Protective Effect Of Green Tea Research Articles

Green tea extract attenuates non alcoholic fatty liver disease by decreasing hyperlipidemia and enhancing Superoxide dismutase activity in cholesterol-fed rats

BACKGROUND/AIM: Health benefits of green tea for a wide variety of ailments, including the cancer, heart disease, and liver disease, were reported. It is believed to have beneficial effects in the prevention and treatment of many diseases, one of which is non-alcoholic fatty liver disease (NAFLD). This study inspects the protective effect of green tea against atherosclerosis and NAFLD in comparative approach between curative and preventive models. MATERIALS AND METHODS: Twenty four of Wistar rats were studied for 150 days. After 15 days of adaptation period, rats were divided into four groups including normal Group (NG), control Hypercholesterolemic diet Group (CHDG), preventive Group (PG) and curative Group (CG) that followed respectively the following regimens: 1 mL/kg of sunflower oil for 150 days, 1 mL/kg of cholesterol solution prepared at 1.5% (w/v) in sunflower oil span 150 days, 1 ml/kg of cholesterol solution at 1.5% (w/v) in sunflower oil with 3 mL/kg GTLE for 60 days and 1 mL/kg of cholesterol solution at 1.5% (w/v) in sunflower oil for 30 days followed by 3 mL/kg of GTLE for 30 days. These both PG and CG groups were ingested with cholesterol 1.5% (w/v) during remaining period. RESULTS: The results showed significant increase, except for NG, during the 30 first days (p≤0.001) in lipid serum profiles including Total Cholesterol (TC), Triacylglycerol (TG) and Low-Density Lipoprotein cholesterol (LDL-c). However, the High-Density Lipoprotein cholesterol (HDL-c) profile decreased during the treatment (p≤0.001). The ingestion of GTLE in treated groups (CG and PG) declined significantly (p≤0.001) in blood lipid concentrations (TC: 67%, TG: 23%, LDL-c: 81.12%) except for the HDL-c that increased up to 15%. The Atherogenic Index (AI) also decreased significantly (p≤0.001) up to 48%, in CG and PG. PG and NG marked same SOD activity values (130.91±7.66 versus 141.31±8.21 U/mL), while CG showed the lowest level. Liver sections were well protected in protective model than curative one.

Gender differences in the protective effects of green tea against amnestic mild cognitive impairment in the elderly Han population.

BackgroundGender differences may contribute to variances in the potential protective effects of tea against cognitive impairment in the elderly.ObjectiveTo examine the association between different types of tea consumption and the risk of amnestic mild cognitive impairment (aMCI) along gender lines.MethodsA cross-sectional study was conducted with reference to 20 communities in China. The sample population included elderly participants aged 60 years or older. A standardized questionnaire was used to collect each participant’s general demographic information. Trained psychologists administrated the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA) to assess participants’ cognitive function. An attending psychiatrist evaluated each participant’s cognitive function. Finally, data from 2,131 participants were analyzed to assess the association.ResultsWith regard to male participants, the percentage of green tea consumption was higher in the normal control group than in the aMCI group (X2=4.64, P=0.031). Logistic regression analysis showed that green tea consumption reduced the risk of aMCI in male participants (OR=0.657, P=0.019), and this finding was highly significant in males aged under 70 years (OR=0.376, P=0.002). Regarding female participants across every age group, the results indicated that tea consumption failed to significantly decrease the risk of aMCI (P>0.05). Unlike green tea, black tea and oolong tea were not correlated with a reduced risk of aMCI in terms of gender or age group. Multiple linear regression analysis also revealed that age, years of education, and green tea consumption (B=0.996, P=0.000) were associated with MoCA and MMSE scores, though only in male participants.ConclusionGreen tea consumption showed a protective effect against aMCI in males but not in females, particularly in males aged <70 years. However, black tea and oolong tea failed to show any protective effect in either males or females.

