Hemispheric Difference of Regional Brain Function Exists in Patients With Acute Stroke in Different Cerebral Hemispheres: A Resting-State fMRI Study.

OBJECTIVE: To explore the different compensatory mechanisms of brain function between the patients with brain dysfunction after acute ischemic stroke (AIS) in the dominant hemisphere and the non-dominant hemisphere based on Resting-state Functional Magnetic Resonance Imaging (Rs-fMRI). METHODS: In this trial, 15 healthy subjects (HS) were used as blank controls. In total, 30 hemiplegic patients with middle cerebral artery acute infarction of different dominant hemispheres were divided into the dominant hemisphere group (DH) and the non-dominant hemisphere group (NDH), scanned by a 3.0 T MRI scanner, to obtain the amplitude of low-frequency fluctuations (ALFF) and regional homogeneity (ReHo) and compare the differences. RESULTS: Compared with the HS, increased ALFF values in the brain areas, such as the bilateral midbrain, were observed in DH. Meanwhile decreased ReHo values in the brain areas, such as the right postcentral gyrus (BA3), were also observed. Enhanced ALFF values in the brain areas, such as the left BA6, and enhanced ReHo values in the brain areas, such as the left precuneus, were observed in the NDH. The ALFF and ReHo values of the right BA9 and precentral gyrus were both increased. Compared with DH, the NDH group showed lower ALFF values in the left supplementary motor area and lower ReHo values in the right BA10. CONCLUSION: After acute infarction in the middle cerebral artery of the dominant hemisphere, a compensation mechanism is triggered in brain areas of the ipsilateral cortex regulating motor-related pathways, while some brain areas related to cognition, sensation, and motor in the contralateral cortex are suppressed, and the connection with the peripheral brain regions is weakened. After acute infarction in the middle cerebral artery of the non-dominant hemisphere, compensatory activation appears in motor control-related brain areas of the dominant hemisphere. After acute middle cerebral artery infarction in the dominant hemisphere, compared with the non-dominant hemisphere, functional specificity in the bilateral supplementary motor area weakens. After acute middle cerebral artery infarction in different hemispheres, there are hemispheric differences in the compensatory mechanism of brain function.

Increased Resting-State Interhemispheric Functional Connectivity of Posterior Superior Temporal Gyrus and Posterior Cingulate Cortex in Congenital Amusia.

Interhemispheric connectivity of the two cerebral hemispheres is crucial for a broad repertoire of cognitive functions including music and language. Congenital amusia has been reported as a neurodevelopment disorder characterized by impaired music perception and production. However, little is known about the characteristics of the interhemispheric functional connectivity (FC) in amusia. In the present study, we used a newly developed voxel-mirrored homotopic connectivity (VMHC) method to investigate the interhemispheric FC of the whole brain in amusia at resting-state. Thirty amusics and 29 matched participants underwent a resting-state functional magnetic resonance imaging (fMRI) scanning. An automated VMHC approach was used to analyze the fMRI data. Compared to the control group, amusics showed increased VMHC within the posterior part of the default mode network (DMN) mainly in the posterior superior temporal gyrus (pSTG) and posterior cingulate cortex (PCC). Correlation analyses revealed negative correlations between the VMHC value in pSTG/PCC and the music perception ability among amusics. Further ROC analyses showed that the VMHC value of pSTG/PCC showed a good sensibility/specificity to differentiate the amusics from the controls. These findings provide a new perspective for understanding the neural basis of congenital amusia and imply the immature state of DMN may be a credible neural marker of amusia.

Impaired face recognition is associated with abnormal gray matter volume in the posterior cingulate cortex in congenital amusia.

