Expression of antioxidant proteins in human intestinal Caco-2 cells treated with dietary flavonoids

Glycine max (soy) based diet improves antioxidant defenses and prevents cell death in cadmium intoxicated lungs

Cadmium (Cd) is a toxic metal and an important environmental contaminant. We analyzed its effects on oligoelements, oxidative stress, cell death, Hsp expression and the histoarchitecture of rat lung under different diets, using animal models of subchronic cadmium intoxication. We found that Cd lung content augmented in intoxicated groups: Zn, Mn and Se levels showed modifications among the different diets, while Cu showed no differences. Lipoperoxidation was higher in both intoxicated groups. Expression of Nrf-2 and SOD-2 increased only in SoCd. GPx levels showed a trend to increase in Cd groups. CAT activity was higher in intoxicated groups, and it was higher in Soy groups vs. Casein. LDH activity in BAL increased in CasCd and decreased in both soy-fed groups. BAX/Bcl-2 semiquantitative ratio showed similar results than LDH activity, confirmed by Caspase 3 immunofluorescence. The histological analysis revealed an infiltration process in CasCd lungs, with increased connective tissue, fused alveoli and capillary fragility. Histoarchitectural changes were less severe in soy groups. Hsp27 expression increased in both intoxicated groups, while Hsp70 only augmented in SoCd. This show that a soy-diet has a positive impact upon oxidative unbalance, cell death and morphological changes induced by Cd and it could be a good alternative strategy against Cd exposure.

Evaluating the Effects of MKAVCFSL Derived from Bighead Carp (Hypophthalmichthys nobilis) Flesh on Antioxidant Activity in Caco-2 Cells In Vitro

The effect of an antioxidative peptide Met-Lys-Ala-Val-Cys-Phe-Ser-Leu (MKAVCFSL) on oxidative stress in Caco-2 cell lines was investigated. Caco-2 cells exposed to excess oxidative stress could be restored when pretreated with the peptide. Reactive oxygen species (ROS) and malondialdehyde (MDA) within the cells could be scavenged by MKAVCFSL. The peptide could also enhance the activity of glutathione peroxidase (GPx), glutathione reductase (GR), and superoxide dismutase (SOD), while catalase (CAT) activity did not show a significant difference between treatment and control samples. Meanwhile, it was observed that peptide treatment increased the concentration of glutathione (GSH). Yet the content of glutathione disulfide (GSSG) was hardly affected. The stability of MKAVCFSL was also assessed and an intact peptide was observed after simulated gastrointestinal digestion. Part of the peptide was hydrolyzed into fragments including MKA, FSL, AVCFSL, and MKAVCF. This study demonstrated that MKAVCFSL derived from bighead carp hydrolysates could ameliorate oxidative stress to protect the Caco-2 cells.

Dietary Modulation of Bacteriophages as an Additional Player in Inflammation and Cancer

Natural compounds such as essential oils and tea have been used successfully in naturopathy and folk medicine for hundreds of years. Current research is unveiling the molecular role of their antibacterial, anti-inflammatory, and anticancer properties. Nevertheless, the effect of these compounds on bacteriophages is still poorly understood. The application of bacteriophages against bacteria has gained a particular interest in recent years due to, e.g., the constant rise of antimicrobial resistance to antibiotics, or an increasing awareness of different types of microbiota and their potential contribution to gastrointestinal diseases, including inflammatory and malignant conditions. Thus, a better knowledge of how dietary products can affect bacteriophages and, in turn, the whole gut microbiome can help maintain healthy homeostasis, reducing the risk of developing diseases such as diverse types of gastroenteritis, inflammatory bowel disease, or even cancer. The present review summarizes the effect of dietary compounds on the physiology of bacteriophages. In a majority of works, the substance class of polyphenols showed a particular activity against bacteriophages, and the primary mechanism of action involved structural damage of the capsid, inhibiting bacteriophage activity and infectivity. Some further dietary compounds such as caffeine, salt or oregano have been shown to induce or suppress prophages, whereas others, such as the natural sweeter stevia, promoted species-specific phage responses. A better understanding of how dietary compounds could selectively, and specifically, modulate the activity of individual phages opens the possibility to reorganize the microbial network as an additional strategy to support in the combat, or in prevention, of gastrointestinal diseases, including inflammation and cancer.

Health Promotion Effects of Soy Isoflavones

Soybeans contain several physiologically active ingredients, such as soy phytosterol, soyasaponin, soy protein, and lecithin, and are therefore expected to express the functionalities of said ingredients. Among them, soy isoflavones have been studied in recent years for their various functions, including their obesity-preventing effect, blood glucose level reducing effect, osteoporosis and breast cancer risk reduction, and anti-oxidative effect, and several health promoting effects and disease preventing effects are expected. For example, it has been determined that soy isoflavones reduce body and fat weight in experiments in which mice were fed a diet containing soy isoflavones in studies on anti-obesity. Epidemiologic studies with humans have also shown that women who consume more soybeans have lower BMI than those who consume less. We previously found that soy isoflavones may have anti-obesity effects in myoblasts through the activation of transcriptional coactivator PGC-1β, which increases energy expenditure. In recent studies, a decrease in blood glucose level due to soy isoflavone was seen in an experiment in which diabetic model mice were fed a diet containing soy isoflavone. It has also been suggested that soy isoflavone intake may increase bone mineral density in postmenopausal women and reduce the risk of breast cancer. This review focuses on the actions of soy isoflavones known to date, including their anti-obesity and anti-diabetic effects, bone loss preventing effects, and cancer risk reduction effects, and introduces reports on the health promotion and disease prevention effects of soy isoflavones.

Role of soybean-derived bioactive compounds in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic, inflammatory condition of the gastrointestinal tract. Patients with IBD present with debilitating symptoms that alter the quality of life and can develop into severe complications requiring surgery. Epidemiological evidence indicates Westernized societies have an elevated IBD burden when compared with Asian societies. Considering the stark contrast between the typical Western and Eastern dietary patterns, it is postulated that differences in food and lifestyle contribute to lower IBD incidence in Asian countries. Soybeans (Glycine max), which are consumed in high quantities and as various preparations in Eastern societies, contain a wealth of natural, biologically active compounds that include isoflavones, bioactive peptides, protease inhibitors, and phytosterols, among many others. These compounds have been shown to improve human health, and preclinical evidence suggests they have potential to improve the prognosis of IBD. This review summarizes the current state of evidence regarding the effects and the mechanisms of action of these soybean-derived bioactive compounds in experimental models of IBD.

