Cytoprotective effect of epigallocatechin-3-gallate against deoxynivalenol-induced toxicity through anti-oxidative and anti-inflammatory mechanisms in HT-29 cells

Nation-Based Occurrence and Endogenous Biological Reduction of Mycotoxins in Medicinal Herbs and Spices

Medicinal herbs have been increasingly used for therapeutic purposes against a diverse range of human diseases worldwide. Moreover, the health benefits of spices have been extensively recognized in recent studies. However, inevitable contaminants, including mycotoxins, in medicinal herbs and spices can cause serious problems for humans in spite of their health benefits. Along with the different nation-based occurrences of mycotoxins, the ultimate exposure and toxicities can be diversely influenced by the endogenous food components in different commodities of the medicinal herbs and spices. The phytochemicals in these food stuffs can influence mold growth, mycotoxin production and biological action of the mycotoxins in exposed crops, as well as in animal and human bodies. The present review focuses on the occurrence of mycotoxins in medicinal herbs and spices and the biological interaction between mold, mycotoxin and herbal components. These networks will provide insights into the methods of mycotoxin reduction and toxicological risk assessment of mycotoxin-contaminated medicinal food components in the environment and biological organisms.

Metabolic and Microbial Modulation of the Large Intestine Ecosystem by Non-Absorbed Diet Phenolic Compounds: A Review

Phenolic compounds represent a diverse group of phytochemicals whose intake is associated with a wide spectrum of health benefits. As consequence of their low bioavailability, most of them reach the large intestine where, mediated by the action of local microbiota, a series of related microbial metabolites are accumulated. In the present review, gut microbial transformations of non-absorbed phenolic compounds are summarized. Several studies have reached a general consensus that unbalanced diets are associated with undesirable changes in gut metabolism that could be detrimental to intestinal health. In terms of explaining the possible effects of non-absorbed phenolic compounds, we have also gathered information regarded their influence on the local metabolism. For this purpose, a number of issues are discussed. Firstly, we consider the possible implications of phenolic compounds in the metabolism of colonic products, such as short chain fatty acids (SCFA), sterols (cholesterol and bile acids), and microbial products of non-absorbed proteins. Due to their being recognized as affective antioxidant and anti-inflammatory agents, the ability of phenolic compounds to counteract or suppress pro-oxidant and/or pro-inflammatory responses, triggered by bowel diseases, is also presented. The modulation of gut microbiota through dietetic maneuvers including phenolic compounds is also commented on. Although the available data seems to assume positive effects in terms of gut health protection, it is still insufficient for solid conclusions to be extracted, basically due to the lack of human trials to confirm the results obtained by the in vitro and animal studies. We consider that more emphasis should be focused on the study of phenolic compounds, particularly in their microbial metabolites, and their power to influence different aspects of gut health.

Epigallocatechin-3-gallate (EGCG) Suppresses the Trafficking of Lymphocytes to Epidermal Melanocytes via Inhibition of JAK2: Its Implication for Vitiligo Treatment

Vitiligo is an inflammatory skin disorder in which activated T cells play an important role in its onset and progression. Epigallocatechin-3-gallate (EGCG), the major chemical constituent of green tea, exhibits remarkable anti-oxidative and anti-inflammatory properties. EGCG administration has been confirmed to decrease the risk of vitiligo; however, the underlying mechanism is undetermined. In this study, we proved that EGCG directly inhibited the kinase activity of Janus kinase 2 (JAK2). In primary cultured human melanocytes, EGCG pre-treatment attenuated interferon (IFN)-γ-induced phosphorylation of JAK2 and its downstream signal transducer and activator of transcription (STAT)1 and STAT3 in a dose-dependent manner. We further examined the chemoattractant expression in melanocytes and demonstrated that EGCG significantly inhibited IFN-γ-induced expression of intracellular adhesion molecule (ICAM)-1, CXCL10, and monocyte chemotactic protein (MCP)-1 in human melanocytes. In addition, EGCG reduced the protein levels of the corresponding receptors including CD11a, CXCR3, and CCR2 in human T lymphocytes. As a consequence, adhesion of human T cells to melanocytes induced by IFN-γ was effectively suppressed by EGCG. Taken together, our results provided new evidence for the effectiveness of EGCG in vitiligo treatment and supported JAK2 as a molecular target for vitiligo medicine development.

