The role of green tea intake in thromboprophylaxis of venous thromboembolism in patients with cancer

Background

Green tea intake has been reported to improve the clinical outcomes of patients with cardiovascular diseases or cancer. It may have a certain role in the development of venous thromboembolism (VTE) among cancer patients. The current study aimed to address this issue, which has been understudied.

Methods

We carried out a retrospective study to explore the role of green tea intake in cancer patients. Patients with and without green tea intake were enrolled in a 1:1 ratio by using propensity scoring matching. The primary and secondary outcomes were VTE development and mortality 1 year after cancer diagnosis, respectively.

Results

The cancer patients with green tea intake (n = 425) had less VTE development (10 [2.4%] vs. 23 [5.4%], p = 0.021), VTE-related death (7 [1.6%] vs. 18 [4.2%], p = 0.026), and fatal pulmonary embolism (PE) (3 [0.7%] vs. 12 [2.8%], p = 0.019), compared with those without green tea intake (n = 425). No intake of green tea was correlated with an increase in VTE development (multivariate hazard ratio (HR) 1.758 [1.476-2.040], p < 0.001) and VTE-related mortality (HR 1.618 [1.242-1.994], p = 0.001), compared with green tea intake. Patients with green tea intake less than 525 mL per day had increased VTE development (area under the curve (AUC) 0.888 [0.829-0.947], p < 0.001; HR1.737 [1.286-2.188], p = 0.001) and VTE-related mortality (AUC 0.887 [0.819-0.954], p < 0.001; HR 1.561 [1.232-1.890], p = 0.016) than those with green tea intake more than 525 mL per day. Green tea intake caused a decrease in platelet (p < 0.001) instead of D-dimer (p = 0.297). The all-cause mortality rates were similar between green tea (39 [9.2%]) and non-green tea (48 [11.3%]) intake groups (p = 0.308), whereas the VTE-related mortality rate in the green tea intake group (7 [1.6%]) was lower than that of the non-green tea intake group (18 [4.2%]) (p = 0.026). The incidences of adverse events were similar between the green tea and non-green tea intake groups.

Conclusion

In conclusion, the current study suggests that green tea intake reduces VTE development and VTE-related mortality in cancer patients, most likely through antiplatelet mechanisms. Drinking green tea provides the efficacy of thromboprophylaxis for cancer patients.

Several lines of antioxidant defense against oxidative stress: antioxidant enzymes, nanomaterials with multiple enzyme-mimicking activities, and low-molecular-weight antioxidants

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are well recognized for playing a dual role, since they can be either deleterious or beneficial to biological systems. An imbalance between ROS production and elimination is termed oxidative stress, a critical factor and common denominator of many chronic diseases such as cancer, cardiovascular diseases, metabolic diseases, neurological disorders (Alzheimer's and Parkinson's diseases), and other disorders. To counteract the harmful effects of ROS, organisms have evolved a complex, three-line antioxidant defense system. The first-line defense mechanism is the most efficient and involves antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). This line of defense plays an irreplaceable role in the dismutation of superoxide radicals (O2•-) and hydrogen peroxide (H2O2). The removal of superoxide radicals by SOD prevents the formation of the much more damaging peroxynitrite ONOO- (O2•-  + NO• → ONOO-) and maintains the physiologically relevant level of nitric oxide (NO•), an important molecule in neurotransmission, inflammation, and vasodilation. The second-line antioxidant defense pathway involves exogenous diet-derived small-molecule antioxidants. The third-line antioxidant defense is ensured by the repair or removal of oxidized proteins and other biomolecules by a variety of enzyme systems. This review briefly discusses the endogenous (mitochondria, NADPH, xanthine oxidase (XO), Fenton reaction) and exogenous (e.g., smoking, radiation, drugs, pollution) sources of ROS (superoxide radical, hydrogen peroxide, hydroxyl radical, peroxyl radical, hypochlorous acid, peroxynitrite). Attention has been given to the first-line antioxidant defense system provided by SOD, CAT, and GPx. The chemical and molecular mechanisms of antioxidant enzymes, enzyme-related diseases (cancer, cardiovascular, lung, metabolic, and neurological diseases), and the role of enzymes (e.g., GPx4) in cellular processes such as ferroptosis are discussed. Potential therapeutic applications of enzyme mimics and recent progress in metal-based (copper, iron, cobalt, molybdenum, cerium) and nonmetal (carbon)-based nanomaterials with enzyme-like activities (nanozymes) are also discussed. Moreover, attention has been given to the mechanisms of action of low-molecular-weight antioxidants (vitamin C (ascorbate), vitamin E (alpha-tocopherol), carotenoids (e.g., β-carotene, lycopene, lutein), flavonoids (e.g., quercetin, anthocyanins, epicatechin), and glutathione (GSH)), the activation of transcription factors such as Nrf2, and the protection against chronic diseases. Given that there is a discrepancy between preclinical and clinical studies, approaches that may result in greater pharmacological and clinical success of low-molecular-weight antioxidant therapies are also subject to discussion.