Comprehensive evaluation of the role of soy and isoflavone supplementation in humans and animals over the past two decades

Soy and soy-based foods are considered healthy, particularly in many Asia-Pacific countries, where soy products have long been consumed. Soy and soy-related products have been found to help prevent the occurrence of cardiovascular diseases and certain types of cancer, such as breast and prostate cancer. These products can also have antioxidative effects that alleviate hot flashes during menopause and bone loss. These biological and therapeutic functions are primarily due to the isoflavones derived from soy, whose structure is similar to the structure of 17-β-oestradiol. Despite the many health benefits for humans and animals, the application of isoflavones remains controversial because of their anti-oestrogenic properties. We focused on general information regarding isoflavones, as well as their structure, function, and application. We summarized evidence showing that dietary or supplemental isoflavones exert protective effects on the health of humans and animals. Based on the literature, we conclude that soy foods and isoflavones may be effective and safe; however, more high-quality trials are needed to fully substantiate their potential use.

Dietary soy isoflavone attenuated growth performance and intestinal barrier functions in weaned piglets challenged with lipopolysaccharide

This study was conducted to investigate the protective roles of soy isoflavone in weaned pigs challenged with lipopolysaccharide (LPS). A total of 72 weaned piglets (14 days of age) were randomly allotted into either 0 (control group) or 40 mg/kg soy isoflavone (ISO) supplementation group. On days 7 and 14, half of the pigs in each group were challenged with LPS. Soy isoflavone increased average daily gain (ADG) and average daily feed intake (ADFI) of piglets challenged with LPS at days 7-14 (P<0.05). The incidence of diarrhea and plasma concentrations of malondialdehyde (MDA) and endotoxin in piglets from LPS group were higher than those in control group (P<0.05). Soy isoflavone reduced the incidence of diarrhea and plasma concentrations of endotoxin in piglets challenged with LPS (P<0.05). LPS challenge decreased (P<0.05) mRNA abundances of β-defensin 2 (pBD-2), mucin (MUC-4), zona occludens 1 (ZO-1), and occludin in jejunal mucosa of piglets, and soy isoflavone upregulated (P<0.05) mRNA abundances of ZO-1 and occludin in jejunal mucosa of piglets challenged with LPS. The present results demonstrated that both p38 and TLR4 pathways in jejunal mucosa of piglets were activated by LPS challenge (P<0.05), and soy isoflavone reduced their activations (P<0.05). Collectively, our results suggested that supplementation of soy isoflavone could partly attenuate the barrier-damaged effects of LPS and improve the intestinal barrier function of weaned piglets, at least partially by inhibiting activations of p38 and TLR4 dependent pathways induced by LPS. This study provides a potential usage of soy isoflavone for alleviating intestinal barrier damages of neonates and piglets.

The Role of Soy Phytoestrogens on Genetic and Epigenetic Mechanisms of Prostate Cancer

Soy phytoestrogens are dietary components with considerable effects on reducing the incidence of prostate cancer. Epidemiological studies demonstrated that occurrence of prostate cancer is relatively low in Asia and Southern Europe, a status associated with consuming of soy isoflavones, such as genistein, daidzein, and glycitein. Soy phytoestrogens exert their activity on molecular mechanisms, including cell-cycle control, induction of apoptosis, inhibition of angiogenesis, and metastasis. In addition, they have antioxidant activity and show regulatory effect on the expression of genes involved in DNA damage and repair. Furthermore, the epigenetic regulation of gene expression can be modified by soy phytoestrogens. They show regulatory effects on gene activity by altering DNA methylation and/or histone modification patterns. In this chapter, we discuss the role of soy phytoestrogens on the genetic and epigenetic mechanisms of prostate cancer. We attempt to provide further insight in order to understand the underlying mechanisms of protective effects of soy phytoestrogens in preventing prostate cancer.

Centaurea cyanus L. Polysaccharides and Polyphenols Cooperation in Achieving Strong Rat Gastric Ulcer Protection

This work was aimed at testing gastroprotective effects of

Effects of methanolic extract form Fuzhuan brick-tea on hydrogen peroxide-induced oxidative stress in human intestinal epithelial adenocarcinoma Caco-2 cells

The present study investigated the protective effect of methanolic extract from Fuzhuan brick‑tea (FME) on hydrogen peroxide (H2O2)‑induced oxidative stress in the human intestinal epithelial adenocarcinoma cell line Caco‑2. Caco‑2 cells were pretreated with different concentrations (50, 100 and 200 µg/ml) of FME for 2 h and then exposed to H2O2 (1 mM) for 6 h. FME did not exhibit a significant cytotoxic effect and increased the cell viability following H2O2 treatment by decreasing lipid peroxidation in Caco‑2 cells. To investigate the protective effect of FME on H2O2‑induced oxidative stress in Caco‑2 cells, the levels of intracellular glutathione (GSH) and the activity of the endogenous antioxidant enzymes catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH‑px) and glutathione S‑transferase (GST), were determined. FME significantly increased the level of GSH and the activity of antioxidant enzymes. The results from the present study demonstrated that FME has a protective effect on H2O2‑induced oxidative damage in Caco‑2 cells through the inhibition of lipid peroxidation and the increase in the activity of antioxidant enzymes. In addition, FME reduced the H2O2‑induced expression of interleukin‑8 at both the mRNA and protein levels in Caco‑2 cells.

Targeting CSCs in tumor microenvironment: the potential role of ROS-associated miRNAs in tumor aggressiveness

Reactive oxygen species (ROS) have been widely considered as critical cellular signaling molecules involving in various biological processes such as cell growth, differentiation, proliferation, apoptosis, and angiogenesis. The homeostasis of ROS is critical to maintain normal biological processes. Increased production of ROS, namely oxidative stress, due to either endogenous or exogenous sources causes irreversible damage of bio-molecules such as DNA, proteins, lipids, and sugars, leading to genomic instability, genetic mutation, and altered gene expression, eventually contributing to tumorigenesis. A great amount of experimental studies in vitro and in vivo have produced solid evidence supporting that oxidative stress is strongly associated with increased tumor cell growth, treatment resistance, and metastasis, and all of which contribute to tumor aggressiveness. More recently, the data have indicated that altered production of ROS is also associated with cancer stem cells (CSCs), epithelial-to-mesenchymal transition (EMT), and hypoxia, the most common features or phenomena in tumorigenesis and tumor progression. However, the exact mechanism by which ROS is involved in the regulation of CSC and EMT characteristics as well as hypoxia- and, especially, HIF-mediated pathways is not well known. Emerging evidence suggests the role of miRNAs in tumorigenesis and progression of human tumors. Recently, the data have indicated that altered productions of ROS are associated with deregulated expression of miRNAs, suggesting their potential roles in the regulation of ROS production. Therefore, targeting ROS mediated through the deregulation of miRNAs by novel approaches or by naturally occurring anti-oxidant agents such as genistein could provide a new therapeutic approach for the prevention and/or treatment of human malignancies. In this article, we will discuss the potential role of miRNAs in the regulation of ROS production during tumorigenesis. Finally, we will discuss the role of genistein, as a potent anti-tumor agent in the regulation of ROS production during tumorigenesis and tumor development.

