Protective Effect of Green Tea Extract and Tea Polyphenols against FK506-Induced Cytotoxicity in Renal Cells

Green Tea Polyphenols Alleviate Kidney Injury Induced by Di(2-Ethylhexyl) Phthalate in Mice

INTRODUCTION

Di(2-ethylhexyl) phthalate (DEHP) is a common plasticizer. Studies have revealed that DEHP exposure can cause kidney damage. Green tea is among the most popular beverages in China. Green tea polyphenols (GTPs) have been proven to have therapeutic effects on organ damage induced by heavy metal exposure. However, few studies have reported on GTP-relieving DEHP-induced kidney damage.

METHODS

C57BL/6J male mice aged 6-8 weeks were treated with distilled water (control group), 1,500 mg/kg/d DEHP + corn oil (model group), 1,500 mg/kg/d DEHP + corn oil + 70 mg/kg GTP (treatment group), corn oil (oil group), and 70 mg/kg GTP (GTP group) by gavage for 8 weeks, respectively. The renal function of mice and renal tissue histopathology of each group were evaluated. The renal tissues of mice in the model, treatment, and control groups were analyzed using high-throughput sequencing. We calculated the differentially expressed microRNAs (miRNAs) and messenger RNAs (mRNAs) using the limma R package, the CIBERSORT algorithm was used to predict immune infiltration, the starBase database was used to screen the miRNA-mRNA regulatory axis, and immunohistochemical analyses were performed to verify protein expression.

RESULTS

GTP alleviated the deterioration of renal function, renal inflammation and fibrosis, and mitochondrial and endoplasmic reticulum lesions induced by DEHP in mice. Differential immune infiltrations of plasma, dendritic, T, and B cells were noted between the model and treatment groups. We found that three differentially expressed miRNAs (mmu-miR-383-5p, mmu-miR-152-3p, and mmu-miR-144-3p), three differentially expressed mRNAs (Ddit4, Dusp1, and Snx18), and three differentially expressed proteins (Ddit4, Dusp1, and Snx18) played crucial roles in the miRNA-mRNA-protein regulatory axes when GTPs mitigate DEHP-induced kidney damage in mice.

CONCLUSION

GTP can alleviate DEHP-induced kidney damage and regulate immune cell infiltration. We screened four important miRNA-mRNA-protein regulatory axes of GTP, mitigating DEHP-induced kidney damage in mice.

Pathway-level multi-omics analysis of the molecular mechanisms underlying the toxicity of long-term tacrolimus exposure

Tacrolimus (TAC)-based treatment is associated with nephrotoxicity and hepatotoxicity; however, the underlying molecular mechanisms responsible for this toxicity have not been fully explored. This study elucidated the molecular processes underlying the toxic effects of TAC using an integrative omics approach. Rats were sacrificed after 4 weeks of daily oral TAC administration at a dose of 5 mg/kg. The liver and kidney underwent genome-wide gene expression profiling and untargeted metabolomics assays. Molecular alterations were identified using individual data profiling modalities and further characterized by pathway-level transcriptomics-metabolomics integration analysis. Metabolic disturbances were mainly related to an imbalance in oxidant-antioxidant status, as well as in lipid and amino acid metabolism in the liver and kidney. Gene expression profiles also indicated profound molecular alterations, including in genes associated with a dysregulated immune response, proinflammatory signals, and programmed cell death in the liver and kidney. Joint-pathway analysis indicated that the toxicity of TAC was associated with DNA synthesis disruption, oxidative stress, and cell membrane permeabilization, as well as lipid and glucose metabolism. In conclusion, our pathway-level integration of transcriptome and metabolome and conventional analyses of individual omics profiles, provided a more comprehensive picture of the molecular changes resulting from TAC toxicity. This study also serves as a valuable resource for subsequent investigations aiming to understand the mechanism underlying the molecular toxicology of TAC.

Controversial Interactions of Tacrolimus with Dietary Supplements, Herbs and Food

Tacrolimus is an immunosuppressive calcineurin inhibitor used to prevent rejection in allogeneic organ transplant recipients, such as kidney, liver, heart or lung. It is metabolized in the liver, involving the cytochrome P450 (CYP3A4) isoform CYP3A4, and is characterized by a narrow therapeutic window, dose-dependent toxicity and high inter-individual and intra-individual variability. In view of the abovementioned facts, the aim of the study is to present selected interactions between tacrolimus and the commonly used dietary supplements, herbs and food. The review was based on the available scientific literature found in the PubMed, Scopus and Cochrane databases. An increase in the serum concentration of tacrolimus can be caused by CYP3A4 inhibitors, such as grapefruit, pomelo, clementine, pomegranate, ginger and turmeric, revealing the side effects of this drug, particularly nephrotoxicity. In contrast, CYP3A4 inducers, such as St. John’s Wort, may result in a lack of therapeutic effect by reducing the drug concentration. Additionally, the use of Panax ginseng, green tea, Schisandra sphenanthera and melatonin in patients receiving tacrolimus is highly controversial. Therefore, since alternative medicine constitutes an attractive treatment option for patients, modern healthcare should emphasize the potential interactions between herbal medicines and synthetic drugs. In fact, each drug or herbal supplement should be reported by the patient to the physician (concordance) if it is taken in the course of immunosuppressive therapy, since it may affect the pharmacokinetic and pharmacodynamic parameters of other preparations.

