Antimutagenic and antimicrobial activities of pu-erh tea

The biological action of water extract of pu-erh tea (WEPT) was evaluated by Salmonella mutagenesis assay and bacteria test. Like green tea, oolong tea and black tea, WEPT showed neither cytotoxicity and nor mutagenicity toward Salmonella typhimurium TA98 and TA100 with or without S9 mix (an external metabolic activation system). WEPT at 0.5-5 mg/plate expressed a dose-dependent inhibitory effect against both the mutagenicity of aflatoxin B₁ (AFB₁), an indirect mutagen which requires metabolic activation, and 4-nitroquinoline-N-oxide (NQNO), a direct mutagen, in Salmonella typhimurium TA98 and TA100. In general, the antimutagenic activity of WEPT against AFB₁ and NQNO was weaker than other tea extract because of the least amount of total catechin in WEPT. For antimicrobial action, WEPT, green tea, oolong tea and black tea at 2.0 mg/ml showed inhibitory effect on growth of Staphylococcus aureus and Bacillus subtilis, but no effect on Escherchia coli. Obviously, WEPT has potential antimicrobial effect on gram-positive Staphylcoccus aureus and B. subtilis than that of gram-negative E. coli. In addition, caffeine and epicatechin (EC), main polyphenolic compounds in WEPT, showed both antimutagenic and antimicrobial effect against strains mentioned above, which may partially account for the antimutagenic and antimicrobial action of pu-erh tea.     

Antioxidant and antiinflammatory activities of cyanidin-3-glucoside and cyanidin-3-rutinoside in hydrogen peroxide and lipopolysaccharide-treated RAW264.7 cells

Cyanidin-3-glucoside (C3G) and cyanidin-3-rutinoside (C3R) are 2 major anthocyanins found in Korean Rubus fruits (blackberries, raspberries, and black raspberries). The antioxidant and antiinflammatory effects of C3G and C3R in RAW264.7 murine macrophage cells were determined. Anthocyanins (5, 10, and 20 μg/mL) significantly (p<0.05) reduced H₂O₂-induced cytotoxicity in H₂O₂-stimulated RAW264.7 cells, compared with control cells. Incubation with C3G or C3R significantly (p<0.05) decreased intracellular reactive oxygen species and DNA damage (Hoechst and comet assay), and the cellular ferric reducing antioxidant power also increased, compared with control cells. Nitric oxide production in LPS-stimulated RAW264.7 cells treated with C3G and C3R was reduced by 41.9 and 34.4%, respectively. In addition, LPS-induced prostaglandin E₂ production was significantly (p<0.05) inhibited by C3G (51.7%) and C3R (58.6%), compared with LPS-stimulated control cells. Protein expressions of iNOS and COX-2 decreased in cells treated with anthocyanins. Anthocyanins down-regulated NF-κB expression and up-regulated I-κB expression in LPS-treated macrophages.     

Cytoprotective effects of pu-erh tea on hepatotoxicity in vitro and in vivo induced by tert-butyl-hydroperoxide

The in vitro and in vivo protective effects of water extract of pu-erh tea (WEPT) on tert-butyl-hydroperoxide (t-BHP)-induced oxidative damage in hepatocytes of HepG2 cells and in rat livers were investigated. After treatment with 200 μg/ml of samples, the survival rate of HepG2 cells induced by t-BHP increased. WEPT concentration-dependently inhibited reactive oxygen species (ROS) generation in HepG2 cells in response to the oxidative challenge induced by t-BHP. Administration of WEPT (0.2, 0.5 and 1.0 g/kg of body weigh) to rats for 56 consecutive days before a single dose of t-BHP (0.5 mmol/kg, i.p.) exhibited a significant (p < 0.01) protective effect by lowering serum levels of glutamate oxaloacetate transaminase (GOT) and glutamate pyruvate transaminase (GPT), as well as reducing the formation of malondialdehyde. Taken together, these results demonstrate that WEPT is able to protect against hepatic damage in vitro and in vivo, suggesting that the drinking of pu-erh tea may protect liver tissue from oxidative damage.     

