Hot-Melt Extrusion Drug Delivery System-Formulated Haematococcus pluvialis Extracts Regulate Inflammation and Oxidative Stress in Lipopolysaccharide-Stimulated Macrophages.

Haematococcus pluvialis contains valuable bioactive compounds, including astaxanthin, proteins, and fatty acids. Astaxanthin is known for its various health benefits, such as preserving the redox balance and reducing inflammation. However, its low stability and poor water solubility present challenges for various applications. Hot-melt extrusion (HME) technology enhances the aqueous solubility of H. pluvialis extracts, increasing the usable astaxanthin content through nanoencapsulation (HME-DDS-applied extracts, ASX-60F and ASX-100F). This study compared the effects of HME-DDS-derived extracts (ASX-60F and ASX-100F) and the non-applied extract (ASX-C) under inflammatory and oxidative stress conditions. In animal models of sepsis, 60F and 100F treatment exhibited higher survival rates and a lower expression of pro-inflammatory biomarkers compared to those treated with C. In lipopolysaccharide-stimulated RAW 264.7 macrophages, nitric oxide (NO) production and the expression of pro-inflammatory mediators such as cyclooxygenase-2 and inducible NO synthase were reduced by 60F or 100F treatments via ERK/p-38 mitogen-activated protein kinase (MAPK) signaling. Moreover, 60F or 100F inhibited reactive oxygen species production regulated by nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling. Collectively, these findings suggest that HME-DDS-derived H. pluvialis extracts exert anti-inflammatory and antioxidant effects by inhibiting MAPK phosphorylation and activating Nrf2/HO-1 expression.