Cellular determinants involving mitochondrial dysfunction, oxidative stress and apoptosis correlate with the synergic cytotoxicity of epigallocatechin-3-gallate and menadione in human leukemia Jurkat T cells

The effect of pomegranate juice supplementation on C-reactive protein levels: GRADE-assessed systematic review and dose-response updated meta-analysis of data from randomized controlled trials

Pomegranate juice (PJ) has a possible anti-inflammatory effect because of its polyphenol content and antioxidants. However, the anti-inflammatory effect of PJ in randomized controlled trials (RCTs) has not been consistent. A previous meta-analysis conducted in 2016 reported a nonsignificant lowering effect of PJ on C-reactive protein (CRP) levels. This systematic review and meta-analysis aim to update the pooled effect size of PJ supplementation on CRP levels in RCT studies. PubMed, Scopus, and Web of Science databases were comprehensively searched until July 2023. Eligible studies were found by screening, their relevant data was extracted, and a risk of bias assessment was performed. The pooled effect size was calculated using a random effect model as the weighted mean difference (WMD) with a 95% confidence interval. This systematic review included 11 studies with 13 effect sizes and 696 participants. Meta-analysis showed that PJ supplementation led to a significant decrease in CRP levels compared to control groups (WMD: -2.55 mg/L; 95%CI: -3.44 to -1.66; p < 0.001). Subgroup analysis demonstrated the significant reduction effect of PJ on CRP levels in studies conducted on the both sexes or only females as well as Iranian population, individuals with 40 years≤, type 2 diabetes, polycystic ovary syndrome, or trials that intervened with PJ dosage of <250 ml/day. Meta-regression and dose-response analysis reported a nonsignificant linear and nonlinear relationship between intervention characteristics (duration and dose of PJ) and CRP changes. The current meta-analysis revealed that PJ supplemantation has a beneficial effect in improving CRP levels. It is recommended to understand this effect better, and find the optimal dose and duration of PJ supplementation to reduce CRP levels in the blood, and repeat meta-analysis after related RCTs are available. For the final proof of these effects, more detailed human studies are needed.

Effects of green tea on lipid profile in overweight and obese women

The effect of green tea administration on serum lipids' concentrations remains unclear as various investigations, which have explored this topic, have produced conflicting results. Gender might be one of the factors influencing the impact of green tea on the lipid profile. Hence, we conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to assess the effect of green tea intake on the lipid profile in overweight and obese women. We searched five databases (Web of Science, SCOPUS, Embase, PubMed/Medline, and Google Scholar) using a combination of MeSH and non-MeSH terms. Results were expressed as weighted mean differences (WMDs) and 95% confidence intervals (CIs) and synthesized with a random-effects model. In total, 15 eligible RCTs with 16 arms (1818 participants) were included in the meta-analysis. The combined effect size revealed a significant reduction in total cholesterol (TC) (WMD: -4.45 mg/dl, 95% CI: -6.63, -2.27, P<0.001) and low-density lipoprotein cholesterol (LDL-C) (WMD: -4.49 mg/dl, 95% CI: -7.50 to -1.47, P=0.003) concentrations following green tea supplementation in overweight and/or obese women. In addition, a more pronounced reduction of triglyceride (TG) levels occurred when the baseline TG value was ≥150 mg/dL (WMD: -24.45 mg/dL, 95% CI: -40.63 to -8.26, P=0.003). Moreover, a significant decrease in TG concentrations occurred in RCTs conducted on overweight subjects (BMI: 25-29.99 kg/m2) (WMD: -5.88 mg/dl, 95% CI: -10.76 to -0.99, P=0.01). In the subgroup analyses based on the study population, a notable increase in high-density lipoprotein cholesterol (HDL-C) values was observed in obese individuals (>30 kg/m2) (WMD: 2.63 mg/dl, 95% CI: 0.10 to 5.16, P=0.041). Consumption of green tea causes a reduction in LDL-C and TC concentrations in overweight and obese women. The decline in TG levels was notable particularly in overweight patients with hypertriglyceridemia at baseline. In addition, a significant increase in HDL-C was detected in obese subjects following intake of green tea.