Napiergrass (Pennisetum purpureum S.) protects oxidative damage of biomolecules and modulates antioxidant enzyme activity

The effects of water extract of napiergrass (Pennisetum purpureum S.) (WEN) on oxidative damage of biomolecules and modulation of antioxidant enzyme activity were investigated. The results showed that WEN displayed marked free radical scavenging, reducing power, as well as ferrous ions chelating effects. WEN has a dose-dependent response for protective action on oxidation of phospholipid, deoxyribose and low-density lipoprotein (LDL) in the range of 0–0.5 mg/ml, indicating that WEN had in vitro protective action on oxidative damage of biomolecules. Oxidative stress induced by H₂O₂ significantly decreased the viability of BNL cells. However, addition of WEN in the medium protected cells from H₂O₂-induced cytotoxicity. Furthermore, treatment of cells with WEN in the range of 0–0.2 mg/ml displayed protective effect from H₂O₂ induced oxidation in a concentration dependent manner. With respect to the effect of WEN on antioxidant enzymes, the results showed the WEN at 0.2 mg/ml enhanced activities of glutathione peroxidase (GPX), glutathione reductase (GR), glutathione transferase (GST) and catalase (CAT) in BNL cells by 2.93-, 35.8-, 4.23-, and 2.78-fold, respectively, compared to the control; WEN increased the GSH content by 3.2-fold, implying that WEN may up-regulate the levels of GSH and antioxidant enzymes in BNL cells. WEN scavenged NO generated by a NO donor, sodium nitroprusside (SNP) and suppressed NO production in lipopolysaccharide (LPS)-activated macrophage RAW 264.7 cells. The determination of ascorbic acid and total anthocyanins as well as HPLC analysis revealed that ascorbic acid, rutin, epicatechin, anthocyanins, p-coumaric acid, quercetin and catechin were present in WEN, which function as in vitro antioxidants by virtue of their ability to scavenge ROS and RNS. Overall, the results obtained showed that WEN is rich in antioxidant components and they can serve as an excellent potential for use as a natural phytochemicals source.     

Antioxidant activities of sea buckthorn leaf tea extracts compared with green tea extracts

The polyphenol, flavonoid, and ascorbic acid contents of sea buckthorn leaf tea extracts, along with antioxidant activities, were compared with green tea extracts under different extraction conditions. Sea buckthorn leaf tea and green tea were extracted using water (SW, GW) and ethanol at room temperature (SE, GE), respectively, and at 80°C (SWH, GWH, SEH, and GEH, respectively). GEH, GWH, SE, and SEH contained more antioxidant compounds and higher activities, and SWH, SEH, GWH, and GEH had elevated antioxidant enzyme activity levels in H₂O₂-treated RAW264.7 cells. Cells treated with SWH and SEH showed elevated expression of nuclear factor (erythroid-derived 2)-like 2 and maintained the cell glutathione (GSH)/glutathione disulfide (GSSG) ratio at levels similar to H₂O₂-untreated controls.     

Anti-inflammatory effect of flavonoids isolated from Korea Citrus aurantium L. on lipopolysaccharide-induced mouse macrophage RAW 264.7 cells by blocking of nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signalling pathways

Citrus fruits are an abundant source of various flavonoids, which have been used as a traditional herbal medicine in Korea and China. Most flavonoids are known to have anti-oxidant, anti-bacterial and analgesic properties. In this study, it was examined whether flavonoids (nobiletin, naringin and hesperidin) isolated from Korea Citrus aurantium L. inhibited the pro-inflammatory mediators including cytokines by blocking nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signalling in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. The flavonoids suppressed mRNA and protein expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in LPS-induced macrophages. The molecular mechanism was associated with inhibition of the degradation/phosphorylation of I-κB-α and nuclear translocation of the NF-κB p-65 as well as phosphorylation of MAPK by flavonoids. These results suggest that flavonoids have anti-inflammatory effects by suppressing expression of COX-2, iNOS and cytokines by blocking the NF-κB and MAPK signalling in RAW 264.7 macrophages.     