Separation and purification of epigallocatechin-3-gallate (EGCG) from green tea using combined macroporous resin and polyamide column chromatography

Epigallocatechin-3-gallate (EGCG) is a major bioactive ingredient of green tea that produces beneficial neuroprotective effects. In this paper, to optimize the EGCG enrichment, thirteen macroporous resins with different chemical and physical properties were systemically evaluated. Among the thirteen tested resins, the H-bond resin HPD826 exhibited best adsorption/desorption capabilities and desorption ratio, as well as weakest affinity for caffeine. The absorption of EGCG on the HPD826 resin followed the pseudo-second-order kinetics and Langmuir isotherm model. The separation parameters of EGCG were optimized by dynamic adsorption/desorption experiments with the HPD826 resin column. Under the optimal condition, the content of EGCG in the 30% ethanol eluent increased by 5.8-fold from 7.7% to 44.6%, with the recovery yield of 72.1%. After further purification on a polyamide column, EGCG with 74.8% purity was obtained in the 40-50% ethanol fraction with a recovery rate of 88.4%. In addition, EGCG with 95.1% purity could be easily obtained after one-step crystallization in distilled water. Our study suggests that the combined macroporous resin and polyamide column chromatography is a simple method for large-scale separation and purification of EGCG from natural plants for food and pharmaceutical applications.

Cytoprotective effects of grape seed extract on human gingival fibroblasts in relation to its antioxidant potential

Cytoprotective effects of short-term treatment with grape seed extract (GSE) upon human gingival fibroblasts (hGFs) were evaluated in relation to its antioxidant properties and compared with those of a water-soluble analog of vitamin E: trolox (Tx). GSE and Tx showed comparable antioxidant potential in vitro against di(phenyl)-(2,4,6-trinitrophenyl)iminoazanium (DPPH; a stable radical), hydroxyl radical (^•OH), singlet oxygen (¹O₂), and hydrogen peroxide (H₂O₂). Pretreatment or concomitant treatment with GSE for 1 min protected hGFs from oxidative stressors, including H₂O₂, acid-electrolyzed water (AEW), and ¹O₂, and attenuated the intracellular formation of reactive oxygen species induced by H₂O₂ and AEW. Tx also reduced the H₂O₂- and AEW-induced intracellular formation of reactive oxygen species, but showed no cytoprotective effects on hGFs exposed to H₂O₂, AEW, or ¹O₂. These results suggest that the cytoprotective effects of GSE are likely exerted independently of its antioxidant potential.

Effects of EGCG content in green tea extract on pharmacokinetics, oxidative status and expression of inflammatory and apoptotic genes in the rat ocular tissues

Green tea extract (GTE) exerts antioxidative activities in ocular tissues of rats, but high levels of (-)-epigallocatechin gallate (EGCG) can induce oxidative stress. In this study, pharmacokinetics, diurnal variation of oxidative status, antioxidation and transcription factors changes in ocular tissues of rats were investigated. Rats were fed intragastrically with GTE and catechin mixtures containing different amounts of EGCG. Plasma and various ocular tissues were taken for pharmacokinetic analysis, oxidation marker testings and gene expression assays. Effects of EGCG on ocular oxidation status were assessed by 8-isoprostane level and reduced/oxidized glutathione ratio. Oxidation, inflammation and apoptosis regulations in retina were evaluated by real-time polymerase chain reaction. Epicatechin, epigallocatechin and EGCG were dominant in various ocular tissues except vitreous humor, where gallocatechin was predominant. Diurnal variation of oxidative status was found in some compartments. GTE caused oxidative stress increase in the plasma, aqueous humor, vitreous humor, cornea and retina but decrease in the lens and choroid-sclera. Catechins mixture containing half dose of EGCG lowered 8-isoprostane in the retina and lens. GTE treatment induced superoxide dismutase 1 and glutathione peroxidase-3 expressions but suppressed catalase in the retina. Our results reveal pro-oxidation of GTE with high EGCG content to the ocular tissues. Optimal EGCG level is needed for protection.

