The Cardioprotective Effects of Remote Ischemic Conditioning in a Rat Model of Acute Myocardial Infarction.

BACKGROUND Cardiac remote ischemic conditioning (RIC) is a noninvasive cardioprotective method in ischemia-reperfusion injury and acute myocardial infarction (AMI). The aims of this study were to investigate the effects of RIC in a rat model of AMI. MATERIAL AND METHODS Adult male Sprague-Dawley rats included the AMI group that underwent ligation of the left anterior descending (LAD) coronary artery (n=24), the RIC group that consisted the AMI rat model treated with RIC once daily in the left hind limb until days 1, 7 and 14 (n=24), and the sham group (n=24). Myocardial infarct size was measured by routine histology with triphenyltetrazolium chloride (TTC) and Masson's trichrome histochemical staining for myocardial necrosis and fibrosis, respectively. Serum levels of Bcl-2, Bax, caspase-3, and inducible nitric oxide synthase (iNOS) were measured by enzyme-linked immunosorbent assay (ELISA). The apoptosis index was detected using the TUNEL assay. Spectrophotometry of the myocardium was used to identify mitochondrial complexes and myocardial ATP. RESULTS The RIC group showed improved cardiac hemodynamics, reduced the size of the myocardial infarction, upregulated expression of Bcl-2, and down-regulation of the levels of Bax, caspase-3, and iNOS, and reduced cardiac myocyte apoptosis and inhibited the opening of the mitochondrial permeability transition pore (MPTP). CONCLUSIONS In a rat model of AMI, RIC improved the hemodynamic index, reduce the levels of apoptosis and myocardial injury, and improved mitochondrial function.

Therapeutic effects of a taurine-magnesium coordination compound on experimental models of type 2 short QT syndrome.

Short QT syndrome (SQTS) is a genetic arrhythmogenic disease that can cause malignant arrhythmia and sudden cardiac death. The current therapies for SQTS have application restrictions. We previously found that Mg· (NH2CH2CH2SO3)2· H2O, a taurine-magnesium coordination compound (TMCC) exerted anti-arrhythmic effects with low toxicity. In this study we established 3 different models to assess the potential anti-arrhythmic effects of TMCC on type 2 short QT syndrome (SQT2). In Langendorff guinea pig-perfused hearts, perfusion of pinacidil (20 µmol/L) significantly shortened the QT interval and QTpeak and increased rTp-Te (P<0.05 vs control). Subsequently, perfusion of TMCC (1-4 mmol/L) dose-dependently increased the QT interval and QTpeak (P<0.01 vs pinacidil). TMCC perfusion also reversed the rTp-Te value to the normal range. In guinea pig ventricular myocytes, perfusion of trapidil (1 mmol/L) significantly shortened the action potential duration at 50% (APD50) and 90% repolarization (APD90), which was significantly reversed by TMCC (0.01-1 mmol/L, P<0.05 vs trapidil). In HEK293 cells that stably expressed the outward delayed rectifier potassium channels (IKs), perfusion of TMCC (0.01-1 mmol/L) dose-dependently inhibited the IKs current with an IC50 value of 201.1 µmol/L. The present study provides evidence that TMCC can extend the repolarization period and inhibit the repolarizing current, IKs, thereby representing a therapeutic candidate for ventricular arrhythmia in SQT2.

Effects of non-invasive remote ischemic conditioning on rehabilitation after myocardial infarction.

Recent studies have demonstrated that remote ischemic conditioning (RIC) creates cardioprotection against ischemia/reperfusion injury and myocardial infarction (MI); however, the effects of non-invasive remote ischemic conditioning (nRIC) on prognosis and rehabilitation after MI (post-MI) remain unknown. We successfully established MI models involving healthy adult male Sprague-Dawley rats. The nRIC group repeatedly underwent 5 min of ischemia and 5 min of reperfusion in the left hind limb for three cycles every other day until weeks 4, 6, and 8 after MI. nRIC improved cardiac hemodynamic function and mitochondrial respiratory function through increasing myocardial levels of mitochondrial respiratory chain complexes I, II, III, IV, and adenosine triphosphate (ATP) and decreasing the activity of nitric oxide synthase (NOS). nRIC could inhibit cardiomyocytes apoptosis and reduce myocardium injury through raising the expression of Bcl-2 and reduced the content of creatine kinase-MB, cardiac troponin I and Bax. The results indicated that long-term nRIC could accelerate recovery and improve prognosis and rehabilitation in post-MI rats.