Antioxidant function of isoflavone and 3,3'-diindolylmethane: are they important for cancer prevention and therapy?

SIGNIFICANCE

Oxidative stress has been mechanistically linked with aging and chronic diseases, including cancer. In fact, oxidative stress status, chronic disease-related inflammation, and cancer occurred in the aging population are tightly correlated. It is well known that the activation of nuclear factor kappa B (NF-κB) plays important roles in oxidative stress, inflammation, and carcinogenesis. Therefore, targeting NF-κB is an important preventive or therapeutic strategy against oxidative stress, inflammation, and cancer.

RECENT ADVANCES

A variety of natural compounds has been found to reduce oxidative stress through their antioxidant activity. Among them, isoflavone, indole-3-carbinol (I3C), and its in vivo dimeric compound 3,3'-diindolylmethane (DIM) have shown their promising effects on the inhibition of NF-κB with corresponding reduction of oxidative stress.

CRITICAL ISSUES

It has been found that isoflavone, I3C, and DIM could inhibit cancer development and progression by regulating multiple cellular signaling pathways that are related to oxidative stress and significantly deregulated in cancer.

FUTURE DIRECTIONS

The antioxidative and anticancer effects of these natural agents make them strong candidates for chemoprevention and/or therapy against human malignancies. However, more clinical trials are needed to evaluate the effects of isoflavone and DIM for the prevention of cancer development and also for the treatment of cancer either alone or in combination with conventional cancer therapeutics.

Functions and action mechanisms of flavonoids genistein and icariin in regulating bone remodeling

Increasingly natural products particularly flavonoids are being explored for their therapeutic potentials in reducing bone loss and maintaining bone health. This study has reviewed previous studies on the two better known flavonoids, genistein and icariin, their structures, functions, action mechanisms, relative potency, and potential application in regulating bone remodeling and preventing bone loss. Genistein, an isoflavone abundant in soy, has dual functions on bone cells, able to inhibit bone resorption activity of osteoclasts and stimulate osteogenic differentiation and maturation of bone marrow stromal progenitor cells (BMSCs) and osteoblasts. Genistein is an estrogen receptor (ER)-selective binding phytoestrogen, with a greater affinity to ERβ. Genistein inhibits tyrosine kinases and inhibits DNA topoisomerases I and II, and may act as an antioxidant. Genistein enhances osteoblastic differentiation and maturation by activation of ER, p38MAPK-Runx2, and NO/cGMP pathways, and it inhibits osteoclast formation and bone resorption through inducing osteoclastogenic inhibitor osteoprotegerin (OPG) and blocking NF-κB signaling. Icariin, a prenylated flavonol glycoside isolated from Epimedium herb, stimulates osteogenic differentiation of BMSCs and inhibits bone resorption activity of osteoclasts. Icariin, whose metabolites include icariside I, icariside II, icaritin, and desmethylicaritin, has no estrogenic activity. However, icariin is more potent than genistein in promoting osteogenic differentiation and maturation of osteoblasts. The existence of a prenyl group on C-8 of icariin molecular structure has been suggested to be the reason why icariin is more potent than genistein in osteogenic activity. Thus, the prenylflavonoids may represent a class of flavonoids with a higher osteogenic activity.

Cadmium-induced oxidative stress and histological damage in the myocardium. Effects of a soy-based diet

Cd exposure has been associated to an augmented risk for cardiovascular disease. We investigated the effects of 15 and 100 ppm of Cd on redox status as well as histological changes in the rat heart and the putative protective effect of a soy-based diet. Male Wistar rats were separated into 6 groups and treated during 60 days as follows: groups (1), (2) and (3) were fed a casein-based diet; groups (4), (5) and (6), a soy-based diet; (1) and (4) were given tap water; (2) and (5) tap water containing 15 ppm of Cd²⁺; and (3) and (6) tap water containing 100 ppm of Cd²⁺. Serum lipid peroxides increased and PON-1 activity decreased in group (3). Lipoperoxidation also increased in the heart of all intoxicated groups; however protein oxidation only augmented in (3) and reduced glutathione levels diminished in (2) and (3). Catalase activity increased in groups (3) and (6) while superoxide dismutase activity increased only in (6). Glutathione peroxidase activity decreased in groups (3) and (6). Nrf2 expression was higher in groups (3) and (6), and MTI expression augmented in (3). Histological examination of the heart tissue showed the development of hypertrophic and fusion of cardiomyocytes along with foci of myocardial fiber necrosis. The transmission electron microscopy analysis showed profound ultra-structural damages. No protection against tissue degeneration was observed in animals fed the soy-based diet. Our findings indicate that even though the intake of a soy-based diet is capable of ameliorating Cd induced oxidative stress, it failed in preventing cardiac damage.

High hydrostatic pressure pre-treatment of whey proteins enhances whey protein hydrolysate inhibition of oxidative stress and IL-8 secretion in intestinal epithelial cells

BACKGROUND

High hyperbaric pressure treatment of whey protein isolate (WPI) causes changes in the protein structure that enhances the anti-oxidant and anti-inflammatory effects of WPI.

OBJECTIVE

The aim of this study was to compare the anti-oxidant and anti-inflammatory effects of pressurized whey protein isolate (pWPI) vs. native WPI (nWPI) hydrolysates in Caco-2 cells exposed to hydrogen peroxide (H(2)O(2)).

DESIGN

Cells were cultured with different concentrations of pWPI or nWPI hydrolysates either 1 h before or 1 h after H(2)O(2). Cell viability, IL-8 secretion, intracellular reactive oxygen species (ROS), and the medium anti-oxidant capacity (FRAP assay) were measured.