The Effects of Green Tea Catechins in Hematological Malignancies

Green tea catechins are bioactive polyphenol compounds which have attracted significant attention for their diverse biological activities and potential health benefits. Notably, epigallocatechin-3-gallate (EGCG) has emerged as a potent apoptosis inducer through mechanisms involving caspase activation, modulation of Bcl-2 family proteins, disruption of survival signaling pathways and by regulating the redox balance, inducing oxidative stress. Furthermore, emerging evidence suggests that green tea catechins can modulate epigenetic alterations, including DNA methylation and histone modifications. In addition to their apoptotic actions, ROS signaling effects and reversal of epigenetic alterations, green tea catechins have shown promising results in promoting the differentiation of leukemia cells. This review highlights the comprehensive actions of green tea catechins and provides valuable insights from clinical trials investigating the therapeutic potential of green tea catechins in leukemia treatment. Understanding these multifaceted mechanisms and the outcomes of clinical trials may pave the way for the development of innovative strategies and the integration of green tea catechins into clinical practice for improving leukemia patient outcomes.

Primary Arterial Hypertension and Drug-Induced Hypertension in Philadelphia-Negative Classical Myeloproliferative Neoplasms: A Systematic Review

The impact of primary arterial hypertension (HTN) in myeloproliferative neoplasms (MPNs) remains unclear, with scant literature available, mostly focusing on cardiovascular risk factors as a singular entity or on organ-specific HTN. Furthermore, available studies reporting findings on drug-induced HTN in MPNs report varying and contradictory findings. In consideration of the above, this study set out to systematically review the available literature and shed light on the occurrence of HTN in MPNs, its association with thrombosis, as well as the drugs used in MPN management that could increase blood pressure. The literature search yielded 598 potentially relevant records of which 315 remained after the duplicates (n = 283) were removed. After we screened the titles and the abstracts of these publications, we removed irrelevant papers (n = 228) and evaluated the full texts of 87 papers. Furthermore, 13 records did not meet the inclusion criteria and were excluded from the systematic review. Finally, a total of 74 manuscripts were entered into the qualitative synthesis and included in the present systematic review. Our systematic review highlights that HTN is the most common comorbidity encountered in MPNs, with an impact on both the occurrence of thrombosis and survival. Moreover, drug-induced HTN remains a challenge in the management of MPNs. Further research should investigate the characteristics of patients with MPNs and HTN, as well as clarify the contribution of HTN to the development of thrombotic complications, survival and management in MPNs. In addition, the relationship between clonal hematopoiesis of indeterminate potential, HTN, cardiovascular disease and MPNs requires examination in upcoming assessments.

The beneficial effect of tart cherry on plasma levels of inflammatory mediators (not recovery after exercise): A systematic review and meta-analysis on randomized clinical trials

BACKGROUND

Chronic inflammation has been classified as one of the most important threats to health. Scientists suggested that tart cherry (TC) can reduce plasma levels of inflammatory mediators. Therefore, the aim of this study was to summarize the effect of TC on circulating C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) among adult participants in non-exercise randomized clinical trials (RCTs).

METHODS AND MATERIALS

The eligible English-language RCTs were found by searching databases including PubMed, Web of Science, Cochrane Library, Scopus, and clinical Trials.gov up to May 2022, with no time limit. We used the mean change from baseline and its standard deviation for both intervention and comparison groups to calculate the effect size. The random-effects model proposed by DerSimonian and Laird was used to estimate the overall summary effect and the heterogeneity. We used PRISMA 2020 guidelines to report this study.

RESULTS

Ten RCTs were included in this study. The results demonstrated that TC had a significant decreasing effect on plasma CRP level compared with the comparison group (weighted mean differences (WMD) = -0.55 mg/L; 95% confidence interval (CI): - 1.03, - 0.06; p = 0.029), but had no significant effect on plasma IL-6 compared with comparison group (WMD = 0.08 pg/mL; 95% CI: -0.02, 0.17; p = 0.10). The effect of TC consumption on plasma TNF-α level was evaluated in only three studies that showed no significant effects (p>0.05).

CONCLUSION

Our results confirmed a significant decreasing effect of TC on CRP. Regarding IL-6 and TNF-α, our study did not present any significant effect of TC.

