Shrimp Waste Extract and Astaxanthin: Rat Alveolar Macrophage, Oxidative Stress and Inflammation

:  Astaxanthin is a carotenoid known to have antioxidant and antiinflammatory properties. This study examined if shrimp astaxanthin modulates the production of superoxide (O−2), nitric oxide (NO), and tumor necrosis factor-α (TNF-α) in rat alveolar macrophages. The oxidative effect was induced by phorbol myristate acetate and lipopolysacharide. The treatment was compared with superoxide dismutase, butylated hydroxytoluene, commercial astaxanthin, N-nitric-L-arginine methyl ester and L- canavanine, all administered as a 43.5-μg/mL dose in the presence of 1% EtOH/0.5% DMSO. All treatments maintained cell viability, as observed in the MTT assay, and shrimp extract increased the viable alveolar macrophages to 168%. Shrimp extract and commercial astaxanthin showed a suppressive effect on the generation of both free radicals O−2 and NO, while purified shrimp astaxanthin was specific to NO. TNF-α secretion was correlated with NO production. However, in this correlation, the shrimp extract completely inhibited TNF-α. In the light of these findings, the antioxidant action demonstrated in this study suggests that the shrimp extract could be considered as a promising source of bioactive substances with antioxidant and anti-inflammatory activity. Practical Application:  The hydrolysis process of shrimp waste generates bioactive products that add economic value to shrimp processing, mainly because they may have applications in nutraceutical and animal feed industry.