Renoprotective Effects of Alpha-1 Antitrypsin against Tacrolimus-Induced Renal Injury

The protective effects of alpha-1 antitrypsin (AAT) in tacrolimus (TAC)-induced renal injury was evaluated in a rat model. The TAC group rats were subcutaneously injected with 2 mg/kg TAC every day for four weeks. The TAC with AAT group was cotreated with daily subcutaneous injections of TAC and intraperitoneal injections of AAT (80 mg/kg) for four weeks. The effects of AAT on TAC-induced renal injury were evaluated using serum biochemistry, histopathology, and Western blotting. The TAC injection significantly increased renal interstitial fibrosis, inflammation, and apoptosis as compared to the control treatment. The histopathological examination showed that cotreatment of TAC and AAT attenuated interstitial fibrosis (collagen, fibronectin, and α-SMA staining), and α-SMA expression in Western blotting was also decreased. Immunohistochemical staining for inflammation (osteopontin and ED-1 staining) revealed improved interstitial inflammation in the TAC with AAT group compared to that in the TAC group. The TAC treatment increased renal apoptosis compared to the control treatment, based on the results of increased immunohistochemical staining of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL), increased caspase-3 activity, and lower Bcl-2 to Bad expression ratio. However, AAT cotreatment significantly changed these markers and consequently showed decreased apoptosis. AAT protects against TAC-induced renal injury via antifibrotic, anti-inflammatory, and antiapoptotic effects.

Inhibition effect of epigallocatechin-3-gallate on the pharmacokinetics of calcineurin inhibitors, tacrolimus, and cyclosporine A, in rats

BACKGROUND

Epigallocatechin-3-gallate (EGCG) is the most biologically active catechin of green tea. Tacrolimus (TAC) and cyclosporine A (CsA) are immunosuppressive agents commonly used in clinical organ transplantation. The present study investigated the effect of EGCG on the pharmacokinetics of TAC and CsA in rats and its underlying mechanisms.

RESEARCH DESIGN AND METHODS

Either TAC or CsA was administered to rats intravenously or orally with or without concomitant EGCG. Polymerase Chain Reaction and Western Blot were used to determine the effect of EGCG on drug-metabolizing enzymes (DMEs), drug transporters (DTs) and nuclear receptors (NRs).

RESULTS

The C_max and AUC of TAC were reduced, and V/F and CL/F of TAC were enhanced after co-administration of EGCG. EGCG increased the Cmax, AUC of CsA at 3 ~ 30 mg∙kg-1 dosages, while decreased those parameters at the dosage of 100 mg∙kg-1. EGCG inhibited the mRNA and protein expressions of DMEs and DTs, such as CYP3A1, A2, UGT1A1, Mdr1 and Mrp2, but upregulated the expressions of Car, Pxr and Fxr.

CONCLUSIONS

These results revealed consumption of high dose EGCG may cause a significant alteration in pharmacokinetics of TAC and distribution/elimination profiles of CsA through the regulation of DMEs, DTs and NRs.

Hormesis and Ginseng: Ginseng Mixtures and Individual Constituents Commonly Display Hormesis Dose Responses, Especially for Neuroprotective Effects

This paper demonstrates that ginseng mixtures and individual ginseng chemical constituents commonly induce hormetic dose responses in numerous biological models for endpoints of biomedical and clinical relevance, typically providing a mechanistic framework. The principal focus of ginseng hormesis-related research has been directed toward enhancing neuroprotection against conditions such as Alzheimer's and Parkinson's Diseases, stroke damage, as well as enhancing spinal cord and peripheral neuronal damage repair and reducing pain. Ginseng was also shown to reduce symptoms of diabetes, prevent cardiovascular system damage, protect the kidney from toxicities due to immune suppressant drugs, and prevent corneal damage, amongst other examples. These findings complement similar hormetic-based chemoprotective reports for other widely used dietary-type supplements such as curcumin, ginkgo biloba, and green tea. These findings, which provide further support for the generality of the hormetic dose response in the biomedical literature, have potentially important public health and clinical implications.

