Safety studies on epigallocatechin gallate (EGCG) preparations. Part 3: teratogenicity and reproductive toxicity studies in rats

Roles of flavonoids in ischemic heart disease: Cardioprotective effects and mechanisms against myocardial ischemia and reperfusion injury

BACKGROUND

Flavonoids are extensively present in fruits, vegetables, grains, and medicinal plants. Myocardial ischemia and reperfusion (MI/R) comprise a sequence of detrimental incidents following myocardial ischemia. Research indicates that flavonoids have the potential to act as cardioprotective agents against MI/R injuries. Several specific flavonoids, e.g., luteolin, hesperidin, quercetin, kaempferol, and puerarin, have demonstrated cardioprotective activities in animal models.

PURPOSE

The objective of this review is to identify the cardioprotective flavonoids, investigate their mechanisms of action, and explore their application in myocardial ischemia.

METHODS

A search of PubMed database and Google Scholar was conducted using keywords "myocardial ischemia" and "flavonoids". Studies published within the last 10 years reporting on the cardioprotective effects of natural flavonoids on animal models were analyzed.

RESULTS

A total of 55 natural flavonoids were identified and discussed within this review. It can be summarized that flavonoids regulate the following main strategies: antioxidation, anti-inflammation, calcium modulation, mitochondrial protection, ER stress inhibition, anti-apoptosis, ferroptosis inhibition, autophagy modulation, and inhibition of adverse cardiac remodeling. Additionally, the number and position of OH, 3'4'-catechol, C2=C3, and C4=O may play a significant role in the cardioprotective activity of flavonoids.

CONCLUSION

This review serves as a reference for designing a daily diet to prevent or reduce damages following ischemia and screening of flavonoids for clinical application.

Epigallocatechin Gallate Affects the Structure of Chromatosomes, Nucleosomes and Their Complexes with PARP1

The natural flavonoid epigallocatechin gallate has a wide range of biological activities, including being capable of binding to nucleic acids; however, the mechanisms of the interactions of epigallocatechin gallate with DNA organized in chromatin have not been systematically studied. In this work, the interactions of epigallocatechin gallate with chromatin in cells and with nucleosomes and chromatosomes in vitro were studied using fluorescent microscopy and single-particle Förster resonance energy transfer approaches, respectively. Epigallocatechin gallate effectively penetrates into the nuclei of living cells and binds to DNA there. The interaction of epigallocatechin gallate with nucleosomes in vitro induces a large-scale, reversible uncoiling of nucleosomal DNA that occurs without the dissociation of DNA or core histones at sub- and low-micromolar concentrations of epigallocatechin gallate. Epigallocatechin gallate does not reduce the catalytic activity of poly(ADP-ribose) polymerase 1, but causes the modulation of the structure of the enzyme-nucleosome complex. Epigallocatechin gallate significantly changes the structure of chromatosomes, but does not cause the dissociation of the linker histone. The reorganization of nucleosomes and chromatosomes through the use of epigallocatechin gallate could facilitate access to protein factors involved in DNA repair, replication and transcription to DNA and, thus, might contribute to the modulation of gene expression through the use of epigallocatechin gallate, which was reported earlier.

Epigallocatechin-3-Gallate Therapeutic Potential in Cancer: Mechanism of Action and Clinical Implications

Cellular signaling pathways involved in the maintenance of the equilibrium between cell proliferation and apoptosis have emerged as rational targets that can be exploited in the prevention and treatment of cancer. Epigallocatechin-3-gallate (EGCG) is the most abundant phenolic compound found in green tea. It has been shown to regulate multiple crucial cellular signaling pathways, including those mediated by EGFR, JAK-STAT, MAPKs, NF-κB, PI3K-AKT-mTOR, and others. Deregulation of the abovementioned pathways is involved in the pathophysiology of cancer. It has been demonstrated that EGCG may exert anti-proliferative, anti-inflammatory, and apoptosis-inducing effects or induce epigenetic changes. Furthermore, preclinical and clinical studies suggest that EGCG may be used in the treatment of numerous disorders, including cancer. This review aims to summarize the existing knowledge regarding the biological properties of EGCG, especially in the context of cancer treatment and prophylaxis.

Therapeutic Activity of Green Tea Epigallocatechin-3-Gallate on Metabolic Diseases and Non-Alcoholic Fatty Liver Diseases: The Current Updates

Green tea polyphenols have numerous functions including antioxidation and modulation of various cellular proteins and are thus beneficial against metabolic diseases including obesity, type 2 diabetes, cardiovascular and non-alcoholic fatty liver diseases, and their comorbidities. Epigallocatechin-3-gallate (EGCG) is the most abundant polyphenol in green tea and is attributed to antioxidant and free radical scavenging activities, and the likelihood of targeting multiple metabolic pathways. It has been shown to exhibit anti-obesity, anti-inflammatory, anti-diabetic, anti-arteriosclerotic, and weight-reducing effects in humans. Worldwide, the incidences of metabolic diseases have been escalating across all age groups in modern society. Therefore, EGCG is being increasingly investigated to address the problems. This review presents the current updates on the effects of EGCG on metabolic diseases, and highlights evidence related to its safety. Collectively, this review brings more evidence for therapeutic application and further studies on EGCG and its derivatives to alleviate metabolic diseases and non-alcoholic fatty liver diseases.

Lead toxicity and potential therapeutic effect of plant-derived polyphenols

BACKGROUND

Due to its unique physical and chemical properties, lead is still used worldwide in several applications, especially in industry. Both environmental and industrial lead exposures remain a public health problem in many developing and rapidly industrializing countries. Plant polyphenols are pleiotropic in their function and have historically made a major contribution to pharmacotherapy.

PURPOSE

To summarize available pre-clinical and limited clinical evidence on plant polyphenols as potential antidotes against lead poisoning and discuss toxic mechanisms of lead.

METHOD

A comprehensive search of peer-reviewed publications was performed from core collections of electronic databases such as PubMed, Web of Science, Google Scholar, and Science Direct. Articles written in English-language from inception until December 2022 were selected.

RESULTS

In this review, we review key toxic mechanisms of lead and its pathological effects on the neurological, reproductive, renal, cardiovascular, hematological, and hepatic systems. We focus on plant polyphenols against lead toxicity and involved mechanisms. Finally, we address scientific gaps and challenges associated with translating these promising preclinical discoveries into effective clinical therapies.

CONCLUSION

While preclinical evidence suggests that plant polyphenols exhibit bioprotective effects against lead toxicity, scant and equivocal clinical data highlight a need for clinical trials with those polyphenols.

Effect of Postnatal Epigallocatechin-Gallate Treatment on Cardiac Function in Mice Prenatally Exposed to Alcohol

Prenatal alcohol exposure affects the cardiovascular health of the offspring. Epigallocatechin-3-gallate (EGCG) may be a protective agent against it, but no data are available regarding its impact on cardiac dysfunction. We investigated the presence of cardiac alterations in mice prenatally exposed to alcohol and the effect of postnatal EGCG treatment on cardiac function and related biochemical pathways. C57BL/6J pregnant mice received 1.5 g/kg/day (Mediterranean pattern), 4.5 g/kg/day (binge pattern) of ethanol, or maltodextrin until Day 19 of pregnancy. Post-delivery, treatment groups received EGCG-supplemented water. At post-natal Day 60, functional echocardiographies were performed. Heart biomarkers of apoptosis, oxidative stress, and cardiac damage were analyzed by Western blot. BNP and Hif1α increased and Nrf2 decreased in mice prenatally exposed to the Mediterranean alcohol pattern. Bcl-2 was downregulated in the binge PAE drinking pattern. Troponin I, glutathione peroxidase, and Bax increased in both ethanol exposure patterns. Prenatal alcohol exposure led to cardiac dysfunction in exposed mice, evidenced by a reduced ejection fraction, left ventricle posterior wall thickness at diastole, and Tei index. EGCG postnatal therapy restored the physiological levels of these biomarkers and improved cardiac dysfunction. These findings suggest that postnatal EGCG treatment attenuates the cardiac damage caused by prenatal alcohol exposure in the offspring.

