Djulis (Chenopodium formosanum) and Its Bioactive Compounds Protect Human Lung Epithelial A549 Cells from Oxidative Injury Induced by Particulate Matter via Nrf2 Signaling Pathway.

The protective effects of water extracts of djulis (Chenopodium formosanum) (WECF) and their bioactive compounds on particulate matter (PM)-induced oxidative injury in A549 cells via the nuclear factor-erythroid 2-related factor 2 (Nrf2) signaling were investigated. WECF at 50-300 µg/mL protected A549 cells from PM-induced cytotoxicity. The cytoprotection of WECF was associated with decreases in reactive oxygen species (ROS) generation, thiobarbituric acid reactive substances (TBARS) formation, and increases in superoxide dismutase (SOD) activity and glutathione (GSH) contents. WECF increased Nrf2 and heme oxygenase-1 (HO-1) expression in A549 cells exposed to PM. SP600125 (a JNK inhibitor) and U0126 (an ERK inhibitor) attenuated the WECF-induced Nrf2 and HO-1 expression. According to the HPLC-MS/MS analysis, rutin (2219.7 µg/g) and quercetin derivatives (2648.2 µg/g) were the most abundant bioactive compounds present in WECF. Rutin and quercetin ameliorated PM-induced oxidative stress in the cells. Collectively, the bioactive compounds present in WECF can protect A549 cells from PM-induced oxidative injury by upregulating Nrf2 and HO-1 via activation of the ERK and JUN signaling pathways.

The Inhibitory Effects of Djulis (Chenopodium formosanum) and Its Bioactive Compounds on Adipogenesis in 3T3-L1 Adipocytes.

The aim of this study was to provide new insights into the role of the ethanolic extracts of Djulis (Chenopodium formosanum, EECF) and its bioactive compounds in preventing adipogenesis in 3T3-L1 adipocytes. The results demonstrated EECF significantly inhibited oil red O-stained material (OROSM), triglyceride levels and glycerol-3-phosphate dehydrogenase (GPDH) activity in 3T3-L1 adipocytes. The expression of the critical molecules involved in lipid synthesis such as PPARγ, C/EBPα and SREBP-1c was attenuated in EECF-treated cells. According to HPLC-DAD and HPLC-MS/MS analysis, rutin, kaempferol, betanin and another nine compounds were present in EECF. The suppression of lipid accumulation by rutin, kaempferol and betanin occurred by decreasing the gene expression of PPARγ, C/EBPα and SREBP-1c. Taken together, these findings suggest the presence of bioactive compounds in EECF may partly account for the anti-adipogenesis of EECF and EECF is therefore a potentially lipid lowering functional food.

Cytoprotective effect of white tea against H2O2-induced oxidative stress in vitro.

The protective effect of water extracts of white tea (WEWT) on oxidative stress in vitro is investigated. WEWT, like water extracts of green tea (WEGT) and water extracts of Pu-erh tea (WEPT), demonstrates a marked inhibition of the oxidation of liposome, albumin and LDLmodel systems. WEWT protects against H2O2-induced cytotoxicity, in a dose-dependent manner. The inhibition of ROS generation and MDA formation by WEWT in H2O2-induced Clone 9 cells parallels the effects on cell viability. Moreover, GSH and antioxidant enzymes may play an important role in the protective effect that is associated with H2O2-induced oxidative stress. The HPLC-DAD and HPLC-MS/MS analysis, shows that sixteen bioactive compounds are present in WEWT, which may partially account for its protective effect against oxidative insult. These results suggest that the mechanism of the protective actions of WEWT is related to its antioxidant potential and the maintenance of the normal redox status of the cell.

Protective effects of sweet orange (Citrus sinensis) peel and their bioactive compounds on oxidative stress.

Protective effects of sweet orange (Citrus sinensis) peel and their bioactive compounds on oxidative stress were investigated. According to HPLC-DAD and HPLC-MS/MS analysis, hesperidin (HD), hesperetin (HT), nobiletin (NT), and tangeretin (TT) were present in water extracts of sweet orange peel (WESP). The cytotoxic effect in 0.2mM t-BHP-induced HepG2 cells was inhibited by WESP and their bioactive compounds. The protective effect of WESP and their bioactive compounds in 0.2mM t-BHP-induced HepG2 cells may be associated with positive regulation of GSH levels and antioxidant enzymes, decrease in ROS formation and TBARS generation, increase in the mitochondria membrane potential and Bcl-2/Bax ratio, as well as decrease in caspase-3 activation. Overall, WESP displayed a significant cytoprotective effect against oxidative stress, which may be most likely because of the phenolics-related bioactive compounds in WESP, leading to maintenance of the normal redox status of cells.

Cytotoxic effect of Eucalyptus citriodora resin on human hepatoma HepG2 cells.