RESULTS

Prior to and after H(2)O(2) exposure, pWPI and nWPI hydrolysates inhibited IL-8 secretion and ROS generation, and increased FRAP activity in a dose-dependent manner. The maximal inhibition of H(2)O(2)-induced IL-8 secretion was greater with 2000 µg mL(-1) of pWPI (50%) vs. nWPI (30%) hydrolysates. At the latter concentration, inhibition of H(2)O(2)-induced ROS formation reached 76% for pWPI, which was greater than for nWPI hydrolysates (32.5%).

CONCLUSIONS

These results suggest that WPI hydrolysates can alleviate inflammation and oxidative stress in intestinal cells exposed to oxidative injury, which is further enhanced by hyperbaric pressure pre-treatment of WPI.

Antioxidant Activity of Methanol Extract of the Lotus Leaf (Nelumbo nucifera Gertn.)

In this study, hydrogen peroxide ( H 2 O 2)-mediated Caco-2 cytotoxicity was employed to investigate the potential antioxidant activity of the methanol extract from the lotus leaf (Nelumbo nucifera Gertn.). A dose-dependent protective effect against reactive oxygen species (ROS)-induced cytotoxicity was observed when Caco-2 cells were treated with 10 mM H 2 O 2 in combination with the methanol extract of the lotus leaf (0.1–0.3 mg/ml). However, no significant effect was found when co-treating Caco-2 cells with 10 mM H 2 O 2 and α-tocopherol. In vitro assay revealed that the extract exhibited scavenging activities on free radicals and hydroxyl radicals, and metal binding ability as well as reducing power, which may explain in part the mechanism behind the extract's ability to protect cells from oxidative damage. In addition, the extract also exhibited concentration-dependent antioxidant activities against hemoglobin-induced linoleic acid peroxidation and Fenton reaction-mediated plasmid DNA oxidation.

Soybean (Glycine max) oil bodies and their associated phytochemicals

Soybean oil bodies were isolated from 3 cultivars (Ustie, K98, and Elena) and the occurrence of 2 classes of phytochemicals (tocopherol isoforms and isoflavones) and strength of their association with isolated oil bodies was evaluated. Tocopherol is shown to be closely associated with soybean oil bodies; δ-tocopherol demonstrated a significantly greater association with oil bodies over other tocopherol isoforms. Isoflavones do not show a significant physical association with oil bodies, although there is some indication of a passive association of the more hydrophobic aglycones during oil body isolation.

PRACTICAL APPLICATION

Oil bodies are small droplets of oil that are stored as energy reserves in the seeds of oil seeds, and have the potential to be used as future food ingredients. If oil body suspensions are commercialized on a large scale, knowledge of the association of phytochemicals with oil bodies will be valuable in deciding species of preference and predicting shelf life and nutritional value.

Radish (Raphanus sativus L. leaf) ethanol extract inhibits protein and mRNA expression of ErbB(2) and ErbB(3) in MDA-MB-231 human breast cancer cells

In this study, we investigated the effects of the ethanol extract of aerial parts of Raphanus sativus L. (ERL) on breast cancer cell proliferation and gene expression associated with cell proliferation and apoptosis in MDA-MB-231 human breast cancer cells. The MDA-MB-231 cells were cultured in the presence or absence of various concentrations (100, 200, or 300 µg/mL) of ERL. ERL significantly decreased cell proliferation after 48 h of incubation (P < 0.05). The protein and mRNA expression of ErbB(2) were decreased significantly in a dose-dependent manner (P < 0.05). The protein expression of ErbB(3) was decreased significantly at an ERL concentration of 300 µg/mL (P < 0.05), and mRNA expression of ErbB(3) was decreased significantly in a dose-dependent manner (P < 0.05). The protein expression of Akt was decreased significantly at the ERL concentration of 200 µg/mL (P < 0.05), and the protein expression of pAkt was decreased significantly in a dose-dependent manner (P < 0.05). The mRNA expression of Akt was decreased significantly at the ERL concentration of 200 µg/mL ERL (P < 0.05). The protein and mRNA expression of Bax were increased significantly at ERL concentrations of 200 µg/mL or higher (P < 0.05). The protein expression of Bcl(2) was increased significantly at ERL concentrations of 100 µg/mL or higher (P < 0.05), and mRNA expression of Bcl(2) was increased significantly at an ERL concentration of 300 µg/mL (P < 0.05). In conclusion, we suggest that Raphanus sativus, L. inhibits cell proliferation via the ErbB-Akt pathway in MDA-MB-231 cells.

Antioxidant effects of the ethanol extract from flower of Camellia japonica via scavenging of reactive oxygen species and induction of antioxidant enzymes

The aim of this study was to investigate the antioxidant properties of the ethanol extract of the flower of Camellia japonica (Camellia extract). Camellia extract exhibited 1,1-diphenyl-2-picrylhydrazyl radical and intracellular reactive oxygen species (ROS) scavenging activity in human HaCaT keratinocytes. In addition, Camellia extract scavenged superoxide anion generated by xanthine/xanthine oxidase and hydroxyl radical generated by the Fenton reaction (FeSO₄ + H₂O₂) in a cell-free system, which was detected by electron spin resonance spectrometry. Furthermore, Camellia extract increased the protein expressions and activity of cellular antioxidant enzymes, such as superoxide dismutase, catalase and glutathione peroxidase. These results suggest that Camellia extract exhibits antioxidant properties by scavenging ROS and enhancing antioxidant enzymes. Camellia extract contained quercetin, quercetin-3-O-glucoside, quercitrin and kaempferol, which are antioxidant compounds.

Suppression of colonic aberrant crypt foci by soy isoflavones is dose-independent in dimethylhydrazine-treated rats

The potential of soy isoflavones (SIs) to reduce colon cancer has been investigated in animal models. These studies have found that outcomes are variable and depend on SI dose. The present study investigated dose-response effects of SIs on colon carcinogenesis in a chemically induced rat cancer model. Sprague-Dawley male rats were injected with 1,2-dimethylhydrazine (DMH) and were provided experimental diets that contained 0, 10, 50, 150, or 500 mg of SI aglycones/kg of diet for 12 weeks. Plasma concentrations of genistein, daidzein, and equol were determined using time-resolved fluoroimmunoassay. Plasma concentrations of these SIs tended to increase in a dose-dependent manner in DMH-treated rats. The numbers of aberrant crypt foci (ACF) and the expression of cyclooxygenase-2 (COX-2) proteins of colons were significantly decreased in the SI-fed groups compared with the control group; however, suppression was not dose-dependent. Furthermore, there were no significant correlations between plasma SI concentrations and ACF or COX-2 expression. Increased SI intake and increased plasma levels of SIs and metabolites were not associated with tissue levels of lipid peroxidation. We conclude that dietary supplementation of SIs suppresses DMH-induced ACF formation and COX-2 expression in a dose-independent manner.