English

Highly active antiretroviral therapy (HAART) is considered toxic and has other life-threatening side effects including dyslipidemia. There is no research report on the health effects of Ethiopian highland green tea. Previous work data from elsewhere suggest that lipid abnormalities are associated with cardiovascular morbidity and mortality. The aim of this study was to investigate the possible protective effect of green tea (Ocimum gratissimum) hydro-ethanolic leaf extract on highly active antiretroviral therapy induced dyslipidemia in albino Wistar rats. Thirty rats of age 10 to 12 weeks and similar weights were selected and divided in to 5 groups of six rats each. Group-I (normal control group) were given distilled water, Group II were given HAART only, Groups III, IV and V were given antiretroviral therapy and 100, 200 and 400 mg/kg of extract, respectively for sixty days. The dissolved crude extracts of different doses were given to rats using oral gavage. On experiment day, the rats were fasted overnight, sacrificed by cervical dislocation and blood was taken by cardiac puncture for lipid profile investigation. Lipid profile was measured spectrophotometrically using standard kits and procedures. Elevated levels of serum total cholesterol, triacylglycerol, low density lipoprotein cholesterol and high density lipoprotein cholesterol were observed in highly active antiretroviral therapy treated group. The rats that received HAART+400 mg of O. gratissimum showed a significant decrement of serum total cholesterol, triglycerides, and low density lipoprotein cholesterol (p<0.05) with no alteration of high density lipoprotein cholesterol. The green tea leaf extract with a dose of 400 mg/kg has a good protective effect against HAART induced dyslipidemia which might be due to its antioxidant property. Key words: Highly active anti-retroviral therapy, green tea leaf extract, dyslipidemia, rats.

Thiocyclam-Induced Reproductive Toxicity, Oxidative Stress and Genomic DNA Damage in Testicular Tissues of Rats: Protective Effects of Green Tea Extract

Thiocyclam is a broad-spectrum nereistoxin analogue insecticide which widely used for agricultural applications. The aim of this study is to investigate the protective effects of green tea (as a principal source of antioxidants) on Thiocyclam-Induced Reproductive Toxicity, Oxidative Stress and Genotoxicity in adult Male Rats. Forty adult male rats were randomly assigned into four groups: control, Thiocyclam (ThC, 15.98 mg/kg b.w.), green tea extract (GTE, 2% w/v as the sole beverage) and (ThC+GTE) group. After 65 days of treatment, blood samples and testicular tissue were collected for measuring the oxidative stress parameters, testosterone level and DNA damage, whereas the reproductive organs were weighed, and Semen analysis and testicular histopathological studies was done. The results revealed that Thiocyclam administration induce a significant reduction in sperm count, sperm motility as well as testosterone level, while increased sperm abnormality. In addition to increased testicular tissue Malondialdehyde (MDA), reduced GSH content and testicular DNA damage evidenced by comet assay. The histological examination of testes revealed degenerative change and disorganization of seminiferous tubules with incomplete spermatogenesis. On the contrary, GTE played a potential protective effect against Thiocyclam induced oxidative stress as well as alleviate the reproductive toxicity by improving the oxidative status, decrease oxidative DNA damage, improving semen characteristics and protective effect against testicular damage, highlighting the protective and therapeutic potentiality of green tea against pesticide-induced reproductive toxicity and its health benefits.

Morphological alterations in the jejunal mucosa of aged rats and the possible protective role of green tea.

Gastrointestinal disorders become more prevalent with ageing. This study is aimed to describe morphological changes that occur in the jejunal mucosa of male albino rats as a result of ageing and the protec-tive effect of green tea (GT) extract. The experiment was performed on sixty rats: thirty young-adult (6-month old, body mass 200-220 g) and thirty old (24-month-old, body mass 220-260 g) animals. Each group was further divided into two subgroups (n = 15 each): control rats and GT-treated rats that received 1.5 mL (300 mg/kg/day) of GT extract for 14 weeks by oral gavage. Sections of the jejunum were stained with hematoxylin and eosin, periodic acid Schiff, toluidine blue and Mallory trichrome methods. The presence of proliferating cell nuclear antigen (PCNA)- and CD68-positive cells was evaluated by immunohistochemical staining. Ultrathin sections were prepared and examined by a transmission electron microscope (TEM). Jejunal sections of the old control rats showed distortion of submucosa and attenuated muscularis externa with decreased height of intestinal villi. The villi also showed partial loss of acidophilic brush border with wide spaces between enterocytes. Swollen, short, blunt or broad villi with abundant mononuclear cell infiltration of lamina propria and congested blood vessels were evident both by light and electron microscopy. The number of PCNA- and CD68-positive cells in jejunal mucosa of old rats was higher than in young rats. The activity of glutathione peroxidase (GPX) and total antioxidant capacity (TAC) in the mucosa of old control rats were lower, whereas malondialdehyde (MDA) levels were higher in the jejunal homogenates of old rats as compared to young control rats. Administration of GT extract protected the jejunal mucosa from age-related changes by restoring its histological structure. The treatment of old rats with GT extract significantly decreased MDA levels in the jejunum and increased TAC and GPX activity. The age-related changes of the morphology of rat jejunum could be ameliorated by prolonged supplementation of the green tea extract.