Impact of heat treatment on anti-oxidative and anti-colon cancer activities of the soluble extracts from black mulberry (Morus nigra L.) using water and ethanol–water solvents

Black mulberry (Morus nigra L.) is an edible fruit with various health functions in the body. In this study, the lyophilized black mulberry was extracted using water and 75% (v/v) ethanol–water, respectively; afterwards, the soluble extracts were subjected to these treatments like ethanol removal, heat treatment at 100 °C for various times, or activated carbon-mediated dephenolization. The assaying results indicated that the used heat treatment led to decreased anthocyanin but increased total phenol and flavonoid contents for the water- and ethanol-extracts, while the dephenolized extracts after the heat treatment also had increased total phenol and flavonoid contents. The performed heat treatment decreased anti-oxidative activities of the water- and ethanol-extracts, resulting in reduced scavenging activities to the DPPH and hydroxyl radicals and lower reducing power for Fe(iii) ions. However, the results from cell experiments also demonstrated that the heat treatment at 100 °C for 45 min caused the water- and ethanol-extracts or dephenolized extracts with higher anti-cancer activity against human colon cancer HCT-116 cells. Overall, the heated extracts were more effective than the unheated counterparts to inhibit cell growth, alter cell morphology, generate more intracellular reactive oxygen species, enhance intracellular Ca²⁺ level, and reduce mitochondrial membrane potential of the cells. It is thereby concluded that the heat treatment of black mulberry might reduce its anti-oxidation but increase its anti-colon cancer effect due to the occurrence of the Maillard reaction and other unidentified reactions, which will deepen our present knowledge and provide a scientific basis to optimize storage or processing conditions of plant-based foods.

Heat treatment of water/ethanol extracts of black mulberry decreased anti-oxidation but increased total phenol content and anti-colon cancer effect in HCT-116 cells.

Shen-Kang protects against tacrolimus-induced renal injury

BACKGROUND/AIMS

Evidence suggests that Shen-Kang (SK), a traditional Chinese herbal medicine, protects against various types of renal injury. In this study, we evaluated whether SK treatment confers renoprotection in a rat model of chronic tacrolimus (TAC) nephropathy.

METHODS

Rats were treated daily with TAC (1.5mg/kg, subcutaneously) and SK (450 mg/kg, intravenously) for 4 weeks. The effects of SK on TAC-induced renal injury were assessed by measuring renal function, urine albumin excretion, histopathology, inflammatory cell infiltration, expression of profibrotic (transforming growth factor β1 [TGF-β1] and TGF-β inducible gene-h3 [βig-h3]) and proinflammatory cytokines, oxidative stress, and apoptotic cell death.

RESULTS

Administration of SK preserved glomerular integrity (fractional mesangial area and Wilms tumor 1-positive glomeruli), attenuated tubulointerstitial fibrosis, and reduced the number of ectodermal dysplasia 1-positive cells, and this was paralleled by improved urine albumin excretion and renal dysfunction. At the molecular level, SK treatment suppressed expression of TGF-β1/Smad2/3, βig-h3, and proinflammatory cytokines. Oxidative stress and apoptotic cell death were significantly decreased with SK treatment, and apoptosis-related genes were regulated toward cell survival (active caspase-3 and the B-cell lymphoma-2/Bcl2-associated X [Bcl-2/Bax] ratio).

CONCLUSION

SK protects against TAC-induced renal injury.

Corneal Toxicity of Topical Tacrolimus Ointment in Mice with Corneal Epithelial Injury

Purpose: To investigate the effect of tacrolimus ointment on corneal epithelium. Methods: Eight-week-old male BALB/c mice were divided into 3 groups. In group 1, no injury was made. In group 2, the central 2-mm corneal epithelium was scraped off. In group 3, the whole corneal and limbal epithelium was removed after absolute ethanol application. In each group, the corneas were observed and treated daily with 0.03% or 0.1% tacrolimus ointment (Protopic^®). The viability of cultivated human corneal epithelial cells was also examined after 24-h incubation with various concentrations of tacrolimus. Results: Tacrolimus ointment significantly delayed the epithelial healing in corneas with epithelial injuries (groups 2 and 3) in dose- and frequency-dependent manners, whereas it did not have any effects on uninjured corneas (group 1). The proportion of terminal deoxynucleotidyl transferase-mediated nick end labeling-positive cells and mRNA levels of inflammatory cytokines were higher in tacrolimus-treated corneas, compared with controls. Tacrolimus did not directly reduce the viability of corneal epithelial cells in culture. Conclusions: Topical application of tacrolimus ointment onto the ocular surface induced toxicity in the cornea with epithelial defects through the impairment of epithelial healing and induction of apoptosis.