The aim of this study was to evaluate the antiproliferative effect of Eucalyptus citriodora resin (ECR) on human hepatoma HepG2 cells. The results from MTT assay and LDH leakage analysis showed that water extracts of ECR (WEECR) in the dose range of 0-500 µg/ml displayed stronger cytotoxic effects on HepG2 cells than other organic solvent extracts of ECR. By flow cytometry analysis, WEECR slowed down the cell cycle at the G0/G1 phase after 24 h of incubation. Moreover, WEECR treatment induced an apoptotic response in HepG2 cells. WEECR-induced apoptosis was in association with the attenuation of mitochondrial transmembrane potentials (ΔΨ(m)), increased Bax/Bcl-2 ratio and activation of caspase-3. In addition, WEECR contained high concentration of phenolics and flavonoids, which may be responsible for the potent cytotoxicity of WEECR on HepG2 cells. Taken together, WEECR may be a potent antihepatoma agent due to apoptosis in HepG2 cells.

Hepatoprotection of emodin and Polygonum multiflorum against CCl(4)-induced liver injury.

CONTEXT: Polygonum multiflorum is known as a medicinal plant. It has been used as a folk medicine which showed antioxidative property. OBJECTIVE: Protective effects of the water extracts (w/v:1/10) from fresh P. multiflorum (WEP) on carbon tetrachloride (CCl(4))-induced liver damage in rats were investigated. MATERIALS AND METHODS: CCl(4) was used for inducing liver damage of SD rats, and WEP and emodin were fed for eight consecutive weeks. RESULTS: We found that emodin levels in fresh WEP was higher than that in ripening WEP. Rats were administered WEP and emodin, the main active compound, for 56 consecutive days. WEP significantly lowered the serum levels of hepatic enzyme markers, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) and reduced the generation of malonaldehyde. Treatment with WEP recovered glutathione S-transferase and catalase activity in rats as compared to treatment with CCl(4) alone. In addition, serum tumor necrosis factor-α, an inflammatory marker, was found to decrease in rats treated with WEP. In histopathological evaluation, fatty degeneration and necrosis were found to be significantly decreased in the CCl(4) plus WEP treatment group. DISCUSSION AND CONCLUSION: WEP may be effective in attenuating liver damage by reducing lipid peroxidation as well as by positively modulating inflammation.

Hepatoprotection of Graptopetalum paraguayense E. Walther on CCl4-induced liver damage and inflammation.

AIM OF THIS STUDY: Graptopetalum paraguayense E. Walther, a vegetable consumed in Taiwan, has been used in folk medicine for protection against liver injury, although its actual efficacy remains uncertain. Therefore, we investigated the protective effects of Graptopetalum paraguayense E. Walther against carbon tetrachloride (CCl(4))-induced liver damage in rats. MATERIALS AND METHODS: Water extracts of Graptopetalum paraguayense E. Walther (WGP) were administered for 8 consecutive weeks to male Sprague-Dawley rats. And a dose-dependent manner in preventing liver damage was confirmed. Moreover, the major ingredient of WGP, gallic acid, was also orally administrated in the CCl(4)-induced rats. The hepatoprotective activity was assessed using various biochemical parameters such as antioxidant enzymes and histopathological studies. RESULTS: WGP ranging from 50 to 300 mg/kg bw administrations significantly lowered serum aspartate transaminase (AST) and alanine transaminase (ALT) levels, and inhibited malondialdehyde (MDA) generation in CCl(4)-treated rats. WGP increased cellular GSH level and antioxidant enzymes, including superoxide dismutase, glutathione reductase, and catalase. Serum tumor necrosis factor-alpha (TNF-α) was decreased in the group treated with CCl(4) plus WGP (150 and 300 mg/kg bw). Histopathological examination of livers showed that WGP reduced fatty degeneration, cytoplasmic vacuolization and necrosis in CCl(4)-treated rats. In contrary, 10mg/kg bw of gallic acid was administrated, this dose was related with WGP (300 mg/kg bw), and had significantly decreased the AST and ALT compared to the CCl(4)-treated group. Aforesaid results suggested that gallic acid from WGP offered antioxidative activity against CCl(4)-induced oxidative liver damage. CONCLUSIONS: Taken together, this study is the first time to suggest that Graptopetalum paraguayense E. Walther exerts hepatoprotection via promoting antioxidative and anti-inflammatory properties against CCl(4)-induced oxidative liver damage.

Inhibition of the epstein-barr virus lytic cycle by andrographolide.

Andrographis paniculata NEES is a medicinal plant that is commonly used in Asia. This work demonstrates that 25 microg/ml of ethanolic extract from A. paniculata (EEAP) and 5 microg/ml of andrographolide, a bioactive compound in EEAP, effectively inhibit the expression of Epstein-Barr virus (EBV) lytic proteins, Rta, Zta and EA-D, during the viral lytic cycle in P3HR1 cells. Transient transfection analysis revealed that the lack of expression of Rta, Zta and EA-D is caused by the inhibition of the transcription of BRLF1 and BZLF1, two EBV immediate-early genes that encode Rta and Zta, respectively. This study finds that the inhibition prevents the virus from producing mature viral particles. Meanwhile, andrographolide is not toxic to P3HR1 cells when the concentration is below 5 microg/ml, indicating that the compound is potentially useful as an anti-EBV drug.

