X-rays and gamma radiation delivered to the abdominal region for cancer treatment encompasses severe damage to the intestinal mucosa, which significantly impairs a patient's quality of life. To a great extent the deleterious effects of x-radiation originate from radiolysis-induced reactive oxygen species. The well-researched powerful antioxidant Pycnogenol® was administered orally to rats prior to x-irradiation with 15 Gy. Histological sections of the intestines showed a dramatically better condition of the mucosal layers compared with the irradiated control animals administered water without Pycnogenol®. Pycnogenol® treatment significantly preserved the height and number of villi as well as the glandular layer and a diminished number of congested vases were present. No intestinal alterations were seen in control animals receiving Pycnogenol® in the absence of radiation. It is concluded that Pycnogenol® provides significant protection from ionizing radiation damage. Copyright © 2006 John Wiley & Sons, Ltd.208676679Block, K.I., Antioxidants and cancer therapy: Furthering the debate (2004) Integr Cancer Ther, 3, pp. 342-348Chida, M., Suzuki, K., Nakanishi-Ueda, T., In vitro testing of antioxidants and biochemical end-point in bovine retinal tissue (1999) Ophthalmic Res, 31, pp. 407-415Devaraj, S., Vega-Lopez, S., Kaul, N., Schönlau, F., Rohdewald, P., Jialal, I., Supplementation with a pine bark extract rich in polyphenols increases plasma antioxidant capacity and alters the plasma lipoprotein profile (2002) Lipids, 37, pp. 931-934Felemovicius, I., Bonsack, M.E., Baptista, M.L., Delaney, J.P., Intestinal radioprotection by vitamin E (alpha-tocopherol) (1995) Ann Surg, 222, pp. 504-508Feng, W.H., Wei, H.L., Liu, G.T., Effect of Pycnogenol on the toxicity of heart, bone marrow and immune organs as induced by antitumour drugs (2002) Phytomedicine, 9, pp. 414-418Grimm, T., Chovanová, Z., Muchová, J., Inhibition of NF-κB activation and MMP-9 secretion by plasma of human volunteers after ingestion of maritime pine bark extract (Pycnogenol®) (2006) J Inflamm (Lond), 3, pp. 1-15Grosse Düweler, K., Rohdewald, P., Urinary metabolites of French maritime pine bark extract in humans (2000) Pharmazie, 55, pp. 364-368Labejof, L.P., Galle, P., Mangabeira, P.A., De Oliveira, A.H., Severo, M.I., Histological changes in rat duodenum mucosa after whole-body gamma irradiation (2002) Cell Mol Biol, 48, pp. 537-545Packer, L., Rimbach, G., Virgili, F., Antioxidant activity and biologic properties of a procyanidin-rich extract from pine (Pinus maritima) bark, Pycnogenol® (1999) Free Radic Biol Med, 27, pp. 704-724Rohdewald, P., A review of the French maritime pine bark extract (Pycnogenol®), a herbal medication with a diverse pharmacology (2002) Int J Clin Pharmacol Ther, 40, pp. 158-168Sigurdson, A.J., Ron, E., Cosmic radiation exposure and cancer risk among flight crew (2004) Cancer Invest, 22, pp. 743-761Somosy, Z., Horvath, G., Telbisz, A., Rez, G., Palfia, Z., Morphological aspects of ionizing radiation response of small intestine (2002) Micron, 33, pp. 167-178Waselenko, J.K., MacVittie, T.J., Blakely, W.F., Medical management of the acute radiation syndrome: Recommendations of the Strategic National Stockpile Radiation Working Group (2004) Ann Intern Med, 140, pp. 1037-1051Weiss, J.F., Landauer, M.R., Radioprotection by antioxidants (2000) Ann N Y Acad Sci, 899, pp. 44-60