Protective effect of polyphenols from Glycyrrhiza glabra against oxidative stress in Caco-2 cells

In the present article, we have investigated the antioxidant properties of methanolic liquorice polyphenol extracts (LPE(s)). Polyphenol extraction was performed with 60% and 100% methanol. Analysis of LPE(s) by thin-layer chromatography revealed that a higher amount of polyphenols was recovered by extraction with 60% methanol. Antioxidant activity measurement of the reducing power, scavenging effect on 2,2'-diphenyl-1-picrylhydrazyl free radical, and hydrogen peroxide scavenging capability have been taken as the parameters for assessment of antioxidant potential of LPE(s). Results have been compared with both natural and synthetic antioxidants. All experimental data have indicated that LPE(s) possess strong antioxidant power proportional to their o-diphenolic and total polyphenolic content, independently from the assay used. Therefore, the LPE(s) antioxidant property was examined against the cytotoxic effects of reactive oxygen species in human colon carcinoma cells. Pretreatment of Caco-2 cells with liquorice polyphenolic extracts provided a remarkable protection against oxidative damage induced by H(2)O(2). The highest oxidative stress protection (72% of cell vitality) was measured in cells pretreated with 0.54 mM polyphenols. This effect seems to be associated to the antioxidant activity of liquorice polyphenolic compounds. Our data suggest that polyphenols from Glycyrrhiza glabra could exert a beneficial action in the prevention of intestinal pathologies related to production of reactive oxygen species.

Drug interactions

Drugs for allergy are often taken in combination with other drugs, either to treat allergy or other conditions. In common with many pharmaceuticals, most such drugs are subject to metabolism by P450 enzymes and to transmembrane transport. This gives rise to considerable potential for drug-drug interactions, to which must be added consideration of drug-diet interactions. The potential for metabolism-based drug interactions is increasingly being taken into account during drug development, using a variety of in silico and in vitro approaches. Prediction of transporter-based interactions is not as advanced. The clinical importance of a drug interaction will depend upon a number of factors, and it is important to address concerns quantitatively, taking into account the therapeutic index of the compound.

Harnessing the fruits of nature for the development of multi-targeted cancer therapeutics

Cancer cells exhibit deregulation in multiple cellular signaling pathways. Therefore, treatments using specific agents that target only one pathway usually fail in cancer therapy. The combination treatments using chemotherapeutic agents with distinct molecular mechanisms are considered more promising for higher efficacy; however, using multiple agents contributes to added toxicity. Emerging evidence has shown that some "natural products" such as isoflavones, indole-3-carbinol (I3C) and its in vivo dimeric product 3,3'-diindolylmethane (DIM), and curcumin among many others, have growth inhibitory and apoptosis inducing effects on human and animal cancer cells mediated by targeting multiple cellular signaling pathways in vitro without causing unwanted toxicity in normal cells. Therefore, these non-toxic "natural products" from natural resources could be useful in combination with conventional chemotherapeutic agents for the treatment of human malignancies with lower toxicity and higher efficacy. In fact, recently increasing evidence from pre-clinical in vivo studies and clinical trials have shown some success in support of the use of rational design of multi-targeted therapies for the treatment of cancers using conventional chemotherapeutic agents in combination with "natural products". These studies have provided promising results and further opened-up newer avenues for cancer therapy. In this review article, we have succinctly summarized the known effects of "natural products" especially by focusing on isoflavones, indole-3-carbinol (I3C) and its in vivo dimeric product 3,3'-diindolylmethane (DIM), and curcumin, and provided a comprehensive view on the molecular mechanisms underlying the principle of cancer therapy using combination of "natural products" with conventional therapeutics.

Leaves of Cassia tora as a novel cancer therapeutic--an in vitro study

Cassia tora Linn (Leguminacea) is a medicinal plant traditionally used as laxative, for the treatment of leprosy and various skin disorders. Preliminary phytochemical analysis of leaf showed the presence of polyphenols (3.7 mg gallic acid equivalent per gram dried leaves). The presence of phenolic compound prompted us to evaluate its antioxidant and antiproliferative potential. In the present study C. tora methanolic leaf extract (CTME) was evaluated for its nitric oxide scavenging activity and reducing power assays using Rutin and BHT as standards. The extract was studied for its lipid peroxidation inhibition assay using rat liver and brain. In all assays, a correlation existed between concentration of extract and percentage inhibition of free radical, reducing power and inhibition of lipid peroxidation. The antiproliferative activity of CTME with Cisplatin, anticancer drug was studied using human cervical cancer cells (HeLa). Proliferation of HeLa was measured by MTT assay, cell DNA content by modified diphenylamine method and apoptosis by Caspase 3 activity. The plant extract induced a marked concentration dependent inhibition on proliferation, reduced DNA content and apoptosis in HeLa. These results clearly indicate that C. tora is effective against free radical mediated diseases.

In vivo, in vitro, and in silico studies of Cu/Zn-superoxide dismutase regulation by molecules in grape seed procyanidin extract

The potential beneficial effects of flavonoids on human health have aroused considerable interest and were initially attributed to their antioxidant activities. Recent studies have speculated that as well as their antioxidant role, flavonoids can act by modulating cell signaling pathways and/or gene expression. In this respect, we have used streptozotocin-induced diabetic rats as an oxidative stress model to study whether grape seed procyanidin extract (GSPE) regulates copper/zinc-superoxide dismutase (Cu/Zn-SOD), an enzyme that defends against oxidative stress. The results indicate that the expression profile of Cu/Zn-SOD in diabetic rats was similar to the profile in nondiabetic rats. Nevertheless, the administration of GSPE increased Cu/Zn-SOD activity in both diabetic and nondiabetic rats. Therefore, to evaluate whether this increase in activity was dose-dependent, we also studied the effect of GSPE on Cu/Zn-SOD expression by using an in vitro model (Fao cell line hepatocytes). The cells were exposed to GSPE doses between 0 and 150 mg/L for 24 h, and the results showed that enzyme activity was enhanced only with 15 mg/L of GSPE. Therefore, we decided to explore whether this increase in Cu/Zn-SOD activity was due to direct interaction between some of the molecules in GSPE and the enzyme (in vitro experiments) and, if so, to analyze how this interaction occurs (in silico experiments). The results of these studies showed that direct interaction between some small- or medium-sized GSPE components and the enzyme is responsible for the increase in Cu/Zn-SOD activity.