The effect of grape (Vitis vinifera) seed extract supplementation on flow-mediated dilation, blood pressure, and heart rate: A systematic review and meta-analysis of controlled trials with duration- and dose-response analysis

The objective of this systematic review and meta-analysis of controlled trials was to assess the long-term effect of grape seed extract (GSE) supplementation on flow-mediated dilation (FMD), systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) in adults. Web of Science, Scopus, Medline, Cochrane Library, and Google Scholar were searched up to May 24, 2021. Nineteen trials were included in this study. Weighted mean difference (WMD) and 95% confidence interval (CI) were calculated using a random-effects model. GSE supplementation significantly reduced DBP (WMD: -2.20 mmHg, 95% CI: -3.79 to -0.60, I² = 88.8%) and HR (WMD: -1.25 bpm, 95% CI: -2.32 to -0.19, I² = 59.5%) but had no significant effects on FMD (WMD: 1.02%, 95% CI: -0.62 to 2.66, I² = 92.0%) and SBP (WMD: -3.55 mmHg, 95% CI: -7.59 to 0.49, I² = 97.4%). Subgroup analysis revealed that the dose and duration of GSE administration and the characteristics of study participants could be sources of between-study heterogeneity. Significant non-linear relationships were found between DBP and the duration of GSE supplementation (P = 0.044) and its dose (P = 0.007). In conclusion, GSE may be beneficial for individuals with or at risk of cardiovascular disease because it may have hypotensive and HR-lowering properties.

Caffeic Acid Enhances the Anti-Leukemic Effect of Imatinib on Chronic Myeloid Leukemia Cells and Triggers Apoptosis in Cells Sensitive and Resistant to Imatinib

Among the phenolic acids tested on the K562 cell line, a model of chronic myeloid leukemia (CML), caffeic acid (CA) was biologically active on sensitive and imatinib (IM)-resistant cells at micro-molar concentration, either in terms of reduction of cell proliferation or triggering of apoptosis. The CA treatment provoked mitochondrial membrane depolarization, genomic DNA fragmentation and phosphatidylserine exposure, hallmarks of apoptosis. Cell cycle analysis following the treatment with comparable cytotoxic concentrations of IM or CA showed marked differences in the distribution profiles. The reduction of cell proliferation by CA administration was associated with increased expression of two cell cycle repressor genes, CDKN1A and CHES1, while IM at a cytotoxic concentration increased the CHES1 but not the CDKN1A expression. In addition, CA treatment affected the proliferation and triggered the apoptosis in IM-resistant cells. Taken together, these data suggested that CA induced the anti-proliferative effect and triggered apoptosis of CML cells by a different mechanism than IM. Finally, the combined administration of IM and CA at suboptimal concentrations evidenced a synergy of action in determining the anti-proliferative effect and triggering apoptosis. The ability of CA to potentiate the anti-leukemic effect of IM highlighted the nutraceutical potential of CA in CML.

Green Tea Polyphenol-Sensitive Calcium Signaling in Immune T Cell Function

Polyphenol compounds found in green tea have a great therapeutic potential to influence multiple human diseases including malignancy and inflammation. In this mini review, we describe effects of green tea and the most important component EGCG in malignancy and inflammation. We focus on cellular mechanisms involved in the modification of T cell function by green tea polyphenol EGCG. The case is made that EGCG downregulates calcium channel activity by influencing miRNAs regulating expression of the channel at the post-transcriptional level.

Adipogenesis as a Potential Anti-Obesity Target: A Review of Pharmacological Treatment and Natural Products

Obesity is recognized as a severe threat to overall human health and is associated with type 2 diabetes mellitus, dyslipidemia, hypertension, and cardiovascular diseases. Abnormal expansion of white adipose tissue involves increasing the existing adipocytes' cell size or increasing the number through the differentiation of new adipocytes. Adipogenesis is a process of proliferation and differentiation of adipocyte precursor cells in mature adipocytes. As a key process in determining the number of adipocytes, it is a possible therapeutic approach for obesity. Therefore, it is necessary to identify the molecular mechanisms involved in adipogenesis that could serve as suitable therapeutic targets. Reducing bodyweight is regarded as a major health benefit. Limited efficacy and possible side effects and drug interactions of available anti-obesity treatment highlight a constant need for finding novel efficient and safe anti-obesity ingredients. Numerous studies have recently investigated the inhibitory effects of natural products on adipocyte differentiation and lipid accumulation. Possible anti-obesity effects of natural products include the induction of apoptosis, cell-cycle arrest or delayed progression, and interference with transcription factor cascade or intracellular signaling pathways during the early phase of adipogenesis.