Evaluation of the anti-inflammatory effects of phloretin and phlorizin in lipopolysaccharide-stimulated mouse macrophages

Many reports suggest that phloretin and phlorizin have antioxidant properties and can inhibit glucose transportation, the anti-inflammatory effects and mechanism of phloretin and phlorizin remain unclear. This study aims to evaluate the anti-inflammatory effects of phloretin and phlorizin in LPS-stimulated murine RAW264.7 macrophages. RAW264.7 cells were pretreated with various concentrations of phloretin or phlorizin (3–100 μM) and cell inflammatory responses were induced with LPS. Pretreated with 10 μM phloretin significantly inhibited the levels of NO, PGE₂, IL-6, TNF-α, iNOS and COX-2. Furthermore, it was demonstrated that phloretin suppressed the nuclear translocation of NF-κB subunit p65 proteins, and decreased phosphorylation in MAPK pathways. Surprisingly, phlorizin did not suppress the inflammatory response in LPS-stimulated RAW264.7 cells. These results suggest that phloretin has an anti-inflammatory effect that reduces levels of proinflammatory cytokines and mediators in RAW264.7 cells.     

Isolation and synergism of in vitro anti-inflammatory and quinone reductase (QR) inducing agents from the fruits of Morinda citrifolia (noni)

The tropical fruits and fruit products of Morinda citrifolia, commonly known as noni, are consumed as a food or dietary supplement with purported health benefits. The objective of this study was to investigate the potential anti-inflammatory and cancer preventive effects of noni fruit puree extracts. Bioassay-guided fractionation of an ethyl acetate (EtOAc) extract of noni, comprising ~ 2% noni puree solids, led to the isolation of scopoletin (1), rutin (2), and quercetin (3). Quantitative HPLC analysis of the EtOAc extract revealed levels (dry weight basis) of scopoletin at 0.62 ??mol/g, quercetin at 0.26 ??mol/g and rutin at 0.045 ??mol/g. Scopoletin and quercetin inhibited the production of nitric oxide (NO) in a concentration-dependent manner in lipopolysaccharide (LPS)-induced RAW 264.7 macrophage cells and exhibited quinone reductase (QR) induction in cultured Hepa 1c1c7 cells. Increases in QR activity in induced cells were associated with increases in QR protein as confirmed by Western blots. Combinations of scopoletin and quercetin at a low (< 10 ??M) concentration resulted in synergistic suppression in nitric oxide (NO) production and down-regulated inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 expressions in LPS-induced RAW 264.7 macrophage cells. These results suggest that the combinations of noni compounds with different groups of chemical structures might be useful to efficiently suppress inflammatory and carcinogenic processes related to iNOS and COX-2 gene overexpression. These findings may provide some basis for the purported in vitro anti-inflammatory and anti-cancer effects of noni fruits as functional foods and dietary supplements.     

Toona sinensis and its major bioactive compound gallic acid inhibit LPS-induced inflammation in nuclear factor-κB transgenic mice as evaluated by in vivo bioluminescence imaging

In the present study, we investigated the anti-inflammatory effects of a nutritious vegetable Toona sinensis (leaf extracts, TS) and its major bioactive compound gallic acid (GA) by analysing LPS-induced NF-κB activation in transgenic mice, using bioluminescence imaging. Mice were challenged intraperitoneally with LPS (1 mg/kg) and treated orally with TS or GA (100 or 5 mg/kg, respectively). In vivo and ex vivo imaging showed that LPS increased NF-κB luminescence in the abdominal region, which was significantly inhibited by TS or GA. Immunohistochemical and ELISA analyses confirmed that TS and GA inhibited LPS-induced NF-κB, interleukin-1β, and tumour necrosis factor-α expression. Microarray analysis revealed that biological pathways associated with metabolism and the immune responses were affected by TS or GA. Particularly, LPS-induced thioredoxin-like 4B (TXNL4B) 2 expression in the small intestine, and TXNL4B, iNOS, and COX-2 expression in RAW 264.7 cells were significantly inhibited by TS or GA. Thus, the anti-inflammatory potential of TS was mediated by the downregulation of NF-κB pathway.     

