Evaluation of the Antifungal Effect of Rhus verniciflua Stokes Extract for Oral Application Potential

Background and Objectives: This study confirms the possibility of using Rhus verniciflua Stokes (RVS) extract as a natural treatment for oral candidiasis. Materials and Methods: RVS was extracted with 70% ethanol to examine the antioxidant activity through polyphenol, flavonoid content, and DPPH (1,1-diphenyl-2-picrylhydrazyl). To evaluate the antifungal effect against Candida albicans (C. albicans; KCTC 7965/ATCC 10231) and evaluate the stability of RVS, a water-soluble tetrazolium salt (WST-1) assay was performed in human keratinocytes (HaCaT). Results: The findings revealed that RVS extract has fairly high antioxidant activity. The clear zones of the RVS extract against C. albicans increased in diameter due to the inhibition of fungal growth at higher concentrations. Treatment with the 1.25 mg/mL RVS extract had a more than 99% antifungal effect against C. albicans, and the 20 mg/mL RVS extract had a 100% antifungal effect. The WST-1 assay showed that the RVS extract induced low cell viability in the HaCaT cells, which inhibited their proliferation, and the RVS extract is also toxic to normal cells. Conclusions: Although the RVS extract with high antioxidant activity showed clear antifungal activity against C. albicans, it exhibited a low survival rate. Therefore, the development of a safe natural antibiotic is necessary.

Isolation and Identification of Fisetin: An Antioxidative Compound Obtained from Rhus verniciflua Seeds

The goal of this study was to provide basic data for the development of functional food and health materials for Rhus verniciflua (R. verniciflua) seeds. We investigated an antioxidative compound obtained from these seeds. Solvent fractionation was carried out on a 50%-ethanol extract of the seeds. The DPPH and ABTS radical-scavenging activity and superoxide dismutase (SOD) activity were measured, and high antioxidant activity was seen in the ethyl acetate fraction. The antioxidant compounds in the ethyl acetate fraction were isolated using silica-gel column chromatography by adjusting the solvent between chloroform and methanol. Fraction numbers 2–7 showed activity of more than 50%. Next, primary column chromatography was used to mix and concentrate the fractions that demonstrated antioxidant activity. The fractions were then subjected to secondary column chromatography to obtain subfraction 4, which showed high antioxidant activity. The separation of subfraction 4 was then performed using high-performance liquid chromatography (HPLC). Three peaks were identified and peak number 2 was judged to be the primary antioxidative compound, which was then isolated by pure separation. Finally, the purified subfraction peak number 2 was identified as a fisetin compound by liquid chromatography–mass spectrometry (LC–MS), nuclear magnetic resonance (NMR), and HPLC.

Effect of fermented Rhus verniciflua stokes extract on liver function parameters in healthy Korean adults: a double-blind randomized controlled trial

BACKGROUND

Fermented Rhus verniciflua Stokes extract (FRVE) reported an anti-hepatic lipidemic property mediated by the upregulation of AMP-activated protein kinase (AMPK) in cell and animal models. However, it remains unclear whether there is an effect of FRVE on liver disease-related parameters and serum lipid levels in humans. We investigated the effects of FRVE intake for 12 weeks on liver disease-related parameters and serum lipid profiles in Korean adults.

METHODS

A randomized, double-blind, placebo-controlled study was conducted among 79 subjects. An aqueous extract of fermented Rhus verniciflua Stokes that was filtered and fermented was prepared. For 12 weeks, the test group (n = 39) consumed two capsules of FRVE (main components: fustin 129 mg and fisetin 59 mg) once daily. The control group (n = 40) consumed two placebo pills (main component: lactose 627.0 mg) once daily. A 1:1 randomization of control and test was performed using computer-generated randomization. Both before and after FRVE intake, anthropometric parameters, liver function-related parameters, and clinical laboratory parameters were measured. The effects between the test and control groups were compared using the Mann-Whitney U test and independent t-test, and the difference between baseline and follow-up values was compared using Wilcoxon rank-sum test and paired t-test.

RESULTS

There was no significant difference when comparing the change values of liver disease-related parameters and serum lipid profiles in between groups.

CONCLUSIONS

In our study, we did not confirm the significance in liver function parameters and serum lipid profiles.

TRIAL REGISTRATION

The study protocol was registered in the Clinical Research Information Service (CRIS: https://cris.nih.go.kr/cris/index.jsp ) under number KCT0005687. Registered on 2 December 2020.