Targeting of the Alox12-12-HETE in Blast Crisis Chronic Myeloid Leukemia Inhibits Leukemia Stem/Progenitor Cell Function

Introduction

Chronic myeloid leukemia (CML) is a myeloid malignancy characterized by the oncogene BCR-ABL. CML responds well to therapy targeting BCR-ABL in the chronic phase but is resistant to treatment when it progresses to the blast phase (BP). This study attempted to address whether arachidonate 12-lipoxygenase (Alox12) confers to CML drug resistance.

Materials and Methods

We analyzed the expression of Alox12 using Western blotting, ELISA, and RT-PCR methods. Loss of functional analysis was performed using cellular activity assays on CML and normal hematopoietic stem/progenitor cells (HSPCs).

Results

Alox12 and 12-Hydroxyeicosatetraenoic acid (12-HETE) are overexpressed in BP-CML but not HSPCs, and that Alox12-12-HETE axis is regulated by BCR-ABL. The Alox12-12-HETE axis is required for CML. Specific Alox12 inhibitor inhibits colony formation, survival, and self-renewal capacity in BP-CML HSPCs, and to a significantly greater extent than in normal HSPCs. Of note, the Alox12 inhibitor significantly augments dasatinib’s efficacy in BP-CML HSPCs. Mechanism studies show that Alox12 inhibition does not affect activities of essential signaling pathways involved in maintaining stem cell function, such as Wnt, p53, and bone morphogenetic protein (BMP). In contrast, we show that Alox12 inhibition disrupts nicotinamide adenine dinucleotide phosphate (NADPH) homeostasis and induces oxidative stress and damage in CML HSPCs and committed cells.

Conclusion

Alox12-12-HETE axis is a specific and critical regulator of BP-CML HSPCs functions. Pharmacological inhibition of Alox12 may be useful in BP-CML.

Pharmaconutrition in the Clinical Management of COVID-19: A Lack of Evidence-Based Research But Clues to Personalized Prescription

A scientific interest has emerged to identify pharmaceutical and nutritional strategies in the clinical management of coronavirus disease 2019 (COVID-19). The purpose of this narrative review is to critically assess and discuss pharmaconutrition strategies that, secondary to accepted treatment methods, could be candidates in the current context of COVID-19. Oral medicinal doses of vitamin C (1–3 g/d) and zinc (80 mg/d elemental zinc) could be promising at the first signs and symptoms of COVID-19 as well as for general colds. In critical care situations requiring parenteral nutrition, vitamin C (3–10 g/d) and glutamine (0.3–0.5 g/kg/d) administration could be considered, whereas vitamin D3 administration (100,000 IU administered intramuscularly as a one-time dose) could possess benefits for patients with severe deficiency. Considering the presence of n-3 polyunsaturated fatty acids and arginine in immune-enhancing diets, their co-administration may also occur in clinical conditions where these formulations are recommended. However, despite the use of the aforementioned strategies in prior contexts, there is currently no evidence of the utility of any nutritional strategies in the management of SARS-CoV-2 infection and COVID-19. Nevertheless, ongoing and future clinical research is imperative to determine if any pharmaconutrition strategies can halt the progression of COVID-19.

Effects of green coffee bean extract on C-reactive protein levels: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND & OBJECTIVE

The effects of green coffee bean extract (GCBE) supplementation on inflammatory biomarkers have been widely spread. The purpose of this article was to assess the impact of GCBE supplementation on C-reactive protein (CRP) levels.

METHODS

The literature search was performed in four databases (Scopus, PubMed, the Cochrane Library, and Google Scholar) to identify studies that examined the influence of GCBE supplementation on CRP levels up to August 2019. Mean and standard deviation (SD) of the outcomes were used to estimate the weight mean difference (WMD) between intervention and control groups for the follow-up period.