Secondary metabolites as potential drug candidates against Zika virus, an emerging looming human threat: Current landscape, molecular mechanism and challenges ahead

Nature has given us yet another wild card in the form of Zika virus (ZIKV). It was found in 1947, but has only recently become an important public health risk, predominantly to pregnant women and their unborn offspring. Currently, no specific therapeutic agent exists for ZIKV and treatment is mainly supportive. Natural products (NPs) can serve as a major source of potent antiviral drugs. To create this review, a comprehensive search was conducted from different databases (PubMed, ScienceDirect, Google scholar). A statistical analysis on the number of publications related to NPs and ZIKV was conducted to analyse the trend in research covering the period 1980-2020. From the data collated in this review, a number of NPs have been found to be inhibitive towards different stages of the ZIKV lifecycle in in vitro studies. For instance, baicalin, (-)-epigallocatechin gallate, curcumin, nanchangmycin, gossypol, cephaeline, emetine, resveratrol, berberine, amongst others, can prevent viral entry by attacking ZIKV E protein. Compounds luteolin, myricetin, astragalin, rutin, (-)-epigallocatechin gallate, carnosine, pedalitin, amongst others, inhibited NS2B-NS3 protease activity which consequently hamper replication. Interestingly, a few NPs had the ability to arrest both viral entry and replication, namely baicalin, (-)-epigallocatechin gallate, curcumin, cephaeline, emetine, and resveratrol. To the best of our knowledge, we obtained only one in vivo study conducted on emetine and results showed that it decreased the levels of circulating ZIKV by approximately 10-fold. Our understanding on NPs exhibiting anti-ZIKV effects in in vivo testing as well as clinical trials is limited. Our trend analysis showed that interest in searching for a cure or prevention against Zika in NPs is negligible and there are no publications yet covering the clinical evaluation. NPs with anti-ZIKV property can a winning strategy in controlling the bio-burden of an epidemic or pandemic. We therefore opine that in the future, more research should be devoted to ZIKV. This review attempts to provide baseline data and roadmap to pursuit detailed investigations for developing potent and novel therapeutic agents to prevent and cure ZIKV infection.

Evaluation of the effect of green tea and its constituents on embryo development in a zebrafish model

As one of the most popular beverages, green tea has attracted much interest for its beneficial effects on human health. However, the toxicity of green tea and its underlying mechanism are still poorly understood. Here, we evaluated the effect of green tea and its constituents on development by exposing zebrafish embryos to them. Morphologic results demonstrated that 0.1% and 0.2% green tea increased mortality, delayed epiboly of gastrulation, and shortened body length. Green tea altered the expression pattern of dlx3, cstlb, myod, and papc and decreased the expression levels of wnt5 and wnt11, suggesting that green tea disturbed convergence and extension movement through the downregulation of wnt5 and wnt11. The increased expression of the dorsal gene chordin and reduced expression of wnt8 and its target genes vox and vent in embryos exposed to 0.1% and 0.2% green tea indicated that green tea could affect dorsoventral differentiation by inhibiting the wnt8 signaling pathway. Additionally, green tea could inhibit epiboly progression by disrupting F-actin organization or removing F-actin in vegetal yolks during gastrulation. However, no malformation was caused by exposure to the five catechins and gallic acid individually. The mixture of constituents showed a similar effect to green tea solution on the embryos, such as smaller eyes and head, shorter body length, and slower heart rate, which indicated that the effect of green tea solution on embryo development was mainly due to the comprehensive effect of multiple components in the green tea solution.

Effect of Green Tea on Weight Gain and Semen Quality of Rabbit Males

The goal of the current study was to evaluate the action of the green tea plant (Camellia sinensis, L) on male rabbit reproduction and some non-reproductive indexes. Male rabbits were fed either a standard diet (control group) or a diet enriched with green tea powder (experimental groups; E): 5 g (E1) or 20 g (E2) per 100 kg of the milled complete feed mixture. Weight gain, sperm concentration, total and progressive motility, as well as haematological, and biochemical parameters and changes in testicular tissue histomorphology were evaluated. Feeding with green tea, at both tested concentrations, decreased weight gain per week and the total average weight gain compared to the control group (p < 0.05). Furthermore, green tea decreased sperm concentration, motility and progressive motility in the group fed with a lower dose (5 g) of green tea powder (p < 0.05), whilst a higher dose (20 g) was neutral. Some haematological and biochemical indexes, like medium-size cell count (MID), mean corpuscular haemoglobin concentration (MCHC), platelet percentage (PCT), levels of phosphorus (P) and total proteins (TP) were decreased in one or both experimental groups (p < 0.05), whilst the triglyceride level (TG) was increased in the E2 group (p < 0.05). The thicknesses of the testicular seminiferous tubules and epithelial layer were not affected by any concentration of green tea powder (p > 0.05). These observations suggest that green tea in the diet may have an adverse effect on rabbit growth and sperm quality, but their effect may be potentially dose-dependent.

Catechins protect against acrylamide- and glycidamide-induced cellular toxicity via rescuing cellular apoptosis and DNA damage

Acrylamide (AA) occurs in both various environmental and dietary sources and has raised widespread concern as a probable carcinogen. Glycidamide (GA) is the main genotoxic metabolite through P450 2E1 (CYP2E1). In the present study, we investigate the protective effect of (-)-epigallocatechin gallate (EGCG) and (-)-epicatechin (EC) against AA- and GA-induced hepatotoxicity in HepG2 cells. The results demonstrated that EC and EGCG inhibited AA- and GA-induced cytotoxicity and mitochondria-mediated cellular apoptosis. Moreover, exposure to AA (100 μg/mL) and GA (50 μg/mL) caused cell cycle arrest and DNA damage, while EC and EGCG ranging from 12.5 to 50 μg/mL rescued cell cycle arrest and inhibited DNA damage. Furthermore, EC and EGCG down-regulated pro-apoptotic protein Bax and Caspase 3 after 24 h treatment in HepG2 cells exposed to AA (100 μg/mL) or GA (50 μg/mL). Also, the intervention with EC or EGCG up-regulated DNA repair related protein PARP and down-regulated expression of cleaved-PARP. Besides, EC exerted better protective effect than EGCG against AA- and GA-induced cytotoxicity in HepG2 cells. Altogether, EC and EGCG were effective in protecting AA- and GA-induced hepatotoxicity via rescuing cellular apoptosis and DNA damage, as well as promoting cell cycle progression in HepG2 cells.

Increased dosage and treatment time of Epigallocatechin-3-gallate (EGCG) negatively affects skeletal parameters in normal mice and Down syndrome mouse models

Bone abnormalities affect all individuals with Down syndrome (DS) and are linked to abnormal expression of DYRK1A, a gene found in three copies in people with DS and Ts65Dn DS model mice. Previous work in Ts65Dn male mice demonstrated that both genetic normalization of Dyrk1a and treatment with ~9 mg/kg/day Epigallocatechin-3-gallate (EGCG), the main polyphenol found in green tea and putative DYRK1A inhibitor, improved some skeletal deficits. Because EGCG treatment improved mostly trabecular skeletal deficits, we hypothesized that increasing EGCG treatment dosage and length of administration would positively affect both trabecular and cortical bone in Ts65Dn mice. Treatment of individuals with DS with green tea extract (GTE) containing EGCG also showed some weight loss in individuals with DS, and we hypothesized that weights would be affected in Ts65Dn mice after EGCG treatment. Treatment with ~20 mg/kg/day EGCG for seven weeks showed no improvements in male Ts65Dn trabecular bone and only limited improvements in cortical measures. Comparing skeletal analyses after ~20mg/kg/day EGCG treatment with previously published treatments with ~9, 50, and 200 mg/kg/day EGCG showed that increased dosage and treatment time increased cortical structural deficits leading to weaker appendicular bones in male mice. Weight was not affected by treatment in mice, except for those given a high dose of EGCG by oral gavage. These data indicate that high doses of EGCG, similar to those reported in some treatment studies of DS and other disorders, may impair long bone structure and strength. Skeletal phenotypes should be monitored when high doses of EGCG are administered therapeutically.

