Protective effects of a Chotosan Fraction and its active components on β-amyloid-induced neurotoxicity

Chotosan (CTS) is a traditional Kampo prescription used to treat chronic headache and hypertension. Recent clinical studies demonstrated that CTS has ameliorative effects on dementia. This study aims to identify the anti-Alzheimer components in cm. beta-amyloid (A beta) is considered to play a central role in the pathophysiology of Alzheimer's disease. CTS-E, a fraction of CTS, showed significant protective effects on A beta-induced neurotoxicity. High-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry was used for the qualitative analysis of it. Among the identified constituents, neuroprotective effects against A beta(25-35)-induced neurotoxicity of 10 major compounds were tested by MTT assay. Their inhibitory action on A beta(1-42) self-induced aggregation was measured by Thioflavin T-binding assay. The results showed that caffeic acid, chlorogenic acid, 1,5-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid and 4,5-dicaffeoylquinic acid had significant neuroprotective effects on A beta(25-35)-induced neurotoxicity. Besides these phenolic acids, nobiletin and hesperidin could also inhibit A beta(1-42) self-induced aggregation. In conclusion, the neuroprotective fraction, CTS-E, could protect PC12 cells from A beta-induced neurotoxicity. Anti-oxidative effects may at least partly mediate the neuroprotective effects of it. Phenolic acids from Chrysanthemi Flos and flavonoids from Citri Reticulatae Pericarpium might be the effective constituents in CTS-E. (C) 2016 Elsevier Ireland Ltd. All rights reserved.