Abstract

Author(s): Fontenla, M.; Cena, A.; Fontenla, R.; Pintos, S.; Sosa, L.; Prchal, A.; Fontenla, S

Objectives: to study the effects of soy milk consumption in the occurrence of dysplastic crypt foci (DCF) in an experimental model of colon cancer. To relate oxidative stress with apoptotic activity and genomic unsteadiness.

Methods: experimental model of colon cancer was achieved by subcutaneous injections of 1,2-dimetilhidrazina (DMH, 20 mg/Kg) twice a week during eight weeks in adult male Wistar rats. Three groups were studied: A) Normal control: saline injections and standard diet (commercial formula and water ad libitum); B) Carcinogenesis control: DMH inoculation and standard diet; C) Experimental: DMH inoculation, soy diet (commercial formula and soy milk). Four rats of each group were study 4, 5 and 6 months after last inoculation: colon tissue was processed with conventional histological techniques; protein P53 was determined by inmunhistochemistry. Apoptotic activity was measured by Tunel test, Nitric Oxide in serum and malondialdehyde in liver homogenates were also determined.

Results: Experimental rats did not develop cancer in the studied period, while we found tumors in carcinogenesis control groups in the 5th month. Dysplastic indicators (DCF) were related with P53 over expression, augmented apoptotic activity and decreases of nitric oxide and malondialdehyde.

Conclusions: Soy milk intake as diet supplement for prolonged time could delay de DCF emergence. These anticancers effects may be due to the soy antioxidative action, that could decrease the accumulative ADN damage.