EGCG prevents pressure overload‑induced myocardial remodeling by downregulating overexpression of HDAC5 in mice

Myocardial remodeling is a complex pathological process and its mechanism is unclear. The present study investigated whether epigallocatechin gallate (EGCG) prevents myocardial remodeling by regulating histone acetylation and explored the mechanisms underlying this effect in the heart of a mouse model of transverse aortic constriction (TAC). A TAC mouse model was created by partial thoracic aortic banding (TAB). Subsequently, TAC mice were injected with EGCG at a dose of 50 mg/kg/day for 12 weeks. The hearts of mice were collected for analysis 4, 8 and 12 weeks after TAC. Histopathological changes in the heart were observed by hematoxylin and eosin, Masson trichrome and wheat germ agglutinin staining. Protein expression levels were investigated using western blotting. Cardiac function of mice was detected by echocardiography. The level of histone acetylated lysine 27 on histone H3 (H3K27ac) first increased and then decreased in the hearts of mice at 4, 8 and 12 weeks after TAC. The expression levels of two genes associated with pathological myocardial remodeling, atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), also increased initially but then decreased. The expression levels of histone deacetylase 5 (HDAC5) gradually increased in the hearts of mice at 4, 8 and 12 weeks after TAC. Furthermore, EGCG increased acetylation of H3K27ac by inhibiting HDAC5 in the heart of TAC mice treated with EGCG for 12 weeks. EGCG normalized the transcriptional activity of heart nuclear transcription factor myocyte enhancer factor 2A in TAC mice treated for 12 weeks. The low expression levels of myocardial remodeling‑associated genes (ANP and BNP) were reversed by EGCG treatment for 12 weeks in TAC mice. In addition, EGCG reversed cardiac enlargement and improved cardiac function and survival in TAC mice when treated with EGCG for 12 weeks. Modification of the HDAC5‑mediated imbalance in histone H3K27ac served a key role in pathological myocardial remodeling. The present results show that EGCG prevented and delayed myocardial remodeling in TAC mice by inhibiting HDAC5.

(Poly)phenol toxicity in vivo following oral administration: A targeted narrative review of (poly)phenols from green tea, grape, and anthocyanin-rich extracts

Fruit- and vegetable-derived (poly)phenols are secondary plant metabolites that may have beneficial effects on human health when consumed regularly. Recent years have seen rapid growth in both consumer demand for and research interest in (poly)phenol-rich dietary supplements, natural colorants, and functional foods. As these products continue to enter the marketplace and (poly)phenol intake patterns change from traditional food products to these sources, attention must be paid to the potential for toxicity from consuming elevated doses of (poly)phenols. To date, much remains unknown regarding the safety of high doses of (poly)phenols, especially in vivo. In this targeted narrative review, we summarize evidence from in vivo investigations of (poly)phenol toxicity after oral administration of green tea extracts, grape-derived phenolics, and anthocyanin-rich extracts. There is limited evidence of overt toxicity from oral ingestion of these (poly)phenol-rich sources, though more research on the safety of high doses-as well as defining what constitutes a "high" dose of both individual and complex mixtures of (poly)phenols-is needed before these observations can be used to create dietary guidance for consumers.

Pharmaceuticals targeting signaling pathways of endometriosis as potential new medical treatment: A review

Endometriosis (EM) is defined as endometrial tissues found outside the uterus. Growth and development of endometriotic cells in ectopic sites can be promoted via multiple pathways, including MAPK/MEK/ERK, PI3K/Akt/mTOR, NF-κB, Rho/ROCK, reactive oxidative stress, tumor necrosis factor, transforming growth factor-β, Wnt/β-catenin, vascular endothelial growth factor, estrogen, and cytokines. The underlying pathophysiological mechanisms include proliferation, apoptosis, autophagy, migration, invasion, fibrosis, angiogenesis, oxidative stress, inflammation, and immune escape. Current medical treatments for EM are mainly hormonal and symptomatic, and thus the development of new, effective, and safe pharmaceuticals targeting specific molecular and signaling pathways is needed. Here, we systematically reviewed the literature focused on pharmaceuticals that specifically target the molecular and signaling pathways involved in the pathophysiology of EM. Potential drug targets, their upstream and downstream molecules with key aberrant signaling, and the regulatory mechanisms promoting the growth and development of endometriotic cells and tissues were discussed. Hormonal pharmaceuticals, including melatonin, exerts proapoptotic via regulating matrix metallopeptidase activity while nonhormonal pharmaceutical sorafenib exerts antiproliferative effect via MAPK/ERK pathway and antiangiogenesis activity via VEGF/VEGFR pathway. N-acetyl cysteine, curcumin, and ginsenoside exert antioxidant and anti-inflammatory effects via radical scavenging activity. Natural products have high efficacy with minimal side effects; for example, resveratrol and epigallocatechin gallate have multiple targets and provide synergistic efficacy to resolve the complexity of the pathophysiology of EM, showing promising efficacy in treating EM. Although new medical treatments are currently being developed, more detailed pharmacological studies and large sample size clinical trials are needed to confirm the efficacy and safety of these treatments in the near future.

From the lab to the people: major challenges in the biological treatment of Down syndrome

Down syndrome (DS) refers to a genetic condition due to the triplication of human chromosome 21. It is the most frequent autosomal trisomy. In recent years, experimental work has been conducted with the aim of removing or silencing the extra chromosome 21 (C21) in cells and normalizing genetic expression. This paper examines the feasibility of the move from laboratory studies to biologically treating “bone and flesh” people with DS. A chromosome or a gene therapy for humans is fraught with practical and ethical difficulties. To prevent DS completely, genome editing would have to be performed early on embryos in the womb. New in vitro findings point toward the possibility of epigenetic silencing the extra C21 in later embryonic or fetal life, or even postnatally for some aspects of neurogenesis. These possibilities are far beyond what is possible or allowed today. Another approach is through epigenetic regulation of the overexpression of particular genes in C21. Research with mouse modeling of DS is yielding promising results. Human applications have barely begun and are questioned on ethical grounds.

Zika virus pathogenesis and current therapeutic advances

Zika virus (ZIKV) is an emerging arthropod-borne flavivirus that, upon infection, results in teratogenic effects and neurological disorders. ZIKV infections pose serious global public health concerns, prompting scientists to increase research on antivirals and vaccines against the virus. These efforts are still ongoing as the pathogenesis and immune evasion mechanisms of ZIKV have not yet been fully elaborated. Currently, no specific vaccines or drugs have been approved for ZIKV; however, some are undergoing clinical trials. Notably, several strategies have been used to develop antivirals, including drugs that target viral and host proteins. Additionally, drug repurposing is preferred since it is less costly and takes less time than other strategies because the drugs used have already been approved for human use. Likewise, different platforms have been evaluated for the design of vaccines, including DNA, mRNA, peptide, protein, viral vectors, virus-like particles (VLPSs), inactivated-virus, and live-attenuated virus vaccines. These vaccines have been shown to induce specific humoral and cellular immune responses and reduce viremia and viral RNA both in vitro and in vivo. Importantly, most of these vaccines have entered clinical trials. Understanding the viral disease mechanism will provide better strategies for developing therapeutic agents against ZIKV. This review provides a comprehensive summary of the viral pathogenesis of ZIKV and current advancements in the development of vaccines and drugs against this virus.

Effect of epigallocatechin-3-gallate (EGCG) on embryos inseminated with oxidative stress-induced DNA damage sperm

Cryopreservation can induce damage in human spermatozoa through reactive oxygen species (ROS) generation. To reduce the potential risk of oxidative stress-induced sperm DNA damage, addition of different epigallocatechin-3-gallate (EGCG) concentrations were performed to determine the optimum concentration which was beneficial for IVF outcome for both fresh and frozen-thawed sperm. Next, the mouse sperm model exhibiting oxidative stress-induced DNA damage by exogenously treating with H₂O₂ but overcoming the low fertilization rate of frozen-thawed sperm was used to investigate the effect of EGCG on the embryonic development and the potential EGCG-mediated effects on ataxia telangiectasia mutated (ATM) pSer-1981 in zygotes, the latter was known for leading to the activation of major kinases involved in the DNA repair pathway and the cell cycle checkpoint pathway. We found the fertilization and embryonic development of embryos inseminated with frozen-thawed sperm was impaired compared to fresh sperm. EGCG promoted the development of embryos inseminated with both types of sperm at optimum concentration. In embryos inseminated with the H₂O₂ sperm, fertilization, embryonic development, and the time at which the cleavage rate of one-cell embryos reached ≥95% were not affected by EGCG treatment. However, the EGCG-treated group required less time to achieve 50% cleavage rate of one-cell embryos, and the EGCG-treated zygotes showed enhanced expression of ATM (pSer-1981) than the untreated group. EGCG at optimum concentrations may exert beneficial effects by modulating the ATM activation and moving up the time to enter into mitotic (M) phase.