Protective effects of green tea on olanzapine-induced-metabolic syndrome in rats

Atypical antipsychotics particularly olanzapine are associated with obesity and serious metabolic disturbances. As green tea (Camellia sinensis) is generally associated with beneficial effects on obesity and other metabolic disturbances, this study was undertaken to evaluate the effect of green tea aqueous extract (GTAE) on olanzapine induced weight gain and metabolic abnormalities in rats. Male Wistar rats were divided into eight groups: control, olanzapine (5mg/kg/day, IP.), GTAE (25, 50 and 100mg/kg/day, IP.) plus olanzapine and GTAE (25, 50 and 100mg/kg/day, IP.). Treatments were continued for 11 days. Body weight gain, average food and water intake were measured during the experiment. Plasma lipid, glucose and leptin levels, mean systolic blood pressure and total locomotion were evaluated at the end of experiment. Olanzapine induced significant weight gain at the end of treatment (10.38% of body weight) when compared to control (3.13% of body weight) in male Wistar rats. Average food and water intake were increased by olanzapine treatment. 11days olanzapine administration led to hyperleptinemia, hyperglycemia and dyslipidemia. Olanzapine also increased mean systolic blood pressure and decreased total locomotion. GTAE decreased significantly body weight gain and average food and water intake, improved the changes in lipid profile as well as fasting blood glucose, and finally decreased hyperleptinemia and hypertension induced by olanzapine. Results of this study demonstrated that GTAE could exert protective effects against olanzapine induced obesity partially due to its lowering effect on leptin. GTAE improved other metabolic abnormalities including dyslipidemia, hyperglycemia and hypertension induced by olanzapine in rats.

Protective Effects of Green Tea and Moringa Leave Extracts and Their Bio-Yoghurts against Oxidative Effects of Lead Acetate in Albino Rats

Protective Effects of Green Tea and Moringa Leave Extracts and Their Bio-Yoghurts against Oxidative Effects of Lead Acetate in Albino Rats

Assessing self-reported green tea and coffee consumption by food frequency questionnaire and food record and their association with polyphenol biomarkers in Japanese women.

Despite the demonstrated protective effects of green tea and coffee intake against several chronic diseases, finding between studies have not been consistent. One potential reason of this discrepancy is the imprecision in the measurement of tea or coffee consumption using food frequency questionnaire (FFQ) and food record (FR) in epidemiological studies. In a sample of 57 healthy Japanese women, intake of green tea and coffee was estimated by a validated FFQ and a 3-day FR, while their plasma and urine concentrations of polyphenol biomarkers were measured by HPLC. The polyphenols assessed included (-)-epigallocatechin gallate (EGCG), (-)-epicatechin gallate (ECG), (-)-epigallocatechin (EGC) and (-)- epicatechin (EC), caffeic acid (CA) and chlorogenic acid (CGA). Green tea consumption estimated by FFQ and FR showed moderate association, while strong association was detected for coffee consumption. Urinary green tea polyphenol concentrations were moderately-strongly associated with FR-estimated intake, while the associations were weak with FFQ. Similarly, coffee polyphenols in urine were moderately associated with FR-estimated coffee intake, whereas FFQ showed poor correlation. The associations between urinary and plasma polyphenols ranged from moderate to high. The results indicated that firstly, the FFQ tends to overestimate green tea intake. Secondly, the urinary polyphenols are preferred over plasma polyphenols as a potential surrogate marker of the short-term green tea and coffee intake, while their use as an indicator of long-term consumption is not reliable.

