Detection of astaxanthin at different regions of the brain in rats treated with astaxanthin nanoemulsion

Context: Astaxanthin (Ast), a compound used widely as a dietary supplement, has high antioxidant properties but poor oral bioavailability. To benefit from its nutritional values in cognitive function, Ast was formulated into a nanoemulsion which may improve its penetration through the blood-brain barrier (BBB). Aim: The present study aims to quantitate the Ast nanoemulsion in different regions of the brain tissue using the high-performance liquid chromatography method. Materials and Methods: Sprague-Dawley rats were fed with Ast nanoemulsion formulation daily (40, 80, and 160 mg/kg body weight, bw) for 28 days before brain tissues were harvested, extracted, and quantified. A simple, sensitive, and reliable method using high-performance liquid chromatography with an ultraviolent detector was developed and validated to quantify Ast in the brain. Statistical Analysis: Data were analyzed using the ToolPak Data Analysis in Excel for t-test and analysis of variance single factor with Tukey post hoc analysis. Results: The calibration curve demonstrated a linear regression with an r(2 )of 0.9998 and absolute recovery ranging from 97.8% to 109.6%. The hippocampus of the 160 mg/kg bw treatment group showed a significantly higher concentration of Ast (77.9 +/- 17.3 mu g/g) compared to the cortex (22.3 +/- 4.2 mu g/g) and cerebellum (33.1 +/- 5.4 mu g/g). Ast was detected in the cerebellum of the 80 mg/kg bw (29.4 +/- 7.8 mu g/g) treatment group with the amount not being significantly different to the 160 mg/kg bw (33.1 +/- 5.4 mu g/g) treatment group. Conclusions: It was evident that the Ast nanoemulsion formulated was able to cross the BBB and may provide protective benefits.