Suppressive effect of carotenoid extract of Dunaliella salina alga on production of LPS-stimulated pro-inflammatory mediators in RAW264.7 cells via NF-κB and JNK inactivation

The carotenoid extract from Dunaliella salina was used to evaluate the suppressive effects on lipopolysaccharide (LPS)-induced pro-inflammatory mediators in RAW264.7 cells. The extract composed all-trans forms of α-carotene (28.8 mg/g extract), β-carotene (471.1 mg/g extract), lutein (7.1 mg/g extract) and zeaxanthin (7.2 mg/g extract), 13- or 13′-cis-β-carotene (12.1 mg/g extract), 9- or 9′-cis-α-carotene (19.1 mg/g extract) and 9- or 9′-cis-β-carotene (440.3 mg/g extract) dose-dependently reduced the production of interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α), the protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), and the secretion of nitric oxide (NO) and prostaglandin E₂ (PGE₂) in LPS-activated RAW264.7 cells. Its attenuation of LPS-induced inflammatory responses was closely related to inhibition of the nuclear NF-κB p50 subunit translocation by blocking inhibitor of κBα (IκB) phosphorylation and degradation correlated with suppressing IκB kinase (IKK) α/β phosphorylation, as well as down-regulation of the c-Jun NH₂-terminal kinase (JNK) activation.     

Statistics-based optimization of extracellular polysaccharide production from Hirsutella sinensis using a fermentation process and in vitro immunomodulatory activity

A 3 factor, 3 level Box-Behnken factorial design combined with response surface methodology was used to optimize the fermentation process for production of extracellular polysaccharide (EPS) from Hirsutella sinensis. The 3 independent variables were temperature (X₁), initial pH (X₂), and the glucose concentration (X₃). Experimental data were fitted to a 2^nd order polynomial equation using multiple regression. The optimal fermentation conditions of the production of EPS were a temperature of 18.21°C, an initial pH of 5.81, and a glucose concentration of 7.39 g/L. The maximum predicted EPS production of 2.41 g/L was close to the actual experimental EPS yield (2.42±0.038%), demonstrating the model validity. EPS from H. sinensis had a direct in vitro immuno-stimulating activity using murine macrophage RAW264.7 cells, and stimulated release of several major cytokines (IL-1β, NF-κB, TNF-α, and iNOS) in a dose-dependent manner.     

Anti-inflammatory activity of ethanolic extract of Sargassum sagamianum in RAW 264.7 cells

Aim of the study is to evaluate the antiinflammatory effects of ethanolic extract of the marine brown alga Sargassum sagamianum collected from Yeonhwari coast of Korea. Ethanolic extract of S. sagamianum (SA-E extract) inhibited expression of nitric oxide (NO) and cytokines (IL-6, IL-1β, and TNF-α) as well as inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 in lipopolysaccharide (LPS)-induced RAW 264.7 cells without affecting cell viability. In addition, the expression of nuclear factor (NF)-κB p65 was suppressed by SA-E extract. Furthermore, the rate of formation of edema in the mouse ear was reduced by 46% at the highest dose tested (250 mg/kg) compared to that in the control. This study suggests that SA-E extract exerts potent inhibitory effects on LPS-induced expression of inflammatory mediators such as NO, iNOS, COX-2, and cytokines in macrophages through suppression of the NF-κB p65 pathway. SA-E extract might have potential clinical applications as an anti-inflammatory agent.     

Antioxidant and anti-inflammatory properties of taiwanese yam (Dioscorea japonica Thunb. var. pseudojaponica (Hayata) Yamam.) and its reference compounds

Dioscorea japonica Thunb. var. pseudojaponica (DP) is consumed as food and widely used in traditional Chinese medicine in Taiwan. The aims of this study are to investigate the antioxidant and anti-inflammatory effects of ethanol extract of DP (EDP) and its reference compounds. Fingerprint chromatogram from HPLC indicated that EDP contains gallic acid and vanillic acid. EDP was evaluated for its antioxidant effects and LPS-induced nitrite oxide (NO) production in RAW264.7 cells. EDP decreased the LPS-induced NO production and expressions of iNOS and COX-2 in RAW264.7 cells. In-vivo anti-inflammatory activities of EDP were assessed in mouse paw oedema induced by λ-carrageenan (Carr). We investigated the antioxidant mechanism of EDP via studies of the activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) and the levels of malondialdehyde (MDA) in the oedematous paw. The results showed that EDP might be a natural antioxidant and anti-inflammatory agent.