The Platelet Aggregation Inhibition Activity of Polyphenols can be mediated by 67kda Laminin Receptor: A New Therapeutic Strategy For the Treatment of Venous Thromboembolism

BACKGROUND

Thrombotic disease is still a major killer. Aspirin, Ticagrelor, Clopidogrel, etc. are the most widely used conventional antiplatelet drugs. The significant number of patients who are resistant to this drug shows a poor outcome.

OBJECTIVE

Developing a new antiplatelet agent with a stable antiplatelet effect and minimal bleeding risk is required for a patient who is resistant to antiplatelet drugs.

METHOD

Protein-ligand docking was performed using Autodock Vina 1.1.2 to study the interaction of 67LR with different Polyphenols.

RESULT

Among the 18 polyphenols, thearubigin has the highest binding affinity towards 67LR and gallic acid shows the lowest binding affinity. Among the 18 molecules, the top 10 molecules from the highest to lowest binding affinity range from-10.6 (thearubigin) to -6.5 (Epigallocatechin).

CONCLUSION

Polyphenols may inhibit platelet aggregation through 67 LR and can be an alternative treatment for Thrombotic Disease. Moreover, it will be interesting to know whether polyphenols interfere with the same pathways as aspirin and clopidogrel. Effective polyphenols could help prototype the compound development of novel antiplatelet agents.

Tea Plant (Camellia sinensis): A Current Update on Use in Diabetes, Obesity, and Cardiovascular Disease

The tea plant (C. sinensis) has traditionally been consumed worldwide as "tea" for its many health benefits, with the potential for the prevention and therapy of various conditions. Regardless of its long history, the use of tea plants in modern times seems not to have changed much, as the beverage remains the most popular form. This review aimed to compile scientific information about the role and action of tea plants, as well as their status concerning clinical applications, based on the currently available evidence, with a focus on metabolic syndrome, mainly covering obesity, diabetes, and cardiovascular disease. It has been recognized that these diseases pose a significant threat to public health, and the development of effective treatment and prevention strategies is necessary but still challenging. In this article, the potential benefits of tea plants and their derived bioactive components (such as epigallocatechin-3-gallate) as anti-obesity, anti-diabetic, and anti-cardiovascular agents are clearly shown and emphasized, along with their mechanisms of action. However, according to the status of the clinical translation of tea plants, particularly in drug development, more substantial efforts in well-designed, randomized, controlled trials are required to expand their applications in treating the three major metabolic disorders and avoiding the toxicity caused by overconsumption.

Subchronic Toxicity Study of Alternanthera philoxeroides in Swiss Albino Mice Having Antioxidant and Anticoagulant Activities

Alternanthera philoxeroides, a tropical herb and edible vegetable, has been popular as a medicinal plant. Applying in vitro approach, we initially attempted to assess the phytochemicals, bioactive chemicals, as well as antioxidant and anticoagulant activities of this plant. Following that, the in vivo toxicological effects of methanolic extracts of A. philoxeroides using different doses on the kidney, heart, lung, liver, stomach, brain, and blood of female Swiss Albino mice were investigated. We estimated phytochemicals content as well as antioxidant activity through DPPH, NO, CUPRAC, and reducing power assays, followed by the anticoagulant activities of PT  and aPTT  and bioactive compounds using HPLC. To confirm the biocompatibility of A. philoxeroides extracts, histopathological and hematological parameters were examined in a mice model. Total phenol, flavonoid, and tannin content in A. philoxeroides was 181.75 ± 2.47 mg/g, 101.5 ± 3 .53 mg/g, and 68.58 ± 0.80 mg/g, respectively. Furthermore, the HPLC study confirmed the presence of four phenolic compounds: catechin, tannic acid, gallic acid, and vanillic acid. The methanolic extract of A. philoxeroides showed considerable antioxidant activity in all four antioxidant assay methods when compared to the standard. In comparison to ascorbic acid, A. philoxeroides also demonstrated a minor concentration-dependent ferric and cupric reduction activity. In vivo evaluation indicated that A. philoxeroides extracts (doses: 250, 500, and 1000 mg/kg) had no negative effects on the relative organ or body weight, or hematological indicators. Our study concluded that A. philoxeroides had significant antioxidant and anticoagulant activities and demonstrated no negative effects on the body or relative organ weight, histopathological, and hematological indices in the mouse model.

