Indrayani Phadtare - March 30, 2020
Extraction of shrimp oil enriched in astaxanthin from shrimp waste, and its potential role in obesity
Shrimp waste is a valuable source of shrimp oil (SO), rich in highly unsaturated fatty acids (HUFA) of the omega (n)-3 class and astaxanthin (ASTX), a highly potent antioxidant that exist in either free form or esterified form (ASTX-E). Fish oil enriched in n-3 HUFA, and free astaxanthin, have previously been shown to improve insulin resistance, and to decrease fat accumulation. We are investigating the effects of SO rich in n-3 HUFA and astaxanthin on insulin resistance and fat accumulation using 3T3-L1 preadipocytes. Extraction of SO from wet shrimp waste was performed by the Soxhlet method using hexane and acetone (2:3) as solvents. Total lipids, fatty acids composition, and astaxanthin content of the shrimp extracts were measured. SO was found to be rich in phospholipids, n-3 HUFA and ASTX-E. 3T3-L1 preadipocytes were differentiated to mature adipocytes in the presence or absence of SO, shrimp extract, fish oil, fish oil plus ASTX-E or ASTX-E, for 8 days. Fully differentiated mature adipocytes were either stained with Oil-Red-O to measure fat accumulation, or total RNA was extracted to measure the mRNA expression of genes involved in adipogenesis. Preliminary findings showed a trend towards decreasing the mRNA expression of adipogenic genes in SO, shrimp extract and ASTX-E treated cells, compared to control cells. On the other hand, fish oil -alone or in combination with ASTX-E showed an increase in the mRNA expression of adipogenic genes, compared to control cells. Future studies will measure insulin sensitivity/ glucose uptake in 3T3-L1 cells treated with SO, fish oil and astaxanthin. Our findings will establish whether shrimp oil rich in astaxanthin, and a combination of fish oil with astaxanthin improve insulin sensitivity and/or decrease fat accumulation.