Tea epigallocatechin-3-gallate increases 8-isoprostane level and induces caudal regression in developing rat embryos

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.

Catechins: Protective mechanism of antioxidant stress in atherosclerosis

Tea has long been valued for its health benefits, especially its potential to prevent and treat atherosclerosis (AS). Abnormal lipid metabolism and oxidative stress are major factors that contribute to the development of AS. Tea, which originated in China, is believed to help prevent AS. Research has shown that tea is rich in catechins, which is considered a potential source of natural antioxidants. Catechins are the most abundant antioxidants in green tea, and are considered to be the main compound responsible for tea's antioxidant activity. The antioxidant properties of catechins are largely dependent on the structure of molecules, and the number and location of hydroxyl groups or their substituents. As an exogenous antioxidant, catechins can effectively eliminate lipid peroxidation products. They can also play an antioxidant role indirectly by activating the endogenous antioxidant system by regulating enzyme activity and signaling pathways. In this review, we summarized the preventive effect of catechin in AS, and emphasized that improving the antioxidant effect and lipid metabolism disorders of catechins is the key to managing AS.

The effects of five types of tea solutions on epiboly process, neural and cardiovascular development, and locomotor capacity of zebrafish

The effects of teas on embryonic development are still known little. The objective of this study was to compare and analyze developmental effects of green tea, delicate flavor oolong tea, strong flavor oolong tea, black tea, and pu'er tea using zebrafish embryos. Embryos were exposed in tea solutions from one-cell stage; the morphology, locomotor capacity, and gene expression of embryos or larvae were analyzed. The results showed that either tea could decrease the length of body and the size of head and eyes. The effect of green tea had the most significant effects on morphology. Only green tea disturbed cell movement, epiboly, and nervous system development. All five tea solutions caused heart structure alternations and lowered heart rates, and effects caused by green tea were severe. Green tea inhibited the formation of dorsal aorta and segmental arteries and decreased the velocity and total movement distance of larvae. In conclusion, the toxicity of green tea to epiboly, neural and cardiovascular development, and locomotor capacity is more severe than that of other teas. Our study played a warning role for safety consumption of teas and provided references for further study of tea's physiological and pharmacological effects and biological activity.

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.

Effect of the consumption of green tea extract during pregnancy and lactation on metabolism of mothers and 28d-old offspring

The objective was to investigate the effects of the maternal consumption of the green tea extract during pregnancy and lactation on mothers and offspring metabolism. The female Wistar rats, on the first day of pregnancy until the end of lactation, was divided into groups: MC– received water and ME– received green tea extract (400 mg/kg body weight/day), both ingested control diet. After lactation, at day 28^th post-partum, the mothers and pups from each mother were euthanized and composed the groups: FC– pup from mother received water and FE– pup from mother received green tea extract. The ME group increased IL-10/TNF-α ratio and IL-1β content in the mesenteric and IL-1β content in retroperitoneal adipose tissues, and decreased catalase activity. The FE group decreased the retroperitoneal adipose tissue relative weight and SOD activity, but increased adiponectin, LPS, IL-10 and IL-6 content and IL-10/TNF-α ratio in retroperitoneal, IL-10 and TNF-α content in gonadal, and IL-6 content in mesenteric adipose tissues. In summary, the maternal consumption of green tea extract associated with control diet ingestion during pregnancy and lactation altered the inflammatory status of mothers and 28d-old offspring. These data elucidate the effects of green tea during pregnancy and lactation on maternal and offspring metabolism.

Morphology-Based Whole Embryo Culture for Developmental Toxicity of Drugs

In vivo pregnant study protocols covering preconceptional exposure as well as prenatal and postnatal development including the lactation period to screen the toxic effects on specific elements of the highly complicated reproductive cycle are time-consuming and expensive. Morphology-based whole embryo culture is the most common alternative in vitro embryotoxicity method to evaluate the early developmental toxicity of drugs. Here we share our procedures and experience in the whole embryo culture for drug embryotoxicity assessments.

