Effects of Dietary DNA from Chum Salmon Milt on Memory and Age-related Changes in Senescence-accelerated Mice

The effects of dietary DNA (sodium salt), extracted from chum salmon milt, on memory, age-related changes and fertility were investigated in the P-8 strain of senescence-accelerated mice (SAMP8). Mice were fed a diet without (control group) or with 0.1% DNA for 10 months (DNA group). In passive and active avoidance tests, the age-induced deterioration of memory was reduced significantly in the DNA group (p < 0.05). To evaluate the degree of senescence, we scored physical changes of aging, including movement and appearance, and found that these changes were significantly lower in the DNA group (p < 0.05). Moreover, concentration and mobility of spermatozoa were significantly enhanced (p < 0.05), and the activities of superoxide dismutase and catalase in the liver were significantly higher in the DNA group (p < 0.05). It has been suggested that these changes in aging and fertility are due to the fact that dietary DNA enhances antioxidant activity, indicating that dietary DNA may be effective in preventing the deterioration of memory with aging and age-related physical changes in the body. (Received Mar. 31, 2008; Accepted Jul. 11, 2008)