Beneficial Effects by Intake of <i>Euphausiacea pacifica</i> on High-Fat Diet-Induced Obesity

Abstract

Obesity is a major health problem showing increased incidence in developed and developing countries. We examined the effect of Euphausia pacifica (E. pacifica) (Pacific Krill) on high-fat diet (HFD)-induced obesity in C57BL/6 mice. No significant differences were observed in average food intake between the HFD and HFD with E. pacifica group, or the low-fat diet (LFD) and LFD with E. pacifica group for 18 weeks. The increased ratio of body weight in the HFD containing E. pacifica group was significantly reduced, being 10% lower than that with HFD group in the 18th week (HFD, 298.6 18.8% vs. HFD with E. pacifica, 267.8 16.2%; p<0.05), while the ratio for the LFD containing E. pacifica group was reduced by 4% compared with LFD group (LFD, 244.2 11.6% vs. LFD with E. pacifica, 234.1 18.0%). There were no effects of E. pacifica on total cholesterol levels in serum and liver, whereas the supplement of E. pacifica tended to decrease triglyceride levels in the HFD groups. The leptin level in serum was significantly decreased in the HFD group (p<0.01) by E. pacifica. The adipocyte area (1926 1275 μm 2 ) in the HFD containing E. pacifica group was significantly reduced by 20% (p<0.001) compared with the HFD group. These results suggested that E. pacifica supplementation in the diet is beneficial for the prevention of HFD-induced obesity.Key words Euphausia pacifica; obesity prevention; leptin; triglyceride; high-fat diet Obesity is a major health problem, 1) and its incidence has increased by the over-intake of calorie-rich diets and exerciselacking lifestyles in developed and developing countries. 2),3) The prevalence varies from 12 to 41%. 4) Metabolic syndrome is a cluster of metabolic abnormalities consisting essentially of obesity, especially abdominal obesity. Furthermore, metabolic syndrome is a risk factor for type 2 diabetes, 5) cardiovascular, 6) dyslipidemia and hypertension. 7,8) Thus metabolic syndrome is a major health problem that must be resolved. Although it is important to improve physical activity and dietary habits to reduce obesity, it is really difficult to reduce body weight. Current anti-obesity drugs have safety issues, 9,10) so a safe anti-obesity drug is strongly required. On the other hand, if some foods show an anti-obesity effect, it is considered that they should be non-toxic and safe for humans.Euphausia pacifica (E. pacifica) (Pacific Krill) (Fig. 1) is the dominant euphausiid species in the subarctic North Pacific and also broadly distributes in far eastern sea area. 11) It plays an important role in the marine food chain and many predators depend on this species for food. 12,13) E. pacifica has been studied for morphology and ecology, 12) whereas there are few reports on the physiological and pharmacological effects. E. pacifica contains mineral (4.0%), lipid (1.8%), protein (19.1%), vitamin (0.8%) and so on and is used in some rice crackers, pasta relish, rice and some noodles and seasonings in Japan. However, most E. pacifica is not an effective use, because only feed for cultured fish...

Supplementation of krill oil with high phospholipid content increases sum of EPA and DHA in erythrocytes compared with low phospholipid krill oil

“…This ratio did not change in the current study, suggesting that TC and LDL-C increase might not be detrimental. These results support findings from our previous study which demonstrated an incremental increase [ 8 ], as well as other studies showing no change [ 6 , 7 , 36 ], in plasma concentrations of total and LDL cholesterol in normolipidemic participants after krill oil supplementation. Both LPL and HPL krill oils were well tolerated by the participants and caused no adverse effects which shows the safety nature of krill oil.…”

Enhanced increase of omega-3 index in healthy individuals with response to 4-week n-3 fatty acid supplementation from krill oil versus fish oil

“…Although krill oil supplementation has demonstrated hypolipidemic activity in some studies, this effect is found to be more pronounced with participants with hyperlipidemia [ 11 , 36 , 38 ]. Similar results were found in previous studies with normolipidemic participants in whom there was no effect on serum lipids [ 10 , 17 , 39 ]. Reduction of serum TG by n-3 PUFA also depends on their baseline concentrations [ 36 , 38 , 40 ].…”

Hydroxyeicosapentaenoic acids from the Pacific krill show high ligand activities for PPARs

“…Although lipids are major bioactive compounds in krill oil, we found in a previous study that a watersoluble extract from Pacifi c krill could suppress weight gain in mice caused by a high fat diet. The levels of triglycerides in the livers of mice given a water-soluble extract from Pacifi c krill decreased ( 32 ).…”