The degraded polysaccharide from Pyropia haitanensis represses amyloid beta peptide-induced neurotoxicity and memory in vivo.

An antioxidant polysaccharide, porphyran, from red algae Pyropia haitanensis, is introduced as a protective agent against neurotoxicity-induced amyloid β peptide (Aβ) of Alzheimer's disease (AD) mice. Then the activity of acetylcholinesterase (AChE) and choline acetyltransferase (CHAT) in the cortical and hippocampal tissue were examined by colorimetric method. Results showed that porphyran significantly ameliorated the learning and memory impairment induced by Aβ1-40. Biochemical analysis showed that porphyran increased ChAT activity and decreased AChE activity in the cortical and hippocampal tissue. The mechanism may be related with the increase of cerebral acetylcholine content. Porphyran has a potential of developing anti-aging drug.