RESULTS

Five (5) studies, with 6 arms, reported CRP as an outcome. Statistically, the use of GCBE supplements resulted in a significant change in CRP levels (WMD: -0.017 mg/dL, 95 % CI: -0.032, -0.003, p = 0.018), whose overall findings were obtained from random-effects model. In addition, a significantly greater reduction in CRP was noted for studies with doses of GCBE supplements ≥ 1000 mg/d (WMD: -0.015 mg/dL, 95 % CI: -0.020, -0.010, p < 0.000), length of intervention < 4 weeks (WMD: -0.015 mg/dL, 95 % CI: -0.020, -0.010, p < 0.001), and for non-healthy subjects (WMD: -0.019 mg/dL, 95 % CI: -0.027, -0.011, p < 0.001). Dyslipidemia, hypertension and non-alcoholic fatty liver disease were the ailments of the studies that encompassed non-healthy patients.

CONCLUSIONS

This meta-analysis shows that the use of GCBE supplements resulted in a statistical decrease in CRP levels, mainly for non-healthy subjects. However, due to the limited number of studies, further randomized clinical trials are crucial in this regard.

Exercise Training and Vitamin C Supplementation Affects Ferritin mRNA in Leukocytes without Affecting Prooxidative/Antioxidative Balance in Elderly Women

Physical training and antioxidant supplementation may influence iron metabolism through reduced oxidative stress and subsequent lowering of mRNA levels of genes that are easily induced by this stress, including those responsible for iron homeostasis. Fifteen elderly women participated in our 12-week experiment, involving six weeks of training without supplementation and six weeks of training supported by oral supplementation of 1000 mg of vitamin C daily. The participants were divided into two groups (n = 7 in group 1 and n = 8 in group 2). In group 1, we applied vitamin C supplementation in the first six weeks of training, while in group 2 during the remaining six weeks of training. In both phases, the health-related training occurred three times per week. Training accompanied by vitamin C supplementation did not affect prooxidative/antioxidative balance but significantly decreased ferritin heavy chain (FTH) and ferritin light chain (FTL) mRNA in leukocytes (for FTH mRNA from 2^64.24 to 2^11.06, p = 0.03 in group 1 and from 2^60.54 to 2^16.03, p = 0.01 in group 2, for FTL mRNA from 2^20.22 to 2^4.53, p = 0.01 in group 2). We concluded that vitamin C supplementation might have caused a decrease in gene expression of two important antioxidative genes (FTH, FTL) and had no effect on plasma prooxidative/antioxidative balance.

The effect of green tea supplementation on obesity: A systematic review and dose-response meta-analysis of randomized controlled trials

The effects of green tea (GT) in obese subjects have been evaluated in different studies, but no consensus has been obtained due to the heterogeneity of the results. The dosage, the type of extract, and the duration of the intervention are the main contributors to the heterogeneity of the results. Therefore, the present systematic review and meta-analysis aimed to evaluate the efficacy and dose-response relationship of GT. Several databases were searched from inception to September 2019 to identify clinical trials that examined the influence of GT supplements on obesity indices in humans. Combined results using the random-effects model indicated that body weight (WMD: -1.78 kg, 95% CI: -2.80, -0.75, p = .001) and body mass index (BMI) (WMD: -0.65 kg/m² , 95% CI: -1.04, -0.25, p = .001) did change significantly following GT administration. The reduction in waist circumference (WC) after GT consumption was significant in subjects in trials employing GT ≥800 mg/day (WMD: -2.06 cm) and with a treatment duration <12 weeks (WMD: -2.39 cm). Following the dose-response evaluation, GT intake did alter body weight, with a more important reduction when the GT dosage was <500 mg/day and the treatment duration was of 12 weeks. The results of present meta-analysis study support the use of GT for the improvement of obesity indices. Thus, we suggest that the use of GT can be combined with a balanced and healthy diet and regular physical exercise in the management of obese patients.