Biological evaluation of a cytotoxic 2-substituted benzimidazole copper(II) complex: DNA damage, antiproliferation and apoptotic induction activity in human cervical cancer cells.

Exploring novel chemotherapeutic agents is a great challenge in cancer medicine. To that end, 2-substituted benzimidazole copper(II) complex, [Cu(BMA)Cl2]·(CH3OH) (1) [BMA = N,N'-bis(benzimidazol-2-yl-methyl)amine], was synthesized and its cytotoxicity was characterized. The interaction between complex 1 and calf thymus DNA was detected by spectroscopy methods. The binding constant (K b = 1.24 × 10(4 )M(-1)) and the apparent binding constant (K app = 6.67 × 10(6 )M(-1)) of 1 indicated its moderate DNA affinity. Complex 1 induced single strand breaks of pUC19 plasmid DNA in the presence of H2O2 through an oxidative pathway. Cytotoxicity studies proved that complex 1 could inhibit the proliferation of human cervical carcinoma cell line HeLa in both time- and dose-dependent manners. The results of nuclei staining by Hoechst 33342 and alkaline single-cell gel electrophoresis proved that complex 1 caused cellular DNA damage in HeLa cells. Furthermore, treatment of HeLa cells with 1 resulted in S-phase arrest, loss of mitochondrial potential, and up-regulation of caspase-3 and -9 in HeLa cells, suggesting that complex 1 was capable of inducing apoptosis in cancer cells through the intrinsic mitochondrial pathway.

[Study on the constituents of essential oil of Shunaoxin dropping pills by GC-MS].

OBJECTIVE: To study the constituents of essential oil from Shunaoxin dropping pills by GC-MS. METHODS: The essential oil from Shunaoxin dropping pills were extracted by absolute alcohol and analyzed by GC-MS. RESULTS: 15 components from the essential oil of Shunaoxin dropping pills were identified. CONCLUSION: The main components in the essential oil of Shunaoxin dropping pills are lactones such as Z-ligustilide, senkyunolide A,3-butylphthalide and 3-butylidenephthalide, other components are organic acids such as ethyl linoleate, 9,12-octadecadienoic acid and ethyl palmitate.

Activities of a novel Schiff base copper(II) complex on growth inhibition and apoptosis induction toward MCF-7 human breast cancer cells via mitochondrial pathway.

In this study, we investigated the newly synthesized Schiff base copper(II) complex, [Cu(II)(5-Cl-pap)(OAc)(H(2)O)]·2H(2)O (1) (5-Cl-pap=N-2-pyridiylmethylidene-2-hydroxy-5-chloro-phenylamine), inducing growth inhibition and apoptosis in human breast cancer cell line MCF-7 and its potential antitumor mechanism. The results of cytotoxicity research, fluorescence microscopic observation and flow cytometric analysis revealed that complex 1 could significantly suppress MCF-7 cell viability and induce apoptosis. Comet assay indicated that severe DNA fragmentation in MCF-7 cells was induced after treatment with complex 1. Flow cytometric analysis showed that the antitumor effect of complex 1 on MCF-7 cells was associated with the cell cycle arrest. In addition, atomic absorption analyses displayed that complex 1 caused a rapid increase of intracellular copper uptake in MCF-7 cells in a time-dependent manner. The present work suggested that the antitumor mechanism of complex 1 on MCF-7 cells might be via the mitochondrial pathway, based on the up-regulated expression of Bax and activation of caspase-9 and caspase-3.