Congenital amusia is as a neurodevelopment disorder primarily defined by impairment in pitch discrimination and pitch memory. Interestingly, it has been reported that individuals with congenital amusia also exhibit deficits in face recognition (prosopagnosia). One explanation of such comorbidity is that the neural substrates of pitch recognition and face recognition may be similar. To test this hypothesis, face recognition ability was assessed using the Cambridge Face Memory Test (CFMT) and gray matter volume was determined through voxel-based morphometry (VBM) among participants with and without congenital amusia. As expected, participants with amusia performed worse on the CFMT test and showed reduced gray matter volume (GMV) in the middle temporal gyrus (MTG), the superior temporal gyrus (STG), and the posterior cingulate cortex (PCC) in the right hemisphere, when compared with matched controls. Furthermore, correlation analyses demonstrated that the CFMT score was positively related to MTG, STG, and PCC GMV in all participants, while separate analyses of each group found a positive correlation of CFMT score and PCC GMV in amusics. These findings suggest that face recognition is associated with a widely distributed microstructural network in the human brain and the PCC plays an important role in both pitch recognition and face recognition in amusics. In addition, neurodevelopmental disorders such as congenital amusia and prosopagnosia may share a common neural substrate.

Therapeutic effect of valsartan against doxorubicin-induced renal toxicity in rats.

OBJECTIVES: Doxorubicin (DXR)-induces glomerular atrophy and fibrosis in rat kidneys. The objective of the current study was to investigate the protective effects of valsartan on DXR-induced glomerular toxicity and its mechanisms of actions in rats. MATERIALS AND METHODS: Male Sprague-Dawley (SD) rats were divided into four groups, and each group contains ten rats. First group was control and was treated with saline only. Treatment groups were injected with DXR (6.5 mg/kg) alone, or intragastric gavage with 10 mg/kg or 20 mg/kg of valsartan after DXR treatment. RESULTS: Rats treated with DXR only showed significant changes in concentrations of urinary protein, serum creatinine (SCr), and blood urea nitrogen (BUN). Moreover, glomerular structural damages were observed in rats treated with DXR. Valsartan significantly alleviated the effect of DXR. Dramatic elevation in malondialdehyde (MDA), nitric oxide (NO), nitric oxide synthase (NOS) and significant reductions in the levels of reduced glutathione (GSH), glutathione peroxidase (GPx), superoxide dismutase (SOD) were seen after DXR treatment. These effects were effectively ameliorated by co-administration with valsartan. CONCLUSION: The findings of our study indicate that valsartan may play an important role in protecting DXR-induced renal toxicity, at least in part, through its antioxidant properties.

Repaglinide inhibits cyclosporine A-induced renal tubular toxicity by affecting apoptosis and Bax and Bcl-2 expression

Background/aim: Repaglinide (RG) is a prandial glucose regulator used for the treatment of type 2 diabetes. Our recent study showed that RG plays an important role in cyclosporine A (CsA)-induced nephrotoxicity through its antioxidant properties. However, it is not known whether or not RG has any protective effect on CsA-induced renal tubular toxicity by affecting apoptosis and expression of apoptosis-associated protein. The purpose of this study was to investigate the effects of RG on CsA-induced renal tubule apoptosis and Bax and Bcl-2 protein expression in rats. Materials and methods: Forty male Sprague Dawley rats weighing 250­300 g were randomly divided into four groups: administrations of olive oil (control, per os (PO)), CsA (30 mg/kg in olive oil, subcutaneous (SC)), and RG (0.2 or 0.4 mg/kg, PO) plus CsA (30 mg/kg in olive oil, SC) every day for 15 days. Results: Our results showed that SC administration of CsA (30 mg/kg) to rats produced marked injury and apoptosis, elevation of Bax protein expression, and inhibition of Bcl-2 protein expression in the kidneys, which were reversed significantly by oral administration of RG (0.2 or 0.4 mg/kg). Conclusion: The findings of our study indicate that RG may play an important role in protecting the kidneys through inhibiting apoptosis, Bax , and Bcl-2 protein expression.

Antioxidant properties of repaglinide and its protections against cyclosporine A-induced renal tubular injury.