ABBREVIATIONS

ROS: reactive oxygen species; EGCG: epigallocatechin-3-gallate; ATM: ataxia telangiectasia mutated; M: mitotic.

Safety Assessment of Camellia sinensis-Derived Ingredients As Used in Cosmetics

Cosmetic ingredients derived from Camellia sinensis (tea) plant parts function as antioxidants and skin conditioning agents-humectant and miscellaneous. The Cosmetic Ingredient Review (CIR) Expert Panel (Panel) reviewed relevant animal and human data related to these ingredients. The use of the leaf ingredients in beverages results in much larger systemic exposures than those possible from cosmetic use. Accordingly, concern over the systemic toxicity potential of leaf-derived ingredients is mitigated. Because product formulations may contain multiple botanical ingredients, each containing the same constituents of concern, formulators are advised to be aware of these constituents and to avoid reaching levels that may lead to sensitization or other toxic effects. The Panel concluded that the C sinensis leaf-derived ingredients are safe in the present practices of use and concentration described in this safety assessment when formulated to be nonsensitizing. However, the available data are insufficient to determine whether the non-leaf-derived ingredients are safe for use in cosmetics.

Supplementation of Plants with Immunomodulatory Properties during Pregnancy and Lactation-Maternal and Offspring Health Effects

A pregnant woman’s diet consists of many products, such as fruits, vegetables, cocoa, tea, chocolate, coffee, herbal and fruit teas, and various commercially available dietary supplements, which contain a high number of biological active plant-derived compounds. Generally, these compounds play beneficial roles in women’s health and the development of fetus health. There are, however, some authors who report that consuming excessive amounts of plants that contain high concentrations of polyphenols may negatively affect the development of the fetus and the offspring’s health. Important and problematic issues during pregnancy and lactation are bacterial infections treatment. In the treatment are proposals to use plant immunomodulators, which are generally considered safe for women and their offspring. Additional consumption of biologically active compounds from plants, however, may increase the risk of occurrences to irreversible changes in the offspring’s health. Therefore, it is necessary to carry out safety tests for immunomodulators before introducing them into a maternal diet. Here, we present data from animal experiments for the four most-studied plants immunomodulators genus: Rhodiola, Echinacea, Panax, and Camellia, which were used in maternal nutrition.

Inositol and antioxidant supplementation: Safety and efficacy in pregnancy

Pregnancies complicated by diabetes have largely increased in number over the last 50 years. Pregnancy is characterized by a physiologic increase in insulin resistance, which, associated with increased oxidative stress and inflammations, could induce alterations of glucose metabolism and diabetes. If not optimally controlled, these conditions have a negative impact on maternal and foetal outcomes. To date, one can resort only to diet and lifestyle to treat obesity and insulin resistance during pregnancy, and insulin remains the only therapeutic option to manage diabetes during pregnancy. However, in the last years, in a variety of experimental models, inositol and antioxidants supplementation have shown insulin-sensitizing, anti-inflammatory, and antioxidant properties, which could be mediated by some possible complementary mechanism of action. Different isomers and multiple combinations of these compounds are presently available: Aim of the present review article is to examine the existing evidence in order to clarify and/or define the effects of different inositol- and antioxidant-based supplements during pregnancy complicated by insulin resistance and/or by diabetes. This could help the clinician's evaluation and choice of the appropriate supplementation regimen.

Tannins and vascular complications of Diabetes: An update

BACKGROUND

Diabetes mellitus is a chronic metabolic disorder associated with persistent increased level of glucose in the blood. According to a report by World Health Organisation (WHO), prevalence of diabetes among adults over 18 years of age had reached to 8.5% in year 2014 which was 4.7% in 1980s. The Prolong increased level of glucose in blood leads to development of microvascular (blindness, nephropathy and neuropathy) and macrovascular (cardiovascular and stroke) degenerative complications because of uncontrolled level of glucose in blood. This also leads to the progression of oxidative stress and affecting metabolic, genetic and haemodynamic system by activation of polyol pathway, protein kinase C pathway, hexosamine pathway and increases advanced glycation end products (AGEs) formation. Diabetes mellitus and its associated complications are one of the major leading causes of mortality worldwide. Various natural products like alkaloids, glycosides, flavonoids, terpenoids and polyphenols are reported for their activity in management of diabetes and its associated diabetic complications. Tannins are systematically studied by many researchers in past few decades for their effect in diabetes and its complications.

AIM

The present review was designed to compile the data of tannins and their beneficial effects in the management of diabetic complications.

METHOD

Literature search was performed using various dataset like pubmed, EBSCO, proQuest Scopus and selected websites including the National Institutes of Health (NIH) and the World Health Organization (WHO).

RESULTS

Globally, more than 400 natural products have been investigated in diabetes and its complications. Tannins are the polyphenolic compounds present in many medicinal plants and various dietary sources like fruits, nuts, grains, spices and beverages. Various reports have shown that compounds like gallic acid, ellagic acid, catechin, epicatechin and procynidins from medicinal plants play major role in controlling progression of diabetes and its related complications by acting on molecular pathways and key targets involved in progression. Many chemists used above mentioned phyto-constituents as a pharmacophore for the developing new chemical entities having higher therapeutic benefits in management of diabetic complications.

CONCLUSION

This review focuses on the role of various tannins in prevention and management of diabetic complications like diabetic nephropathy, diabetic neuropathy, diabetic retinopathy and diabetic cardiomyopathy. It will help researchers to find some leads for the development of new cost effective therapy using dietary source for the management of diabetic complications.

Nanochemoprevention with therapeutic benefits: An updated review focused on epigallocatechin gallate delivery

Epigallocatechin gallate (EGCG) is a natural phenolic compound found in many plants, especially in green tea, which is a popular and restorative beverage with many claimed health benefits such as antioxidant, anti-cancer, anti-microbial, anti-diabetic, and anti-obesity activities. Despite its great curative potential, the poor bioavailability of EGCG restricts its clinical applcation. However, nanoformulations of EGCG are emerging as new alternatives to traditional formulations. This review focuses on the nanochemopreventive applications of various EGCG nanoparticles such as lipid-based, polymer-based, carbohydrate-based, protein-based, and metal-based nanoparticles. EGCG hybridized with these nanocarriers is capable of achieving advanced functions such as targeted release, active targeting, and enhanced penetration, ultimately increasing the bioavailability of EGCG. In addition, this review also summarizes the challenges for the use of EGCG in therapeutic applications, and suggests future directions for progress.

Epigallocatechin gallate & curcumin prevent transforming growth factor beta 1-induced epithelial to mesenchymal transition in ARPE-19 cells

Background & objectives

Proliferative vitreoretinopathy (PVR) is characterized by the presence of epiretinal membrane (ERM), which exerts traction and detaches the retina. Epithelial to mesenchymal transition (EMT) of the retinal pigment epithelial (RPE) cells underlies ERM formation. Adjuvant therapies aimed at preventing recurrence of PVR after surgery mostly failed in clinical trials. This study was aimed to evaluate the anti-EMT properties of bio-active compounds epigallocatechin gallate (EGCG), curcumin and lycopene as inhibitors of EMT induced by transforming growth factor beta 1 (TGF-β1) in cultured ARPE-19 cells.

Methods

ARPE-19 cells were treated with TGF-β1 alone or co-treated with EGCG (1-50 μM), lycopene (1-10 μM) and curcumin (1-10 μM). The mRNA and protein expression of EMT markers, alpha-smooth muscle actin, vimentin, zonula occludens-1 and matrix metalloproteinase-2 (MMP-2), were assessed by reverse transcription polymerase chain reaction/quantitative polymerase chain reaction and immunofluorescence/enzyme linked immunosorbent assay. Activity of MMP-2 was assessed by zymography. Functional implications of EMT were assessed by proliferation assay (MTT assay) and migration assay (scratch assay). Western-blot for phosphorylated Smad-3 and total Smad-3 was done to delineate the mechanism.

Results

EGCG and curcumin at 10 μM concentration reversed EMT, inhibited proliferation and migration through Smad-3 phosphorylation, when induced by TGF-β1 in ARPE-19 cells. Lycopene did not prevent EMT in ARPE-19 cells.