Study on potential antitumor mechanism of a novel Schiff base copper(II) complex: synthesis, crystal structure, DNA binding, cytotoxicity and apoptosis induction activity.

A new cytotoxic copper(II) complex with Schiff base ligand [Cu(II)(5-Cl-pap)(OAc)(H(2)O)]·2H(2)O (1) (5-Cl-pap=N-2-pyridiylmethylidene-2-hydroxy-5-chloro-phenylamine), was synthesized and structurally characterized by X-ray diffraction. Single-crystal analysis revealed that the copper atom shows a 4+1 pyramidal coordination, a water oxygen appears in the apical position, and three of the basal positions are occupied by the NNO tridentate ligand and the fourth by an acetate oxygen. The interaction of Schiff base copper(II) complex 1 with DNA was investigated by UV-visible spectra, fluorescence spectra and agarose gel electrophoresis. The apparent binding constant (K(app)) value of 6.40×10(5) M(-1) for 1 with DNA suggests moderate intercalative binding mode. This copper(II) complex displayed efficient oxidative cleavage of supercoiled DNA, which might indicate that the underlying mechanism involve hydroxyl radical, singlet oxygen-like species, and hydrogen peroxide as reactive oxygen species. In addition, our present work showed the antitumor effect of 1 on cell cycle and apoptosis. Flow cytometric analysis revealed that HeLa cells were arrested in the S phase after treatment with 1. Fluorescence microscopic observation indicated that complex 1 can induce apoptosis of HeLa cells, whose process was mediated by intrinsic mitochondrial apoptotic pathway owing to the activation of caspase-9 and caspase-3.

[Effects of Dioscorea septemloba on bone metabolism in ovariectomized rats].

OBJECTIVE: To investigate the effects of the decoction of Rhizoma Dioscorea septemlobae (RD) on the bone metabolism in ovariectomized rats. METHOD: Thirty female, 3-month-old Wistar rats without pregnancy and deliver were randomly divided into 6 groups: sham (sham-operation), ovariectomy (OVX), OVX + diethylstilbestrol, OVX + high dose RD (4 g x kg(-1) x d(-1)), OVX + middle dose RD (2 g x kg(-1) x d(-1)) and OVX + low dose RD (1 g x kg(-1) x d(-1)) (n = 5 in every group). After 12-week period of continuous treatment, the urinary samples and blood samples were collected for the determination of serum estrodiol (E2), calcium (Ca), phosphorus (P), bone glaprotein (BGP), alkaline phosphatase (ALP), urinary calcium/creatinine (Ca/Cr), phosphorus/ creatinine (P/Cr) and deoxypyridioline/creatinine (DPD/Cr). The uteri were removed and weighed. The bone mineral density (BMD) and the biomechanical parameters of the femur of the rats in every group were determined, respectively. RESULT: The coefficient of uteri in every dose group of OVX + RD was significantly higher than that in the OVX group (P < 0.01). The concentration of serum ALP, BGP and urinary DPD/Cr, Ca/Cr in the OVX group was significantly higher than that in the sham group (P < 0.05), respectively, However, that in the every dose of OVX + RD was lower than that in the OVX group, respectively. There was no significan difference in the concentration of serum Ca, P and urinary P/Cr in every group, respectively. The bone mineral density (BMD) in the OVX group was (0.032 +/- 0.007) g x cm(-2) and was significantly lower than that in the sham group (P < 0.01). However, the value in the group of every dose OVX + RD was significantly higher than that in the OVX group (P < 0.05, P < 0.01), respectively. The maximum loading, deflection and the maximum strain of the femur in the OVX group were (125.78 +/- 15.48) N, (1.87 +/- 0.22) mm, (9.34 +/- 1.10) % and were significantly lower than those in the sham group (P < 0.05, P < 0.01), respectively. The maximum loading and maximum stress were increased in different extent in the every dose group of OVX + RD, respectively. CONCLUSION: The decoction of RD can inhibit bone absorption, decline bone turnover and improve the loss of bone in ovariectomized rats.