EFFECTS OF SHORT-TERM MODERATE EXERCISE TRAINING AND OAT BETA-GLUCAN ON MACROPHAGE CYTOTOXICITY

Abstract

Exercise can increase anticancer function of various immune components and decrease the risk of certain site-specific cancers including B16 melanoma metastasis to the lungs in mice (Davis et al. Am J Physiol. 274(43): R1454-R1459, 1998). Consumption of oat beta-glucan (OBG), a soluble fiber from oat bran and mild immune system enhancer has also been shown to protect against certain forms of cancer in rodents, but there are no studies on the interaction between exercise and OBG on these variables. PURPOSE To determine the effects of short-term moderate exercise training and OBG on peritoneal macrophage cytotoxicity to B16 melanoma cells in mice. METHODS Male C57BL/6 mice (n = 32) were randomly assigned to one of four groups: Exercise groups (EX-OBG and EX-H2O) ran for 1 h on a treadmill for 6 consecutive days at 36m/min, 8% grade. Control mice (CON-OBG and CON-H2O) were exposed to the same environment, but remained in their cages throughout the exercise period. OBG was consumed in the drinking water (∼3.6mg/day) (Ex-OBG and Con-OBG) for 10 consecutive days (including the exercise days) prior to sacrifice. Following rest or exercise on the last day of training, mice were sacrificed and peritoneal macrophages were obtained via i.p. lavage. Cytotoxicity of peritoneal macrophages against the mouse tumor cell line B16 melanoma was determined at various effector (macrophage): target (B16) ratios. RESULTS Both moderate exercise and OBG significantly increased macrophage cytotoxicity (P < 0.05), but there was no additive effect of OBG in exercise animals. CONCLUSION These data suggest that although not additive in their effects both short-term moderate exercise training and oat beta-glucan consumption can increase macrophage cytotoxicity to the murine B16 melanoma tumor cell line.