Menadione-induced apoptosis in U937 cells involves Bid cleavage and stefin B degradation

Earlier studies showed that the oxidant menadione (MD) induces apoptosis in certain cells and also has anticancer effects. Most of these studies emphasized the role of the mitochondria in this process. However, the engagement of other organelles is less known. Particularly, the role of lysosomes and their proteolytic system, which participates in apoptotic cell death, is still unclear. The aim of this study was to investigate the role of lysosomal cathepsins on molecular signaling in MD-induced apoptosis in U937 cells. MD treatment induced translocation of cysteine cathepsins B, C, and S, and aspartic cathepsin D. Once in the cytosol, some cathepsins cleaved the proapoptotic molecule, Bid, in a process that was completely prevented by E64d, a general inhibitor of cysteine cathepsins, and partially prevented by the pancaspase inhibitor, z-VAD-fmk. Upon loss of the mitochondrial membrane potential, apoptosome activation led to caspase-9 processing, activation of caspase-3-like caspases, and poly (ADP-ribose) polymerase cleavage. Notably, the endogenous protein inhibitor, stefin B, was degraded by cathepsin D and caspases. This process was prevented by z-VAD-fmk, and partially by pepstatin A-penetratin. These findings suggest that the cleaved Bid protein acts as an amplifier of apoptotic signaling through mitochondria, thus enhancing the activity of cysteine cathepsins following stefin B degradation.

Cabazitaxel and silibinin co-encapsulated cationic liposomes for CD44 targeted delivery: A new insight into nanomedicine based combinational chemotherapy for prostate cancer

Cancer stem cells (CSCs) are the promising targets for cancer chemotherapy that cannot be eliminated by conventional chemotherapy. In this study cationic liposomes of cabazitaxel (CBX) and silibinin (SIL) were prepared with an aim to kill cancer cells and CSCs for prostate cancer. CBX act as cancer cell inhibitor and SIL as CSC inhibitor. Hyaluronic acid (HA), an endogenous anionic polysaccharide was coated on cationic liposomes for targeting CD44 receptors over expressed on CSCs. Liposomes were prepared by ethanol injection method with particle size below 100 nm and entrapment efficiency of more than 90% at 10% w/w drug loading. Liposomes were characterized by dynamic light scattering, transmission electron microscopy, ¹H nuclear magnetic resonance and scanning electron microscopy-energy dispersive x-ray spectroscopy. Liposomes were evaluated for their anticancer action in androgen independent human prostate cancer cell lines (PC-3 and DU-145). HA coated liposomes showed potential cytotoxicity over other groups with low IC₅₀, significantly inhibited cell migration and induced apoptosis. Synergistic cytotoxic effect was also observed with HA coated liposomes that resulted in colony formation inhibition and G2/M phase arrest. Proficient cytotoxicity against CD44⁺ cells (14.87 ± 0.41% in PC-3 and 33.95 ± 0.68% in DU-145 cells) indicated the efficiency of HA coated liposomes towards CSC targeting. Hence, the outcome of this combinational therapy with CD44 targeting indicates the suitability of HA coated CBX and SIL co-loaded liposomes as a potential approach for eradicating prostate cancer and herein might provide a insight for future studies.

Simple discrimination of sub-cycling cells by propidium iodide flow cytometric assay in Jurkat cell samples with extensive DNA fragmentation

Human leukemia Jurkat T cells were analyzed for apoptosis and cell cycle by flow cytometry, using the Annexin V/propidium iodide (PI) standard assay, and a simple PI staining in Triton X-100/digitonin-enriched PI/RNase buffer, respectively. Cells treated with doxorubicin or menadione displayed a very strong correlation between the apoptotic cell fraction measured by the Annexin V/PI assay, and the weight of a secondary cell population that emerged on the forward scatter (FS)/PI plot, as well as on the side scatter (SS)/PI and FL1/PI plots generated from parallel cell cycle recordings. In both cases, the Pearson correlation coefficients were >0.99. In cell cycle determinations, PI fluorescence was detected on FL3 (620/30 nm), and control samples exhibited the expected linear dependence of FL3 on FL1 (525/40 nm) signals. However, increasing doses of doxorubicin or menadione generated a growing subpopulation of cells displaying a definite right-shift on the FS/FL3, SS/FL3 and FL1/FL3 plots, as well as decreased PI fluorescence, indicative of ongoing fragmentation and loss of nuclear DNA. By gating on these events, the resulting fraction of presumably sub-cycling cells (i.e. cells with cleaved DNA, counting sub-G0/G1, sub-S and sub-G2/M cells altogether) was closely similar to the apoptotic rate assessed by Annexin V/PI labeling. Taken together, these findings suggest a possible way to recognize the entire population of cells undergoing apoptotic DNA cleavage and simultaneously determine the cell cycle distribution of non-apoptotic cells in PI-labeled cell samples with various degrees of DNA fragmentation, using a simple and reproducible multiparametric analysis of flow cytometric recordings.

