A neuroprotective polysaccharide from Hyriopsis cumingii.

A water-soluble polysaccharide from Hyriopsis cumingii (HCp) was isolated by hot-water extraction and ethanol precipitation. We investigated the preliminary neuroprotective activity of HCp on cerebral ischemia/reperfusion (I/R)-induced rat brain tissue injury using the middle cerebral artery occlusion (MCAO) model. The structural analysis showed that the major component of HCp (HP-I) is an α-(1→4)-d-glucan branched with a single α-d-glucose at C-6 every five residues on average and has a weight-average molecular weight of about 2.65 × 10(5). Pharmacological studies revealed that HCp improves and restores nerve function impairment, significantly increases brain tissue total superoxide dismutase activity, lowers malondialdehyde content effectively, and reduces brain levels of caspase-3 mRNA expression in a dose-effect manner, indicating that H. cumingii polysaccharide possesses significant neuroprotective effects.