Enhancement of Annexin V in response to combination of epigallocatechin gallate and quercetin as a potent arrest the cell cycle of colorectal cancer / Aumento da anexina V em resposta à combinação de galato de epigalocatequina e quercetina como uma potente parada do ciclo celular do câncer colorretal

Colorectal cancer (CRC) is one of the most common cancers leading to comorbidities and mortalities globally. The rational of current study was to evaluate the combined epigallocatechin gallate and quercetin as a potent antitumor agent as commentary agent for therapeutic protocol. The present study investigated the effect of epigallocatechin Gallate (EGCG) (150mg) and quercetin (200mg) at different proportions on proliferation and induction of apoptosis in human colon cancer cells (HCT-116). Cell growth, colonogenic, Annexin V in addition cell cycle were detected in response to phytomolecules. Data obtained showed that, the colony formation was inhibited significantly in CRC starting from the lowest concentration tested of 10 µg/mL resulting in no colonies as visualized by a phase-contrast microscope. Data showed a significant elevation in the annexin V at 100 µg/mL EGCG(25.85%) and 150 µg/mL quercetin (48.35%). Moreover, cell cycle analysis showed that this combination caused cell cycle arrest at the G1 phase at concentration of 100 µg/mL (72.7%) and 150 µg/mL (75.25%). The combined effect of epigallocatechin Gallate and quercetin exert antiproliferative activity against CRC, it is promising in alternative conventional chemotherapeutic agent.

O câncer colorretal (CCR) é um dos cânceres mais comuns, levando a comorbidades e mortalidade em todo o mundo. O racional do presente estudo foi avaliar a combinação de galato de epigalocatequina e quercetina como um agente antitumoral potente como agente de comentário para protocolo terapêutico. O presente estudo investigou o efeito de galato de epigalocatequina (EGCG) (150 mg) e quercetina (200 mg) em diferentes proporções na proliferação e indução de apoptose em células de câncer de cólon humano (HCT-116). O crescimento celular, colonogênico, anexina V, além do ciclo celular foram detectados em resposta a fitomoléculas. Os dados obtidos mostraram que a formação de colônias foi inibida significativamente no CRC a partir da concentração mais baixa testada de 10 µg/mL, resultando em nenhuma colônia conforme visualizado por um microscópio de contraste de fase. Os dados mostraram uma elevação significativa na anexina V a 100 µg/mL de EGCG (25,85%) e 150 µg/mL de quercetina (48,35%). Além disso, a análise do ciclo celular mostrou que essa combinação causou parada do ciclo celular na fase G1 na concentração de 100 µg/mL (72,7%) e 150 µg/mL (75,25%). O efeito combinado da epigalocatequina galato e quercetina exerce atividade antiproliferativa contra o CCR, é promissor como agente quimioterápico alternativo convencional.

Epigallocatechin-3-gallate ameliorates lipopolysaccharide-induced acute lung injury by suppression of TLR4/NF-κB signaling activation

Acute lung injury (ALI) is a serious clinical syndrome with a high rate of mortality. The activation of inflammation is well-recognized as a vital factor in the pathogenesis of lipopolysaccharide (LPS)-induced ALI. Therefore, suppression of the inflammatory response could be an ideal strategy to prevent ALI. Epigallocatechin-3-gallate (EGCG), mainly from green tea, has been shown to have an anti-inflammatory effect. The aim of the study was to explore whether EGCG alleviates inflammation in sepsis-related ALI. Male BALB/C mice were treated with EGCG (10 mg/kg) intraperitoneally (ip) 1 h before LPS injection (10 mg/kg, ip). The results showed that EGCG attenuated LPS-induced ALI as it decreased the changes in blood gases and reduced the histological lesions, wet-to-dry weight ratios, and myeloperoxidase (MPO) activity. In addition, EGCG significantly decreased the expression of pro-inflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 in the lung, serum, and bronchoalveolar lavage fluid, and alleviated the expression of TLR-4, MyD88, TRIF, and p-p65 in the lung tissue. In addition, it increased the expression of IκB-α and had no influence on the expression of p65. Collectively, these results demonstrated the protective effects of EGCG against LPS-induced ALI in mice through its anti-inflammatory effect that may be attributed to the suppression of the activation of TLR 4-dependent NF-κB signaling pathways.

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.

Chronic oral epigallocatechin-gallate alleviates streptozotocin-induced diabetic neuropathic hyperalgesia in rat: involvement of oxidative stress

