Neural cell protective compounds isolated from Phoenix hanceana var. formosana

• Published in: Phytochemistry (Oxford) Vol. 70; no. 9; pp. 1173 - 1181
• Main Authors: Lin, Yi-Pei, Chen, Tai-Yuan, Tseng, Hsiang-Wen, Lee, Mei-Hsien, Chen, Shui-Tein
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier 01.06.2009
• Subjects: Animals; Apigenin - chemistry; Apigenin - isolation & purification; Apigenin - pharmacology; apoptosis; Apoptosis - drug effects; Biological and medical sciences; catechin; Catechin - chemistry; Catechin - isolation & purification; Catechin - pharmacology; Chemical constitution; cultured cells; cytotoxicity; Fundamental and applied biological sciences. Psychology; Glucosides - chemistry; Glucosides - isolation & purification; Glucosides - pharmacology; isovitexin; luteolin; Luteolin - chemistry; Luteolin - isolation & purification; Luteolin - pharmacology; Magnoliopsida - chemistry; medicinal properties; Molecular Structure; neurons; Neuroprotective Agents - chemistry; Neuroprotective Agents - isolation & purification; Neuroprotective Agents - pharmacology; neuroprotective effect; Oxidopamine - pharmacology; PC12 Cells; Phoenix; Phoenix hanceana var. formosana; phytochemicals; Plant physiology and development; Plants, Medicinal - chemistry; Quercetin - analogs & derivatives; Quercetin - chemistry; Quercetin - isolation & purification; Quercetin - pharmacology; Rats; Stereoisomerism; Taiwan; Taiwan; Neuroprotection; Monocotyledones; Isovitexin; Luteolin-7-0-β-D-glucopyranoside; Neuroprotective activity; Flavonoid; Assay; Prevention; Polyphenol; Angiospermae; Phoenix; Cellular ROS scavenging assay; Luteolin; Catechin; Antiapoptosis; Phoenix hanceana var. formosana; Chemical structure; 6-Hydroxydopamine; Woody plant; In vitro; Radical scavenger; (+)-Catechin; Plant origin; Phenols; Isolation; Spermatophyta; Palmae
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/j.phytochem.2009.06.006

A platform for screening drugs for their ability to protect neuronal cells against cytotoxicity was developed. Nerve growth factor (NGF) differentiates PC12 cells into nerves, and these differentiated PC12 cells enter apoptosis when challenged with 6-hydroxydopamine (6-OHDA). A screening spectrophotometer was used to assay cytotoxicity in these cells; pretreatment with test samples allowed identification of compounds that protected against this neuronal cytotoxicity. The 95% ethanol extract of Phoenix hanceana Naudin var. formosana Beccari. (PH) showed potential neuroprotective activity in these assays. The PH ethanol extract was further fractionated by sequential partitioning with n-hexane, ethyl acetate (EtOAc), n-butanol (n-BuOH), and water. Subsequent rounds of assaying resulted in the isolation of ten constituents, and their structures were characterized by various spectroscopic techniques and identified by comparison with previous data as: isoorientin (1), isovitexin (2), veronicastroside (3), luteolin-7-O-β-d-glucopyranoside (4), isoquercitrin (5), tricin-7-neohesperidoside (6), tricin-7-O-β-d-gluco-pyranoside (7), (+)-catechin (8), (-)-epicatechin (9), and orientin 7-O-β-d-glucopyranoside (10). Among these compounds, isovitexin (2), luteolin-7-O-β-d-glucopyranoside (4) and (+)-catechin (8) showed significant neuroprotective activity in cell viability (WST-8 reduction), anti-apoptosis (Annexin V-FITC/propidium iodide double-labeled flow cytometry), and cellular ROS scavenging assays (besides isovitexin (2)), as well as a decreased caspase-8 activity in 6-OHDA-induced PC12 cells. Hence, isovitexin (2), luteolin-7-O-β-d-glucopyranoside (4), and (+)-catechin (8) protected PC12 cells from 6-OHDA-induced apoptotic neurotoxicity.