Effects of dietary green tea (Camellia sinensis L.) supplementation on growth performance, lipid metabolism, and antioxidant status in a sturgeon hybrid of Sterlet (Huso huso ♂×Acipenser ruthenus ♀) fed oxidized fish oil.

Lipid content of diet is very susceptible to oxidation, especially when stored for a long time, so for evaluating protective effects of green tea in fish received oxidized oil, this study was done. Lipid content of diet was replaced by oxidized fish oil (OFO) in 0, 50, and 100%. Green tea extract (GTE) was added to diet in three levels, 0, 5, and 100mg/kg giving a total of nine experimental diets. Two hundred and seventy sturgeon hybrid of Sterlet (Huso huso ♀×Acipenser ruthenus ♂) with initial weight of 212.6±0.7g after 2weeks adaptation randomly divided in 27 fiberglass tanks with 700L volume. Fish were fed satiated three times daily. After 6weeks, biometry was done to evaluate growth performance and blood samples were taken for biochemical analysis. The result showed that feeding with oxidized oil had no effects on growth. However, in fish fed GTE, growth indices improved slightly. Feeding with OFO reduced serum total cholesterol, triacylglycerol, and low-density lipoprotein, while increased high density lipoprotein. Dietary GTE moderated the effects of OFO on lipid metabolism. Feeding with the OFO increased activity of serum superoxide dismutase, catalase, glutathione peroxidase, and malondialdehyde contents. In fish received both OFO and GTE, reduced activity of serum antioxidant enzymes and malondialdehyde content was recorded in compare to fish fed only OFO. According to the result of the present study, it can be argued that feeding of sturgeon hybrid of Sterlet with OFO has negative effects on lipid metabolism and antioxidant status, whereas GTE dosages used in this study have protective effects on fish from the adverse effects of oxidized oil.

Protective Effects of Green tea, Clove and Thyme against Mullet (Mugil cephalus) Lipid Hydrolysis and Oxidation: Role of Natural Antioxidants

Protective Effects of Green tea, Clove and Thyme against Mullet (Mugil cephalus) Lipid Hydrolysis and Oxidation: Role of Natural Antioxidants

Patulin Induced Oxidative Stress Mediated Apoptotic Damage in Mice, and its Modulation by Green Tea Leaves

The present study demonstrates the antioxidant and hepatic protective effects of Green tea leaves (GTL). The serum level of aspartate aminotransferase and alanine aminotransferase was analyzed. The liver antioxidant enzymes such as SOD, CAT, GPx, GR, GSH, lipid peroxidation and protein carbonyls, ROS content were estimated. The histology of liver tissue was observed and the protein expression of SOD, CAT, Caspase-3 and p53 was investigated by Western blotting. Effectiveness of GTL extract in preventing patulin induced liver damage showed significant reduction in serum ALT and AST to 19% and 85% respectively, the increase in antioxidant levels and lipid peroxidation products with patulin treatment were also reduced with GTL supplementation. The patulin induced increase in hepatic protein carbonyls was significantly reduced by 141-111% with 100 and 200mg/kg b.wt GTL and in ROS was significantly reduced by 171-140% with 100 and 200mg/kg b.wt GTL administration respectively. Also showed protection against hepatic tissue damage and protein expression in mice. This study showed remarkable antioxidant and hepatic protective effects of GTL.

GENO PROTECTIVE AND ANTI-APOPTOTIC EFFECT OF GREEN TEA AGAINST PERINATAL LIPOPOLYSACCHARIDE-EXPOSURE INDUCED LIVER TOXICITY IN RAT NEWBORNS.