Analgesic and anti-Inflammatory effect of UP3005, a botanical composition Containing two standardized extracts of Uncaria gambir and Morus alba

Background:

Osteoarthritis (OA) is a chronic debilitating degenerative joint disease characterized by cartilage degradation and synovial inflammation exhibited by clinical symptoms such as joint swelling, synovitis, and inflammatory pain. Present day pain relief therapeutics heavily relies on the use of prescription and over the counter nonsteroidal anti-inflammatory drugs as the first line of defense where their long-term usage causes detrimental gastrointestinal and cardiovascular-related side-effects. As a result, the need for evidence based safer and efficacious alternatives from natural sources to overcome the most prominent and disabling symptoms of arthritis is a necessity.

Materials and Methods:

Describe the anti-inflammatory and analgesic effect of UP3005, a composition that contains a standardized blend of two extracts from the leaf of Uncaria gambir and the root bark of Morus alba in carrageenan-induced rat paw edema, abdominal constriction (writhing’s) and ear swelling assays in mouse with oral dose ranges of 100–400 mg/kg.

Results:

In vivo, statistically significant improvement in pain resistance, and suppression of paw edema and ear thickness in animals treated with UP3005 were observed compared with vehicle-treated diseased rats and mice. Ibuprofen was used a reference compound in all the studies. In vitro, enzymatic inhibition activities of UP3005 were determined with IC50 values of 12.4 μg/ml, 39.8 μg/ml and 13.6 μg/ml in cyclooxygenase-2 (COX-1), COX-2 and lipoxygenase (5-LOX) enzyme activity assay, respectively.

Conclusions:

These data suggest that UP3005, analgesic and anti-inflammatory agent of botanical origin with balanced dual COX-LOX inhibition activity, could potentially be used for symptom management of OA.

UP3005, a Botanical Composition Containing Two Standardized Extracts of Uncaria gambir and Morus alba, Improves Pain Sensitivity and Cartilage Degradations in Monosodium Iodoacetate-Induced Rat OA Disease Model

Osteoarthritis (OA) is a multifactorial disease primarily noted by cartilage degradation in association with inflammation that causes significant morbidity, joint pain, stiffness, and limited mobility. Present-day management of OA is inadequate due to the lack of principal therapies proven to be effective in hindering disease progression where symptomatic therapy focused approach masks the actual etiology leading to irreversible damage. Here, we describe the effect of UP3005, a composition containing a proprietary blend of two standardized extracts from the leaf of Uncaria gambir and the root bark of Morus alba, in maintaining joint structural integrity and alleviating OA associated symptoms in monosodium-iodoacetate- (MIA-) induced rat OA disease model. Pain sensitivity, micro-CT, histopathology, and glycosaminoglycans (GAGs) level analysis were conducted. Diclofenac at 10 mg/kg was used as a reference compound. UP3005 resulted in almost a complete inhibition in proteoglycans degradation, reductions of 16.6% (week 4), 40.5% (week 5), and 22.0% (week 6) in pain sensitivity, statistically significant improvements in articular cartilage matrix integrity, minimal visual subchondral bone damage, and statistically significant increase in bone mineral density when compared to the vehicle control with MIA. Therefore, UP3005 could potentially be considered as an alternative therapy from natural sources for the treatment of OA and/or its associated symptoms.

