Protective effect of the herbal preparation, STW 5, against intestinal damage induced by gamma radiation in rats

Purpose: STW 5 (marketed as Iberogast (R), Steigerwald Arzneimittelwerk GmbH, Darmstadt, Germany) is a herbal preparation reported to possess anti-inflammatory properties and antioxidant activity. We investigated the effect of STW 5 against intestinal injury induced after whole body exposure to ionizing radiation (IR). Materials and methods: Intestinal mucositis was induced in rats by irradiation at a level of 6 Gy. STW 5 (5 ml/kg) was delivered orally for 5 days before irradiation and 2 days after. Rats were sacrificed, jejunum homogenates were tested to assess biochemical parameters indicating intestinal injury and jejunum segments were exposed to semi-quantitative histological examination. Results: IR led to an increase in overall damage severity (ODS) score associated with a significant rise in tumor necrosis factor (TNF-alpha) and thiobarbituric acid reactive substances (TBARS) by 46% and 50% (p <= 0.05), respectively, whereas the reduced glutathione (GSH), sucrase and alkaline phosphatase enzyme activities were significantly decreased by 68%, 76% and 25% (p <= 0.05), respectively, in intestinal homogenates. IR led to a reduction of plasma citrulline. Pre-treatment with STW 5 guarded against the changes in ODS score and in all parameters measured. Conclusion: Pre-treatment with STW 5 has the potential to decrease the severity of radiation-induced mucositis.