Background:This study aims to examine the protective effect of green tea on the disturbances in oxidative stress and apoptosis related factors, mostly produced due to perinatal lipopolysaccharide (LPS) exposure, that subsequently induces liver cell damage.Materials and Methods:Anti-free radical, Antioxidant, scavenging, geno-protective, and antiapoptotic activity of aqueous green tea extract (AGTE) were assessed against LPS-induced hepatic dysfunction in newborn-rats. AGTE at doses of 100 & 200 mg/kg was orally administered daily to rat dams, during gestation and lactation.Results:AGTE was observed to exhibit protective effects by significantly attenuating LPS-induced alterations in serum AST, ALT, bilirubin, and albumin levels. Significant increase in the total antioxidant capacity (TAC), DNA contents, and reduction in nitric oxide (NO) levels were observed in AGTE treated rats comparing LPS-toxicated ones. Additionally, AGTE treatment significantly down-regulated apoptotic markers and this effect was directly correlated to the degree of hepatic fibrosis. The possible mechanisms of the potential therapeutic-liver protective effect of AGTE could be due to free radical scavenging potential and antiapoptotic properties caused by the presence of antioxidant polyphenolic components in AGTE.Conclusion:We thereby propose, based on our findings, that the anti-free radical and anti-apoptotic inducing properties of AGTE active constituents attribute to its functional efficacy as anti-fibrotic agent.

Green tea infusion protects against alcoholic liver injury by attenuating inflammation and regulating the PI3K/Akt/eNOS pathway in C57BL/6 mice.

Alcohol intake is a major risk factor for the pathogenesis of alcoholic liver diseases. Accumulating evidence suggests that green tea protects against alcoholic liver injury; however, the underlying mechanisms remain unclear. The present study investigated the role of endothelial nitric oxide synthase (eNOS) in the protective effects of green tea against alcohol-induced liver injury and inflammation. Ethanol was intragastrically administered to male C57BL/6 mice once a day, and the mice were allowed free access to green tea infusion or water for two weeks. We assessed the plasma levels of alanine aminotransferase and aspartate aminotransferase, hepatic contents of thiobarbituric acid reactive substances, malondialdehyde and triglyceride and hepatic mRNA expression of pro-inflammatory cytokines (interleukin-1β, tumor necrosis factor-α, and interleukin-6). Our results showed that compared with water alone, green tea infusion markedly reduced liver damage, hepatic oxidative stress, hepatic lipid accumulation and inflammatory response. Green tea infusion also significantly reduced hepatic nuclear factor-κB expression and its downstream inflammatory mediators (inducible nitric oxide synthase and cyclooxygenase-2) mRNA levels in ethanol-treated mice. Additionally, green tea infusion significantly activated hepatic phosphorylated phosphatidylinositol 3-kinase (PI3K) and phosphorylated protein kinase B (Akt), which are associated with the upregulation of phosphorylated eNOS expression and the increase of plasma nitric oxide levels in ethanol-treated mice. Furthermore, the protective effects of green tea infusion were considerably inhibited by the eNOS inhibitor NG-nitro-l-arginine methyl ester in ethanol-treated mice. In conclusion, our study demonstrated that the protective effects of green tea infusion on alcohol-induced liver injury and inflammation involve the modulation of the PI3K/AKT/eNOS pathway.

Camellia sinensis Prevents Perinatal Nicotine-Induced Neurobehavioral Alterations, Tissue Injury, and Oxidative Stress in Male and Female Mice Newborns.

Nicotine exposure during pregnancy induces oxidative stress and leads to behavioral alterations in early childhood and young adulthood. The current study aimed to investigate the possible protective effects of green tea (Camellia sinensis) against perinatal nicotine-induced behavioral alterations and oxidative stress in mice newborns. Pregnant mice received 50 mg/kg C. sinensis on gestational day 1 (PD1) to postnatal day 15 (D15) and were subcutaneously injected with 0.25 mg/kg nicotine from PD12 to D15. Nicotine-exposed newborns showed significant delay in eye opening and hair appearance and declined body weight at birth and at D21. Nicotine induced neuromotor alterations in both male and female newborns evidenced by the suppressed righting, rotating, and cliff avoidance reflexes. Nicotine-exposed newborns exhibited declined memory, learning, and equilibrium capabilities, as well as marked anxiety behavior. C. sinensis significantly improved the physical development, neuromotor maturation, and behavioral performance in nicotine-exposed male and female newborns. In addition, C. sinensis prevented nicotine-induced tissue injury and lipid peroxidation and enhanced antioxidant defenses in the cerebellum and medulla oblongata of male and female newborns. In conclusion, this study shows that C. sinensis confers protective effects against perinatal nicotine-induced neurobehavioral alterations, tissue injury, and oxidative stress in mice newborns.

