate aminotransferase (ALT&AST) as well as gamma glutamyl transpeptidase activities were observed due to irradiation throughout the experimental time. Administration of silymarin as single (70 mg kg −1), fractionated (490 mg kg −1) oral doses or as intravenous (i.v.) injection (50 mg kg −1), caused significant protection. Intravenous treatment showed the most pronounced protection. The protective effect of silymarin was attributed to its antioxidant and free radicals scavenging properties.