Effects of Quercetin on Gene and Protein Expression of NOX and NOS after Myocardial Ischemia and Reperfusion in Rabbit

The involvement of endoplasmic reticulum stress in flavonoid-induced protection on cardiac cell death caused by ischaemia/reperfusion

OBJECTIVES

We have investigated whether endoplasmic reticulum stress and Bcl-2 proteins were linked to the protective effect exerted by flavonoids on ischaemia/reperfusion-induced cardiac damage.

METHODS

Cell viability and immunoblotting were performed.

KEY FINDINGS

H9c2 cardiac muscle cells were exposed to flavonoids such as biochanin A, daidzein, genistein, luteolin, quercetin and rutin, followed by ischaemia 12 h/reperfusion 4 h. The flavonoids protected against cell death induced by ischaemia/reperfusion. Flavonoid treatment significantly increased the expression level of the anti-apoptotic protein, Bcl-2, but decreased that of the proapoptotic protein, Bax. The flavonoids down-regulated the expression levels of endoplasmic reticulum stress proteins, glucose-regulated protein-78, activating transcription factor 6alpha, X-box binding protein 1, inositol-requiring protein-1, phosphor-eukaryotic initiation factor 2alpha, and C/EBP-homologous protein.

CONCLUSIONS

This study suggested that the protective mechanisms of flavonoids included regulation of Bcl-2/Bax proteins as well as the endoplasmic reticulum stress proteins.

Acute treatment with polyphenol quercetin improves postischemic recovery of isolated perfused rat hearts after global ischemia

Quercetin is a plant-derived bioflavonoid with potentially beneficial effects on the cardiovascular system. Studies focused on the efficiency of flavonoids against ischemia-reperfusion (I/R) injury have demonstrated that quercetin exerts robust protective effects in renal, cerebral, and hepatic I/R models. However, there is only limited evidence about the effect of quercetin on myocardial I/R injury. Therefore, the aim of the current study was to examine the effect of quercetin on isolated rat heart during ischemia and reperfusion. Rat hearts perfused according to Langendorff at 37 degrees C were examined during 25 min global ischemia followed by 120 min reperfusion. Quercetin (15 micromol/L) was administered either 15 min before ischemia (group Q1), or during the entire reperfusion period (group Q2). Changes in functional parameters of the hearts were measured during the initial 40 min of reperfusion. At the end of the experiment, the hearts were stained with tetrazolium to estimate the size of infarction (IS). Our study showed that quercetin improved postischemic recovery of functional parameters of isolated hearts in both treated groups. This improvement was manifested by significantly higher values of left ventricular developed pressure (LVDP) and the maximal rates of pressure development and fall (+(dP/dt)max and -(dP/dt)max) and by significantly lower increase of end-diastolic pressure. Coronary flow was not significantly changed during reperfusion in the group treated before ischemia, but was significantly increased in the group treated during reperfusion. Quercetin also significantly reduced IS in both groups, more markedly in postischemically treated group. We conclude that acute quercetin treatment exerts significant positive effects on isolated hearts during I/R injury. These results are consistent with the beneficial effects of quercetin and other flavonoids on the cardiovascular system.

Flavonols and cardiovascular disease

Flavonols, and specially quercetin, are widely distributed in plants and are present in considerable amounts in fruits and vegetables. In addition to their anti-oxidant effect, flavonols interfere with a large number of biochemical signaling pathways and, therefore, physiological and pathological processes. There is solid evidence that, in vitro, quercetin and related flavonols exert endothelium-independent vasodilator effects, protective effect on nitric oxide and endothelial function under conditions of oxidative stress, platelet antiaggregant effects, inhibition of LDL oxidation, reduction of adhesion molecules and other inflammatory markers and prevention of neuronal oxidative and inflammatory damage. The metabolites of quercetin show partial protective effects on endothelial function and LDL oxidation. Quercetin produces undisputed antihypertensive and antiatherogenic effects, prevents endothelial dysfunction and protects the myocardium from ischemic damage. It has no clear effects on serum lipid profile and on insulin resistance. Human intervention trials with isolated flavonols demonstrate an antihypertensive effect. The meta-analysis of epidemiological studies show an inverse association between flavonol (together with flavone) intake and coronary heart disease and stroke. Therefore, although there is no solid proof yet, a substantial body of evidence suggests that quercetin may prevent the most common forms of cardiovascular disease contributing to the protective effects afforded by fruits and vegetables.

Phenotypically directed multimodal therapy for chronic prostatitis/chronic pelvic pain syndrome: a prospective study using UPOINT

OBJECTIVES

Large, controlled trials in chronic pelvic pain syndrome (CPPS) have failed due to patient heterogeneity. To phenotype CPPS patients, we developed the UPOINT system with 6 domains (Urinary, Psychosocial, Organ-Specific, Infection, Neurologic/Systemic and Tenderness). In this study, we treated patients with multimodal therapy based on the UPOINT phenotype and measured response after at least 6 months.

METHODS

Patients with CPPS were offered multimodal therapy based on the UPOINT phenotype (eg, Urinary: alpha blocker or antimuscarinic; Organ-specific: quercetin; Tenderness: physical therapy). One hundred patients agreed to therapy and were reexamined after 26 weeks. Primary endpoint was a minimum 6-point drop in NIH-Chronic Prostatitis Symptom Index (CPSI).

RESULTS

Mean age was 46 years, and median symptom duration was 24 months. A median of 3 UPOINT domains were positive, the most common being Organ-specific (70%), Tenderness (64%), and Urinary (59%). With a median 50-week follow-up, 84% had at least a 6-point fall in CPSI. Number of domains and initial CPSI did not predict response. Mean changes (+/-SD) for CPSI subscores were pain 11.5+/-3.2 to 6.1+/-3.9, urine 4.7+/-3.1 to 2.6+/-2.0, QOL 9.1+/-2.3 to 4.5+/-2.8, and total 25.2+/-6.1 to 13.2+/-7.2 (all P<.0001). No domain predicted outcome; however, quercetin use resulted in a greater CPSI decrease.

CONCLUSIONS

Multimodal therapy using UPOINT leads to significant improvement in symptoms and quality of life. Moreover, a placebo-controlled trial for every therapy combination is not feasible, and results using UPOINT compare favorably with all large trials of monotherapy.