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Unipolar depressive disorder may become one of the major leading causes of disease burden by 2030 according to the World Health Organization (WHO). Thus, the discovery of antidepressive foods is attractive and could have considerable impacts worldwide. We investigated the antidepressant-like effects of Perilla frutescens seed oil on adult male rats subjected to a forced swimming test (FST). Forty Sprague-Dawley rats were housed and fed various diets, including soybean oil-rich, eicosapentaenoic acid (EPA)-rich, and P. frutescens seed oil-rich diets for 6 weeks. After the dietary intervention, animals were tested using an FST and were sacrificed after the test. We analyzed the fatty acid profiles of red blood cells (RBCs) and the brain prefrontal cortex (PFC). Levels of brain-derived neurotrophic factor (BDNF), serotonin, and dopamine in the PFC were also determined. After the FST, the imipramine, EPA-rich, and P. frutescens seed oil-rich groups showed significant shorter immobility time and longer struggling time than the control group (p < 0.05). Levels of BDNF in the P. frutescens seed oil-rich group and levels of serotonin in the EPA-rich group were significantly (p < 0.05) higher than those of the control group. Moreover, the BDNF concentration in the PFC was significantly positively correlated with the struggling time. However, there were no significant differences in dopamine levels between the intervention groups and the control group. In conclusion, a P. frutescens seed oil-rich diet exhibited antidepressant-like properties through modulation of fatty acid profiles and BDNF expression in the brain during an FST.

Poria cocos (Fu Ling) and Dioscorea opposita (Chinese Yam) were suggested to have potential benefits in blood sugar control. However, little is known about the underlying mechanisms. In this study, we investigated the anti-inflammatory and hypoglycemic effects of Poria cocos and Dioscorea opposita extracts in prediabetic rats. Fifty streptozotocin-injected rats with a mimic prediabetic status were gavaged with a single dose of either D. opposita (0.35 g kg À1 per day) or P. cocos (0.14 g kg À1 per day), a combination dose comprising single doses of the 2 herbal extracts, or vehicle for a 6-week treatment.Each group contained 10 rats. Blood and selected organ samples were collected during the study. The results indicated that administering the extracts singly or in combination for 6 week, significantly reduced the fasting blood-glucose level. The levels of interleukin-6 in plasma and selected organs significantly decreased during the treatment. The concentration of plasma free fatty acids (FFA) and the ratio of n À 6/n À 3 polyunsaturated fatty acids (PUFAs) were also significantly lowered after the 6 week intervention. The results indicate that administering P. cocos and D. opposita extracts produced anti-inflammatory effects in prediabetic rats by reducing the levels of interleukin-6 and the FFA ratio of n À 6/n À 3 PUFAs.

No abstract

Nutritional deficit of n-3 polyunsaturated fatty acids (PUFAs) is closely related to cognitive impairment and depression in later life. Cognitive impairment and depression lead to comorbidities, such as metabolic syndrome, in elderly people. The aim of this study is to evaluate the effects of dietary n-3 PUFAs on cognition and depressive-like behavior in an accelerated senescence rat model with prediabetic status. Rats were cotreated with d-gal and sucrose solution for 7 months and then fed fish-oil- or flaxseed-oil-rich diets for 3 months. Cognitive impairment analysis and depressive-like behavioral testing were conducted using the Morris water maze (MWM) test and forced swimming test (FST), respectively. The MWM test results revealed that the d-gal + sucrose + flaxseed oil (DSFS) group had a significantly shorter mean latency time in the short-term spatial memory trial on day 2 than did the d-gal + sucrose + fish oil (DSFO) group. The FST results demonstrated that the DSFO group exhibited a significantly shorter immobility time and longer climbing time than did the control group. Western blot analysis of the receptor for advanced glycation end-product (RAGE) level identified a significant difference in the DSFO group compared with the control group. Significantly lower n-6/n-3 PUFA ratios were observed in the frontal cortices of the DSFO and DSFS groups. In conclusion, fish and flaxseed oils exerted a protective effect on cognitive impairment and decreased the incidence of depressive-like behavior in d-gal- and sucrose-fed prediabetic aging rats. n-3 PUFA-rich oil diets, particularly the fish oil diet, reduced the plasma levels of nonesterified fatty acids, tumor necrosis factor-α, and brain dopamine and RAGE expression but not glycemic status, resulting in an improvement in the time of escape latency and the time spent in the target quadrant in the MWM test.