Green Tea Induced Cellular Proliferation and the Expression of Transforming Growth Factor-β1 in the Jejunal Mucosa of Fasting Rats

Objective: The aim of this study was to understand whether or not the protective effect of green tea after fasting-induced damage in the jejunal mucosa of rat is dependent on cell proliferation and the stimulation of specific growth factors. Materials and Methods: Sixty adult male Wistar rats were used in this study. The animals were divided randomly into 5 groups, with 12 in each group (G1-5). The animals in G1 (control group) were fed a rat chow diet and water ad libitum. The animals in G2 (fasting group) were fasted for 3 days. The animals in the G3, G4, and G5 groups were fasted for 3 days as G2, but were given water (G3), green tea (G4), or a vitamin E (G5) solution, respectively, for another 7 days. The animals were euthanized, and the jejunum was removed and processed for histological and immunohistochemical analysis. Results: Compared to the G3 group, the jejunal mucosa of G4 rats showed a 70.6% higher level (p < 0.001) of expression of proliferating cell nuclear antigen and 98% higher level (p = 0.0001) of the expression of transforming growth factor-β1 (TGF-β1), whereas the level of fibroblast growth factor-1 (FGF-1) and insulin-like growth factor-1 (IGF-1) expression was 22 and 11% lower, respectively, in G4 animals as compared to G3 rats. These differences in the expression of FGF-1 and IGF-1 in G4 animals were not statistically significant. Conclusion: In this study, green tea repaired the fasting-induced damage in the jejunal mucosa of rats, mainly by inducing a significant expression of TGF-β1 in the jejunal mucosa.

In vitro Effects of Epigallocatechin Gallate on Sister Chromatid Exchange in the Lymphocytes Exposed to Glyphosate

Purpose: Green tea is known as a potent anti-oxidant, anti-carcinogen, and genetic protector. Glyphosate (N-phosphonomethyl glycine) is a widely used non-selective herbicide that causes DNA damage. The present study was conducted to investigate the protective effects of green tea in human blood lymphocytes exposed to glyphosate using the Sister Chromatid Exchange (SCE) frequency method. Methods: Peripheral blood was obtained from 10 volunteers and cultured through four different conditions. Four groups were divided into control, glyphosate only (300 ng/mL), glyphosate and low ($20{mu}m$) concentrations of epigallocatechin gallate (EGCG) and glyphosate and high ($100{mu}m$) concentrations of EGCG. Results: The glyphosate exposed groups had a higher mean SCE frequency ($10.33{pm}2.50$) than the control group ($6.38{pm}2.28$, p&lt;0.001). The low concentrations of EGCG groups had a lower mean SCE frequency ($9.91{pm}1.93$) than the glyphosate-only group, although this difference was not significant (p=0.219). However, the high concentration group ($9.49{pm}1.85$) had a significantly lower SCE frequency than the glyphosate-only group (p=0.001). Conclusion: EGCG has a gene protective effect in human lymphocytes exposed to the genotoxicity of glyphosate in the case of high concentrations.

Renal and hepato protective effects of green tea (camellia sinensis) extract on wistar rats treated with sodium oxalate

Nowadays different foods and vegetables are contaminated with oxalates of sodium and calcium, present in pesticides and chemical fertilisers. Even many drugs contain sodium oxalate, which is a causative agent of urolithiasis and hepatic cell damage. Herbal plant supplements may reduce this drug induced toxicity. Renal and hepatoprotective effects of the aqueous extracts of green tea (Camellia sinensis) were studied in sodium oxalate treated rats. Green tea extract was administered orally to Wistar rats for 20 days, exposed to sodium oxalate in different doses (100 mg/kg body weight and 200 mg/kg body weight. It was administered at a dose of 100 mg/kg body weight, which caused hepatic and renal cell damage. As a result, the different stress marker enzyme activity (Aspartate Transaminase, Alanine Transaminase and Alkaline Phosphatase) were increased. Green tea extract have an ameliorative effect on sodium oxalate induced damage and can also reduce the tissue cholesterol level in both liver and kidney.

Protective effect of green tea against neuro-functional alterations in rats treated with MnO2 nanoparticles.