Tetrahydrocurcumin Ameliorates Tacrolimus-Induced Nephrotoxicity Via Inhibiting Apoptosis

BACKGROUND

Calcineurin inhibitors are effective immunosuppressive agents, but associated adverse effects such as nephrotoxicity may limit efficacy. Tacrolimus (FK506) is an immunosuppressive drug used mainly to lower the risk of organ rejection after allogeneic organ transplant. Adverse effects of FK-506 can prompt patients to end treatment despite the efficacy. In the present study, we investigated the protective effect and mechanism of tetrahydrocurcumin (THC) on FK506-induced renal damage, apoptosis, and oxidative stress to evaluate its possible use for kidney protection.

MATERIALS AND METHODS

The effect of THC on FK506-induced kidney cell damage was investigated in LLC-PK1 cells. LLC-PK1 cells were pretreated with THC at concentrations of dose for 2 hours followed by addition of FK506 for 24 hours. LLC-PK1 cells were treated with FK506 and THC, and cell viability and glutathione was measured. The number of apoptotic cells was measured using an annexin V/propidium iodide staining with flow cytometry. The effect of apoptosis by THC in LLC-PK1 cells was determined by measuring the caspase-9, caspase-3, B-cell lymphoma-2 (Bcl-2), and Bcl-2-associated X protein levels using Western blotting analyses.

RESULTS

FK506-induced LLC-PK1 renal cell damage was markedly ameliorated by THC treatment. THC protected LLC-PK1 cells by preventing FK506-induced glutathione decrease. THC protects against FK506-induced apoptosis in LLC-PK1 cells. Apoptosis was significantly decreased, and Bcl-2 was elevated in the THC-treated group. Bcl-2-associated X protein, caspase-3, and caspase-9 were decreased in the THC-treated group.

CONCLUSION

These results collectively provide therapeutic evidence that THC ameliorates the FK506-induced renal damage via antioxidant effect and apoptosis inhibition.

Colletotrichum gloeosporioides- Contaminated Tea Infusion Blocks Lipids Reduction and Induces Kidney Damage in Mice

When the homogenate of fresh tea tree leaves was fermented to produce black tea beverage, the Colletotrichum gloeosporioides (main pathogen or endophyte of Camellia sinensis) may be mixed into the fermentation liquor. However, it was unclear whether C. gloeosporioides-contaminated tea beverage would damage human health. Therefore, we investigated the changes of functional components and the influences on mice. C. gloeosporioides was added to the green tea infusion. After cultivation of 48 h, tea polyphenols, caffeine, and L-theanine decreased by 31.0, 26.2, and 8.3%, respectively. The contaminated tea infusion showed brown stain, and produced a group of toxic materials named phthalic acid esters. The animal study showed that green tea without contamination significantly decreased levels of alanine aminotransferase, triglycerides, free fatty acids, low-density lipoprotein, and increased insulin level compared with obese mice. On the contrary, contaminated tea lost the effects on these indicators. Furthermore, the urea nitrogen and serum creatinine levels significantly increased in the contaminated tea-drinking mice. Altogether, our results indicate that C. gloeosporioides contamination can reduce the amount of functional components of green tea. Therefore, it inhibits some health-care function of lipid-lowering. In addition, the toxic components in contaminated tea infusion might induce renal damage.

Green tea activity and iron overload induced molecular fibrogenesis of rat liver

Iron overload toxicity was shown to associate with chronic liver diseases which lead to hepatic fibrosis and subsequently the progression to cancer through oxidative stress and apoptotic pathways. Green tea potential activity as chelating, anti-oxidative, or anti-apoptotic mechanisms against metal toxicity was poorly clarified. Here, we are trying to evaluate the anti-oxidant and anti-apoptotic properties of green tea in the regulation of serum hepcidin levels, reduction in iron overloads, and improve of liver fibrosis in iron overloaded experimental rats. Three groups of male adult rats were randomly classified into three groups and treated as follows: control rats, iron treated rats for two months in drinking water followed by either vehicle or green tea extract (AGTE; 100 mg/kg) treatment for 2 more months. Thereafter, we studied the effects of AGTE on iron overload-induced lipid peroxidation, anti-oxidant depletion, liver cell injury and apoptosis. Treatment of iron-overloaded rats with AGTE resulted in marked decreases in iron accumulation within liver, depletion in serum ferritin, and hepcidin levels. Iron-overloaded rats had significant increase in malonyldialdehyde (MDA), a marker of lipid peroxidation and nitric oxide (NO) in liver when compared to control group. Also, significant change in cytochrome c and DNA content as apoptotic markers were reported in iron treated rats. The effects of iron overload on lipid peroxidation, NO levels, cytochrome c and DNA content were significantly reduced by the intervention treatment with AGTE (P < 0.001). Furthermore, the endogenous anti-oxidant capacities/levels (TAC) in liver were also significantly decreased in chronic iron overload and administration of AGTE restored the decrease in the hepatic antioxidant activities/levels. Also, hepatic hepcidin was shown to be significantly correlated with oxidative and apoptotic relating biomarkers as well as an improvement in liver fibrosis of iron treated rats following AGTE treatment. In-vitro analysis showed that, the improvement in iron toxicity of the liver depend mainly on antioxidant and protective ability of green tea polyphenolic compounds especiallyepigallocatechin-3-gallate (EGCG). Our study showed that green tea extract (GTE) ameliorates iron overload induced hepatotoxicity, apoptosis and oxidative stress in rat liver via inhibition of hepatic iron accumulation; improve of liver antioxidant capacity, and down regulation of serum hepcidin as well as reduction in the release of apoptotic relating proteins.

