Anti-Inflammatory and Antioxidant Properties of beta-Sitosterol in Copper Sulfate-Induced Inflammation in Zebrafish (Danio rerio)

beta-Sitosterol, which is used extensively in pharmaceuticals, nutraceuticals, and cosmetics, has high nutritional value along with immunomodulatory and anti-inflammatory properties. In this study, we investigated the antioxidant and anti-inflammatory effects of beta-sitosterol in zebrafish and explored the associated molecular mechanisms. In an in vivo antioxidant experiment, zebrafish (Danio rerio) larvae were treated with different concentrations of beta-sitosterol and then exposed to a nonlethal concentration of CuSO4 to induce oxidative stress. Treatment with beta-sitosterol at 70 or 100 mu g/mL significantly reduced CuSO4-induced oxidative stress in the zebrafish, demonstrating the strong antioxidant activity of beta-sitosterol. Treatment with beta-sitosterol protected zebrafish larvae against oxidative damage from CuSO4 by upregulating the expressions of sod and gpx4b. In a zebrafish model of inflammation, pretreatment with beta-sitosterol before CuSO4 exposure inhibited neutrophil recruitment and damage to lateral line neuromasts, indicating a potent anti-inflammatory effect derived from reductions in the expressions of il-8 and myd88. The results demonstrate the antioxidative and anti-inflammatory activities of beta-sitosterol and suggest that beta-sitosterol may be useful for the treatment of various inflammatory diseases.