Interpretation & conclusions

EGCG and curcumin are potent in preventing EMT induced by TGF-β1 in ARPE-19 cells and therefore, proposed as potential molecules for further pre-clinical evaluation in PVR management.

A review of interventions against fetal alcohol spectrum disorder targeting oxidative stress

INTRODUCTION

Fetal alcohol spectrum disorder is caused by maternal ethanol exposure; it causes physical, behavioral, cognitive, and neural impairments (Murawski et al., 2015). Mechanisms of FASD causing damage are not yet fully elucidated. Oxidative stress might be one of its mechanisms (Henderson et al., 1995). Yet no effective treatment against FASD has been found other than ethanol abstention (Long et al., 2010).

METHODS

This review summarizes relevant literatures regarding interventions targeting oxidative stress that may relieve fetal alcohol spectrum disorder.

RESULTS

Astaxanthin was found to mitigate embryonic growth retardation induced by prenatal ethanol treatment through ameliorating the down regulation of hydrogen peroxide (H2O2) and malondialdehyde (MDA) caused by alcohol in a mice model (Zheng et al., 2014; Vabulas et al., 2002). Vitamin E protected against fatal alchol spectrum disorders by ameliorating oxidative stress in rat models (Mitchell et al., 1999a), and yielded a better outcome when it was combined with Vitamin C (Packer et al., 1979; Peng et al., 2005). Vitamin C mitigated embryonic retardation caused by alcohol and reversed ethanol induced NF-κB activation and ROS (reactive oxygen species) formation in a Xenopus laevis model (Peng et al., 2005). Beta carotene supplement was proved to protect against neurotoxicity in hippocampal cultures of embryos induced by alcohol in a rats model (Mitchell et al., 1999a). Prenatal folic acid supplement reversed the decrease of body weight caused by maternal ethanol treatment and ameliorated the increment of glutathione reductase specific activities as well as the increase of thiobarbituric acid reactive substances (TBARS) induced by alcohol in a rats model (Cano et al., 2001). Omega-3 fatty acids reversed the decrease of reduced glutathione (GSH) levels in brain caused by prenatal ethanol treatment in a rats model (Patten et al., 2013). EUK-134 treatment reduced the incidence of forelimb defects caused by ethanol treatment in a mice model (Chen et al., 2004). Pretreatment of activity-dependent neurotrophic factor-9 (ADNF-9) and NAPVSIPQ (NAP) protected against prenatal ethanol induced fetal death as well as fetal growth abnormalities in a mice model, and such treatment reversed the decrease of the rate of reduced glutathione (GSH)/ oxidative glutathione (GSSG) caused by alcohol (Spong et al., 2001).

CONCLUSION

By now interventions against fetal alcohol spectrum disorder targeting oxidative stress includes astaxanthin, Ascorbic acid (Vitamin C), Vitamin E, beta-carotene, (-)-Epigallocatechin-3-gallate (EGCG), Omega-3 fatty acids, etc (see Fig. 1). However, most interventions are only assayed in animal models, more clinical trials are needed to show whether antioxidants make an effort against FASD damage.

Toxicological effects of Camellia sinensis (green tea): A review

Many scientific articles proved that green tea (GT), Camellia sinensis, has a great potential to manage central nervous system, cardiovascular, and metabolic diseases and treat cancer and inflammatory disorders. However, it is important to consider that "natural" is not always "safe." Some relevant articles reported side effects of GT, detrimental effects on health. The aim of this study is to provide a classified report about the toxicity of GT and its main constituents in acute, subacute, subchronic, and chronic states. Furthermore, it discusses on the cytotoxicity, genotoxicity, mutagenicity, carcinogenicity, and developmental toxicity of GT and its main constituents. The most important side effects have been reported hepatotoxicity and gastrointestinal disorders specially while consumed on an empty stomach. GT and its main components are not major teratogen, mutagen, or carcinogen substances. However, there is limited data in using them during pregnancy, and they should be used with caution in pregnancy, breast-feeding, and susceptible people. Because GT and its main components have a wide variety of drug interactions, consideration should be taken in coadministration of them with narrow therapeutic indexed drugs. Furthermore, they evoke selective cytotoxicity on cancerous cells that could engage them as an adjuvant substance in cancer therapy.

The safety of green tea and green tea extract consumption in adults - Results of a systematic review

A systematic review of published toxicology and human intervention studies was performed to characterize potential hazards associated with consumption of green tea and its preparations. A review of toxicological evidence from laboratory studies revealed the liver as the target organ and hepatotoxicity as the critical effect, which was strongly associated with certain dosing conditions (e.g. bolus dose via gavage, fasting), and positively correlated with total catechin and epigallocatechingallate (EGCG) content. A review of adverse event (AE) data from 159 human intervention studies yielded findings consistent with toxicological evidence in that a limited range of concentrated, catechin-rich green tea preparations resulted in hepatic AEs in a dose-dependent manner when ingested in large bolus doses, but not when consumed as brewed tea or extracts in beverages or as part of food. Toxico- and pharmacokinetic evidence further suggests internal dose of catechins is a key determinant in the occurrence and severity of hepatotoxicity. A safe intake level of 338 mg EGCG/day for adults was derived from toxicological and human safety data for tea preparations ingested as a solid bolus dose. An Observed Safe Level (OSL) of 704 mg EGCG/day might be considered for tea preparations in beverage form based on human AE data.

Repeated dose 28-day oral toxicity study of a botanical composition composed of Morus alba and Acacia catechu in rats

Patients with osteoarthritis experience debilitating pain and loss of joint function that requires chronic treatment. While nonsteroidal anti-inflammatory drugs (NSAIDs) have been effective for temporary symptomatic relief, their long term usage has been limited by their associated side-effects. UP1306, a standardized novel composition from the extracts of root barks of Morus alba and the heartwoods of Acacia catechu, has been used in over the counter joint care dietary supplements as a safer alternative. These two medicinal plants have long track records of safe human consumption. Here we evaluated the potential adverse effects of orally administered UP1306 in Sprague Dawley rats following a 28-day repeated oral dose toxicity study. UP1306 at doses of 500, 1000 and 2000 mg/kg/day were administered orally to rats for 4 weeks. A 2-week recovery group from the high dose (2000 mg/kg) and vehicle treated groups were included. No morbidity or mortality was observed for the duration of the study. No significant differences between groups in body weights, food consumption, hematology, clinical chemistry, organ weights, gross pathology and histopathology were documented. Minor aberrations from the normal observed for the main groups were considered reversible as they were not evident in the recovery period. In conclusion, the no-observed-adverse-effect-level (NOAEL) of UP1306 was considered to be the highest dose tested, 2000 mg/kg/day, both for male and female rats.

Epigallocatechin-3-Gallate (EGCG) Promotes Autophagy-Dependent Survival via Influencing the Balance of mTOR-AMPK Pathways upon Endoplasmic Reticulum Stress

The maintenance of cellular homeostasis is largely dependent on the ability of cells to give an adequate response to various internal and external stimuli. We have recently proposed that the life-and-death decision in endoplasmic reticulum (ER) stress response is defined by a crosstalk between autophagy, apoptosis, and mTOR-AMPK pathways, where the transient switch from autophagy-dependent survival to apoptotic cell death is controlled by GADD34. The aim of the present study was to investigate the role of epigallocatechin-3-gallate (EGCG), the major polyphenol of green tea, in promoting autophagy-dependent survival and to verify the key role in connecting GADD34 with mTOR-AMPK pathways upon prolonged ER stress. Our findings, obtained by using HEK293T cells, revealed that EGCG treatment is able to extend cell viability by inducing autophagy. We confirmed that EGCG-induced autophagy is mTOR-dependent and PKA-independent; furthermore, it also required ULK1. We show that pretreatment of cells with EGCG diminishes the negative effect of GADD34 inhibition (by guanabenz or siGADD34 treatment) on autophagy. EGCG was able to delay apoptotic cell death by upregulating autophagy-dependent survival even in the absence of GADD34. Our data suggest a novel role for EGCG in promoting cell survival via shifting the balance of mTOR-AMPK pathways in ER stress.

Black Tea (Camellia sinensis) Extract Induced Prenatal and Postnatal Toxicity in Experimental Albino rats

Background

Tea (Camellia sinensis) being the most widely drank beverage and despite having numerous beneficial role toward health and disease, its safety evaluation during pregnancy and prenatal, postnatal developmental period need to be monitored.

