Influence of green tea consumption on cigarette smoking-induced biochemical changes in plasma and blood

Anti-atherogenic role of green tea (Camellia sinensis) in South Indian smokers

ETHNOPHARMACOLOGICAL RELEVANCE

Green tea (Camellia sinensis) is a popular beverage consumed all over the world due to its health benefits. Many of these beneficial effects of green tea are attributed to polyphenols, particularly catechins.

AIM OF THE STUDY

The present study focuses on underlying anti-platelet aggregation, anti-thrombotic, and anti-lipidemic molecular mechanisms of green tea in South Indian smokers.

MATERIALS AND METHODS

We selected 120 South Indian male volunteers for this study to collect the blood and categorised them into four groups; control group individuals (Controls), smokers, healthy control individuals consuming green tea, and smokers consuming green tea. Smokers group subjects have been smoking an average 16-18 cigarettes per day for the last 7 years or more. The subjects (green tea consumed groups) consumed 100 mL of green tea each time, thrice a day for a one-year period.

RESULTS

LC-MS analysis revealed the presence of multiple phytocompounds along with catechins in green tea extract. Increased plasma lipid peroxidation (LPO), protein carbonyls, cholesterol, triglycerides, and LDL-cholesterol with decreased HDL-cholesterol levels were observed in smokers compared to the control group and the consumption of green tea showed beneficial effect. Furthermore, docking studies revealed that natural compounds of green tea had high binding capacity with 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMG-CoA) when compared to their positive controls, whereas (-) epigallocatechin-3-gallate (EGCG) and (-) epicatechin-gallate (ECG) had high binding capacity with sterol regulatory element-binding transcription factor 1 (SREBP1c). Further, our ex vivo studies showed that green tea extract (GTE) significantly inhibited platelet aggregation and increased thrombolytic activity in a dose dependent manner.

CONCLUSION

In conclusion, in smokers, catechins synergistically lowered oxidative stress, platelet aggregation and modified the aberrant lipid profile. Furthermore, molecular docking studies supported green tea catechins' antihyperlipidemic efficacy through strong inhibitory activity on HMG-CoA reductase and SREBP1c. The mitigating effects of green tea on cardiovascular disease risk factors in smokers that have been reported can be attributed majorly to catechins or to their synergistic effects.

Racial Health Disparity and COVID-19

Abstract

The infection by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and resultant coronavirus diseases-19 (COVID-19) disproportionally affects minorities, especially African Americans (AA) compared to the Caucasian population. The AA population is disproportionally affected by COVID-19, in part, because they have high prevalence of underlying conditions such as obesity, diabetes, and hypertension, which are known to exacerbate not only kidney diseases, but also COVID-19. Further, a decreased adherence to COVID-19 guidelines among tobacco smokers could result in increased infection, inflammation, reduced immune response, and lungs damage, leading to more severe form of COVID-19. As a result of high prevalence of underlying conditions that cause kidney diseases in the AA population coupled with tobacco smoking make the AA population vulnerable to severe form of both COVID-19 and kidney diseases. In this review, we describe how tobacco smoking interact with SARS-CoV-2 and exacerbates SARS-CoV-2-induced kidney diseases including renal failure, especially in the AA population. We also explore the role of extracellular vesicles (EVs) in COVID-19 patients who smoke tobacco. EVs, which play important role in tobacco-mediated pathogenesis in infectious diseases, have also shown to be important in COVID-19 pathogenesis and organ injuries including kidney. Further, we explore the potential role of EVs in biomarker discovery and therapeutics, which may help to develop early diagnosis and treatment of tobacco-induced renal injury in COVID-19 patients, respectively.

Graphical Abstract

Association between health risk factors and dietary flavonoid intake in cohort studies

The aim of this study was to identify the health risk factors associated with flavonoid intake in cohort studies investigating the association between dietary polyphenols and the risk of cardiovascular disease (CVD). A systematic search of the PubMed and EMBASE databases was performed. Prospective studies with the background characteristics given for categories of flavonoid intake were eligible to inclusion. A bivariate meta-analysis summarising the intercepts and slopes of the linear regression and a dose-response meta-analysis of differences in means were used to analyse the relationships. The intake of total flavonoids was inversely associated with BMI, alcohol consumption, saturated fat intake, and current smoking, and positively associated with vitamin E, folate, fibre, beta-carotene intake, multivitamin supplement use, and high physical activity. The results of this study underline the importance of considering the association between dietary flavonoid consumption and CVD risk in the context of a healthy lifestyle.

Protective effect of the medicinal herb infusion "horchata" against oxidative damage in cigarette smokers: An ex vivo study

Cigarette smoking has been associated with an increase in oxidative stress (OS) and is considered a predisposing factor to chronic noncommunicable diseases, whilst dietary antioxidants has been proposed as an alternative to cope with this oxidative stress. In this study, 20 smokers and 20 non-smokers were studied with the aim of determining their antioxidant status, as well as the ability of an infusion of 23 medicinal plants, to counteract the damage caused by OS. The plasma, red blood cells (RBCs) and polymorphonuclear cells (PBMCs) of both groups were incubated or not with the horchata infusion extract and then the OS markers, genotoxicity, nanostructure of RBCs membrane and genes related to oxidative responses and cellular functionality were evaluated. Up to 33 different compounds, mainly quercetin glycosides, were identified in the extract. A significant deterioration in the antioxidant status in smokers compared to non-smokers was found. The horchata infusion extract improved the nanostructure of RBCs and DNA damage, as well as the activity of the endogenous antioxidant enzymes and markers of oxidative damage to lipid, and proteins in plasma, RBCs and PBMCs in both groups, whilst no significant changes were found in the expression of different genes related to OS response.