Phytoalexin-enriched functional foods

Functional foods have been a developing area of food science research for the past decade. Many foods are derived from plants that naturally contain compounds beneficial to human health and can often prevent certain diseases. Plants containing phytochemicals with potent anticancer and antioxidant activities have spurred development of many new functional foods. This has led to the creation of functional foods to target health problems such as obesity and inflammation. More recent research into the use of plant phytoalexins as nutritional components has opened up a new area of food science. Phytoalexins are produced by plants in response to stress, fungal attack, or elicitor treatment and are often antifungal or antibacterial compounds. Although phytoalexins have been investigated for their possible role in plant defense, until recently they have gone unexplored as nutritional components in human foods. These underutilized plant compounds may possess key beneficial properties including antioxidant activity, anti-inflammation activity, cholesterol-lowering ability, and even anticancer activity. For these reasons, phytoalexin-enriched foods would be classified as functional foods. These phytoalexin-enriched functional foods would benefit the consumer by providing "health-enhanced" food choices and would also benefit many underutilized crops that may produce phytoalexins that may not have been considered to be beneficial health-promoting foods.

Prevention of chemically induced mammary tumorigenesis by daidzein in pre-pubertal rats: the role of peroxidative damage and antioxidative enzymes

Isoflavones are biologically active plant derived compounds that have several health promoting effects. In the present study hitherto unknown effects of one of the well known isoflavonoids, daidzein, has been evaluated on its chemo-preventive action against breast cancers in pre-pubertal rats. Either daidzein (500 mug/g bwt) or vehicle, dimethyl sulphoxide (DMSO), was administered at 16th, 18th, and 20th day post-partum and the chemopreventive efficacy was evaluated in dimethylbenz[a]nthracene (DMBA) induced Sprague-Dawley rats, at 50th day. To elucidate the mechanism of action, the antioxidative status was also examined in the liver and mammary gland of prebubertal rats using two different doses of daidzein (0.5 mg/kg bwt and 50 mg/kg bwt, p.o.) for 10 days. The specific activity of antioxidant enzymes as well as reduced glutathione (GSH) level and peroxidative damage were evaluated spectrophotometrically, both in liver as well as in mammary gland. Animals treated with daidzein pre-pubertally, showed a significant reduction in the tumorigenesis of mammary gland up to 37.4% as compared to animals induced for tumors with DMBA. In animals treated with 50 mg/kg of daidzein, a significant increase in the specific activities of the antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione transferase (GST), DT-diaphorase (DTD), and in GSH content were observed in both liver and mammary gland. Expectedly, the specific activity of lactate dehydrogenase (LDH) and level of peroxidative damage was decreased, as compared to that of control group of animals. Our results suggest that, daidzein can be considered as a potent chemopreventive agent against mammary carcinogenesis in pre-pubertal animals, with modulation of antioxidant enzymes being one of its mechanisms of actions.

Isoflavone daidzein possesses no antioxidant activities in cell-free assays but induces the antioxidant enzyme catalase

Epidemiologic studies have shown that dietary intake of isoflavonones is associated with several properties beneficial to human health. It has been suggested that at least some of these effects are related to the antioxidant activity of isoflavonoids. We analyzed the antioxidant activity of the major isoflavones found in soybeans, but none of these compounds showed prominent antioxidant effects in cell-free assay systems (trolox equivalent antioxidant capacity assay and 2,2-diphenyl-1-picrylhydrazyl assay). Therefore, we examined the hypothesis that the antioxidative effects of isoflavones are caused indirectly by up-regulation of antioxidative enzymes, thereby lowering intracellular concentration of reactive oxygene species. Daidzein shows a significant induction of catalase promoter activity at 100 micromol/L in a reporter gene assay and at 200 micromol/L in Northern blot experiments. Another hypothesis for antioxidant effects caused by isoflavones is due to metabolism by intestinal bacteria. Analyzing the daidzein metabolites 3'-OH-daidzein and 6-OH-daidzein in our cell culture model, we found strong antioxidant effects (2,2-diphenyl-1-picrylhydrazyl and trolox equivalent antioxidant capacity assay). We conclude that isoflavone daidzein up-regulates the antioxidant enzyme catalase but shows only little antioxidant capacity per se. Antioxidant effects of this dietary isoflavonone may also be due to formation of the antioxidant metabolites 6-OH-daidzein and 3'-OH-daidzein.

Soy isoflavones in the management of postmenopausal osteoporosis

This is a review article designed to address the effects of soy isoflavones on bone metabolism in postmenopausal women and their place in the prevention and treatment of postmenopausal osteoporosis. Soy isoflavones are natural products that could be used as an alternative to menopausal hormone therapy because they are structurally and functionally related to 17beta-estradiol. In vitro and animal studies have shown that they act in multiple ways to exert their bone-supporting effects. They act on both osteoblasts and osteoclasts through genomic and nongenomic pathways. Epidemiological studies and clinical trials suggest that soy isoflavones have beneficial effects on bone mineral density, bone turnover markers, and bone mechanical strength in postmenopausal women. However, there are conflicting results related to differences in study design, estrogen status of the body, metabolism of isoflavones among individuals, and other dietary factors. The long-term safety of soy isoflavone supplements remains to be demonstrated.

Multi-targeted therapy of cancer by genistein

Soy isoflavones have been identified as dietary components having an important role in reducing the incidence of breast and prostate cancers in Asian countries. Genistein, the predominant isoflavone found in soy products, has been shown to inhibit the carcinogenesis in animal models. There is a growing body of experimental evidence showing that the inhibition of human cancer cell growth by genistein is mediated via the modulation of genes that are related to the control of cell cycle and apoptosis. It has been shown that genistein inhibits the activation of NF-kappaB and Akt signaling pathways, both of which are known to maintain a homeostatic balance between cell survival and apoptosis. Moreover, genistein antagonizes estrogen- and androgen-mediated signaling pathways in the processes of carcinogenesis. Furthermore, genistein has been found to have antioxidant properties, and shown to be a potent inhibitor of angiogenesis and metastasis. Taken together, both in vivo and in vitro studies have clearly shown that genistein, one of the major soy isoflavones is a promising agent for cancer chemoprevention and further suggest that it could be an adjunct to cancer therapy by virtue of its effects on reversing radioresistance and chemoresistance. In this review, we attempt to provide evidence for these preventive and therapeutic effects of genistein in a succinct manner highlighting comprehensive state-of-the-art knowledge regarding its multi-targeted biological and molecular effects in cancer cells.