Comparison of protective effects between cultured Cordyceps militaris and natural Cordyceps sinensis against oxidative damage.

The Chinese herb DongChong-XiaCao originating from Cordyceps sinensis is widely used as a traditional medicine in China for treatment of a wide variety of diseases. The extracts of Cordyceps sinensis (CSE) and Cordyceps militaris (CME) are well-known for their biological effects. In the present study, the antioxidant efficiency of CME and CSE in protecting lipid, protein, and low-density lipoprotein (LDL) against oxidative damage was investigated. CME and CSE showed weakly inhibitory effect on liposome oxidation, that of CME being superior to that of CSE. As for the protein oxidation model system, the inhibitory effect of CME on protein oxidation was inferior to that of CSE. CME and CSE at 1.0 mg/mL showed 50.5 and 67.1% inhibition of LDL oxidation, respectively. The contents of bioactive ingredients cordycepin and adenosine in CME are higher than those of CSE; however, both cordycepin and adenosine showed no significant antioxidant activity as determined by the Trolox equivalent antioxidant capacity method. Polyphenolic and flavonoid contents are 60.2 and 0.598 microg/mL in CME and 31.8 and 0.616 microg/mL in CSE, respectively, which may in part be responsible for their antioxidant activities. In addition, a polysaccharide present in CME and CSE displayed antioxidant activity, which suggested that the activity might be derived partly from polysaccharides of CME and CSE. The tendency to scavenge the ABTS(*)(+) free radical and the reducing ability of CME and CSE display concentration-dependent manners, suggesting that CME and CSE may be potent hydrogen donators. On the basis of the results obtained, the protective effects of CME and CSE against oxidative damage of biomolecules are a result of their free radical scavenging abilities.

Antioxidant properties of roasted coffee residues.

The antioxidant activity of roasted coffee residues was evaluated. Extraction with four solvents (water, methanol, ethanol, and n-hexane) showed that water extracts of roasted coffee residues (WERCR) produced higher yields and gave better protection for lipid peroxidation. WERCR showed a remarkable protective effect on oxidative damage of protein. In addition, WERCR showed scavenging of free radicals as well as the reducing ability and to bind ferrous ions, indicating that WERCR acts as both primary and secondary antioxidants. The HPLC analyses showed that phenolic acids (chlorogenic acid and caffeic acid) and nonphenolic compounds [caffeine, trigonelline, nicotinic acid, and 5-(hydroxymethyl)furfuraldehyde] remained in roasted coffee residues. These compounds showed a protective effect on a liposome model system. The concentrations of flavonoids and polyphenolic compounds in roasted coffee residues were 8,400 and 20,400 ppm, respectively. In addition, the Maillard reaction products (MRPs) remaining in roasted coffee residues were believed to show antioxidant activity. These data indicate that roasted coffee residues have excellent potential for use as a natural antioxidant source because the antioxidant compounds remained in roasted coffee residues.

Effects of pu-erh tea on oxidative damage and nitric oxide scavenging.

The effects of pu-erh tea, which is prepared by fermentation of tea, on oxidative damage and nitric oxide scavenging, compared with various other brands of tea were investigated. The total antioxidant activity was determined using the Trolox equivalent antioxidant capacity (TEAC) assay. The results showed that TEAC values of the 200 microg/mL water extracts of pu-erh tea (WEPT), green tea, oolong tea, and black tea were 86.3, 85.3, 87.4, and 80.3 (microg/mL), respectively, indicating that WEPT showed a significant antioxidant activity. WEPT, like green tea extract, oolong tea extract, and black tea extract, exhibited a remarkable protective effect in lipid (liposome) and nonlipid (protein and deoxyribose) model systems, implying that it is an inhibitor of lipid and nonlipid oxidative damage. It also exhibited metal-binding ability, reducing power, and scavenging effect for free radicals. Moreover, WEPT showed a decreasing effect on nitric oxide production of lipopolysaccharide-induced RAW 264.7 macrophages. In addition, the results revealed that epicatechin (EC), flavonoid, ascorbic acid, and polyphenolic compounds are present in WEPT, which may partially account for the protective effect on oxidative damage. Thus, WEPT may have potential as an antioxidant and as a nitric oxide scavenging agent.

Identification of an antioxidant, ethyl protocatechuate, in peanut seed testa.

The antioxidant activity and identification of the antioxidant component of peanut seed testa were investigated. The antioxidant activity of peanut seed testa was studied in the linoleic acid model system by using the ferric thiocyanate method. Among the five organic solvent extracts, the ethanolic extracts of peanut seed testa (EEPST) produced higher yields and stronger antioxidant activity than other organic solvent extracts. EEPST was separated into 17 fractions on silica gel column chromatography. Fraction 17, which showed the largest yield and significant antioxidant activity, was separated by thin-layer chromatography. Four major antioxidative subfractions were present. Subfraction 17-2 was found to be effective in preventing oxidation of linoleic acid. This subfraction was further fractionated and isolated and characterized by UV, MS, IR, and (1)H NMR techniques. The active compound was identified as ethyl protocatechuate (3,4-dihydroxybenzoic acid ethyl ester).