Luteolin Causes 5'CpG Demethylation of the Promoters of TSGs and Modulates the Aberrant Histone Modifications, Restoring the Expression of TSGs in Human Cancer Cells.

Cancer progression is linked to abnormal epigenetic alterations such as DNA methylation and histone modifications. Since epigenetic alterations, unlike genetic changes, are heritable and reversible, they have been considered as interesting targets for cancer prevention and therapy by dietary compounds such as luteolin. In this study, epigenetic modulatory behaviour of luteolin was analysed on HeLa cells. Various assays including colony forming and migration assays, followed by biochemical assays of epigenetic enzymes including DNA methyltransferase, histone methyl transferase, histone acetyl transferase, and histone deacetylases assays were performed. Furthermore, global DNA methylation and methylation-specific PCR for examining the methylation status of CpG promoters of various tumour suppressor genes (TSGs) and the expression of these TSGs at transcript and protein level were performed. It was observed that luteolin inhibited migration and colony formation in HeLa cells. It also modulated DNA methylation at promoters of TSGs and the enzymatic activity of DNMT, HDAC, HMT, and HAT and reduced the global DNA methylation. Decrease in methylation resulted in the reactivation of silenced tumour suppressor genes including FHIT, DAPK1, PTEN, CDH1, SOCS1, TIMPS, VHL, TP53, TP73, etc. Hence, luteolin-targeted epigenetic alterations provide a promising approach for cancer prevention and intervention.

Effect of the anti-retroviral drug, rilpivirine, on human subcutaneous adipose cells and its nutritional management using quercetin.

Rilpivirine, a recently developed drug of choice for initial treatment of HIV-1 infection, can greatly reduce HIV-related inflammation, but in turn, may be associated with adverse secondary effects, including disturbances in lipid metabolism and ultimately in adipose tissue distribution and function. In recent years, research findings on the benefits of anti-oxidant foods and supplements have been employed in counter-acting both oxidative stress as well as inflammation in order to reduce the adverse side effects of anti-retroviral therapy. One such natural flavonoid which possesses anti-inflammatory and anti-oxidative properties is quercetin. This study investigated the effect of quercetin in overcoming the side effects incurred due to rilpivirine administration. The results show substantial reduction in the accumulation of triglyceride levels in a dose- and time-dependent manner for adipose cells treated with either rilpivirine or quercetin alone and in combination, as evidenced by morphological pictures and quantitative measurement of triglycerides throughout the differentiation process. Levels of inflammatory markers such as resistin and IL-8 were increased as compared to the untreated cells. No significant changes in leptin were observed on treatment of adipose cells with rilpivirine alone and its levels were almost comparable to control. Levels of oxidative markers like superoxide dismutase, catalase, and glutathione were also decreased. Treatment with quercetin showed a decrease in the inflammatory status and an increase in the oxidative status of adipose cells, thereby exhibiting its anti-inflammatory and anti-oxidative properties. However, further assessment of lipid metabolism and adipose tissue function in patients administered with rilpivirine-based regimes is advisable considering that totally neutral effects of rilpivirine on lipid homeostasis cannot be anticipated from the current study in vitro. It is concluded that rilpivirine causes an anti-adipogenic and pro-inflammatory response pattern but only at high concentrations, whereas quercetin has been observed to decrease inflammation and restore the levels of anti-oxidant enzymes.

Effects of rilpivirine, 17ß-estradiol and ß-naphthoflavone on the inflammatory status of release of adipocytokines in 3T3-L1 adipocytes in vitro.

Rilpivirine is a non-nucleoside reverse transcriptase inhibitor, recently developed as a drug of choice for initial anti-retroviral (ARV) treatment of HIV-1 infection, whereas estradiol is a major component of hormonal contraceptives. Both drugs have effects on lipid metabolism, impairment of adipocyte differentiation and alteration of adipose tissue distribution and function.This study investigated the effects of different concentrations of either rilpivirine or estradiol either alone or in combination on adipocyte differentiation and adipocytokines status in vitro in the absence and presence of ß-naphthoflavone, (BNF),a potent agonist of the aryl hydrocarbon receptor. 3T3-L1 human pre-adipocytes were cultured and differentiated with different concentrations of treatment drugs. After 10 days of differentiation procedure, cells were examined for their morphology and viability. Glycerol,adiponectin, leptin, resistin and interleukin-8 (IL-8) were quantified using commercially available kits. The results show that either rilpivirine or estradiol individually or during their combination can evoke significant increases in glycerol release and a concomitant significant decrease of adiponectin from adipocytes. These effects were dose-dependent. The effects of combined treatments were much larger than individual concentration for each drug. Both drugs had little of no effect on leptin levels, except for a small decrease with 10 µM rilpivirine alone or when combined with estradiol. In addition, both drugs evoked small increases in the release of resistin and interleukin-8 with significant values at higher doses compared to untreated adipocytes.When adipocytes were pretreated with BNF, either rilpivirine or, estradiol or when combined evoked a much larger release in glycerol and a much larger decrease in adiponectin compared to the absence of BNF. In contrast, BNF pretreatment had little of no effect on either leptin, resistin or IL-8 metabolism compared to the results obtained in the presence of either rilpivirine or estradiol alone or in combination.These results show that rilpivirine and estradiol either alone or when combined or pretreated with BNF can evoke marked effects on glycerol and cytokines levels from adipocytes. However, their mechanism (s) in inducing adipogenesis warrants further investigation of different transcription factors at gene expression levels.

Cytochrome allelic variants and clopidogrel metabolism in cardiovascular diseases therapy.

Clopidogrel and aspirin are among the most prescribed dual antiplatelet therapies to treat the acute coronary syndrome and heart attacks. However, their potential clinical impacts are a subject of intense debates. The therapeutic efficiency of clopidogrel is controlled by the actions of hepatic cytochrome P450 (CYPs) enzymes and impacted by individual genetic variations. Inter-individual polymorphisms in CYPs enzymes affect the metabolism of clopidogrel into its active metabolites and, therefore, modify its turnover and clinical outcome. So far, clinical trials fail to confirm higher or lower adverse cardiovascular effects in patients treated with combinations of clopidogrel and proton pump inhibitors, compared with clopidogrel alone. Such inconclusive findings may be due to genetic variations in the cytochromes CYP2C19 and CYP3A4/5. To investigate potential interactions/effects of these cytochromes and their allele variants on the treatment of acute coronary syndrome with clopidogrel alone or in combination with proton pump inhibitors, we analyze recent literature and discuss the potential impact of the cytochrome allelic variants on cardiovascular events and stent thrombosis treated with clopidogrel. The diversity of CYP2C19 polymorphisms and prevalence span within various ethnic groups, subpopulations and demographic areas are also debated.