OBJECTIVES: Repaglinide (RG) is an antihyperglycemic agent used for the treatment of non-insulin-dependent diabetes mellitus. It has a good safety and efficacy profile in diabetic patients with complications in renal impairment and is an appropriate treatment choice, even for individuals with more severe degrees of renal malfunctions. The aim of the present study was to examine the protective effect of RG on cyclosporine A (CsA)-induced rat renal impairment and to evaluate the antioxidant mechanisms by which RG exerts its protective actions. MATERIALS AND METHODS: Fifty male Sprague-Dawley rats weighing 250-300 g were randomly divided into five groups: administrations of olive oil (control, PO), RG (0.4 mg/kg, PO), CsA (30 mg/kg in olive oil, SC), RG (0.2 or 0.4 mg/kg, PO) plus CsA (30 mg/kg in olive oil SC) every day for 15 days. RESULTS: SC administration of CsA (30 mg/kg) to rats produced marked elevations in the levels of renal impairment parameters such as urinary protein, N-acetyl-beta-D-glucosaminidase (NAG), serum creatinine (SCr), and blood urea nitrogen (BUN). It also caused histologic injury to the kidneys. Oral administration of RG (0.2 and 0.4 mg/kg) markedly decreased all the aforementioned changes. In addition, CsA caused increases in the levels of malondialdehyde (MDA) and decreases in superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), glutathione reductase (GSR), glutathione-S-transferase (GST), and glutathione in kidney homogenate, which were reversed significantly by both doses of RG. CONCLUSION: The findings of our study indicate that RG may play an important role in protecting the kidney from oxidative insult.

Cisplatin-mediated cytotoxicity through inducing CYP4A 11 expression in human renal tubular epithelial cells.

Cisplatin (CP) is a major antineoplastic drug for the treatment of solid tumors, but it has dose-dependent renal tubular toxicity. Previous studies have shown that induction of cytochrome P450 (CYP) by CP may play a role in the renal injury of CP. The aim of this study was to investigate the relationship between CP-induced toxicity and CYP4A11 expression in human renal tubular epithelial cells (HK-2). 20-Hydroxyeicosatetraenoic acid (20-HETE) is a CYP4A11 metabolite of arachidonic acid that plays an important role in renal injury. The activity of lactate dehydrogenase (LDH) was determined by spectrophotometer. CYP4A11 expression was analyzed by immunocytochemistry. CYP4A11 mRNA and protein expression were evaluated by RT-PCR and Western blot analyses. Results showed that 20-HETE (1, 10, 50 µM), a CYP4A11 metabolite of arachidonic acid, significantly increased lactate dehydrogenase (LDH) release in these cells. When CP (10(-4) M) and 20-HETE (1, 10, 50 µM) were co-applied to these cells, CP-induced LDH release was significantly exaggerated by 20-HETE. Furthermore, clofibrate, a CYP4A inducer, also increased LDH release in CP-treated cells. In contrast, the CYP4A inhibitor N-Hydrocy-N'-(-4-butyl-2-methylphenyl) formamidine (HET-0016) decreased LDH release in CP-treated cells. Immunocytochemical analysis showed that CYP4A11expression was much stronger in CP-(10(-4) M) treated cells than that in clofibrate-treated cells. Further RT-PCR and Western blot analyses demonstrated that CYP4A11 mRNA and protein expression were significantly up-regulated in CP- (10(-4) M) treated cells compared to the clofibrate group. The findings of this study indicate that CP is a potent inducer of CYP4A11, and it exerts its toxic functions via the induction of CYP4A11 and 20-HETE generation.

Amlodipine prevents adriamycin-induced toxicity in cultured rat mesangial cells by up-regulation of Smad6, Smad7 expression.

Extensive studies have demonstrated that transforming growth factor-beta (TGF-ß) plays an important role in the progression of renal diseases. A central component of TGF-ß is the TGF-ß family-specific Smad signal transduction pathway. TGF-ß signals through Smad2, 4 to mediate renal fibrosis, whereas induction of Smad6, 7 inhibits renal fibrosis and inflammation. Amlodipine is the most frequently used antihypertensive drug among dihydropyridines. It is beneficial to the kidney and is widely used in treating kidney diseases. The aim of this study was to investigate effects of amlodipine on adriamycin-induced changes of lactate dehydrogenase (LDH) and expression of Smad6, 7 in rat mesangial cells. Results showed that amlodipine (10(-8) to 10(-5)mol/l) significantly decreased LDH activity in rat mesangial cells when given in combination with TGF-ß1 (P<0.01); amlodipine (10(-7), 10(-6)mol/l) significantly increased Smad6, 7 mRNA and protein expression in cells treated with adriamycin and TGF-ß1 (P<0.01). In conclusion, amlodipine protects against adriamycin-induced toxicity in rat mesangial cells by up-regulation of Smad6, 7 expressions.