Inhalation of manganese-containing metal fumes at workplaces can cause central nervous damage including a Parkinson-like syndrome. Oxidative stress is likely to be involved in the pathomechanism, due to the presence of nano-sized metal oxide particles with high biological and chemical activity. Oxidative damage of the nervous system could be prevented or ameliorated by properly applied antioxidants, preferably natural ones such as green tea, a popular drink. The aim of this work was to see if orally applied green tea brew could diminish the functional neurotoxicity of manganese dioxide nanoparticles introduced into the airways of rats. Young adult male Wistar rats were treated intratracheally for 6 weeks with a suspension of synthetic MnO2 nanoparticles (4 mg/kg body weight), and received green tea brew (1 g leaves 200 mL-1 water) as drinking fluid. Reduced body weight gain, indicating general toxicity of the nanoparticles, was not influenced by green tea. However, in rats receiving green tea the nervous system effects-changes in the spontaneous and evoked cortical activity and peripheral nerve action potential-were diminished. The use of green tea as a neuroprotective functional drink seems to be a viable approach. © 2016 Society of Chemical Industry.

Protective effect of (-)-epigallocatechin gallate on ultraviolet b-induced skin damage in hairless mice

Purpose : To investigate the protective effect of green tea (-)-epigallocatechin gallate (EGCg) on ultraviolet B (UV-B)-induced skin damages in hairless mice in order to develop a natural sunscreen compound for use in skin care products and cosmetics. Methods : EGCg was dissolved in acetone at concentrations of 1.0, 10.0 and 50.0 mg/mL, and topically applied to the skin of hairless mice at doses of 0.2 mL/cm2, with acetone as control. The mice were then irradiated by 100 μW/cm2 UV-B for 30 min daily. EGCg treatment and UV-B irradiation were carried out daily for 28 consecutive days. The mice were then sacrificed and their dorsal skin examined by transmission electron microscopy (TEM) on the 28th day. Results : UV-B irradiation induced severe macroscopic skin damage including chapping, cracking and abnormal desquamation in the treated hairless mice. EGCg showed dose-dependent protective effects against UV-B induced damage on the skin. Treatments with 10.0 and 50.0 mg/mL EGCg alleviated UVB- induced skin damage by suppressing both keratinocyte apoptosis and mitochondrial dysfunction, along with inhibiting the production of melanin pigment. Conclusion : Topical application of green tea EGCg shows dose-dependent protective effect against UV-B-induced damage on hairless mouse skin. Thus, the plant compound can potentially be used as an alternative agent for photoprotection against UV-B exposure. Keywords : UV-B, Green tea EGCg, Photoprotection, Stratum corneum, Mitochondrion, Melanosome

Morphological and morphometric study of protective effect of green tea in gentamicin-induced nephrotoxicity in rats

AimsOne of the most popular beverages worldwide, green tea, was investigated for its potential protective effect in a rat model of gentamicin-induced nephrotoxicity by monitoring functional and morphological changes in kidneys. Main methodsThe study was conducted on four groups of rats: control group (C), treated with only gentamicin (GM), treated with only green tea (GT) and treated with both gentamicin and green tea (GT+GM). Kidney function, oxidant and antioxidant parameters of renal tissue, as well as histopathological studies were assessed. Morphometric analysis was used to quantify these histopathological changes. Key findingsGentamicin caused significant elevations in serum creatinine and urea and oxidative stress parameter (AOPP), while antioxidative enzyme catalase was significantly decreased. Histological sections of kidneys in GM group revealed necrosis of proximal tubules, vacuolation of cytoplasm and massive mononuclear inflammatory infiltrates in interstitium. Coadministration of green tea with gentamicin histologically showed renoprotective effect. Histological results were confirmed and quantified by morphometric analysis. Also in this group we measured ameliorated parameters of renal functions and antioxidative defense. SignificanceRegenerative potential of green tea after renal injury induced by gentamicin could be explained through the decrease of oxidative stress and lipid peroxidation. Green tea is a natural antioxidant, with many health promoting effects, widely available and in accordance to that affordable. Because of the established habits, people largely consume it as a beverage. It could be beneficial in the reduction of oxidative stress and changes caused by it primarily in renal tubules and interstitium.