Ethanol extract of Brazilian red propolis induces apoptosis in human breast cancer MCF-7 cells through endoplasmic reticulum stress.

Propolis, a natural product collected from plants by honey bees, is commonly used in folk medicines. Endoplasmic reticulum (ER) stress is known to induce apoptosis through the induction of CCAAT/enhancer-binding protein homologous protein (CHOP). Here, we investigated whether ethanol extracts of propolis and caffeic acid phenethyl ester (CAPE) induce apoptosis, mitochondrial dysfunction, and ER stress in human breast cancer MCF-7 cells and human fibroblasts. Among several ethanol extracts of propolis and CAPE, Brazilian red propolis (BRP) significantly reduced MCF-7 cell viability through the induction of mitochondrial dysfunction, caspase-3 activity, and DNA fragmentation but did not affect those of fibroblasts. Moreover, treatment with BRP significantly induced CHOP expression in MCF-7 cells compared to fibroblasts. Further, pretreatment with a chemical chaperone, 4-phenylbutyric acid, suppressed BRP-triggered MCF-7 cell death. Overall, we revealed that an ethanol extract of BRP induces MCF-7 cell apoptosis through, at least in part, ER stress-related signaling.

Effect of hypoxia mimetic cobalt chloride on the expression of extracellular-superoxide dismutase in retinal pericytes.

The initial clinical stage of diabetic retinopathy (DR) is characterized by the development of intraretinal microvascular abnormalities. The increased formation of reactive oxygen species (ROS) is thought to be a key event in the pathogenesis of DR. Extracellular-superoxide dismutase (EC-SOD) is an anti-inflammatory enzyme that is distributed mainly in vascular cells and protects cells from ROS by scavenging superoxide anion. Treatment with cobalt chloride (CoCl(2)) decreased the expression of EC-SOD but not other SOD isozymes in pericytes accompanied with an increase of intracellular ROS production. Pre-treatment with N-acetylcysteine (NAC) significantly suppressed the ROS production and down-regulation of EC-SOD. We observed the activation of caspase-3 and DNA fragmentation as signs of apoptotic process by CoCl(2) treatment. In addition, these phenomena were significantly inhibited by pre-treatment with NAC. EC-SOD enhancer 4-phenyl butyric acid also suppressed the caspase-3 activation. It is known that the presence of a high level of EC-SOD throughout the vessel walls might have an important protective role against superoxide in the vascular system. The decrease in EC-SOD expression accompanied with elevation of ROS level in pericytes under hypoxia might induce and/or promote the ROS-triggered apoptosis of pericytes and the development of pathogenesis in DR.

Preoperative plasma brain natriuretic peptide level is an independent predictor of postoperative atrial fibrillation following off-pump coronary artery bypass surgery.

PURPOSE: Atrial fibrillation (AF) is a frequent complication after coronary artery bypass surgery. Postoperative AF can lead to thromboembolic events, prolonged hospital stay, and increased costs. Recent reports have shown that an elevated plasma brain natriuretic peptide (BNP) level is associated with AF. The purpose of this prospective study was to test the hypothesis that preoperative BNP level is a predictor of postoperative AF following off-pump coronary artery bypass surgery (OPCAB). METHODS: One hundred and fifty patients without a history of AF undergoing elective isolated OPCAB were enrolled. Plasma BNP level was measured preoperatively. Heart rate and rhythm were continuously monitored during the first 72 h after surgery. RESULTS: Twenty-six patients (17.3%) exhibited postoperative AF. This proportion is similar to those reported in earlier studies. Univariate analysis demonstrated that age (odds ratio [OR], 1.060; 95% confidence interval [CI], 1.008 to 1.114; P = 0.023), previous myocardial infarction (MI; OR, 2.628; 95% CI, 1.031 to 6.697; P = 0.043), and BNP level (OR, 7.336; 95% CI, 2.401 to 22.409 / log BNP level; P < 0.001) were accurate predictors of postoperative AF. Stepwise multivariate regression analysis indicated age (OR, 1.059; 95% CI, 1.002 to 1.120; P = 0.043) and BNP level (OR, 6.272; 95% CI, 1.980 to 19.861/log BNP level; P = 0.002) as the only independent predictors of postoperative AF. CONCLUSION: Preoperative BNP level is an independent predictor of postoperative AF following OPCAB. Our findings permit us to stratify the risk of AF and to plan prophylactic strategies in high-risk patients.