Phytotherapy of nephrotoxicity-induced by cancer drugs: an updated review

Context:

Kidney is one of the vital organs maintaining homeostasis of body and thus dysfunction of kidney affects quality of life and health severely. Anticancer drugs, particularly chemotherapeutic agents, cause high toxicity leading kidney dysfunction and irreparable kidney injury. Therefore, attention has recently been paid to seeking out alternatives such as nature-based drugs that are effective but less toxic. In this regard, this systematic review article is to report and introduce the most important medicinal plants and their derivatives that are used to reduce anticancer drug-induced nephrotoxicity. Evidence Acquisitions: The word nephrotoxicity alongside the words cancer or chemotherapy in combination with some herbal terms such as medicinal plant, plants, herbs, and extracts were administered to search for relevant publications indexed in PubMed.

Results:

According to this study, 16 medicinal plants, 12 plant-based derivatives, and three traditional plant-based formulations were found to help control and modulate anticancer drug-induced nephrotoxicity indices.

Conclusions:

Anticancer drugs cause nephrotoxicity through activating pathways of oxidative stress, damage-associated molecular patterns (DAMPs) production, inflammatory processes, and cell apoptosis, while medicinal plants and their derivatives can cause reduction in nephrotoxicity and anticancer drugs side effects via their antioxidant and anti-inflammatory properties.

Protective effect of ginsenoside Rb1 against tacrolimus-induced apoptosis in renal proximal tubular LLC-PK1 cells

Background

The aim of the present study was to evaluate the potential protective effects of six ginsenosides (Rb1, Rb2, Rc, Rd, Rg1, and Rg3) isolated from Panax ginseng against tacrolimus (FK506)-induced apoptosis in renal proximal tubular LLC-PK1 cells.

Methods

LLC-PK1 cells were treated with FK506 and ginsenosides, and cell viability was measured. Protein expressions of mitogen-activated protein kinases, caspase-3, and kidney injury molecule-1 (KIM-1) were evaluated by Western blotting analyses. The number of apoptotic cells was measured using an image-based cytometric assay.

Results

Reduction in cell viability by 60μM FK506 was ameliorated significantly by cotreatment with ginsenosides Rg1 and Rb1. The phosphorylation of p38, extracellular signal-regulated kinases, and KIM-1, and cleavage of caspase-3, increased markedly in LLC-PK1 cells treated with FK506 and significantly decreased after cotreatment with ginsenoside Rb1. The number of apoptotic cells decreased by 6.0% after cotreatment with ginsenoside Rb1 (10μM and 50μM).

Conclusion

The antiapoptotic effects of ginsenoside Rb1 on FK506-induced apoptosis were mediated by the inhibition of mitogen-activated protein kinases and caspase activation.

Protective effects of green tea and its main constituents against natural and chemical toxins: A comprehensive review

Toxins are natural or chemical poisonous substances with severe side effects on health. Humans are generally exposed by widespread toxic contaminations via air, soil, water, food, fruits and vegetables. Determining a critical antidote agent with extensive effects on different toxins is an ultimate goal for all toxicologists. Traditional medicine is currently perceived as a safe and natural approach against toxins. In this regard, we focused on the protective effects of green tea (Camellia sinensis) and its main components such as catechin, epicatechin, epicatechin gallate, gallocatechin, epigallocatechin and epigallocatechin gallate as a principal source of antioxidants against both natural and chemical toxins. This literate review demonstrates that protective effects of green tea and its constituents were mainly attributed to their anti-oxidative, radical scavenging, chelating, anti-apoptotic properties and modulating inflammatory responses. Although, some studies reveal they have protective effects by increasing toxin metabolism and neutralizing PLA₂, proteases, hyaluronidase and l-amino acid oxidase enzymes.

Protective effect of Korean Red Ginseng against FK506-induced damage in LLC-PK1 cells

BACKGROUND

Compound FK506 is an immunosuppressant agent that is frequently used to prevent rejection of solid organs upon transplant. However, nephrotoxicity due to apoptosis and inflammatory response mediated by FK506 limit its usefulness. In this study, the protective effect of Korean Red Ginseng (KRG) against FK506-induced damage in LLC-PK1 pig kidney epithelial cells was investigated.

