Edaravone, a Radical Scavenger, May Enhance or Produce Antiproliferative Effects of Fluvastatin, Amlodipine, Ozagrel, GF109203X, Y27632 on Cultured Basilar Artery Smooth Muscle Cells

Protein Kinase C Isozymes and Autophagy during Neurodegenerative Disease Progression

Protein kinase C (PKC) isozymes are members of the Serine/Threonine kinase family regulating cellular events following activation of membrane bound phospholipids. The breakdown of the downstream signaling pathways of PKC relates to several disease pathogeneses particularly neurodegeneration. PKC isozymes play a critical role in cell death and survival mechanisms, as well as autophagy. Numerous studies have reported that neurodegenerative disease formation is caused by failure of the autophagy mechanism. This review outlines PKC signaling in autophagy and neurodegenerative disease development and introduces some polyphenols as effectors of PKC isozymes for disease therapy.

The efficacy of edaravone (radicut), a free radical scavenger, for cardiovascular disease

Edaravone was originally developed as a potent free radical scavenger, and has been widely used to treat acute ischemic stroke in Japan since 2001. Free radicals play an important role in the pathogenesis of a variety of diseases, such as cardiovascular diseases and stroke. Therefore, free radicals may be targets for therapeutic intervention in these diseases. Edaravone shows protective effects on ischemic insults and inflammation in the heart, vessel, and brain in experimental studies. As well as scavenging free radicals, edaravone has anti-apoptotic, anti-necrotic, and anti-cytokine effects in cardiovascular diseases and stroke. Edaravone has preventive effects on myocardial injury following ischemia and reperfusion in patients with acute myocardial infarction. Edaravone may represent a new therapeutic intervention for endothelial dysfunction in the setting of atherosclerosis, heart failure, diabetes, or hypertension, because these diseases result from oxidative stress and/or cytokine-induced apoptosis. This review evaluates the potential of edaravone for treatment of cardiovascular disease, and covers clinical and experimental studies conducted between 1984 and 2013. We propose that edaravone, which scavenges free radicals, may offer a novel option for treatment of cardiovascular diseases. However, additional clinical studies are necessary to verify the efficacy of edaravone.

New method for absolute spinal cord ischemia protection in rabbits

OBJECTIVE

This study aims to establish a superior procedure to prevent spinal cord damage after severe spinal cord ischemia during aortic surgery. We examined the synergistic effect of topical hypothermia of the spinal cord combined with radical scavenger infusion into the clamped segment of the aorta to prevent spinal cord damage in an animal model.

METHODS

Spinal cord ischemia was induced in rabbits by clamping the aorta between the renal artery and aortic bifurcation for 30 minutes. Rabbits were divided into four groups of 16 each: group I, sham-operated; group II, edaravone (6 mL, 4°C, 1 mg/kg); group III, saline (6 mL, 4°C) with transvertebral cooling pads; group IV, edaravone (6 mL, 4°C, 1 mg/kg) and transvertebral cooling pads. Solutions were injected into the clamped segment of the aorta. Postoperative assessments included the Tarlov score, spinal cord histopathology, and measurement of malondialdehyde levels in the spinal cord tissue.

RESULTS

At 48 hours after reperfusion, the mean Tarlov scores in groups I, II, III, and IV were 4.0, 1.5, 1.9, and 4.0, respectively. The mean number of normal motor neurons was significantly higher in groups I (54.1) and IV (53.7) than in groups II (32.8) and III (36.3; P < .001). The mean malondialdehyde level in groups I (19.8 nmol/mL) and IV (22.6 nmol/mL) was significantly lower than in groups II (64.8 nmol/mL) and III (60.9 nmol/mL; P < .001). At 168 hours after reperfusion, the mean Tarlov scores in groups I, II, III, and IV were 4.0, 1.1, 1.3, and 4.0, respectively. The mean number of normal motor neurons was significantly higher in groups I (52.9) and IV (50.8) than in groups II (22.4) and III (25.9; P < .001). The mean malondialdehyde level in groups I (20.7 nmol/mL) and IV (23.4 nmol/mL) was significantly lower than in groups II (68.9 nmol/mL) and III (61.6 nmol/mL; P < .001).

CONCLUSION

In a rabbit model with aortic clamping up to 30 minutes, which consistently produces complete paraplegia in rabbits, spinal cord damage was partially reduced by topical cooling with transvertebral cooling pads or the injection of edaravone into the clamped segment of aorta, but was more effectively protected by a combined use of these two strategies.

Polychlorinated biphenyls (PCBs) enhance metastatic properties of breast cancer cells by activating Rho-associated kinase (ROCK)

Background

Polychlorinated biphenyls (PCBs) are a family of structurally related chlorinated aromatic hydrocarbons. Numerous studies have documented a wide spectrum of biological effects of PCBs on human health, such as immunotoxicity, neurotoxocity, estrogenic or antiestrogenic activity, and carcinogensis. The role of PCBs as etiologic agents for breast cancer has been intensively explored in a variety of in vivo, animal and epidemiologic studies. A number of investigations indicated that higher levels of PCBs in mammary tissues or sera correlated to breast cancer risk, and PCBs might be implicated in advancing breast cancer progression.