Overexpression of miR-126 sensitizes osteosarcoma cells to apoptosis induced by epigallocatechin-3-gallate

Background

miR-126 plays an important role in the proliferation, invasion, migration, and chemotherapeutics resistance in cancer. Epigallocatechin-3-gallate (EGCG), as the major polyphenolic constituent present in green tea, is a promising anticancer agent. However, the role of miR-126 in EGCG anticancer remains unclear. Here, we investigated the effects of miR-126 and EGCG on cell viability, apoptosis, cell cycle distribution of osteosarcoma cells and the sensitization of miR-126 on osteosarcoma cells to EGCG.

Methods

The cell viability, apoptosis and cycle distribution were analyzed using MTT assay and flow cytometry.

Results

Our results showed that EGCG (0.025, 0.05, 0.1, 0.2 g/L) suppresses proliferation of osteosarcoma MG63 and U2OS cells in a concentration-dependent and time-dependent manner and the inhibitory effects of 0.05 g/L EGCG on U2OS cells were roughly equivalent to 20 μM cisplatin (DDP); miR-126 could promote apoptosis and inhibit proliferation in U2OS cells but without significant effects on cell cycle G1 phase arrest; EGCG suppressed proliferation of U2OS cells through induction of cell cycle G1 arrest and apoptotic death; overexpression of miR-126 enhanced the inhibitory effects of EGCG on proliferation in U2OS cells via promotion of apoptosis.

Conclusions

Our results demonstrate that enhanced expression of miR-126 increased the sensitivity of osteosarcoma cells to EGCG through induction of apoptosis.

Cytoprotective effect of short-term pretreatment with proanthocyanidin on human gingival fibroblasts exposed to harsh environmental conditions

Our previous study showed that exposing mouse fibroblasts to proanthocyanidin (PA) for only 1 min accelerated cell proliferation in a concentration-dependent manner. In this study, exposing human gingival fibroblasts (HGFs) to PA for 1 min similarly accelerated the proliferative response of the cells. Besides the accelerated proliferative response, PA showed a cytoprotective effect on HGFs exposed to harsh environmental conditions; short-term exposure of HGFs in the mitotic phase to pure water or physiological saline resulted in a lower recovery of viable cells. Pretreatment and concomitant treatment with PA improved the low recovery of cells exposed to pure water or physiological saline. In addition, HGFs exposed to PA for 1 min proliferated well even after being cultured in serum-free medium. In 100% confluent HGFs, being cultured in serum-free medium resulted in a high intracellular reactive oxygen species (ROS) level, but pretreatment with PA prevented the cells from increasing intracellular ROS. Thus, the results suggest that a short-term PA treatment exerts cytoprotective effects on HGFs exposed to harsh environmental conditions by improving the intracellular oxidative stress response.

Molecular mechanism of epigallocatechin-3-gallate in human esophageal squamous cell carcinoma in vitro and in vivo

Epigallocatechin-3-gallate (EGCG), the major polyphenol of green tea, has been shown to inhibit proliferation in various types of tumors. However, few studies concerning the role and mechanism of EGCG in esophageal squamous cell carcinoma are available. Therefore, the antitumor mechanism of EGCG needs to be investigated. The present study aimed to examine the antitumor effect of EGCG on the human esophageal squamous cell carcinoma cell lines, Eca-109 and Te-1, in vitro and in vivo. Cell viability was assessed using the MTT assay and tumor formation and growth in murine xenograft models with or without EGCG treatment. Cell cycle analysis and levels of reactive oxygen species (ROS) were detected using flow cytometry. Apoptosis was measured by Annexin/propidium iodide staining. Caspase-3 cleavage and vascular endothelial growth factor (VEGF) expression were detected using western blot analysis and immunohistochemistry in tumor cell lines and tumor xenografts, respectively. The results showed that EGCG inhibited proliferation in the Eca-109 and Te-1 cells in a time- and dose-dependent manner. Tumor cells were arrested in the G1 phase and apoptosis was accompanied by ROS production and caspase-3 cleavage. In a mouse model, EGCG significantly inhibited the growth of Eca-109 tumors by increasing the expression of cleaved-caspase-3 and decreasing VEGF protein levels. Taken together, the results suggest that EGCG inhibits proliferation and induces apoptosis through ROS production, caspase-3 activation, and a decrease in VEGF expression in vitro and in vivo. Furthermore, EGCG may have future clinical applications for novel approaches to treat esophageal squamous cell carcinoma.

