Effect of Ovary Lipid of Skipjack Tuna on Rat Serum Components after Stress Application

Anti-anxiety effect of ovary lipid extracted from Skipjack tuna (Katsuwonus pelamis) in rats

Using an elevated plus-maze test, we evaluated anxiety level in rats given ovary lipid extracted from Skipjack tuna (Katsuwonus pelamis; OLS). The percentage of open time was significantly higher in rats given OLS than in rats in the control group, but lower than in rats given diazepam (1.0 mg/kg body weight). Based on this fact and findings about other indicators, this study showed that OLS does not have as fast-acting and strong an anti-anxiety effect as diazepam but that continuous ingestion of OLS causes an anti-anxiety effect in animals.

Effect of Ovary Lipid from Skipjack Tuna (Katsuwonus pelamis) on Brain Monoamines in Rats

In our previous experiments with rats, ovary lipid from Skipjack Tuna (Katsuwonus pelamis) (OLS) was shown to have a mitigating effect on anxiety and/or fear in elevated T-maze tests. This suggests that OLS has some effect on the central nervous system (CNS) of rats. Thus, we performed experiments to examine the status of CNS in rats given OLS. The effect of OLS on chronic stress was also examined at the same time. The feed for control rats used oil and fat that have the same energy percentages for n-6 and n-3 fatty acids and the same n-6/n-3 ratio as OLS. As a result, rats given OLS for 28 days had lower serotonin levels in various brain areas regardless of stress application, showing that OLS affected the serotonin nervous system. From this, it was inferred that the ability of OLS to mitigate anxiety and/or fear resulted from its action on CNS, especially the serotonin nervous system. Substances other than the essential fatty acids may have been responsible for the action of OLS on monoamines and the metabolites. The effect of OLS on CNS, especially the serotonin nervous system, suggests that OLS may suppress anxiety.