Due to the anti-diabetic and antioxidant activity of green tea epigallocatechin-gallate [EGCG], this research study was conducted to evaluate, for the first time, the efficacy of chronic treatment of EGCG on alleviation of hyperalgesia in streptozotocin-diabetic [STZ-diabetic] rats. Male Wistar rats were divided into control, diabetic, EGCG-treated-control and diabetic and sodium salicylate [SS]-treated control and diabetic groups. For induction of diabetes, STZ was intraperitoneally injected [IP] at a single dose of 60 mg/Kg. EGCG was orally administered daily at doses of 20 and 40 mg/Kg for seven weeks; one week after diabetes induction. Finally, hyperalgesia was assessed using standard formalin, hot tail immersion and paw pressure tests. Meanwhile, markers of oxidative stress in brain were measured. Diabetic rats showed a marked chemical, thermal and paw pressure hyperalgesia, indicating that the development of diabetic neuropathy and EGCG treatment at a dose 40 mg/Kg significantly ameliorated the alteration in hyperalgesia [p < 0.05] in diabetic rats as compared with untreated diabetics. EGCG treatment [40 mg/Kg] also significantly decreased diabetes-induced thiobarbituric acid reactive substances formation [p < 0.05] and nitrite [p < 0.05] content and reversed the reduction of antioxidant defensive enzyme superoxide dismutase [p < 0.05]. The results may suggest therapeutic potential of EGCG for the treatment of diabetic hyperalgesia through the attenuation of oxidative stress

Adiponectin, insulin and nitric oxide levels in hyperlipidemia and hypercholesterolemia in addition to streptozotocin-indined diabetes mellitus and normal rats intraperitonially injected with anthocyanin and epicatechin extracts

Normal and streptozotocin-induced diabetic rats were intraperitonially injected with hibiscus anthocyanin [90 mg/Kg bw] and green tea epicatechin [60 mg/Kg bw] extracts daily for two weeks. In addition, normal and diabetic rats were force fed on high-fat diet for two weeks. Rats suffering from hypercholesterolemia were used for induction of diabetes mellitus and fed on a hypercholesterolemic diet for two weeks using non-diabetic hypercholesterolemic rats as positive control. At the end of the experiment, serum glucose insulin, adiponectin, nitric oxide and lipid profile were measured. Anthocyanin and epicatechin extracts significantly decreased the elevated levels of glucose, nitric oxide, triglycerides, total cholesterol and LDL-C in serum of diabetic rats, while adiponectin was slightly increased. The concentrations of serum glucose, nitric oxide, triglycerides, total cholesterol and LDL-C were greatly increased, while adiponectin level was significantly decreased in diabetic rats fed high-fat or high-cholesterol diets. These results indicate that increased nitric oxide and [or] decreased adiponectin in serum may result in increasing the glucose, triglycerides, total cholesterol and LDL-C levels in diabetic, hyperlipidemic and hypercholesterolemic rats

Evaluation of platelet aggregation in platelet concentrates: storage implications / Efeito das catequinas (catequina e epicatequina) na agregação plaquetária

Os flavonóides representam um dos grupos fenólicos mais importantes e diversificados entre os produtos de origem natural. Dentre os compostos fenólicos temos os derivados flavânicos (flavan-3-óis e flavan-3,4-dióis) que podem se polimerizar originando taninos. O representante mais importante do grupo dos flavan-3-óis é a catequina. Estes compostos exibem inúmeros efeitos biológicos incluindo ação antiviral, antioxidante e antitrombótica. No presente trabalho foi avaliado o efeito das catequinas (catequina e epicatequina) sobre a função plaquetária. Foram estudados vinte indivíduos adultos, clinicamente saudáveis. A agregação plaquetária foi avaliada em plasma rico em plaquetas (PRP) e plaquetas lavadas utilizando-se agonistas colágeno (2,0 µg/ml) e trombina (0,25U/ml), respectivamente. Como controle utilizou-se o veículo da droga (DMSO 0.2 por cento). O pré-tratamento das plaquetas com epicatequina (200 µg/ml) causou inibição significativa da agregação para o colágeno (9.0 ± 7.8 por cento) e para a trombina (10.0 ± 2.2) em relação aos respectivos controles (70.0 ± 7.8) e (68.0 ± 5.0), (p<0.001; Student t-test). Por outro lado, a catequina não promoveu inibição da resposta de agregação. Conclui-se que a epicatequina apresenta potencial antiagregante.

Os flavonóides representam um dos grupos fenólicosmais importantes e diversificados entre os produtosde origem natural. Dentre os compostos fenólicos temosos derivados flavânicos (flavan-3-óis e flavan-3,4-dióis) que podem se polimerizar originando taninos.O representante mais importante do grupodos flavan-3-óis é a catequina. Estes compostos exibeminúmeros efeitos biológicos incluindo açãoantiviral, antioxidante e antitrombótica. No presentetrabalho foi avalia(catequina e epicatequina) sobre a função plaquetária.Foram estudados vinte indivíduos adultos,clinicamente saudáveis. A agregação plaquetária foiavaliada em plasma rico em plaquetas (PRP) e plaquetaslavadas utilizando-se agonistas colágeno (2,0μg/ml) e trombina (0,25U/ml), respectivamente.Como controle utilizou-se o veículo da droga (DMSO0.2%). O pré-tratamento das plaquetas com epicatequina(200 μg/ml) causou inibição significativa daagregação para o colágeno (9.0 ± 7.8%) e para atrombina (10.0 ± 2.2) em relação aos respectivoscontroles (70.0 ± 7.8) e (68.0 ± 5.0), ( p<0.001;Student t-test). Por outro lado, a catequina não promoveuinibição da resposta de agregação. Concluise que a epicatequina apresenta potencial antiagregantedo o efeito das catequinas.