METHODS

LLC-PK1 cells were exposed to FK506 with KRG and cell viability was measured. Western blotting and RT-PCR analyses evaluated protein expression of MAPKs, caspase-3, and KIM-1. TLR-4 gene expression was assessed. Caspase-3 activities were also determined. The number of apoptotic cells was measured using an image-based cytometric assay.

RESULTS

The reduction in LLC-PK1 cell viability by 60μM FK506 was recovered by KRG cotreatment in a dose-dependent manner. The phosphorylation of p38, p44/42 MAPKs (ERK), KIM-1, cleaved caspase-3, and TLR-4 mRNA expression was increased markedly in LLC-PK1 cells treated with 60μM FK506. However, with the exception of p-ERK, elevated levels of p-p38, KIM-1, cleaved caspase-3, and TLR-4 mRNA expression were significantly decreased after cotreatment with KRG. Activity level of caspase-3 was also attenuated by KRG cotreatment. Moreover, image-based cytometric assay showed that apoptotic cell death was increased by 60μM FK506 treatment, whereas it was decreased after cotreatment with KRG.

CONCLUSION

Taken together, these results suggest that the molecular mechanism of KRG in the FK506-induced nephrotoxicity may lead to the development of an adjuvant for the inhibition of adverse effect FK506 in the kidney.

Ameliorative Influence of Green Tea Extract on Copper Nanoparticle-Induced Hepatotoxicity in Rats

The potential toxicity of copper nanoparticles (CNPs) to the human health and environment remains a critical issue. In the present study, we investigated the protective influence of an aqueous extract of green tea leaves (GTE) against CNPs-induced (20-30 nm) hepatotoxicity. Four different groups of rats were used: group I was the control, group II received CNPs (40 mg/kg BW), group III received CNPs plus GTE, and group IV received GTE alone. We highlighted the hepatoprotective effect of GTE against CNPs toxicity through monitoring the alteration of liver enzyme activity, antioxidant defense mechanism, histopathological alterations, and DNA damage evaluation. The rats that were given CNPs only had a highly significant elevation in liver enzymes, alteration in oxidant-antioxidant balance, and severe pathological changes. In addition, we detected a significant elevation of DNA fragmentation percentage, marked DNA laddering, and significance over expression of both caspase-3 and Bax proteins. The findings for group III clarify the efficacy of GTE as a hepatoprotectant on CNPs through improving the liver enzyme activity, antioxidant status, as well as suppressing DNA fragmentation and the expression of the caspase-3 and Bax proteins. In conclusion, GTE was proved to be a potential hepatoprotective additive as it significantly ameliorates the hepatotoxicity and apoptosis induced by CNPs.

Tacrolimus and mycophenolate mofetil associations

Gastrointestinal risk factors after organ transplantation are prevalent, due to the chronic use of immunosuppressant. The immunosuppressive drugs such as tacrolimus/mycophenolate mofetil (TAC/MMF) association are the most commonly used therapy. TAC and MMF have been implicated in gastrotoxicity, but their direct effects, alone and combined, on intestinal cells are not completely elucidated. This study investigated the effect of TAC and MMF alone and combined on human colon carcinoma cells. Our results demonstrated that TAC and MMF individually inhibit clearly cells proliferation, enhanced free radicals, lipid peroxidation production, induced DNA lesions and reduced mitochondrial membrane potential. In this study, we also showed that the two molecules TAC and MMF combined at high concentrations amplified the cell damage. Furthermore, the TAC (5 µM) prevented cell death induced by MMF (half maximal inhibitory concentration (IC50)). Also, MMF (50 µM) induced cytoprotection in HCT116 cells against TAC (IC50) toxicity. Our findings provide additional evidence that oxidative damage is the major contribution of TAC and MMF combined toxicities. In fact, MMF and TAC exert a gastroprotective effect by modulating reactive oxygen species production. These data underscore the pleiotropic effect of TAC and MMF on HCT116 cells that play a preventive and critical role on intestinal function.

EGCG inhibit chemical reactivity of iron through forming an Ngal-EGCG-iron complex

Accumulated evidence indicates that the interconversion of iron between ferric (Fe(3+)) and ferrous (Fe(2+)) can be realized through interaction with reactive oxygen species in the Fenton and Haber-Weiss reactions and thereby physiologically effects redox cycling. The imbalance of iron and ROS may eventually cause tissue damage such as renal proximal tubule injury and necrosis. Many approaches were exploited to ameliorate the oxidative stress caused by the imbalance. (-)-Epigallocatechin-3-gallate, the most active and most abundant catechin in tea, was found to be involved in the protection of a spectrum of renal injuries caused by oxidative stress. Most of studies suggested that EGCG works as an antioxidant. In this paper, Multivariate analysis of the LC-MS data of tea extracts and binding assays showed that the tea polyphenol EGCG can form stable complex with iron through the protein Ngal, a biomarker of acute kidney injury. UV-Vis and Luminescence spectrum methods showed that Ngal can inhibit the chemical reactivity of iron and EGCG through forming an Ngal-EGCG-iron complex. In thinking of the interaction of iron and ROS, we proposed that EGCG may work as both antioxidant and Ngal binding siderphore in protection of kidney from injuries.