Increased expression of catalase in human hepatoma cells by the soy isoflavone, daidzein

The reduced incidence of cancer that has been observed in Asian population traditionally consuming soy-based food has been linked to the antioxidant potential of soy isoflavones, in particular daidzein and genistein. The present study was undertaken in order to test the antioxidative potential of daidzein and to examine the effect of daidzein treatment on the expression of the antioxidant enzyme catalase in the human hepatoma cell lines Huh-7 and HepG2. Daidzein itself did not display radical scavenging activity but it significantly increased the activity of the antioxidant enzyme catalase. Huh-7 cells were much more susceptible to daidzein cytotoxicity than HepG2 cells and showed much lower basal activity in luciferase reporter gene assays with the 3.2 kb fragment of the human catalase promoter. However, treatment with daidzein at a non-toxic concentration resulted in a similar induction of promoter activity in both cell lines. Reporter gene studies with different promoter constructs in HepG2 cells restrict the potential localization of the main regulatory elements for basal and inducible activity of the catalase promoter to a region approximately 120 bp to 300 bp upstream of the start codon of the catalase gene. From our results, we conclude that in human hepatoma cells daidzein at a non-toxic concentration increases the activity of human catalase and induces the transcription of the catalase gene via interaction with the proximal part of the promoter.

Effect of biotic elicitors on enrichment of antioxidant properties and induced isoflavones in soybean

The antioxidant properties of methanolic extracts from soybean obtained with germination, wounding, and application of biotic elicitors were evaluated. Also, the relationship between observed antioxidant properties and compositional changes in isoflavone content was determined. The 2 biotic elicitors used in this study were the food-grade fungus Aspergillus sojae and A. sojae cell wall extract. Isoflavone content was determined by C(18) reverse phase high-performance chromatography coupled with a photodiode array detector. Antioxidant activities of the extracts were measured using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and beta-carotene cooxidation in a linoleate system. Higher antioxidant activities were observed in wounded and elicitor-treated extracts when compared with nonwounded control extracts. In addition, the phenolic content was higher in extracts from wounded and elicitor-treated soybean. Germination for 3 d slightly decreased total isoflavone content (-4.3%); however, wounding increased total isoflavone content (25.8%). The soybean extracts from seeds treated with A. sojae biotic elicitors had the highest total isoflavone contents (9.8 to 11.6 mg/g extract) and displayed the highest antioxidant activities in both the DPPH and beta-carotene assays. Also identified in the wounded and elicitor-treated extracts were the induced isoflavones glyceollins that contributed to the higher isoflavone contents observed.

Effect of reddening-ripening on the antioxidant activity of polyphenol extracts from cv. 'Annurca' apple fruits

Apple is among the most consumed fruits worldwide, and several studies suggest that apple polyphenols could play a role in the prevention of degenerative diseases. 'Annurca' apple fruit undergoes, after harvest, a typical reddening treatment to turn the apples' skin red, and it is noted for its high firmness. This paper reports the effect of reddening-ripening treatment on polyphenol concentration and antioxidant activity of both peel and flesh extracts. The in vitro antioxidant properties have been compared with the protective effect against the cytotoxic effects of reactive oxygen species using Caco-2 cells as model system. Pretreatment of cells with different polyphenolic apple extracts provides a remarkable protection against oxidative damage. This effect seems to be associated with the antioxidant activity of 'Annurca' apple polyphenolic compounds. The flesh has antioxidant properties comparable to those possessed by the peel. Neither the reddening nor the fruit conservation causes changes in the antioxidant properties possessed by this apple variety. The data indicate that polyphenolic compounds in 'Annurca' apples are relatively stable in the peel and also in the flesh; therefore, the health benefits of polyphenols should be maintained during long-term storage. Finally, a diet rich in apple antioxidants could exert a beneficial effect in the prevention of intestinal pathologies related to the production of reactive oxygen species.

Soy isoflavones protect the intestine from lipid hydroperoxide mediated oxidative damage

The effects of 24 h supplementation of human colon carcinoma cells (Caco-2) with isoflavones, genistein, and daidzein and their activities against oleic acid hydroperoxide mediated oxidative stress were investigated. Genistein, at 25, 50, and 100 microM, and daidzein, at 25 and 50 microM, did not induce cell injury to Caco-2 cells. Both compounds reduced cell injury and DNA damage mediated by 5 microM oleic acid hydroperoxides in Caco-2 cells. The effects of genistein and daidzein on antioxidant enzymes were dependent upon the compound and its concentration.

Dietary phenolic antioxidants, caffeic acid and Trolox, protect rainbow trout gill cells from nitric oxide-induced apoptosis

Caffeic acid (CA) and Trolox are phenolic acids that have beneficial antioxidant effect, but the underlying mechanisms involved are not fully understood. The extent to which CA and Trolox protect against sodium nitroprusside (SNP)-induced oxidative cell injury was investigated in cultured rainbow trout gill cells. The cells exposed to SNP for 24 h displayed a dose-dependent leakage of lactate dehydrogenase (LDH) and decreased cell viability as indicated by the MTT assay (mitochondrial dehydrogenase activity). Both effects were prevented by treatment with 50 microM CA or Trolox. CA or Trolox, protected against SNP-induced caspase-3 activation and DNA fragmentation, indicating a reduction of apoptosis. Thus, the results indicate that SNP induced cell death is caspase-3 related apoptosis and the treatment with CA inhibited the apoptotic pathway. In addition, we studied the effect of CA and Trolox on expression of zinc-responsive antioxidant genes such as metallothioneins (MT), glutathione-S-transferase (GST Class pi) and glucose-6-phosphate dehydrogenase (G6PD) in cultured gill cells. CA, 100 microM, increased accumulation of mRNA for MTA, MTB, GST and G6PD in cells. Thus, in addition to its ability to sequester free radicals, CA may protect against oxidative stress through expression of zinc-induced antioxidant proteins. Because of these properties we suggest that CA could be a beneficial additive to fish feeds in aquaculture.

