8-hydroxy-2--deoxyguanosine and Intestinal-Polyps

Brazilian propolis, a folk medicine, is used worldwide as an alternative medicine to prevent colon cancer. The objective of the study was to test in a small pilot biomarker study in a high-risk group the safety and efficacy of propolis for colon cancer prevention, which has not been evaluated in humans.. Subjects with adenoma polyps recently removed from the colon were randomly assigned to a propolis group of 15 and a placebo group of 16. In a double-blind study, the propolis group received capsules containing 165 μmol artepillin C and 150 μmol other polyphenols per day for 3 months. Prior to and at the end of the experiments, their blood was analyzed using biochemical tests, and specimens from the normal-appearing sigmoid colon mucosa were biopsied endoscopically to examine the levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and mRNA expressions of proliferating cell nuclear antigen, cyclin D1, and Bax.. Propolis extract significantly increased the mRNA level of cyclin D1 in the sigmoid colon mucosa, and the other biomarkers remained unchanged. Blood biochemical tests showed significantly higher activity of creatine phosphokinase (CPK), 143 ± 52 units/ml in the propolis group and 104 ± 38 units/ml in the placebo group (p = 0.026), at the end of the study. The increase in CPK activity in the propolis group was due to the increase of the myocardial band form of CPK. On the other hand, laxative treatment prior to endoscopic biopsy significantly increased 8-OHdG levels.. The results from our pilot study did not provide evidence that Brazilian propolis was effective in preventing changes occurring during early stages of colon cancer. In contrast, propolis may have detrimental side effects on muscle tissue, including myocardial cells.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adenomatous Polyps; Aged; Biomarkers; Brazil; Colon; Colorectal Neoplasms; Creatine Kinase; Cyclin D1; Deoxyguanosine; Double-Blind Method; Female; Humans; Intestinal Polyps; Male; Middle Aged; Phenylpropionates; Pilot Projects; Plant Extracts; Polyphenols; Proliferating Cell Nuclear Antigen; Propolis; RNA, Messenger

To clarify the role of oxidative stress in aging of colorectal tissue, we analyzed the 8-hydroxydeoxyguanosine (8-OH-dG) levels in colorectal biopsy samples from normal tissue of patients with either colorectal cancer (n = 15) or benign colorectal polyps (n = 40). An age-associated increase of 8-OH-dG was observed (p =.002), although the 8-OH-dG levels were not significantly different between the patients with cancer and those with polyps. These results suggest an increased level of 8-OH-dG formation in human colorectal tissue with age.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Aged; Aged, 80 and over; Aging; Colon; Colonic Polyps; Colorectal Neoplasms; DNA; Guanine; Humans; Intestinal Polyps; Middle Aged; Oxidative Stress; Rectum