Nutrition phytochemicals affecting platelet signaling and responsiveness: implications for thrombosis and hemostasis

Cardiovascular disease, in particular due to arterial thrombosis, is a leading cause of mortality and morbidity, with crucial roles of platelets in thrombus formation. For multiple plant-derived phytochemicals found in common dietary components, claims have been made regarding cardiovascular health and antiplatelet activities. Here we present a systematic overview of the published effects of common phytochemicals, applied in vitro or in nutritional intervention studies, on agonist-induced platelet activation properties and platelet signaling pathways. Comparing the phytochemical effects per structural class, we included general phenols: curcuminoids (e.g., curcumin), lignans (honokiol, silybin), phenolic acids (caffeic and chlorogenic acid), derivatives of these (shikimic acid) and stilbenoids (isorhapontigenin, resveratrol). Furthermore, we evaluated the flavonoid polyphenols, including anthocyanidins (delphinidin, malvidin), flavan-3-ols (catechins), flavanones (hesperidin), flavones (apigenin, nobiletin), flavonols (kaempferol, myricetin, quercetin), isoflavones (daidzein, genistein); and terpenoids including carotenes and limonene; and finally miscellaneous compounds like betalains, indoles, organosulfides (diallyl trisulfide) and phytosterols. We furthermore discuss the implications for selected phytochemicals to interfere in thrombosis and hemostasis, indicating their possible clinical relevance. Lastly, we provide guidance on which compounds are of interest for further platelet-related research.

Immunomodulatory effects of polysaccharides enzymatic hydrolysis from Hericium erinaceus on the MODE-K/DCs co-culture model

The aim of this study was to explore the indirect immunomodulatory activities and its mechanism of enzymatic hydrolysis of Hericium erinaceus polysaccharides (EHEP) in the MODE-K/DCs co-culture model. According to the TEER value, transmission of phenol red and AKP activity of MODE-K cells, single model was established in order to evaluate the eligibility of MODE-K cells monolayer. Then the MODE-K/DCs co-culture model was set up and HEP and EHEP were added into the apical chamber, DCs were obtained for the expression of key surface markers, the ability of phagocytosis, the morphology, the secretion of cytokines and the production of target proteins. We found that after 21 d of culture, the MODE-K cells monolayer became intact and dense, which can be used for the MODE-K/DCs co-culture model. Under the treatment of HEP and EHEP, immature DCs become into mature DCs with the high expression of CD86 and MHCII, the low antigens up-taking, the typical morphology, the more content of IL-12 and TNF-α and the high level of TLR4, MyD88 and NF-κB proteins. However, compared with HEP, EHEP showed the better immunomodulatory activities. These findings indicated that EHEP could indirectly affect the immune function of DCs in the MODE-K/DCs co-culture model.

Molecular mechanisms underlying health benefits of tea compounds

Tea is one of the three most widely consumed beverages in the world, not only because of its unique flavor but also due to its various health benefits. The bioactive components in tea, such as polyphenols, polysaccharides, polypeptides, pigments, and alkaloids, are the main contributors to its health functions. Based on epidemiological surveys, the consumption of tea and its compounds in daily life has positive effects on cardiovascular diseases, cancers, hepatopathy, obesity, and diabetes mellitus. In experimental studies, the antioxidant, anti-inflammatory, anti-cancer, anti-obesity, cardiovascular protective, liver protective, and hypoglycemic activities of tea and the related mechanisms of action have been widely investigated. The regulation of several classical signaling pathways, such as nuclear factor-κB (NF-κB), AMP activated protein kinase (AMPK), and wingless/integrated (Wnt) signaling, is involved. Clinical trials have also demonstrated the potential of tea products to be applied as dietary supplements and natural medicines. In this paper, we reviewed and discussed the recent literature on the health benefits of tea and its compounds, and specifically explored the molecular mechanisms involved.