Human development: from conception to maturity

Abstract The main objective of this review was to describe and emphasize the care that a woman must have in the period prior to pregnancy, as well as throughout pregnancy and after the birth of the baby, cares and duties that should continue to be followed by mother and child throughout the first years of the child’s life. Such cares are of nutritional, behavioral and lifestyle natures, and also involve the father and the whole family. Human development, from conception to maturity, consists of a critical and important period due to the multitude of intrinsic genetic and environmental factors that influence, positively or negatively, the person's entire life. The human being, who originated and passed his/her first phase of development in the womb, receives influence from different factors: a) of parental origin (father and mother), including health and lifestyle of the father and mother, genetic inheritance, nutrition of the mother prior to and during pregnancy; b) events that affected the mother and hence the child under development in intrauterine life, at birth (delivery), during perinatal period, and throughout the early years of life. The fragility of development continues throughout the preschool, school and adolescent periods during which proper nutrition with a balanced lifestyle is essential and depends on guidance from the parents, caregivers and teachers.

Green tea catechins are potent anti-oxidants that ameliorate sodium iodate-induced retinal degeneration in rats

Green tea extracts exhibit anti-oxidative and anti-inflammatory actions in different disease conditions. We hypothesized that green tea extract and its catechin constituents ameliorate sodium iodate-induced retinal degeneration in rats by counteracting oxidative stress. In this study, adult Sprague-Dawley rats were intravenously injected with a single dose of sodium iodate. Green tea extract (GTE; Theaphenon-E) or combinations of its catechin constituents, including (−)-epigallocatechin gallate (EGCG), were administered intra-gastrically before injection. Live imaging analysis using confocal scanning laser ophthalmoscopy and spectral-domain optical coherence tomography showed a progressive increase of degenerating profile across the retinal surface and decrease in thickness of outer nuclear layer (ONL) at Day-14 of post-injection. These lesions were significantly ameliorated by Theaphenon-E and catechin combinations with EGCG. Catechins with exclusion of EGCG did not show obvious protective effect. Histological analyses confirmed that Theaphenon-E and catechins containing EGCG protect the retina by reducing ONL disruption. Retinal protective effects were associated with reduced expression of superoxide dismutase, glutathione peroxidase and caspase-3, and suppression of 8-iso-Prostaglandin F_2α generation in the retina. In summary, GTE and its catechin constituents are potent anti-oxidants that offer neuroprotection to the outer retinal degeneration after sodium iodate insult, among which EGCG is the most active constituent.

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

•

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

•

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

•

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

•

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

•

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.

The influence of aqueous and hydro-alcoholic extracts of roots and rhizomes of Rhodiola kirilowii on the course of pregnancy in mice

Plants belonging to the Rhodiola genus, originating from Asia, are traditionally used as tonic, adaptogen, antidepressant and anti-inflammatory drugs. These plants have also potent immunomodulatory properties and in some situations possibly could be used instead of standard antibiotic therapy (e.g. during pregnancy or lactation). The aim of our present study was to establish whether aqueous (RKW) or hydro-alcoholic (RKW-A) extracts from roots and rhizomes of Rhodiola kirilowii given to pregnant mice influence the course of pregnancy and the number of progeny. Performed HPLC analysis showed that the RKW-A extract had a generally higher concentration of all identified polyphenols. The highest differences were observed for (+)-catechin, p-coumaric acid and naringenin. Everyday addition of the RKW or RKW-A extract did not change the length of pregnancy. At the same time, both RKW and RKW-A extracts significantly increased the number of mated females without offspring but only in the RKW-A group we noticed a few neonatal deaths in the first 5 days after delivery. The results reported in the present study do not encourage to the use of R. kirilowii hydro-alcoholic extracts supplementation during pregnancy and lactation, however the possibility of limited dietary intake of R. kirilowii water extract should be thoroughly examined.

Evaluation of reproductive and developmental toxicities of Pu-erh black tea (Camellia sinensis var. assamica) extract in Sprague Dawley rats

ETHNOPHARMACOLOGICAL RELEVANCE

Pu-erh black tea, which is obtained by first parching crude green tea leaves and followed by secondary fermentation with microorganisms, has been believed to be beneficial beverages for health in PR China. But its potential toxicity when administered at a high dose as concentrated extract has not been completely investigated.

