Ellagic acid and derivatives from Cochlospermum angolensis Welw. extracts: HPLC-DAD-ESI/MSn profiling, quantification and in vitro anti-depressant, anti-cholinesterase and anti-oxidant activities.

摘要

Introduction - Cochlospermum angolensis Welw. bark is a medicinal plant consumed for the treatment of hepatic diseases and for the prophylaxis of malaria. Nevertheless, there are few studies concerning its chemical composition and biological potential. Objective - Since phenolic compounds are described as powerful anti-oxidants and neuroprotective agents, the purpose of this study was to characterise the phenolic profile of this species and to extend the knowledge on its medicinal properties, namely its potential against oxidative stress, Alzheimer's disease and depression. Methods - The phenolic composition of aqueous and hydromethanolic extracts was characterised by HPLC-DAD-ESI/MSn. Anti-radical potential was tested against 2,2-diphenyl-1-picrylhdrazyl, superoxide anion and nitric oxide radicals, and neuroprotective effect was assessed against acetylcholinesterase, butyrylcholinesterase and monoamine oxidase A. Results - Eight compounds were characterised for the first time. Hydromethanolic extract was richer in methyl ellagic acid and its derivatives, while aqueous extract had higher amounts of ellagic acid and its derivatives. Methyl ellagic acid pentoside isomer and ellagic acid were the major compounds in the two extracts, respectively. Both extracts and ellagic acid revealed radical scavenging capacity stronger than that of ascorbic acid, but a weak effect on cholinesterases was observed. Their anti-depressant activity was also very strong. Conclusion - The results provided evidence of the value of C. angolensis as a source of health-promoting anti-oxidants and anti-depressant compounds, with potential to be used as a raw product for food and pharmaceutical industries.