Therapeutic effects of glutamic acid in piglets challenged with deoxynivalenol

The mycotoxin deoxynivalenol (DON), one of the most common food contaminants, primarily targets the gastrointestinal tract to affect animal and human health. This study was conducted to examine the protective function of glutamic acid on intestinal injury and oxidative stress caused by DON in piglets. Twenty-eight piglets were assigned randomly into 4 dietary treatments (7 pigs/treatment): 1) uncontaminated control diet (NC), 2) NC+DON at 4 mg/kg (DON), 3) NC+2% glutamic acid (GLU), and 4) NC+2% glutamic acid + DON at 4 mg/kg (DG). At day 15, 30 and 37, blood samples were collected to determine serum concentrations of CAT (catalase), T-AOC (total antioxidant capacity), H₂O₂ (hydrogen peroxide), NO (nitric oxide), MDA (maleic dialdehyde), DAO (diamine oxidase) and D-lactate. Intestinal morphology, and the activation of Akt/mTOR/4EBP1 signal pathway, as well as the concentrations of H₂O₂, MDA, and DAO in kidney, liver and small intestine, were analyzed at day 37. Results showed that DON significantly (P<0.05) induced oxidative stress in piglets, while this stress was remarkably reduced with glutamic acid supplementation according to the change of oxidative parameters in blood and tissues. Meanwhile, DON caused obvious intestinal injury from microscopic observations and permeability indicators, which was alleviated by glutamic acid supplementation. Moreover, the inhibition of DON on Akt/mTOR/4EBP1 signal pathway was reduced by glutamic acid supplementation. Collectively, these data suggest that glutamic acid may be a useful nutritional regulator for DON-induced damage manifested as oxidative stress, intestinal injury and signaling inhibition.

Ginsenoside metabolite compound K promotes recovery of dextran sulfate sodium-induced colitis and inhibits inflammatory responses by suppressing NF-κB activation

Phytogenic compounds with anti-oxidant and anti-inflammatory properties, such as ginsenoside metabolite compound K (CK) or berberine (BBR), are currently discussed as promising complementary agents in the prevention and treatment of cancer and inflammation. The latest study showed that ginsenoside Rb1 and its metabolites could inhibit TNBS-induced colitis injury. However, the functional mechanisms of anti-inflammation effects of ginsenoside, particularly its metabolite CK are still not clear. Here, using dextran sulfate sodium (DSS)-induced colitis in mice, clinical parameters, intestinal integrity, pro-inflammatory cytokines production, and signaling pathways in colonic tissues were determined. In mild and sever colitis mice, CK and BBR (as a positive agent) alleviated colitis histopathology injury, ameliorated myeloperoxidase (MPO) activity, reduced pro-inflammatory cytokines production, such as, IL-6, IL-1β, TNF-α, and increased anti-inflammatory cytokine IL-10 production in both mice colon tissues and blood. Nevertheless, the results revealed that CK and BBR inhibited NF-κB p65 nuclear translocation, downregulated p-IκBα and upregulated IκBα, indicating that CK, as well as BBR, suppressed the activation of the NF-κB pathway in the progression of colitis with immunofluorescence, immunohistochemical and western blotting analysis. Furthermore, CK inhibited pro-inflammatory cytokines production in LPS-activated macrophages via down-regulation of NF-κB signaling pathway. Taken together, our results not only reveal that CK promotes the recovery of the progression of colitis and inhibits the inflammatory responses by suppressing NF-κB activation, but also suggest that CK downregulates intestinal inflammation through regulating the activation of macrophages and pro-inflammatory cytokines production.