AIM OF THE STUDY

The present study was aimed at evaluating potential reproductive and developmental toxicities of Pu-erh black tea extract (BTE) in Sprague Dawley rats.

MATERIALS AND METHODS

Growing rats were given BTE by gavage at levels of 0, 200, 700 and 2500mg/kg/day as the F0 generation in reproductive toxicity study. Additionally, BTE was administered to mate female rats from gestation day 0.5 through 19.5 at the doses of 0, 200, 700 and 2500mg/kg/day to evaluate the developmental toxicity.

RESULTS

In the reproductive toxicity study, only 2500mg/kg/day BTE reduced the body weight gain and altered the relative organ weights including testes, prostata and ovary both for F0 parents and F1 offspring compared to the controls. High dose of BTE (2500mg/kg/day) administration caused developmental disturbances in embryo-to-foetus period including resorbed embryos, decreased embryo size and skeletal anomalies.

CONCLUSION

In conclusion, the no-observed-adverse-effect level of BTE is 700mg/kg/day both for reproductive toxicity and developmental toxicities.

Evaluation of oral subchronic toxicity of Pu-erh green tea (camellia sinensis var. assamica) extract in Sprague Dawley rats

ETHNOPHARMACOLOGICAL RELEVANCE

Pu-erh green tea, originally produced in the Yunnan province of P.R. China for about 1700 years, is believed to be beneficial to health in Asian countries. The potential toxicity of Pu-erh green tea when administered at high doses via concentrated extract, however, has not been completely investigated.

THE AIM OF THE STUDY

The present study was aimed to evaluate the potential toxicity of Pu-erh green tea extract (PGTE) of sub-chronic administration to Sprague Dawley (SD) rats.

MATERIALS AND METHODS

Growing SD rats were administrated orally by gavage with PGTE at doses of 0, 1250, 2500, and 5000 mg/kg/day for 91 consecutive days. Clinical observations, including survival, hematology, serum biochemistry, urinalysis and histopathological examination were measured to monitor treatment-related adverse effects in rats.

RESULTS

The results showed that oral administration of high dose of PGTE led to body weight gain suppression, liver and calcium deposition dysfunctions.

CONCLUSIONS

In conclusion, the no-observed-adverse-effect level for Pu-erh green tea extract derived from the results of the present study was 2500 mg/kg/day for both genders.

Translational regulation of glutathione peroxidase 4 expression through guanine-rich sequence-binding factor 1 is essential for embryonic brain development

Phospholipid hydroperoxide glutathione peroxidase (GPx4) is a moonlighting selenoprotein, which has been implicated in basic cell functions such as anti-oxidative defense, apoptosis, and gene expression regulation. GPx4-null mice die in utero at midgestation, and developmental retardation of the brain appears to play a major role. We investigated post-transcriptional mechanisms of GPx4 expression regulation and found that the guanine-rich sequence-binding factor 1 (Grsf1) up-regulates GPx4 expression. Grsf1 binds to a defined target sequence in the 5'-untranslated region (UTR) of the mitochondrial GPx4 (m-GPx4) mRNA, up-regulates UTR-dependent reporter gene expression, recruits m-GPx4 mRNA to translationally active polysome fractions, and coimmunoprecipitates with GPx4 mRNA. During embryonic brain development, Grsf1 and m-GPx4 are coexpressed, and functional knockdown (siRNA) of Grsf1 prevents embryonic GPx4 expression. When compared with mock controls, Grsf1 knockdown embryos showed significant signs of developmental retardations that are paralleled by apoptotic alterations (TUNEL staining) and massive lipid peroxidation (isoprostane formation). Overexpression of m-GPx4 prevented the apoptotic alterations in Grsf1-deficient embryos and rescued them from developmental retardation. These data indicate that Grsf1 up-regulates translation of GPx4 mRNA and implicate the two proteins in embryonic brain development.