Lipid rafts as potential mechanistic targets underlying the pleiotropic actions of polyphenols

Polyphenols have attracted a lot of global attention due to their diverse biological actions against cancer, obesity, and cardiovascular diseases. Although extensive research has been carried out to elucidate the mechanisms of pleiotropic actions of polyphenols, this remains unclear. Lipid rafts are distinct nanodomains enriched in cholesterol and sphingolipids, present in the inner and outer leaflets of cell membranes, forming functional platforms for the regulation of cellular processes and diseases. Recent studies focusing on the interaction between polyphenols and cellular lipid rafts shed new light on the pleiotropic actions of polyphenols. Polyphenols are postulated to interact with lipid rafts in two ways: first, they interfere with the structural integrity of lipid rafts, by disrupting their structure and clustering of the ordered domains; second, they modulate the downstream signaling pathways mediated by lipid rafts, by binding to receptor proteins associated with lipid rafts, such as the 67 kDa laminin receptor (67LR), epidermal growth factor receptor (EGFR), and others. This study aims to elaborate the mechanism of interaction between polyphenols and lipid rafts, and describe pleiotropic preventive effects of polyphenols.

Hemostatic activity of aqueous extract of Myrtus communis L. leaf in topical formulation: In vivo and in vitro evaluations

ETHNOPHARMACOLOGICAL RELEVANCE

Myrtus communis L. (MC) is a well-known medicinal plant in traditional Persian medicine, which contains a large amount of phenolic compounds (mainly hydrolyzable tannins). As mentioned in ancient literature, MC was widely used to control bleeding in every part of the body. Nevertheless, there is no pharmacological study on the anti-hemorrhagic activity of this plant till now.

AIM OF THE STUDY

The current in vivo and in vitro study aimed at evaluating the hemostatic activity of M. communis aqueous leaf extract (MCE) in topical formulation.

MATERIALS AND METHODS

Two parameters of bleeding time and amount in tail bleeding model were measured in vivo in rats treated with MCE (1%, 2.5%, 5%, 7.5%, 10%, 15%, and 20% w/v), 5% M. communis aqueous leaf extract gel (G), tannic acid (TA) (1%, 2.5%, 5%, 7.5%, and 10%), normal saline (NS), and the Monsel's solution (MS), a commercial hemostatic agent. Also, the effect of 5% MCE and 5% TA on PT (prothrombin time) and aPTT (activated partial thromboplastin time) as well as protein precipitation and platelet aggregation were assessed in vitro.

RESULTS

In the rat-tail bleeding model, bleeding time and amount significantly (P < 0.001) reduced by the application of 5% MCE solution on the cut tail compared with the NS group. The bleeding time and amount in the MS group were not significantly different from those of the 5% MCE group. Platelet microaggregates were detected by fluorescent microscope. PT and aPTT values increased >120 s and >180 s by 5% MCE, respectively. Also, protein precipitation and significant reduction in serum proteins were observed in the 5% MCE group.

CONCLUSION

The current study provided new insights into the hemostatic effect of MCE, which may be partially mediated by platelet aggregation activity. Hence, it could be evaluated as the resource of new plant origin hemostatic agent.

Tea consumption is associated with a reduced risk of coronary heart disease in female but not male populations in Guangzhou, China

BACKGROUND/OBJECTIVES

The association between tea consumption and risk of coronary heart disease (CHD) remains controversial. This study aimed to determine whether tea consumption has an effect on CHD risk in Chinese adults.

SUBJECTS/METHODS

In this hospital-based case-control study, 267 cases of CHD and 235 non-CHD controls were enrolled. Blood samples from all cases were examined. Cardiac function indices (left ventricular ejection fraction, left ventricular end-diastolic dimension, lactate dehydrogenase, and creatine kinase of the muscle or brain type), blood lipid index (high-density lipoprotein cholesterol), and blood coagulation function indices (fibrinogen and activated partial thromboplastin time) were recorded. Tea consumption of study participants was assessed by a specifically designed questionnaire. The baseline characteristics of the study populations were recorded, and CHD-related biomarkers were detected. Differences in baseline characteristics of the study participants were examined using t-tests for continuous variables and chi-squared tests for categorical variables. Unconditional logistic regression was used to measure the association between tea and CHD.

RESULTS

There were significant differences in cardiac function indices, blood lipid index, and blood coagulation indices between CHD cases and controls (P < 0.05). We found tea consumption reduced CHD risk in female participants (adjusted odds ratio (OR) = 0.484, 95% CI: 0.242–0.968, P = 0.0403). Regarding the type of tea consumed, the risk of CHD was reduced in women who drank partially fermented tea (adjusted OR = 0.210, 95% CI: 0.084–0.522, P = 0.0008). Analytic results for the amount of tea consumed per unit time showed CHD risk was reduced in women who consumed 1–2 cups of tea per day (adjusted OR = 0.291, 95% CI: 0.131–0.643, P = 0.0023). A tea-drinking frequency of > 6 days/week was beneficial for CHD prevention (adjusted OR = 0.183, 95% CI: 0.049–0.679, P = 0.0112). When analyzed according to the duration of tea consumption, the risk of CHD was reduced in participants who had been drinking tea for 10–20 years (adjusted OR = 0.360, 95% CI: 0.137–0.946, P = 0.0382).