Chemical composition, antimicrobial and antioxidant activities of essential oil from Ampelopsis megalophylla.

Chemical composition, antimicrobial and antioxidant activities of the essential oil of Ampelopsis megalophylla were evaluated in this research. GC-MS analysis of the essential oil revealed 42 compounds, representing 88.54% of the oil. The major compounds were borneol (10.81%), α-pinene (6.74%) and ß-elemene (6.23%). The antimicrobial activity of the essential oil was evaluated against 13 micro-organisms using the disc diffusion and broth microdilution methods. Results demonstrated higher effects of this oil against Gram-positive bacteria than the other reference strains tested. The antioxidant effect of the essential oil was evaluated by using 1,1-Diphenyl-2-picrylhydrazyl (DPPH) and 2,20-azinobis-3-ethylbenzthiazoline-6-sulfonate scavenging assays. The essential oil exhibited moderate antioxidant activity.

Protective effect of 20-hydroxyeicosatetraenoic acid (20-HETE) on adriamycin-induced toxicity of human renal tubular epithelial cell (HK-2).

20-Hydroxyeicosatetraenoic acid is a cytochrome P4504A11 metabolite of arachidonic acid that plays an important role in the regulation of human renal functions. In the present study, we investigated the role of 20-hydroxyeicosatetraenoic acid on adriamycin induced toxicity in human renal tubular epithelial cells. Results showed that cell viability was decreased significantly and lactate dehydrogenase activity was increased significantly in a concentration-dependent manner when human renal tubular epithelial cells were incubated with adriamycin (10⁻7-10⁻³ mol/l) for 24h. In contrast, 20-hydroxyeicosatetraenoic acid (0.1, 1, 10, 50 µmol/l) increased cell survival and decreased lactate dehydrogenase activity concentration dependently in human renal tubular epithelial cells. When 20-hydroxyeicosatetraenoic acid (10, 50 µmol/l) was co-administered with adriamycin (10⁻³ mol/l), it significantly increased cell viability and decreased lactate dehydrogenase activity. On the other hand, N-hydroxy-N'-(4-butyl-2-methylphenyl)formamidine (HET-0016) (1 µM), a selective inhibitor of 20-hydroxyeicosatetraenoic acid synthesizing enzyme exaggerated cell viability reduction and lactate dehydrogenase activity augmentation induced by adriamycin. Adriamycin suppressed the expression of cytochrome P4504A11 gene and its protein production in human renal tubular epithelial cells. Furthermore, adriamycin was more effective than N-hydroxy-N'-(4-butyl-2-methylphenyl)formamidine at lowering the expression of cytochrome P4504A11 gene and its protein. These results suggest that 20-hydroxyeicosatetraenoic acid may protect adriamycin-induced toxicity of human renal tubular epithelial cells, meanwhile, adriamycin-induced toxicity of human renal tubular epithelial cells possibly involves inhibiting cytochrome P4504A11 expression.

Ligustrazine inhibits lipopolysaccharide-induced proliferation by affecting P27, Bcl-2 expression in rat mesangial cells.

Ligustrazine has a renoprotective effect against nephritis. In the present study, we investigated the roles of ligustrazine on lipopolysaccharide-induced changes of proliferation, cell cycle in cultured rat mesangial cells. 3-(4,5-dimethyltiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay revealed that rat mesangial cells treated with lipopolysaccharide (10mg/l) underwent significant proliferation compared with control group. This effect was significantly inhibited by ligustrazine (400 to 2500 mg/l). Flow cytometric analysis revealed that cells treated with lipopolysaccharide showed significant reduction in the ratio of G0/G1 phase and significant elevation in the ratio of S+G2/M phase. The changes of cell cycle induced by lipopolysaccharide were reversed by ligustrazine. In addition, lipopolysaccharide suppressed P27 protein expression was significantly increased by ligustrazine (100, 500, 2500 mg/l). Moreover, rat mesangial cells treated with lipopolysaccharide showed scanty apoptosis with up-regulation of Bcl-2expression, while Bax protein expression was not changed. Ligustrazine (100, 500, 2500 mg/l) significantly reversed lipopolysaccharide-induced up-regulation of Bcl-2 protein and increased apoptotic cell death. In summary, ligustrazine displayed a significant inhibiting effect on lipopolysaccharide-induced proliferation through increasing P27 and decreasing Bcl-2 protein expression in rat mesangial cells.

