Antitumorigenic and cytotoxic properties of an ethanol extract derived from Rhus verniciflua Stokes (RVS)

In this study, the antioxidant, cytotoxic, and antitumorigenic activities o f a fractionated, ethanol extract derived from Rhus verniciflua Stokes (RVS ), a plant indigenous to Korea, China, and Japan, were determined. Physicoc hemical analysis and sodium dodecyl sulfate polyacrylamide gel electrophore sis (SDS-PAGE) results indicated that the active component of a Sephadex G- 150-fractionated RVS extract (PII fraction) was a copper-containing glycopr otein, possibly a plant laccase. Antioxidant activity of the fractionated R VS extract, observed in both aqueous and lipid in vitro oxidation reactions using 1, 1-diphenyl 2-picrylhydrazyl (DPPH) radical, site-specific Fenton- reaction deoxyribose, and a model lipid emulsion test system, indicated an affinity for protection against hydroxyl and peroxyl radicals. Cultured mou se brain neurons were protected against glucose oxidase-induced hydroxyl ra dical in the presence of the fractionated RVS extract (e.g., 58% protection at 4.9 muM and 95% protection with 22.7 muM RVS). RVS was further shown to protect against in vitro Fen ton-reaction-induced single- and double-stran d scission in supercoiled plasmid DNA. Further testing for bioactivity of t he fractionated RVS extract was based on the affinity to inhibit cell proli feration in cultured HeLa and CT-26 tumor cells. The presence of RVS result ed in 70% cell death after 24 h of incubation in both cell lines at a minim um concentration of 2.48;muM RVS. Data demonstrate multiple bioactive chemo preventative properties of a Sephadex G-150-fractionated extract derived fr om RVS.