Associations between habitual flavonoid intake and hospital admissions for atherosclerotic cardiovascular disease: a prospective cohort study

BACKGROUND

Flavonoids, compounds found in plant-based foods and beverages, might ameliorate vascular damage and atherosclerosis. Therefore, our aim was to assess the association between flavonoid intake and hospital admissions due to atherosclerotic cardiovascular disease.

METHODS

In this prospective cohort study, participants from the Danish Diet, Cancer, and Health Study were cross-linked with Danish nationwide registries. Eligible participants were aged 50-65 years, had no previous history of atherosclerotic cardiovascular disease, and had completed a food-frequency questionnaire at baseline. We examined associations between flavonoid intake (calculated from food-frequency questionnaires with use of the Phenol-Explorer database) and hospital admissions for atherosclerotic cardiovascular disease, ischaemic heart disease, ischaemic stroke, or peripheral arterial disease. We obtained hazard ratios (HRs) using restricted cubic splines based on Cox proportional hazards models.

FINDINGS

Of the participants recruited to the Danish Diet, Cancer, and Health study between 1993 and 1997, our study population was comprised of 53 552 participants, with a median follow-up of 21 years (IQR 15-22). During follow-up, 8773 participants were admitted to hospital for atherosclerotic cardiovascular disease. We observed non-linear associations between flavonoid intake and hospital admissions, plateauing at total flavonoid intakes of approximately 1000 mg per day. Compared with an intake of 175 mg per day, an intake of 1000 mg per day was associated with a 14% lower risk of atherosclerotic cardiovascular disease (HR 0·86, 95% CI 0·81-0·91). For disease subtypes, we observed a 9% lower risk of ischaemic heart disease (0·91, 0·85-0·98), a non-significant 9% lower risk of ischaemic stroke (0·91, 0·82-1·01), and a 32% lower risk of peripheral artery disease (0·68, 0·60-0·78). The overall associations were stronger in smokers than in non-smokers, as well as stronger in consumers of high (>20 g per day) quantities of alcohol than in those consuming low-to-moderate (≤20 g per day) quantities.

INTERPRETATION

Our results suggest that ensuring an adequate consumption of flavonoid-rich foods, particularly in subpopulations at risk of atherosclerosis such as smokers and consumers of high quantities of alcohol might mitigate some of the risk of atherosclerotic cardiovascular disease. More studies are needed to support and validate these data.

FUNDING

Danish Cancer Society.

Flavonoid intake is associated with lower mortality in the Danish Diet Cancer and Health Cohort

Flavonoids, plant-derived polyphenolic compounds, have been linked with health benefits. However, evidence from observational studies is incomplete; studies on cancer mortality are scarce and moderating effects of lifestyle risk factors for early mortality are unknown. In this prospective cohort study including 56,048 participants of the Danish Diet, Cancer, and Health cohort crosslinked with Danish nationwide registries and followed for 23 years, there are 14,083 deaths. A moderate habitual intake of flavonoids is inversely associated with all-cause, cardiovascular- and cancer-related mortality. This strong association plateaus at intakes of approximately 500 mg/day. Furthermore, the inverse associations between total flavonoid intake and mortality outcomes are stronger and more linear in smokers than in non-smokers, as well as in heavy (>20 g/d) vs. low-moderate (<20 g/d) alcohol consumers. These findings highlight the potential to reduce mortality through recommendations to increase intakes of flavonoid-rich foods, particularly in smokers and high alcohol consumers.

Iron-based nanoparticles prepared from yerba mate extract. Synthesis, characterization and use on chromium removal

Iron-based nanoparticles were synthesized by a rapid method at room temperature using yerba mate (YM) extracts with FeCl₃ in different proportions. Materials prepared from green tea (GT) extracts were also synthesized for comparison. These materials were thoroughly characterized by chemical analyses, XRD, magnetization, SEM-EDS, TEM-SAED, FTIR, UV-Vis, Raman, Mössbauer and XANES spectroscopies, and BET area analysis. It was concluded that the products are nonmagnetic iron complexes of the components of the extracts. The applicability of the materials for Cr(VI) (300 μM) removal from aqueous solutions at pH 3 using two Cr(VI):Fe molar ratios (MR), 1:3 and 1:0.5, has been tested. At Cr(VI):Fe MR = 1:3, the best YM materials gave complete Cr(VI) removal after two minutes of contact, similar to that obtained with commercial nanoscale zerovalent iron (N25), with dissolved Fe(II), and with a likewise prepared GT material. At a lower Cr(VI):Fe MR (1:0.5), although Cr(VI) removal was not complete after 20 min of reaction, the YM nanoparticles were more efficient than N25, GT nanoparticles and Fe(II) in solution. The results suggest that an optimal Cr(VI):Fe MR ratio could be reached when using the new YM nanoparticles, able to achieve a complete Cr(VI) reduction, and leaving very low Cr and Fe concentrations in the treated solutions. The rapid preparation of the nanoparticles would allow their use in removal of pollutants in soils and groundwater by direct injection of the mixture of precursors.