ascorbic-acid and nitrosobis(2-oxopropyl)amine

Antioxidative vitamins are known to inhibit metastasis. Therefore we evaluated the impact of vitamins A (retinol), C (ascorbic acid) and E (alpha-tocopherol) on liver metastasis in a model of ductal pancreatic adenocarcinoma in hamster.. One hundred and twenty male Syrian hamsters were randomized into 8 groups (Gr.) (n = 15). Gr. 1-4 were given 0.5 ml normal saline subcutaneously (s.c.) weekly, whereas Gr. 5-8 received 10 mg N-nitrosobis(2-oxopropyl)amine (BOP)/kg body weight s.c. for 3 months for tumor induction. In the 13th week Gr. 2 and 6 were administered retinol, Gr. 3 and 7 received ascorbic acid and Gr. 4 and 8 were given alpha-tocopherol orally. No treatment was performed in Gr. 1 and 5. After 24 weeks animals were sacrificed, pancreas and liver were histologically determined. Activities of glutathione-peroxidase (GSH-Px), superoxide dismutase (SOD) and concentration of thiobarbituric-acid-reactive substances (TBARS) were analyzed in hepatic tissue.. Retinol and alpha-tocopherol decreased the incidence of liver metastases (44.4 vs. 86.7%, p < 0.05). The number and size of liver metastases were significantly reduced by retinol. Activities of GSH-Px and SOD were increased and concentration of TBARS was decreased in NML and LiMe by all vitamins.. Obviously, antioxidative vitamins prevent oxidative stress in hepatocytes. This may be one mechanism decreasing liver metastasis in pancreatic cancer in the present trial.

Topics: Administration, Oral; Animals; Antineoplastic Agents; Antioxidants; Ascorbic Acid; Carcinoma, Pancreatic Ductal; Cricetinae; Disease Models, Animal; Glutathione Peroxidase; Lipid Peroxidation; Liver Neoplasms; Male; Mesocricetus; Neoplasm Metastasis; Nitrosamines; Pancreatic Neoplasms; Superoxide Dismutase; Thiobarbituric Acid Reactive Substances; Vitamin A; Vitamin E

Persistent oxidative stress is thought to play an important role in carcinogenesis. Vitamins may influence oxygen radical metabolism and thus inhibit tumor growth. In the present trial the effects of Vitamins (Vit.) A, C and E on neoplastic growth and lipid peroxidation in pancreatic tissue were evaluated on chemically-induced pancreatic adenocarcinoma in the Syrian hamster. The incidence of pancreatic cancer was decreased by Vit. A (64.3%) and Vit. C (71.4%) as compared to the control group (100%, P<0.05). All vitamins increased the activity of superoxidedismutase (SOD) in pancreatic carcinomas. Accumulation of vitamins in tumor cells seems to be responsible for high levels of SOD and consecutive intracellular increase of hydrogen peroxide levels. Since this effect is selectively toxic for tumor cells it might be one of the mechanisms decreasing the incidence of pancreatic cancer in our trial.

Topics: alpha-Tocopherol; Animals; Antineoplastic Agents; Antioxidants; Ascorbic Acid; Carcinoma, Pancreatic Ductal; Cell Division; Cricetinae; Glutathione Peroxidase; Lipid Peroxidation; Mesocricetus; Nitrosamines; Oxidative Stress; Pancreatic Neoplasms; Superoxide Dismutase; Thiobarbituric Acid Reactive Substances; Vitamin A; Vitamins

The effects of vitamins E and E, beta-carotene and selenium on development of N-nitrosobis(2-oxopropyl)amine (BOP)-induced pancreatic tumours in hamsters were investigated. Dietary supplementation of vitamin C, alone as well as in combination with beta-carotene resulted in consistently lower numbers of advanced ductular lesions. The differences with the controls, however, did not reach the level of statistical significance. Beta-Carotene alone demonstrated no inhibitory effect on the development of (pre)neoplastic lesions in the pancreas. Vitamin E or Se, either alone or in combination, had no effect on the development of advanced ductular lesions in BOP-treated hamsters.

Topics: Adenocarcinoma; Animals; Ascorbic Acid; beta Carotene; Body Weight; Carcinogens; Carcinoma, Ductal, Breast; Carotenoids; Cricetinae; Diet; Male; Mesocricetus; Nitrosamines; Organ Size; Pancreatic Neoplasms; Selenium; Vitamin E