Objective

This study was to evaluate the toxicity of black tea extract (BTE) in experimental pregnant rats and on their pups during prenatal and postnatal developmental periods.

Materials and Methods

Pregnant female (120 ± 10 g) Wister albino rats were chosen for this study. Group 1 was control group where pregnant female rats were treated with saline. Group 2 and Group 3 were pregnant female rats treated with 50 mg and 100 mg BTE/kg/day, respectively, throughout prenatal and postnatal periods. All three groups of rats were provided food and drinking water ad libitum. Animals were examined through their urinary and serum parameters, histopathological studies, and biomorphometric studies in pups. All data were expressed as mean ± standard deviation with significance between the controls and the treated groups (n = 6). Collected data were subjected to the analysis of variance and Tukey test; P < 0.05 was considered as statistically significant.

Results

BTE produced significant alterations in urinary calcium, creatinine, and urea during prenatal period; exhibited proteinuria, ketonuria, and histology showed nephrotoxicity during postnatal period, and BTE also showed a significant increase in serum proinflammatory cytokines and decreased anti-inflammatory cytokines level compared to control group. BTE caused significant changes in biomorphometric parameters in the pups as compared with pups of control mothers.

Conclusion

This study confirmed the BTE-induced toxicity in pregnant rats and their pups.

SUMMARY

Black tea (Camellia sinensis) is the most widely drank beverage. This study was to evaluate the toxicity BTE in experimental pregnant rats and on their pups during prenatal and postnatal developmental periods. Animals were examined through their urinary and serum parameters, histopathological studies, and biomorphometric studies in pups. BTE.induced toxicity in pregnant rats and their pups. Abbreviations used: BTE: Black tea extract, IL-1α: Interleukin 1 alpha, IL-1 β: Interleukin 1 beta, IL-6: Interleukin 6, IL-10: Interleukin 10, TNF-α: Tumor necrosis factor alpha.

Potential benefit of (-)-epigallocatechin-3-gallate for macrovascular complications in diabetes

Vascular problems are the most common complications in diabetes. Substantial evidence from epidemiological and pathophysiological studies show that hyperglycemia is a major risk factor for macrovascular complications in patients with diabetes. (-)-Epigallocatechin-3-gallate (EGCG), the major catechin derived from green tea, is known to exert a variety of cardiovascular beneficial effects. The protective effects of EGCG in diabetes are also evident. However, whether EGCG is beneficial against macrovascular complications that occur in diabetes remains unknown. Our previous studies demonstrated that treatment of EGCG inhibits high glucose-induced vascular smooth muscle cell proliferation and suppresses high glucose-mediated vascular inflammation in human umbilical vein endothelial cells. Therefore, we hypothesize that EGCG might be an effective potential candidate to reduce the macrovascular complications in diabetes.

Safety Evaluation of Green Tea Polyphenols Consumption in Middle-aged Ovariectomized Rat Model

This work evaluates chronic safety in middle-aged ovariectomized rats supplemented with different dosages of green tea polyphenols (GTP) in drinking water. The experiment used 6-mo-old sham (n = 39) and ovariectomized (OVX, n = 143) female rats. All sham (n = 39) and 39 of the OVX animals received no GTP treatment and their samples were collected for outcome measures at baseline, 3 mo, and 6 mo (n = 13 per group for each). The remaining OVX animals were randomized into 4 groups receiving 0.15%, 0.5%, 1%, and 1.5% (n = 26 for each) of GTP (wt/vol), respectively, in drinking water for 3 and 6 mo. No mortality or abnormal treatment-related findings in clinical observations or ophthalmologic examinations were noted. No treatment-related macroscopic or microscopic findings were noted for animals administered 1.5% GTP supplementation. Throughout the study, there was no difference in the body weight among all OVX groups. In all OVX groups, feed intake and water consumption significantly decreased with GTP dose throughout the study period. At 6 mo, GTP intake did not affect hematology, clinical chemistry, and urinalysis, except for phosphorus and blood urea nitrogen (increased), total cholesterol, lactate dehydrogenase, and urine pH (decreased). This study reveals that the no-observed-adverse-effect level (NOAEL) of GTP is 1.5% (wt/vol) in drinking water, the highest dose used in this study.

Epigallocatechin gallate, an active green tea compound inhibits the Zika virus entry into host cells via binding the envelope protein

Emerging infections of Zika virus (ZIKV) are associated with serious consequences like microcephaly and Guillain-Barré syndrome. It leads to a situation of global health emergency and demand an intensive research investigation to develop safe and effective therapeutics. Various efforts have been made to reduce the pathological pressure of ZIKV, but no effective drug has been introduced against ZIKV infections. A recent study has reported the inhibition of ZIKV entry into the host cells by an active green tea ingredient, Epigallocatechin Gallate (EGCG) in Vero E6cells. The effect of EGCG seems remarkable but lacking the information of the mechanism of action. In this study, we have investigated the binding site (Site1) of EGCG on envelope protein and provided the insights into various interactions of molecule with the binding site using molecular docking studies. Further, using molecular dynamics approaches we proposed the possible associated mechanism of inhibition of ZIKV entry by EGCG molecule. EGCG has found to interact with several residues and providing stability to the protein conformations up to 50ns simulations.

Safety assessment of green tea based beverages and dried green tea extracts as nutritional supplements

The safety of green tea infusions and green tea extract (GTE)-based products is reviewed regarding catechins. Epigallocatechin 3-gallate (EGCG), the major catechin present in green tea, is suspected of being responsible for liver toxicity reported in humans consuming food supplements. Intake of EGCG with green tea infusions and GTE-based beverages is up to about 450mg EGCG/person/day in Europe and higher in Asia. Consumption of green tea is not associated with liver damage in humans, and green tea infusion and GTE-based beverages are considered safe in the range of historical uses. In animal studies, EGCG's potency for liver effects is highly dependent on conditions of administration. Use of NOAELs from bolus administration to derive a tolerable upper intake level applying the margin of safety concept results in acceptable EGCG-doses lower than those from one cup of green tea. NOAELs from toxicity studies applying EGCG with diet/split of the daily dose are a better point of departure for risk characterization. In clinical intervention studies, liver effects were not observed after intakes below 600mg EGCG/person/day. Thus, a tolerable upper intake level of 300mg EGCG/person/day is proposed for food supplements; this gives a twofold safety margin to clinical studies that did not report liver effects and a margin of safety of 100 to the NOAELs in animal studies with dietary administration of green tea catechins.

Targeting arachidonic acid pathway by natural products for cancer prevention and therapy

Arachidonic acid (AA) pathway, a metabolic process, plays a key role in carcinogenesis. Hence, AA pathway metabolic enzymes phospholipase A₂s (PLA₂s), cyclooxygenases (COXs) and lipoxygenases (LOXs) and their metabolic products, such as prostaglandins and leukotrienes, have been considered novel preventive and therapeutic targets in cancer. Bioactive natural products are a good source for development of novel cancer preventive and therapeutic drugs, which have been widely used in clinical practice due to their safety profiles. AA pathway inhibitory natural products have been developed as chemopreventive and therapeutic agents against several cancers. Curcumin, resveratrol, apigenin, anthocyans, berberine, ellagic acid, eugenol, fisetin, ursolic acid, [6]-gingerol, guggulsteone, lycopene and genistein are well known cancer chemopreventive agents which act by targeting multiple pathways, including COX-2. Nordihydroguaiaretic acid and baicalein can be chemopreventive molecules against various cancers by inhibiting LOXs. Several PLA₂s inhibitory natural products have been identified with chemopreventive and therapeutic potentials against various cancers. In this review, we critically discuss the possible utility of natural products as preventive and therapeutic agents against various oncologic diseases, including prostate, pancreatic, lung, skin, gastric, oral, blood, head and neck, colorectal, liver, cervical and breast cancers, by targeting AA pathway. Further, the current status of clinical studies evaluating AA pathway inhibitory natural products in cancer is reviewed. In addition, various emerging issues, including bioavailability, toxicity and explorability of combination therapy, for the development of AA pathway inhibitory natural products as chemopreventive and therapeutic agents against human malignancy are also discussed.