Effects of green tea catechins on the pro-inflammatory response after haemorrhage/resuscitation in rats

Plant polyphenols, i.e. green tea extract (GTE), possess high antioxidative and anti-inflammatory capacity, thus being protective in various models of acute inflammation. However, their anti-inflammatory effect and a feasible mechanism in haemorrhage/resuscitation (H/R)-induced liver injury remain unknown. We investigated the effects of GTE and the role of NF-κB in the pathogenesis of liver injury induced by H/R, and their effects on intercellular adhesion molecule-1 (ICAM-1) expression and neutrophil infiltration. Female Lewis rats were fed a standard chow diet (control, ctrl) or a diet containing 0·1 % polyphenolic GTE for five consecutive days before H/R. Rats were haemorrhaged to a mean arterial pressure of 30 (sem 2) mmHg for 60 min and resuscitated. Control groups (sham_ctrl and sham_GTE) underwent surgical procedures without H/R. At 2 h after resuscitation, tissues were harvested. Serum alanine aminotransferase (ALT) and IL-6 were measured. Hepatic necrosis, ICAM-1 expression and polymorphonuclear leucocyte (PMNL) infiltration were assessed. Hepatic expression of IκBα (phospho) was measured. H/R induced strong liver damage with increased necrosis and serum ALT levels. Compared with both sham groups, inflammatory markers (serum IL-6 and hepatic PMNL infiltration) were elevated after H/R (P < 0·05). Also, H/R increased IκBα phosphorylation. GTE administration markedly (P < 0·05) decreased serum ALT and IL-6 levels, hepatic necrosis as well as PMNL infiltration and the expression of ICAM-1 and phosphorylated IκBα compared with H/R. In conclusion, we observed that NF-κB activation plays an important role in the pathogenesis of liver injury after H/R through the up-regulation of hepatic ICAM-1 expression and subsequent PMNL infiltration. GTE pre-treatment prevents liver damage in this model of acute inflammation through a NF-κB-dependent mechanism.

Drug-botanical interactions: a review of the laboratory, animal, and human data for 8 common botanicals

Many Americans use complementary and alternative medicine (CAM) to prevent or alleviate common illnesses, and these medicines are commonly used by individuals with cancer.These medicines or botanicals share the same metabolic and transport proteins, including cytochrome P450 enzymes (CYP), glucuronosyltransferases (UGTs), and P-glycoprotein (Pgp), with over-the-counter and prescription medicines increasing the likelihood of drug-botanical interactions.This review provides a brief description of the different proteins, such as CYPs, UGTs, and Pgp.The potential effects of drug-botanical interactions on the pharmacokinetics and pharmacodynamics of the drug or botanical and a summary of the more common models used to study drug metabolism are described.The remaining portion of this review summarizes the data extracted from several laboratory, animal, and clinical studies that describe the metabolism, transport, and potential interactions of 8 selected botanicals. The 8 botanicals include black cohosh, Echinacea, garlic, Gingko biloba, green tea, kava, milk thistle, and St John's wort; these botanicals are among some of the more common botanicals taken by individuals with cancer.These examples are included to demonstrate how to interpret the different studies and how to use these data to predict the likelihood of a clinically significant drug-botanical interaction.

Inhibition property of green tea extract in relation to reserpine-induced ribosomal strips of rough endoplasmic reticulum (rER) of the rat kidney proximal tubule cells

The aim of this study was to evaluate the effect of green tea in inhibiting and reversing the nephrotoxicity of reserpine--a potent oxidative stress inducer--which induced cellular kidney damage. Serum biochemical parameters, antioxidant enzyme levels, thiobarbituric acid reactive substances (TBARS) and serum transaminases (glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT)) values and histopathology were systematically evaluated. Reserpine exposure led to increase the oxidative stress and organ injury was significantly observed through biochemical parameters and ultrastructural evaluation. Sprague-Dawely (S.D.) rats were intraperitonealy administered reserpine to induce oxidative kidney damage. Experimental rats were given green tea extract according to the protocol given below. Sixty rats were randomly divided into six groups, with 10 rats in each group. Reserpine was found to cause kidney proximal tubule damage, such as stripping and clustering of ribosomes from the rough endoplasmic reticulum (rER) and demolishing of mitochondrial christae with elevated level of oxidative stress markers, such as TBARS. While the ultrastructural study showed a revival of kidney proximal tubule cells as a result of the administration of green tea extract to rats. We suggest that green tea might elevate antioxidant defense system, clean up free radicals, lessen oxidative damages and protect kidney against reserpine-induced toxicity and thus had a potential protective effect.