Effects of amlodipine on TGF-ß-induced Smad2, 4 expressions in adriamycin toxicity of rat mesangial cells.

Transforming growth factor-ß (TGF-ß) is closely associated with progressive renal fibrosis. A central component of TGF-ß-stimulated mesangial cell fibrogenesis is the TGF-ß family-specific Smad signal transduction pathway. This study investigated the expression of TGF-ß-receptor--activated Smad2, its common partner Smad4, and the phosphorylated Smad2 (p-Smad2) in adriamycin-induced toxicity of cultured rat mesangial cells. This in vitro study showed that amlodipine (10(-9) to 10(-5) mol/l) had no effect on the toxicity of rat mesangial cells induced by adriamycin in the absence of TGF-ß1. However, amlodipine (10(-7) to 10(-5) mol/l) reduced the toxicity of rat mesangial cells induced by TGF-ß1 in the absence of adriamycin; moreover, amlodipine (10(-8) to 10(-5) mol/l) significantly reduced adriamycin-induced cytotoxicity when it was given in combination with TGF-ß1; amlodipine (10(-6), 10(-5) mol/l) had no effect on Smad2 mRNA and protein expression induced by adriamycin + TGF-ß1, but it (10(-6), 10(-5) mol/l) dramatically inhibited the down-regulation of p-Smad2 protein expression as well as Smad4 mRNA and protein expression induced by adriamycin + TGF-ß1 in rat mesangial cells. Present study shows that amlodipine exerts a significant inhibition on adriamycin-induced toxicity in rat mesangial cells by affecting the expression of TGF-ß/Smad signaling intermediates p-Smad2 and Smad4.

Differential roles of dihydropyridine calcium antagonist nifedipine, nitrendipine and amlodipine on gentamicin-induced renal tubular toxicity in rats.

In the present study, we investigated the antioxidative potencies of dihydropyridine calcium antagonists prototype nifedipine, the second generation drug nitrendipine, and the long acting, third generation drug amlodipine on gentamicin-induced renal tubular toxicity in Sprague-Dawley rats. In addition, we analyzed the relationship between renal tubular cell apoptosis and the antioxidative properties of these dihydropyridine calcium antagonists. Results showed that treatment with gentamicin alone caused significant changes in the levels of urinary protein, urinary N-acetyl-beta-d-glucosaminidase, serum creatinine, and blood urea nitrogen. Nifedipine and amlodipine effectively reversed the effect of gentamicin on these parameters. In contrast, nitrendipine either had no effect or worsened gentamicin-induced changes in the levels of urinary protein, urinary N-acetyl-beta-d-glucosaminidase, serum creatinine, and blood urea nitrogen. Furthermore, gentamicin treatment caused significant increases in the levels of malondialdehyde, nitric oxide, nitric oxide synthase and significant decreases in the levels of reduced glutathione, glutathione-S-transferase, and superoxide dismutase in kidney tissues. These effects were dramatically reduced by nifedipine and amlodipine but not affected by nitrendipine. In addition to the biochemical changes, histopathological studies showed that gentamicin caused structural damages in the kidneys; renal tubular cell apoptosis, a decrease in Bcl-2 expression and an increase in Bax expression were observed in all rats treated with gentamicin, nifedipine and amlodipine effectively reversed the effect of gentamicin while nitrendipine worsened them. In conclusion, this study clearly indicated that nifedipine and amlodipine protected against gentamicin-induced nephrotoxicity while nitrendipine had little effect, or even worsened.

Hepatotoxicity and gene expression down-regulation of CYP isozymes caused by renal ischemia/reperfusion in the rat.