Fermented-Rhus verniciflua extract ameliorate Helicobacter pylori eradication rate and gastritis

An antibacterial effect of fermented-Rhus verniciflua extract (FRVE), an urushiol-free extract fermented by Fomitella fraxinea, on Helicobacter pylori was evaluated in mice. Minimal inhibitory concentration of FRVE against H. pylori eradication was checked with serial dilution method in vitro. H. pylori infection-induced mice were utilized to determine the effect of oral administration of FRVE with/without standard triple therapy (STT: metronidazole, omeprazole, and clarithromycin) on H. pylori colonization and gastric inflammation. H. pylori was clearly eradicated by FRVE at a concentration of ≥2 mg/ml in vitro. In animal study, FRVE at a concentration of ≥6 mg/ml significantly reduced colonized H. pylori grading (0.2 vs. 2.2, p < .01) and improved gastric inflammation (0.4 vs. 1.6, p < .01) compared to control. STT with FRVE (3 mg/ml) exerted synergistic effect on both H. pylori colonization grade (STT, 0.6 ± 0.9; FRVE, 1.4 ± 0.5; STT + FRVE, 0.8 ± 0.4) and gastric inflammation (STT, 0.4 ± 0.5; FRVE, 1.4 ± 0.5; STT + FRVE,1.0 ± 0.1) compared with single therapy (p < .01). H. pylori eradication rate of FRVE (6 mg/ml) was higher than that of STT (60% vs. 20%). FRVE has potential antibacterial activity against H. pylori infection and can be used as an additional therapy on STT.

Toxicodendron vernicifluum Stokes extract inhibits solid tumor growth and lung metastasis of 4T1 murine mammary carcinoma cells in BALB/c mice

Toxicodendron vernicifluum Stokes has long been used as a food supplement and traditional herbal medicine in East Asia. We applied a new extraction method to produce Toxicodendron vernicifluum Stokes extract (TVSE), that doesn't contain urushiol (an allergenic toxin) but dose have higher levels of some flavonoids such as fustin and fisetin. This study was conducted to investigate the anticancer effects of TVSE in an in vivo system. Fifty BALB/c mice were acclimated for one week and then injected with 4T1 murine mammary carcinoma cells in mammary fat pads. After 7 days, the mice were randomly divided into 5 groups, and orally administered with 0, 50, 100, 200 or 400 mg of TVSE/kg body weight (BW)/day for 20 days. TVSE reduced tumor volume and weight dose-dependently. The expression of Ki67 was significantly reduced and the number of TUNEL-positive apoptotic cells was significantly increased in the TVSE-treated group over 100 mg/kg BW/day. While tumor nodules were not found in the liver, but only in lungs, the number of tumor nodules was reduced in a dose-dependent manner in the TVSE treated groups compared to the control group. In breast tumors, expression of platelet endothelial cell adhesion molecule (PECAM-1) and vascular endothelial growth factor (VEGF) was reduced by TVSE treatment. TVSE treatment significantly suppressed mRNA expression in tumors of matrix metalloproteinase (MMP)-2, tissue inhibitor of metalloproteinase (TIMP)-1, urokinase-type plasminogen activator (uPA), intercellular adhesion molecule (ICAM)-1, and vascular cell adhesion molecule (VCAM)-1 while increasing plasminogen activator inhibitor (PAI)-1. These results suggest that TVSE is potentially beneficial for the suppression of breast cancer growth and its-associated lung metastasis.

Fermented Rhus Verniciflua Stokes Extract Alleviates Nonalcoholic Fatty Liver through the AMPK/SREBP1/PCSK9 Pathway in HFD-Induced Nonalcoholic Fatty Liver Animal Model

Background: We have previously reported the anti-hepatic lipogenic effect of fermented Rhus verniciflua stokes extract (FRVE) in an oleic-acid-treated HepG2 cell model. Methods: Herein, we advanced our understanding and evaluated the impact of FRVE in HFD-fed C57BL/6 mice using an animal model of nonalcoholic fatty liver disease (NAFLD). Milk thistle extract was used as a positive control to compare the effects of FRVE. Results: FRVE decreased body weight, intra-abdominal fat weight, and liver weight. Furthermore, FRVE decreased HFD-induced elevated serum levels of ALT, AST, TC, and TG, and downregulated the increase in hepatic lipid accumulation and TG levels. FRVE reduced hepatic SREBP-1, PCSK-9, SREBP-2, and ApoB mRNA levels. IHC data showed that FRVE reduced the levels of nucleic SREBP-1, increased the levels of LDLR, and upregulated the expression of p-AMPK. Conclusion: Overall, these results demonstrate the anti-hepatic lipidemic effect of FRVE in an animal model. These findings are consistent with our previous study and strongly suggest that FRVE exerts anti-hepatic lipogenic effects by activating AMPK.

Rhus verniciflua Stokes extract suppresses migration and invasion in human gastric adenocarcinoma AGS cells

BACKGROUND/OBJECTIVES

Many studies have suggested that Rhus verniciflua Stokes (RVS) and its extract are anticancer agents. However, RVS had limited use because it contains urushiol, an allergenic toxin. By improving an existing allergen-removal extraction method, we developed a new allergen-free Rhus verniciflua Stokes extract (RVSE) with higher flavonoid content. In this study, we examined whether RVSE inhibits the ability of AGS gastric cancer cells to migrate and invade.