Water-soluble genistin glycoside isoflavones up-regulate antioxidant metallothionein expression and scavenge free radicals

Genistin has antioxidant activities; however, its insolubility in water often limits its biological availability in vivo. Using a novel transglycosylation process, the solubility of genistin glycosides was increased 1000 to 10000-fold, but it was not known whether these modified genistin glycosides maintained antioxidant activity. We found that both genistin and its glycosides similarly up-regulated the transcription of several metallothionein (MT) antioxidant genes (MT1A, MT2A, MT1E, and MT1X), as well as the glucose 6-phosphate dehydrogenase (G6PD) gene in HepG2 cells. This gene induction was mediated by the sequestration of zinc in the cytosol, which up-regulated the metal-responsive transcription factor-1 (MTF-1) that induced MT gene expression. Although not as effective as ascorbic acid, genistin glycosides possessed slightly greater reducing power than genistin. We concluded that genistin and genistin glycosides have a direct antioxidant effect and an indirect antioxidant effect, perhaps via induction of MT by activity of MTF-1.

Soy protein with and without isoflavones fails to substantially increase postprandial antioxidant capacity

Five methods for the assessment of antioxidant capacity [whole plasma conjugated diene formation, low-density lipoprotein oxidation susceptibility, ferric-reducing ability of plasma, oxygen radical absorbance capacity and perchloric-acid-treated oxygen radical absorbance capacity (PCA-ORAC)] were used in a randomized, double blind, crossover study to determine the acute postprandial antioxidant protection imparted by the isoflavone component of soy. On separate days, 16 subjects consumed one of three isocaloric shakes containing 25 g of protein in the form of soy, with 107 mg of total aglycone units of isoflavones, soy with trace isoflavones (<4 mg) or total milk protein. Blood was collected at baseline, 4 h, 6 h and 8 h after consumption. Antioxidant capacity, serum isoflavone levels, fat-soluble antioxidants and plasma vitamin C levels were evaluated. Repeated measures analysis of variance showed no significant differences (P=.05) within treatments over time in four of five antioxidant capacity measurements. Significant differences over time between the soy with trace isoflavones and the total milk protein group were observed using the PCA-ORAC assay. It can be concluded that, on an acute basis, a significant increase in serum antioxidant capacity is not detectable following consumption of soy protein.

Genistein abrogates pre-hemolytic and oxidative stress damage induced by 2,2′-Azobis (Amidinopropane)

The pre-hemolytic mechanism induced by free radicals initiated from water-soluble 2,2'-azobis (2-amidinopropane) hydrochloride (AAPH) and its reversal by genistein was investigated in human erythrocytes. The time course of K+ efflux compared to the occurrence of hemolysis suggests that AAPH-induced hemolysis occurs indirectly via pore formation and band 3 oxidation as expected. However, genistein inhibited hemolysis, LDH release and membrane protein oxidation but not K+ efflux. This indicated that erythrocyte protein oxidation possibly in the hydrophobic core plays a significant role in the membrane pre-hemolytic damage. Chemiluminescence (CL) analysis carried out in non-lysed erythrocytes treated with AAPH showed a dramatic increase in CL indicating both reduced levels of antioxidants and increased membrane lipid peroxide. The V0 value was also increased up to 6 times, denoting a high degree of membrane peroxidation very early in erythrocyte membrane damage. The whole process was inhibited by genistein in a dose-dependent manner. These results indicate that the genistein inhibited both hemolysis and pre-hemolytic damage and also hindered membrane lipid peroxide formation and protein oxidation. In addition, it is suggested that pre-hemolytic damage is mediated mainly by the oxidation of both phospholipid and protein located in the deeper hydrophobic region of the membrane.

Isoflavonoid Photoprotection in Mouse and Human Skin Is Dependent on Metallothionein

Previous studies report that selected topical isoflavonoids are immunoprotective in both mice and humans, when applied following UV irradiation. Isoflavonoids have documented antioxidant activity, but their mechanism of immunomodulation remains unclear. This study examines whether photoimmunoprotection by the isoflavonoids might result from their interaction with one cutaneous antioxidant known to modulate UV photodamage, metallothionein (MT). In mice bearing a null mutation for MT-I and -II, we found that immunoprotection by the isoflavonoid 4',7-dihydroxyisoflavane (equol) against solar-simulated UV radiation (SSUV) or exogenous cis-urocanic acid was abrogated. Topical equol did not activate MT expression in normal mouse skin, but markedly enhanced the increase in MT expression in murine epidermis following SSUV irradiation. Normal human skin, unlike murine, expressed MT in the basal epidermis. Following SSUV irradiation, topical application of the related synthetic isoflavonoid NV-07alpha to human skin also markedly enhanced epidermal MT expression. The NV-07alpha has been reported previously to protect humans against the UV suppression of Mantoux reactions. Thus, epidermal MT expression appears to protect against photoimmunosuppression in both human and mouse skin. We speculate that equol and its related derivative NV-07alpha may activate the MT gene synergistically with SSUV, to produce the enhanced immunoprotective effect.

Antioxidative and Anti-Inflammatory Effects of Saururus chinensis Methanol Extract in RAW 264.7 Macrophages

Natural products are known to be sources of bioactive components exerting antioxidative and anti-inflammatory activities. We evaluated the suppressive effects of the methanol extract (0-45 microg/mL) of the aerial parts of Saururus chinensis (Lour.) Baill (Saururaceae) on lipopolysaccharide (LPS)-stimulated nitric oxide (NO) production and oxidative stress buildup in the RAW 264.7 murine macrophages. Treatment of RAW 264.7 cells with S. chinensis methanol extract (SME) significantly reduced LPS-stimulated NO production in a concentration-dependent manner. Treatment with SME reduced thiobarbituric acid-reactive substances accumulation and enhanced glutathione levels and activities of antioxidative enzymes, including superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase, in LPS-stimulated macrophages compared with LPS-only treated cells. Expression of inducible NO synthase (iNOS) mRNA was also suppressed in SMEtreated cells. The specific DNA binding activities of nuclear factor kappaB (NFkappaB) on nuclear extracts from SME-treated cells were significantly suppressed. These results suggest that SME has antioxidative and anti-inflammatory activities by enhancing antioxidative defense systems and suppressing NO production via the down-regulation of iNOS expression and NFkappaB activity.