Potential anti-adipogenic properties of shrimp oil extracted from shrimp waste using 3T3-L1 preadipocytes

Newfoundland & Labrador (NL) generates tons of shrimp waste every year, which is a valuable source of shrimp oil (SO) rich in omega (n)-3 polyunsaturated fatty acids (PUFA), and astaxanthin (ASTX), a highly potent antioxidant that exist in either free or esterified form (ASTX-E). N-3 PUFA from fish oil (FO), and free astaxanthin, have been shown to inhibit adipogenesis. Since SO contains both n-3 PUFA and ASTX, we hypothesized that SO will inhibit adipogenesis to a greater extent, compared to FO or ASTX. SO was extracted from shrimp waste using Soxhlet method (hexane:acetone 2:3); ASTX, lipids and fatty acids composition was measured. SO was rich in phospholipids, n-3 PUFA and ASTX-E. To investigate the effects on adipogenesis, 3T3-L1 preadipocytes were differentiated to mature adipocytes in the presence or absence of SO or FO emulsions (0.25 mg/ml culture medium) for 8 days. This concentration of SO contained 15.9 ng ASTX-E; thus, cells were also treated with same concentration of ASTX-E and FO+ASTX-E. Mature adipocytes were stained with Oil-Red-O, and the mRNA expression of genes involved in adipogenesis and lipogenesis was measured. SO and ASTX-E decreased fat accumulation, which was consistent with lower mRNA expression of adipogenic and lipogenic genes, compared to control cells. However, FO and FO+ASTX-E increased fat accumulation, along with increasing the mRNA expression of adipogenic and lipogenic genes, and glucose transporter type (GLUT)-4, compared to control cells. These findings suggest that SO and FO regulate adipogenesis via independent pathways, and that SO may have the potential to reduce fat accumulation.