Apoptosis - In this study, we prepared a flavonoid-containing fraction from a crude acetone extract of Rhus verniciflua Stokes (RVS), traditionally used as a food additive and as an herbal medicine, and named RVS chloroform–methanol fraction (RCMF).

This study demonstrated that RCMF exhibited a selective growth inhibition and apoptosis induction on transformed cells.

Our findings suggest that RCMF is an agent which may be capable of inducing growth inhibition and apoptosis of hepatic tumor cells.

(Article)

In this study, we characterized the antioxidant activity of the RVS ethanol extract and identified the active compounds responsible for this activity.

These results suggest that the flavonoid derivatives in F₂ are the compounds in the RVS ethanol extract that act as antioxidants.

(Article)

Combined treatment of an ethanol extract of RVS and LY294002 (a PI3K inhibitor) markedly increased apoptosis compared to treatment with an ethanol extract of RVS alone.

The role of PI3K-Akt/PKB in this process was confirmed by constitutive expression of inactive mutants of this kinase in AGS cells.

These results suggest that an ethanol extract of RVS induces apoptosis via a mitochondrial death pathway in human gastric cancer cells, but not in normal cells, and inhibition of the PI3K-Akt/PKB pathway enhanced the mitochondrial death pathway.

(Article)

Anti-Cancer - Butein (3,4,2',4'-tetrahydroxychalone), a plant polyphenol, is a major biologically active component of the stems of Rhus verniciflua Stokes.

Recently, butein has been shown to suppress the functions of fibroblasts. Because fibroblasts are believed to play an important role in promoting the growth of breast cancer cells, we investigated the ability of butein to inhibit the clonogenic growth of small numbers of breast cancer cells co-cultured with fibroblasts in vitro.

These results suggest that interference with the interaction between fibroblasts and breast cancer cells by the natural herbal compound, butein, should be further investigated as a novel experimental approach for possibly suppressing the growth of micrometastases of breast cancer.

(Article)

The cytotoxic effects of different solvent fractions from an RVS ethanol extract were measured in 11 human cancer cell lines.

The study showed that the ethyl-acetate (EtOAC) fraction was the most cytotoxic.

A purified phenolic-rich EtOAC fraction (PPEF) had a stronger apoptotic effect on these cells.

The results showed that PPEF induces apoptosis only in gastric and breast cancer cell lines, but not in lung, colon or liver cancer cell lines. Therefore, PPEF may have a significant potential as an organ-specific anti-cancer agent.

(Article)

Anti-Inflammatory - This study was designed to isolate the bioactive constituents from the ethanol extract of Toxicodendron vernicifluum bark and evaluate their cytotoxic and anti-inflammatory activities.

Polyphenols including flavonoids were one of the main constituents of Toxicodendron vernicifluum bark, and activities demonstrated by the isolated compounds support the ethnopharmacological use of Toxicodendron vernicifluum as anti-cancer and/or anti-inflammatory agents.

(Article)

In the present study, we isolated sulfuretin from R. verniciflua and demonstrated that sulfuretin inhibited inducible nitric oxide synthase (iNOS) protein and mRNA expression, reduced iNOS-derived NO, suppressed COX-2 protein and mRNA expression, and reduced COX-derived PGE₂ production in lipopolysaccharide (LPS)-stimulated RAW264.7 and murine peritoneal macrophages.

Furthermore sulfuretin induced heme oxygenase (HO)-1 expression through nuclear translocation of nuclear factor E2-related factor 2 (Nrf)2 and increased heme oxygenase (HO) activity in RAW264.7 macrophages.

This indicated that the anti-inflammatory effects of sulfuretin in macrophages might be exerted through a novel mechanism that involves HO-1 expression.

(Article)

The neuroprotective and anti-inflammatory activities of the methanolic extract of Rhus verniciflua Stokes (Anacardiaceae) were investigated with mouse hippocampal and microglial cells.

These results suggest that these flavonoids possess therapeutic potentials as a multipotent agent against neurodegenerative diseases related to oxidative stress and pathological inflammatory responses.

(Article)

Anti-Microbial - We isolated four compounds, fustin, gallic acid, 3′,4′,7-trihydroxyflavone, and fisetin from Rhus verniciflua. These compounds showed electron donation ability (87–94%) that was stronger than butylated hydroxyanisole (52%).

For Gram-negative bacteria, fisetin had the most potent anti-bacterial activity (MIC = 8 μg/ml) against Escherichia coli. 3′,4′,7-Trihydroxyflavone (106%), the 80% ethanolic extract (101%), and ethyl-acetate (98%) had the most powerful α-glucosidase inhibitory effect at 50 μg/ml.

(Article)