Neuroprotective Effect of Corydalis ternata Extract and Its Phytochemical Quantitative Analysis.

The tubers of Corydalis ternata have been used to treat cardiovascular diseases such as hypertension and cardiac arrhythmia. Its active components have anticholinesterase, antiamnesic, and anti-inflammatory activities, and analgesic effects. In the present study, we performed quantitative analyses of the two components of C. ternata, coptisine and berberine, using HPLC. A 70% ethanol extract of C. ternata was prepared and the two components were separated using a C-18 analytical column on a gradient solvent system of acetonitrile and 0.1% (v/v) aqueous trifluoroacetic acid. Recordings were performed at a UV wavelength of 265 nm for two standard components. The established analytical method showed high linearity (correlation coefficient (r)=1.0000) and proper precision (0.49-3.88%), accuracy (97.88-102.7%), and recovery (95.12-103.79%) for two standard components. The amount of the coptisine and berberine was 4.968±0.089 mg/g and 3.73±0.075 mg/g, respectively. In addition, we investigated the effects of coptisine and berberine on acetylcholinesterase activity and amyloid-β aggregation, which are major biomarkers of dementia. Coptisine and berberine decreased acetylcholinesterase activity in a dose-dependent manner (IC50=0.74 and 0.48 µM, respectively). The C. ternata extract exerted an antioxidant activity by stimulating the radical scavenging activity of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), but not 2,2-diphenyl-1-picrylhydrazyl (DPPH). Furthermore, the C. ternata extract reversed the hydrogen peroxide-induced death of HT22 hippocampal cells, indicating its neuroprotective effect. Our results suggest the potential of C. ternata as a therapeutic agent against dementia via the inhibition of acetylcholinesterase activity and neuronal cell death.