Repeated dose studies with pure Epigallocatechin-3-gallate demonstrated dose and route dependant hepatotoxicity with associated dyslipidemia

EGCG (Epigallocatechin-3-gallate) is the major active principle catechin found in green tea. Skepticism regarding the safety of consuming EGCG is gaining attention, despite the fact that it is widely being touted for its potential health benefits, including anti-cancer properties. The lack of scientific data on safe dose levels of pure EGCG is of concern, while EGCG has been commonly studied as a component of GTE (Green tea extract) and not as a single active constituent. This study has been carried out to estimate the maximum tolerated non-toxic dose of pure EGCG and to identify the treatment related risk factors. In a fourteen day consecutive treatment, two different administration modalities were compared, offering an improved [i.p (intraperitoneal)] and limited [p.o (oral)] bioavailability. A trend of dose and route dependant hepatotoxicity was observed particularly with i.p treatment and EGCG increased serum lipid profile in parallel to hepatotoxicity. Fourteen day tolerable dose of EGCG was established as 21.1 mg/kg for i.p and 67.8 mg/kg for p.o. We also observed that, EGCG induced effects by both treatment routes are reversible, subsequent to an observation period for further fourteen days after cessation of treatment. It was demonstrated that the severity of EGCG induced toxicity appears to be a function of dose, route of administration and period of treatment.

Differential effects of Epigallocatechin-3-gallate containing supplements on correcting skeletal defects in a Down syndrome mouse model

SCOPE

Down syndrome (DS), caused by trisomy of human chromosome 21 (Hsa21), is characterized by a spectrum of phenotypes including skeletal abnormalities. The Ts65Dn DS mouse model exhibits similar skeletal phenotypes as humans with DS. DYRK1A, a kinase encoded on Hsa21, has been linked to deficiencies in bone homeostasis in DS mice and individuals with DS. Treatment with Epigallocatechin-3-gallate (EGCG), a known inhibitor of Dyrk1a, improves some skeletal abnormalities associated with DS in mice. EGCG supplements are widely available but the effectiveness of different EGCG-containing supplements has not been well studied.

METHODS AND RESULTS

Six commercially available supplements containing EGCG were analyzed, and two of these supplements were compared with pure EGCG for their impact on skeletal deficits in a DS mouse model. The results demonstrate differential effects of commercial supplements on correcting skeletal abnormalities in Ts65Dn mice. Different EGCG-containing supplements display differences in degradation, polyphenol content, and effects on trisomic bone.

CONCLUSION

This work suggests that the dose of EGCG and composition of EGCG-containing supplements may be important in correcting skeletal deficits associated with DS. Careful analyses of these parameters may lead to a better understanding of how to improve skeletal and other deficits that impair individuals with DS.

Timing of therapies for Down syndrome: the sooner, the better

Intellectual disability (ID) is the unavoidable hallmark of Down syndrome (DS), with a heavy impact on public health. Accumulating evidence shows that DS is characterized by numerous neurodevelopmental alterations among which the reduction of neurogenesis, dendritic hypotrophy and connectivity alterations appear to play a particularly prominent role. Although the mechanisms whereby gene triplication impairs brain development in DS have not been fully clarified, it is theoretically possible to correct trisomy-dependent defects with targeted pharmacotherapies. This review summarizes what we know about the effects of pharmacotherapies during different life stages in mouse models of DS. Since brain alterations in DS start to be present prenatally, the prenatal period represents an optimum window of opportunity for therapeutic interventions. Importantly, recent studies clearly show that treatment during the prenatal period can rescue overall brain development and behavior and that this effect outlasts treatment cessation. Although late therapies are unlikely to exert drastic changes in the brain, they may have an impact on the hippocampus, a brain region where neurogenesis continues throughout life. Indeed, treatment at adult life stages improves or even rescues hippocampal neurogenesis and connectivity and hippocampal-dependent learning and memory, although the duration of these effects still remains, in the majority of cases, a matter of investigation. The exciting discovery that trisomy-linked brain abnormalities can be prevented with early interventions gives us reason to believe that treatments during pregnancy may rescue brain development in fetuses with DS. For this reason we deem it extremely important to expedite the discovery of additional therapies practicable in humans in order to identify the best treatment/s in terms of efficacy and paucity of side effects. Prompt achievement of this goal is the big challenge for the scientific community of researchers interested in DS.

Tea and human health: biomedical functions of tea active components and current issues

Originating in China, tea and tea planting have spread throughout the world since the middle of the Tang dynasty. Now people from 160 countries in the world are accustomed to tea drinking. A brief history of tea's medicinal role in China and its spread to the world are introduced. The effectiveness of tea active components and tea drinking on major human diseases, including cancer, metabolic syndrome, cardiovascular disease, and neurodegenerative diseases, is discussed. Also presented are some related issues, such as the bioavailability of tea active components, the new formulations of tea polyphenols, and the safety for consumers of dietary supplements containing tea polyphenols.

Reproductive and Developmental Toxicity of Orally Administered Botanical Composition, UP446-Part I: Effects on Embryo-Fetal Development in New Zealand White Rabbits and Sprague Dawley Rats

The pharmacotoxicology impacts of dietary supplements taken at the time of pregnancy have remained alarming since women are the frequent herbal medicine users in many countries as a complement to the conventional pregnancy management. The use of herbal medicines and diet supplements in expectant mothers linked closely to the health of the childbearing mothers and the fetuses where the lack of developmental safety data imposes a challenge to make the right choices. Here, we describe the potential adverse effects of UP446, a standardized bioflavonoid composition from the roots of Scutellaria baicalensis and the heartwoods of Acacia catechu, on embryo-fetal development following maternal exposure during the critical period of major organogenesis in rabbits and rats. Pregnant dams were treated orally with UP446 at doses of 250, 500, and 1000 mg/kg/day during gestation. The number of resorptions, implantations, litter size, body weights, and skeletal development was evaluated. Maternal food intake and body, tissue, and placenta weight were also assessed. There were no statistically significant differences in implantation, congenital malformation, embryo-fetal mortalities, and fetuses sex ratios in all dosing groups of both species. Therefore, the no observed adverse effect level of UP446 was considered to be greater than 1000 mg/kg in both the maternal and fetus in both species.

Reproductive and Developmental Toxicity of Orally Administered Botanical Composition, UP446-Part III: Effects on Fertility and Early Embryonic Development to Implantation in Sprague Dawley Rats

In recent years, high prevalence of adverse effects associated to the use of traditional medicines during pregnancy is becoming alarming due to the self-medication of oral supplements by expecting mothers without supervision. Many expectant mothers use alternative and complementary medicines as a supplement to conventional pregnancy management with an inherent belief of considering herbal remedies as harmless. To the contrary, herbal remedies could incur a potential teratogenic risk both to the child bearing mother and the developing fetuses when consumed before or at the time of gestation. Here, we describe the potential adverse effects of orally administered UP446, a standardized bioflavonoid composition from the roots of Scutellaria baicalensis and the heartwoods of Acacia catechu, on fertility and early embryonic development to implantation in Sprague Dawley rats at doses of 250, 500, and 1000 mg/kg. Besides body weight and food consumption, reproductive functions, sperm motility and morphology, estrus cycle, and fertility rate were monitored. There were no statistically significant differences in reproductive function in all UP446 treated groups in both genders. Test substance impacts on reproductive parameters were very minimal. Neither sperm motility nor morphology was affected as a result of oral UP446 administrations in males. There were no treatment-related effects on estrus cycle stages in females. No significant changes in necropsy or histopathology were observed for all the groups. Therefore, the no observed adverse effect level (NOAEL) of UP446 was considered to be 1000 mg/kg, the highest dose tested, in both genders.

