The Effect of Pine Needle Powder on AOM-induced Colon Aberrant Crypt Formation and Antioxidant System in Fisher 344 Male Rats

Pine needles are known as a traditional medicine and their ingestion has been shown to be beneficial to human beings. Following induction of the neoplastic process in rats by azoxymethane (AOM), we determined the effects of pine needle supplementation on colon carcinogenesis and on antioxidant systems in the blood and liver. Five week old male Fisher 344 rats were injected with AOM (15 mg/kg) once a week for two weeks. After the second injection, 18 rats were randomly assigned into two groups and were fed a casein-based high-fat diet (120 g fat and 1 g cholesterol/kg diet) with or without pine needle powder (10%w/w). After 6 weeks, rats receiving pine needle powder showed a 40% lower incidence of the number of colonic preneoplastic lesions (aberrant crypts) and a 52% lower incidence of aberrant crypt foci (p<0.01). A significantly elevated level of erythrocyte catalase activity was observed in the pine needle supplemented group (17.4$\pm$1.1 vs. 24.5$\pm$1.5, p<0.01). Pine needle supplementation also increased liver glutathione peroxidase activity (7.5$\pm$0.6 vs. 14.6$\pm$0.6, p<0.01). Other antioxidant parameters such as erythrocyte glutathione peroxidase, liver catalase activity, and plasma total antioxidant potential (TRAP), showed no statistical differences between the two groups. Our data demonstrate that pine needle supplementation improves the antioxidant system and suppresses the formation of colonic preneoplastic lesions in AOM-treated rats. This result provides additional insights into the chemo-preventative properties of pine needles.