Green tea catechin inhibits lipopolysaccharide-induced bone resorption in vivo

BACKGROUND AND OBJECTIVE

Bone resorption is positively regulated by receptor activator of nuclear factor-kappaB ligand (RANKL). Pro-inflammatory cytokines, such as interleukin (IL)-1beta, promote RANKL expression by stromal cells and osteoblasts. Green tea catechin (GTC) has beneficial effects on human health and has been reported to inhibit osteoclast formation in an in vitro co-culture system. However, there has been no investigation of the effect of GTC on periodontal bone resorption in vivo. We therefore investigated whether GTC has an inhibitory effect on lipopolysaccharide (LPS)-induced bone resorption.

MATERIAL AND METHODS

Escherichia coli (E. coli) LPS or LPS with GTC was injected a total of 10 times, once every 48 h, into the gingivae of BALB/c mice. Another group of mice, housed with free access to water containing GTC throughout the experimental period, were also injected with LPS in a similar manner.

RESULTS

The alveolar bone resorption and IL-1beta expression induced by LPS in gingival tissue were significantly decreased by injection or oral administration of GTC. Furthermore, when GTC was added to the medium, decreased responses to LPS were observed in CD14-expressing Chinese hamster ovary (CHO) reporter cells, which express CD25 through LPS-induced nuclear factor-kappaB (NF-kappaB) activation. These findings demonstrated that GTC inhibits nuclear translocation of NF-kappaB activated by LPS. In addition, osteoclasts were generated from mouse bone marrow macrophages cultured in a medium containing RANKL and macrophage colony-stimulating factor with or without GTC. The number of osteoclasts was decreased in dose-dependent manner when GTC was added to the culture medium.

CONCLUSION

These results suggest that GTC suppresses LPS-induced bone resorption by inhibiting IL-1beta production or by directly inhibiting osteoclastogenesis.

Synergistic effect of green tea polyphenols on their protection against FK506-induced cytotoxicity in renal cells

FK506 (tacrolimus) is a widely used immunosuppressant first employed in the management of rejection in organ transplantation, but now used for autoimmune disease. However, the nephrotoxicity induced by FK506 remains a serious clinical problem. We previously demonstrated that FK506 caused a significant increase in apoptosis of LLC-PK1 cells, a porcine proximal tubule cell line, but the addition of green tea extract and its polyphenolic components suppressed the cell death. Here, we examined the synergistic effect of tea polyphenols on the protection of FK506-induced cell death. The combined treatment with 5 microM (-)-epigallocatechin-gallate (EGCG) and 5 microM of (+)-catechin (C), (-)-epicatechin (EC), (-)-epigallocatechin (EGC) or (-)-epicatechin-gallate (ECG) reduced FK506-induced cytotoxicity in LLC-PK1. Similarly, the combined treatment with 5 microM EGC and 5 microM of C, EC, EGCG or ECG also reduced the cytotoxicity. These results showed that the co-treatments with EGCG and EGC, EGCG or ECG, and EGC and ECG have stronger synergistic effects on the protection of FK506-induced cell death. Furthermore, the combined treatment of EGCG (5 microM) and EGC (5 microM) showed a significant time-dependent suppression of the increased intracellular ROS levels 15 min after the addition of FK506, as well as on caspase activation. The results of these synergistic effects of the constituents of green tea extract suggest that its protective effects may reside in more than just one of its constituent.

Glutamate-induced retinal lipid and protein damage: the protective effects of catechin

Glutamate toxicity has been implicated in various retinal diseases. Green tea leaf extract catechin has protective effects against cellular toxicity. This study investigated the effects of catechin on the glutamate-treated retina. Porcine retinal homogenates were incubated with glutamate (20 nmol) at 37 degrees C for 60 min. Catechin was co-incubated with the glutamate-treated retina in the same condition. The malondialdehyde (MDA) levels were determined as an index of lipid peroxidation (LPO). Differential protein expressions were derived from two-dimensional gel electrophoresis. Mass spectrometry was conducted to identify the proteins. Glutamate increased the retinal MDA (p<0.0001) and catechin reversed the effect (p<0.0001). There were significant changes in seven proteins after the glutamate treatment (p<0.05), namely, heterogeneous ribonucleoprotein, thioredoxin peroxidase, 5-hydroxytryptamine receptor, pyruvate dehydrogenase, ARHA protein, peroxiredoxin 6 and proteasome. Catechin significantly reversed the changes in thioredoxin peroxidase, 5-hydroxytryptamine receptor, peroxiredoxin 6 and pyruvate dehydrogenase (p<0.05). Our study shows that (a) retinal glutamate toxicity is mediated by LPO and protein modification, and (b) catechin ameliorates the toxicity.