MATERIALS/METHODS

The flavonoids content of RVSE was analyzed by HPLC. The effects of RVSE on migration and invasion in AGS cells were analyzed by each assay kit. Matrix metalloproteinase (MMP)-9, plasminogen activator inhibitor-1 (PAI-1) and urokinase-type plasminogen activator (uPA) protein expression was analyzed by protein antibody array. The Phosphorylation of signal transducer and activator of transcription (STAT) 3 were assayed by Western blot analysis.

RESULTS

RVSE treatment with 0-100 μg/mL dose-dependently reduced the ability of AGS cells to migrate and invade. Notably, treatment with RVSE strongly inhibited the expression of MMP-9 and uPA and the phosphorylation of STAT3. In contrast, RVSE treatment dramatically increased the expression of PAI-1. These results indicate that the inhibition of MMP-9 and uPA expression and STAT3 phosphorylation and the stimulation of PAI-1 expression contributed to the decreased migration and invasion of AGS cells treated with RVSE.

CONCLUSIONS

These results suggest that RVSE may be used as a natural herbal agent to reduce gastric cancer metastasis.

Comparison of the main components and bioactivity of Rhus verniciflua Stokes extracts by different detoxification processing methods

BACKGROUND

Rhus verniciflua Stokes is an Asian tree species that is used as a food supplement and traditional medicine in Korea. However, its use is restricted by its potential to cause allergy. Thus, allergen-free R. verniciflua extracts are currently being marketed as a functional health food in Korea. In the present study, three different allergen-free R. verniciflua extracts (DRVE, FRVE, and FFRVE) were produced by detoxification of R. verniciflua, and their properties and constituents were compared.

METHODS

The main components and properties (antibacterial, antioxidant, anticancer, and hepatic lipogenesis inhibitory effects) of the three allergen-free extracts were compared. Moreover, the major phenolic constituents of R. verniciflua, including gallic acid, fustin, fisetin, and quercetin, were analyzed in the three extracts.

RESULTS

DRVE was superior to the two other extracts with regard to antioxidant activity, while FRVE was superior with regard to antimicrobial activity and suppression of hepatic lipogenesis. FRVE exhibited lipid-lowering effects by lowering sterol regulatory element-binding protein 1 and triglyceride levels, and promoting the activation of peroxisome proliferator-activated receptor and AMP-activated protein kinase in an in vitro model of non-alcoholic fatty liver.

CONCLUSIONS

Overall, our findings demonstrate various differences among the three extracts. This suggests that functional and bioactive compounds present in R. verniciflua could be altered by the detoxification process, and this property could be considered in the development of functional health foods in the future.

Optimization of the extraction process for fermented Rhus verniciflua stokes using response surface methodology

Extraction conditions for extraction yield (Y 1 ), total phenolic content (TPC, Y 2 ), and inhibition rate in human gastric carcinoma cells (Y 3 ) were optimized using response surface methodology for fermented Rhus verniciflua stokes (FRV). Optimal extraction conditions for effective use of FRV as a biofunctional material in food and pharmaceutical industries were investigated. Independent variables were extraction temperature (X 1 =25-105°C), extraction time (X 2 =4-20 h), and the solvent to solid ratio (X 3 =10-30 mL/g). A second order polynomial model satisfactorily fitted experimental data with coefficient of determination (R 2 ) values of 0.9613, 0.9851, and 0.8038, respectively, for Y 1 , Y 2 , and Y 3 . Optimal conditions for the highest extraction yield of 2.37%, a total phenol content (TPC) value of 113.75 mg of tannic acid equivalents (TAE)/g, and an inhibition rate of 72.61% were derived at X 1 =89.95°C, X 2 =9.25 h, and X 3 =25 mL/g.

Single and 90-day repeated oral dose toxicity studies of fermented Rhus verniciflua stem bark extract in Sprague-Dawley rats

Fermented Rhus verniciflua stem bark (FRVSB) extract, an urushiol-free extract of Rhus verniciflua Stokes (RVS) fermented with Fomitella fraxinea, has various biological activities. The present study was carried out to investigate the potential toxicity of the FRVSB extract following single and repeated oral administration to Sprague-Dawley rats. In the single dose toxicity study, the FRVSB extract was administered orally to male and female rats at single doses of 0, 2500, 5000, and 10,000mg/kg. No animals died and no toxic changes were observed in clinical signs, body weight, and necropsy findings during the 15-day period following administration. In the repeated dose toxicity study, the FRVSB extract was administered orally to male and female rats for 90days at doses of 0, 556, 1667, and 5000mg/kg/day. There were no treatment-related adverse effects in clinical signs, body weight, food and water consumption, ophthalmic examination, urinalysis, hematology, serum biochemistry, necropsy findings, organ weight, and histopathology at any dose tested. The approximate lethal dose of the FRVSB extract was >10,000mg/kg in both genders, the oral no-observed-adverse-effect level of the FRVSB extract was >5000mg/kg/day in both genders, and no target organs were identified.