Antioxidative and Anti-Inflammatory Neuroprotective Effects of Astaxanthin and Canthaxanthin in Nerve Growth Factor Differentiated PC12 Cells

Nerve growth factor differentiated PC12 cells were used to examine the antioxidative and antiinflammatory effects of astaxanthin (AX) and canthaxanthin (CX). PC12 cells were pretreated with AX or CX at 10 or 20 mu M, and followed by exposure of hydrogen peroxide (H2O2) or 1-methyl-4-phenylpyridinium ion (MPP+) to induce cell injury. H2O2 or MPP+ treatment significantly decreased cell viability, increased lactate dehydrogenase (LDH) release, enhanced DNA fragmentation, and lowered mitochondrial membrane potential (MMP) (P < 0.05). The pretreatments from AX or CX concentration-dependently alleviated H2O2 or MPP+-induced cell death, LDH release, DNA fragmentation, and MMP reduction (P < 0.05). Either H2O2 or MPP+ treatment significantly increased malonyldialdehyde (MDA) and reactive oxygen species (ROS) formations, decreased glutathione content, and lowered glutathione peroxidase (GPX) and catalase activities (P < 0.05). The pretreatments from AX or CX significantly retained GPX and catalase activities, and decreased MDA and ROS formations (P < 0.05). H2O2 or MPP+ treatment significantly decreased Na+-K+-ATPase activity, elevated caspase-3 activity and levels of interleukin (IL)-1, IL-6, and tumor necrosis factor (TNF)-alpha (P < 0.05); and the pretreatments from these agents significantly restored Na+-K+-ATPase activity, suppressed caspase-3 activity and release of IL-1, IL-6, and TNF-alpha (P < 0.05). Based on the observed antioxidative and anti-inflammatory