Methodology/Principal Findings

In the current study, we for the first time report that PCBs greatly promote the ROCK activity and therefore increase cell motility for both non-metastatic and metastatic human breast cancer cells in vitro. In the in vivo study, PCBs significantly advance disease progression, leading to enhanced capability of metastatic breast cancer cells to metastasize to bone, lung and liver. Additionally, PCBs robustly induce the production of intracellular reactive oxygen species (ROS) in breast cancer cells; ROS mechanistically elevate ROCK activity.

Conclusions/Significance

PCBs enhance the metastatic propensity of breast cancer cells by activating the ROCK signaling, which is dependent on ROS induced by PCBs. Inhibition of ROCK may stand for a unique way to restrain metastases in breast cancer upon PCB exposure.

Edaravone for the treatment of acute cerebral infarction: role of endothelium-derived nitric oxide and oxidative stress

Thrombolytic therapy is the most effective therapeutic strategy for the prevention of brain injury and reduction of mortality in patients with acute cerebral infarction. A combination of established thrombolytic therapy and effective neuronal protection therapy has more beneficial effects for patients with acute cerebral infarction. Edaravone (chemical name: 3-methyl-1-phenyl-2-pyrazolin-5-one) is a strong, novel scavenger of free radicals. Several lines of evidence have shown that edaravone has preventive effects on brain injury following ischaemia and reperfusion in patients with brain attack. This review focuses on putative mechanisms underlying the beneficial effects of edaravone on the atherosclerotic process in patients with stroke and on the possibility of edaravone-induced extension of the therapeutic time window in patients with acute cerebral infarction.

Ischemia/reperfusion injury: a review in relation to free tissue transfers

Events during ischemia/reperfusion (I/R) injury include: neutrophil-mediated endothelial cytotoxicity and activation, generation of free radicals, triggering of cytokines and chemokines, and activation of adhesion molecules and complement system. This article briefly reviews events occurring during tissue ischemia and reperfusion in relation to free tissue transfers. The consequences of tissue damage at the microcirculatory level are presented. Preventive measures of I/R injury are outlined.

[Effects of angiotensin II receptor blockers, angiotensin converting enzyme inhibitors, 3-hydroxy-3-methyl glutaryl (HMG) CoA reductase inhibitors, amlodipine and epalrestat on cultured basilar artery smooth muscle cell proliferation]

Proliferation of vascular smooth muscle cells (VSMC) stimulated by oxidative stresses and reactive oxygen species (ROS) may play a pivotal role in the pathogenesis of atherosclerosis. Antiatherosclerotic effects of angiotensin II receptor blockers, angiotensin converting enzyme inhibitors, HMG CoA reductase inhibitors, calcium channel blocker and epalrestat were studied with an in vitro guinea-pig basilar artery smooth muscle cell (GBa-SM3) culture system over 3 days incubated with 0 to 10% of fetal bovine serum. Results demonstrated that simvastatin (0.1 mM), fluvastatin (0.3 mM), amlodipine (0.2 mM) and epalrestat (1 mM) elicited significant (p < 0.05 or 0.01) antiproliferative effects, whereas losartan (1 mM), valsartan (1 mM), enalapril (0.1 mM), captopril (1 mM), trandolapril (0.01 mM), pravastatin (0.7 mM) did not. In conclusion, the present in vitro VSMC culture system may serve as a comprehensive screening method for pleiotropic effects of commonly used therapeutic agents.

Alterations of Antiproliferative Effects of Serum Obtained from Patients with Acute Cerebral Infarction Treated with a Radical Scavenger, Edaravone, with or without Amlodipine Using an in vitro Cultured Basilar Artery Smooth Muscle Cells

The guinea-pig basilar artery smooth muscle cell (GBa-SM3) culture system in the Dulbecco's modified Eagle's medium for 3 days serves as a useful in vitro model for assessing antiproliferative effects of various therapeutic agents on vessels. With use of this system we studied whether human serum obtained from patients with acute cerebral infarction (n = 16) would have a proliferative effect on vessels and whether an administration of a free radical scavenger, edaravone, with or without amlodipine would elicit antiproliferative effects. The control serum was obtained from 3 healthy human subjects. Time courses of the cell growth and survival were measured colorimetrically by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrzolium bromide (MTT) test. The stimulatory effect on the proliferation of GBa-SM3 cells of patients' serum obtained immediately after infarction was significantly (p < 0.05) greater than those obtained from the same patients after the treatment of edaravone for 2 weeks. In addition, the serum obtained from the patients treated by edaravone and amlodipine (n = 7) showed a significantly (p < 0.05) greater antiproliferative effect than that obtained from those treated by edaravone (n = 9). In conclusion, edaravone may have a clinically beneficial antiproliferative effect on vascular smooth muscle cells. Co-administration of amlodipine, possessing an antioxidative calcium channel blocker, with edaravone may be a promising combination to patients with acute cerebral infarction. Further controlled clinical trials with a large number of patients should be warranted.