Abstract: Objective: To compare the effects of Antarctic krill oil, fish oil and arachidonic acid-enriched oil on lipid metabolism in ovariectomized mice with osteoporosis. Methods: Eight-week-old healthy female C57BL/6J mice were subjected to bilateral ovariectomy to establish a model of postmenopausal osteoporosis. Other mice were subjected to a sham operation without ovariectomy and gavaged with normal saline. After successful establishment of the model, the mice were randomly divided into a model control group (normal saline), an Antarctic krill oil group (150 mg/kg mb), a fish oil group (80 mg/kg mb) and an arachidonic acid-enriched oil group (140 mg/ kg mb). After administration for 12 continuous weeks, bone mineral density, total cholesterol (TC) and triglyceride (TG) levels in the serum and liver, and the expression levels of lipid synthesis-related genes in the liver were determined. Results: Antarctic krill oil and fish oil, both rich in n-3 polyunsaturated fatty acids (PUFA), significantly reduced the body fat percentage of osteoporotic mice (P < 0.01), improved blood and liver lipid levels, and significantly down-regulated the mRNA expression of the genes encoding sterol regulatory element binding protein-1c (SREBP-1c), fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), and stearoyl-CoA desaturase1 (SCD1) (P < 0.05, P < 0.01), while arachidonic acid-enriched oil increased blood lipid levels and up-regulated the expression of key lipid synthesis genes in the liver. Conclusion: Antarctic krill oil and fish oil can significantly alleviate lipid metabolism disorders in osteoporotic mice, with the former being more effective, while arachidonic acid-enriched oil has an opposite effect.

Key words: Antarctic krill oil; fish oil; osteoporosis; lipid metabolism