CONCLUSIONS

Tea consumption is associated with a reduced risk of CHD in female but not male populations in Guangzhou.

Preparation and antithrombotic activity identification of Perinereis aibuhitensis extract: a high temperature and wide pH range stable biological agent

In this work, a thermal and wide pH range stable biological agent was extracted from Perinereis aibuhitensis, whose antithrombotic activity was investigated.

Preventive Effects of Catechins on Cardiovascular Disease

Catechins are polyphenolic phytochemicals with many important physiological activities that play a multifaceted health care function in the human body, especially in the prevention of cardiovascular disease. In this paper, various experimental and clinical studies have revealed the role of catechins in the prevention and treatment of cardiovascular disorders, and we review the preventive effects of catechins on cardiovascular disease from the following aspects: Regulating lipid metabolism, regulating blood lipid metabolism, vascular endothelial protection, and reducing blood pressure.

Anti-platelet and anti-thrombogenic effects of shikimic acid in sedentary population

This ex vivo study was performed to evaluate the anti-platelet and anti-thrombogenic potential of shikimic acid (SA), a plant phenolic metabolite. Fasting blood samples were collected from 22 sedentary participants to analyse the effect of varying concentrations of SA (0.1 mM, 0.2 mM, 0.5 mM, 1 mM and 2 mM) on platelet surface-marker expression, platelet aggregation and biomarkers of thrombogenesis. Monocyte-platelet aggregates (CD14/CD42b) and platelet endothelial cell adhesion molecule-1 (PECAM-1 or CD31), effective indicators of thrombus formation were evaluated. Procaspase-activating compound 1 (PAC-1) and P-selectin or CD62P were used to assess platelet activation-related thrombogenesis. Adenosine diphosphate (ADP) was used to stimulate the P2Y1/P2Y12 pathway of platelet activation to mimic the in vivo thrombogenic pathway. Platelet aggregation studies utilised both ADP and collagen as exogenous platelet agonists to target both P2Y1/P2Y12 and GPVI pathways of thrombus formation. It was observed with flow cytometry that SA produced a significant antiplatelet effect on PAC-1 (p = 0.03 at 2 mM) and CD62P (p = 0.017, p = 0.036 at 1 mM and 2 mM respectively) expression in addition to lowering monocyte-platelet aggregate formation (p = 0.013, p < 0.01 and p < 0.01 at 0.5 mM, 1 mM and 2 mM respectively). SA at 1 mM concentration reduced PECAM-1 expression (p = 0.035), signifying a reduction to endothelial leucocyte migration during thrombus growth. SA did not demonstrate a platelet aggregation inhibitory effect by targeting the GPVI collagen pathway but reduced ADP induced platelet aggregation at 2 mM concentration (p < 0.01 at 2 mM). The results suggest that SA, an active metabolite of polyphenol-rich food intake, could play an important role in reducing platelet activation, aggregation related thrombus formation and biomarkers of thrombogenesis in sedentary individuals.

Optimization on condition of epigallocatechin-3-gallate (EGCG) nanoliposomes by response surface methodology and cellular uptake studies in Caco-2 cells

The major component in green tea polyphenols, epigallocatechin-3-gallate (EGCG), has been demonstrated to prevent carcinogenesis. To improve the effectiveness of EGCG, liposomes were used as a carrier in this study. Reverse-phase evaporation method besides response surface methodology is a simple, rapid, and beneficial approach for liposome preparation and optimization. The optimal preparation conditions were as follows: phosphatidylcholine-to-cholesterol ratio of 4.00, EGCG concentration of 4.88 mg/mL, Tween 80 concentration of 1.08 mg/mL, and rotary evaporation temperature of 34.51°C. Under these conditions, the experimental encapsulation efficiency and size of EGCG nanoliposomes were 85.79% ± 1.65% and 180 nm ± 4 nm, which were close with the predicted value. The malondialdehyde value and the release test in vitro indicated that the prepared EGCG nanoliposomes were stable and suitable for more widespread application. Furthermore, compared with free EGCG, encapsulation of EGCG enhanced its inhibitory effect on tumor cell viability at higher concentrations.