Epigallocatechin-3-gallate induces apoptosis in acute promyelocytic leukemia cells via a SHP-1-p38α MAPK-Bax cascade

Acute promyelocytic leukemia (APL) is characterized by a specific chromosomal translation, resulting in a fusion gene that affects the differentiation, proliferation and apoptosis of APL cells. Epigallocatechin-3-gallate (EGCG), a catechin, exhibits numerous biological functions, including antitumor activities. Previous studies have reported that EGCG induces apoptosis in NB4 cells. However, the molecular mechanism underlying EGCG-induced apoptosis remains unclear. The present study aimed to determine the molecular basis of EGCG-induced apoptosis in NB4 cells. EGCG treatment significantly inhibited the viability of NB4 cells in a dose-dependent manner. In addition, EGCG treatment induced apoptosis and increased the levels of (Bcl-2-like protein 4) Bax protein expression. Moreover, EGCG treatment was able to increase phosphorylated (p)-p38α mitogen-activated protein kinase (MAPK) and Src homology 1 domain-containing protein tyrosine phosphatase (SHP-1) expression. Pretreatment with PD169316 (a p38 MAPK inhibitor) partially blocked EGCG-induced apoptosis and inhibited EGCG-mediated Bax expression. Similarly, pretreatment with NSC87877, an inhibitor of SHP-1, partially blocked EGCG-induced apoptosis and inhibited EGCG-mediated increases in p-p38α MAPK and Bax expression. Therefore, the results of the present study indicate that EGCG is able to induce apoptosis in NB4 cells via the SHP-1-p38αMAPK-Bax cascade.

Epigallocatechin-3-gallate (EGCG) up-regulates miR-15b expression thus attenuating store operated calcium entry (SOCE) into murine CD4+ T cells and human leukaemic T cell lymphoblasts

CD4⁺ T cells are key elements in immune responses and inflammation. Activation of T cell receptors in CD4⁺ T cells triggers cytosolic Ca²⁺ release with subsequent store operated Ca²⁺ entry (SOCE), which is accomplished by the pore forming Ca²⁺ release activated Ca²⁺ (CRAC) channel Orai1 and its regulator stromal cell-interaction molecule 2 (STIM2). Green tea polyphenol epigallocatechin-3-gallate (EGCG) acts as a potent anti-inflammatory and anti-oxidant agent for various types of cells including immune cells. However, how post-transcriptional gene regulators such as miRNAs are involved in the regulation of Ca²⁺ influx into murine CD4⁺ T cells and human Jurkat T cells through EGCG is not defined. EGCG treatment of murine CD4⁺ T cells significantly down-regulated the expression of STIM2 and Orai1 both at mRNA and protein levels. Furthermore, EGCG significantly decreased SOCE in both murine and human T cells. EGCG treatment increased miRNA-15b (miR-15b) abundance in both murine and human T cells. Bioinformatics analysis reveals that miR-15b, which has a STIM2 binding site, is involved in the down-regulation of SOCE. Overexpression of miR-15b significantly decreased the mRNA and protein expression of STIM2 and Orai1 in murine T cells. Treatment of Jurkat T cells with 10 μM EGCG further decreased mTOR and PTEN protein levels. EGCG decreased mitochondrial membrane potential (MMP) in both human and murine T cells. In conclusion, the observations suggest that EGCG inhibits the Ca²⁺ entry into murine and human T cells, an effect accomplished at least in part by up-regulation of miR-15b.