Green tea polyphenol (-)-epigallocatechin-3-gallate triggered hepatotoxicity in mice: responses of major antioxidant enzymes and the Nrf2 rescue pathway

(-)-Epigallocatechin-3-gallate (EGCG), a constituent of green tea, has been suggested to have numerous health-promoting effects. On the other hand, high-dose EGCG is able to evoke hepatotoxicity. In the present study, we elucidated the responses of hepatic major antioxidant enzymes and nuclear factor erythroid 2-related factor 2 (Nrf2) rescue pathway to high-dose levels of EGCG in Kunming mice. At a non-lethal toxic dose (75mg/kg, i.p.), repeated EGCG treatments markedly decreased the levels of superoxide dismutase, catalase, and glutathione peroxidase. As a rescue response, the nuclear distribution of Nrf2 was significantly increased; a battery of Nrf2-target genes, including heme oxygenase 1 (HO1), NAD(P)H:quinone oxidoreductase 1 (NQO1), glutathione S-transferase (GST), and those involved in glutathione and thioredoxin systems, were all up-regulated. At the maximum tolerated dose (45mg/kg, i.p.), repeated EGCG treatments did not disturb the major antioxidant defense. Among the above-mentioned genes, only HO1, NQO1, and GST genes were significantly but modestly up-regulated, suggesting a comprehensive and extensive activation of Nrf2-target genes principally occurs at toxic levels of EGCG. At a lethal dose (200mg/kg, i.p.), a single EGCG treatment dramatically decreased not only the major antioxidant defense but also the Nrf2-target genes, demonstrating that toxic levels of EGCG are able to cause a biphasic response of Nrf2. Overall, the mechanism of EGCG-triggered hepatotoxicity involves suppression of major antioxidant enzymes, and the Nrf2 rescue pathway plays a vital role for counteracting EGCG toxicity.

Reproductive and developmental outcomes, and influence on maternal and offspring tissue mineral concentrations, of (-)-epicatechin, (+)-catechin, and rutin ingestion prior to, and during pregnancy and lactation in C57BL/6J mice

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Maternal food intake, body weights, and tissue weights were not affected by the dietary treatments.

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RU2 dams had alterations in liver zinc, copper, and calcium compared to the other treatment groups.

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Fetal and placental weights, and number of implantation sites and resorption sites per litter were similar across treatment groups.

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Offspring food intake, body weight, litter size, survival, sex, and skeletal development were similar among groups.

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EC1 and EC2 offspring had alterations in liver copper and iron (EC2 only). RU1 and RU2 had alterations in liver calcium.

Maternal nutrition can have a significant effect on developmental processes during pregnancy and lactation. While certain flavonoids have been postulated to be beneficial for health, little is known about the effects of ingestion during pregnancy and lactation on the mother and progeny. We report on the effects of maternal consumption of high levels of certain flavonoids on reproductive and developmental outcomes in a mouse model. C57BL/6J female mice were fed a control diet (CT), the CT diet supplemented with 1% or 2% of a mix of epicatechin and catechin (EC1, EC2), or rutin (RU1, RU2) prior to, during pregnancy, and lactation. A subset of dams was killed on gestation day (GD) 18.5 to evaluate fetal outcomes and the remainder was allowed to deliver to evaluate offspring. Maternal food intake, body and tissue weight did not differ among groups. The number of resorptions, implantations, litter size, postnatal survival, body weight, and skeletal development were also similar. Alterations in maternal and offspring liver mineral concentrations were observed. The current results indicate that consumption of high amounts of epicatechin, catechin, and rutin during gestation and lactation is not associated with any marked developmental effects, although changes in liver mineral concentrations were noted.

Concentrated green tea extract induces severe acute hepatitis in a 63-year-old woman--a case report with pharmaceutical analysis

ETNOPHARMACOLOGICAL RELEVANCE: The popularity of concentrated green tea extracts as dietary supplements for a wide range of applications is increasing due to their health-promoting effects attributed to the high amounts of catechins they contain. The most important of the green tea catechins is (-)-epigallocatechin-3-O-gallate (EGCG). While their beneficiary effects have been studied extensively, a small number of adverse events have been reported in the medical literature. Here we present a typical reversible course of severe hepatitis after green tea consumption.

MATERIALS AND METHODS

The case study describes in a 63-year old woman during treatment with green tea-capsules upon recommendation of a cancer support group.

RESULTS

The histological finding was consistent with drug induced hepatitis, and other possible causes of hepatitis were excluded. According to the CIOMS/RUCAM score the causality was assessed as "probable". After discontinuation of medication, followed by extracorporal albumin dialysis, rapid and sustained recovery occurred. Pharmaceutically analysis (HPLC) of the green tea capsules did not give evidence for contaminants but revealed the two typical compounds of green tea, namely (-)-epigallocatechin-3-O-gallate (EGCG, 93.2%) and epicatechin (EC, 6.8%) at a very high dose level.

CONCLUSION

The present case highlights the fact that such concentrated herbal extracts from green tea may not be free of adverse effects under certain circumstances. There is still a lack of a uniform European Union-wide surveillance system for adverse drug reactions of herbal products. Therefore this case underlines the importance of public awareness in the potential risks in use of herbal products.

Cancer prevention trial of a synergistic mixture of green tea concentrate plus Capsicum (CAPSOL-T) in a random population of subjects ages 40-84

Background

Experts agree that one of the more promising strategies in cancer management is early detection coupled with early intervention. In this study, we evaluated an early cancer detection strategy of cancer presence based on serum levels of the cancer-specific transcript variants of ENOX2 in serum coupled with an ENOX2-targeted nutraceutical preparation of green tea concentrate plus Capsicum (Capsol-T®) as a strategy of Curative Prevention® involving early detection coupled with early intervention in early stage cancer when in its most susceptible and manageable stages.

Experimental design

One hundred ten (110) subjects were tested for cancer presence using the ONCOblot® Tissue of Origin 2-D gel/western blot protocol for detection of serum presence of transcript variants of the ENOX2 protein. Subjects testing positive for ENOX2 received 350 mg of Capsol-T® in capsule form every 4 h including during the night for periods of at least 3 to 6 months or longer after which they were again tested for ENOX2 presence using the ONCOblot® Tissue of Origin Cancer Test protocol.

Results

Of the 110 subjects, both male and female, ages 40 to 84, with no evidence of clinical symptoms of cancer, 40% were positive for ENOX2 presence in the ONCOblot® Tissue of Origin Cancer Test. After completion of 3 to 17 months of Capsol-T® use, 94% of subjects subsequently tested negative for ENOX2 presence.

Conclusions

Oral Capsol-T® is well tolerated and, for ENOX2 presence in serum in the absence of clinical cancer symptoms, is consistently effective in reducing the serum ENOX2 levels to below detectable limits.

Catechins in dietary supplements and hepatotoxicity

BACKGROUND

Many herbal dietary supplements (HDS) contain green tea extract (GTE) and its component catechins, although their presence may not always be indicated on the product label.

PURPOSE

Because GTE and catechins have been implicated in human hepatotoxicity in several case reports, our objective was to determine whether catechins were present in HDS that were implicated in hepatotoxicity, even if not identified among the labeled ingredients, and whether these compounds could be associated with liver injury.

METHODS

We assayed 97 HDS implicated in human hepatotoxicity for catechins.

RESULTS

We found that 29 of 73 HDS (39.7%) that did not identify GTE or any of its component catechins on their label contained catechins. Among patients with confirmed hepatotoxicity, there was no statistically significant association between the presence of catechin or the dose consumed and liver injury causality score, severity, or pattern of liver injury. Catechin levels tended to be highest in products used for weight loss, although catechin concentrations were low in most products.

CONCLUSIONS

Many HDS commonly contain catechins that are implicated in hepatotoxicity, although their presence may not be indicated on the product label. Although our results did not establish an association between GTE or catechins with hepatotoxicity, they highlight some of the many complexities and uncertainties that surround the attribution of drug-induced liver injury (DILI) to HDS.

Green tea extract increases mRNA expression of enzymes which influence epigenetic marks in newborn female offspring from undernourished pregnant mother

Biochemical and toxicological properties of catechin remain unclear, e.g.; how catechin affects female offspring from undernourished pregnant dams. Here, to elucidate effects of low prenatal protein on female offspring health status, changes of enzymes which modify epigenetic marks related with metabolism in kidneys from newborns were investigated after continuously administering catechin extracted from green tea to lactating maternal rats after pregnant undernourishment. We found that green tea extract intake during lactation up-regulated the activation of AMP-activated protein kinase in young female offspring from protein-restricted dams and modulated the AMP-activated protein kinase pathway in the kidney. This pathway was indicated to be stimulated by SIRT1 gene expression. The feeding of green tea extract to protein-restricted dams during lactation is likely to up-regulate AMP-activated protein kinase activation and may partly lead to alterations of the AMP-activated protein kinase pathway in female offspring kidneys. In addition, energy metabolism in fetal and offspring period with green tea extract administration might be related to enzymes which modify epigenetic marks such as DNA methyltransferase 1 and 3a.