Renal ischemia/reperfusion (I/R) occurs in many clinical scenarios, including trauma, elective surgery, and transplantation. Events initiated by this process can lead to inflammation in the kidneys, culminating in local injury as well as distant organ dysfunction. The objectives of this study were to investigate the changes in the functions of the liver and the regulation of gene expression of cytochrome P450 (CYP) isozymes after renal I/R. Hepatoxocity was assessed by serum alanine aminotransferase (sALT), serum aspartate aminotransferase (sAST) and liver glutathione-S-transferase (GST) activities, liver glutathione (GSH) level, and histopathological examination. Hepatic cytochrome P4503A1 (CYP3A1) and cytochrome P4502E1 (CYP2E1) activities were measured by erythromycin N-demethylase (ERD) and aniline hydroxylase (ANH) activities, respectively. CYP3A1 and CYP2E1 mRNA expression was determined by RT-PCR. Results showed that activities of sALT and sAST were significantly increased, while hepatic CYP3A1and CYP2E1 activities as well as their respective mRNA levels were significantly decreased after renal I/R. Moreover, hepatic tissue congestion, degeneration, and local necrosis were observed in rats after 1, 4, and 8h renal reperfusion following 2h renal ischemia. In conclusion, the present study suggests that renal I/R can cause hepatotoxicity and gene expression down-regulation of CYP isozymes in rats.

Changes of multiple biotransformation phase I and phase II enzyme activities in human fetal adrenals during fetal development.

AIM: Fetal adrenal, which synthesizes steroid hormones, is critical to fetal growth and development. Our recent research showed that some xenobiotics could interfere with steroidogenesis and induce intrauterine growth retardation in rats. The study on the characteristics of biotransformation enzymes in fetal adrenals still seems to be important with respect to possible significance in xenobiotic-induced fetal development toxicity. In this study, the activities of several important xenobiotic-related phase I and phase II enzymes in human fetal adrenals were examined and compared with those in fetal livers. METHODS: The activity and mRNA expression were determined by enzymatic analysis and RT-PCR. RESULTS: The levels of cytochrome (CYP)2A6, CYP2E1, and CYP3A7 isozymes in fetal adrenals were 82%, 92%, and 33% of those in fetal livers, respectively. There was a good positive correlation between adrenal CYP2A6 activity and gestational time. The values of alpha glutathione S-transferase (GST), pi-GST, and microGST in adrenals were 0.5, 4.4, and 8.3-fold of those in the livers, respectively, and the activity of adrenal pi-GST was negatively correlated with gestational time. The uridine diphosphoglucuronyl transferase activities, which were measured using p-hydroxy-biphenyl and 7-hydroxy-4-methylcoumarin as substrates, were 9% and 3%, respectively, of those in the fetal livers. CONCLUSION: Our investigation suggested that adrenal could be an important xenobiotic-metabolizing organ in fetal development and may play a potential role in xenobiotic-induced fetal development toxicity.

Protective effects of ligustrazine on cisplatin-induced oxidative stress, apoptosis and nephrotoxicity in rats.

Cisplatin is an effective agent against various solid tumors. However, its nephrotoxicity been reported to be a dose-limiting factor for treating various types of tumors. The aim of this study was to determine the protective effects of ligustrazine on cisplatin-induced nephrotoxicity through tissue oxidant/antioxidant parameters, light microscopic evaluation, and tubular apoptosis in rats. Ligustrazine was administered in doses of 50 and 100mg/kg/day intraperitoneally (i.p.), for 7 consecutive days, starting 2 days before a single intraveneous dose of cisplatin (8mg/kg). Results revealed that treatment with cisplatin alone caused significant changes in the levels of urinary protein, urinary N-acetyl-beta-d-glucosaminidase, serum creatinine, blood urea nitrogen, and kidneys histopathological damages. All the aforementioned changes were effectively attenuated by ligustrazine. In addition, cisplatin caused increases in the levels of malondialdehyde, nitric oxide, nitric oxide synthase and decreases in the levels of reduced glutathione, glutathione-S-transferase, superoxide dismutase. These changes were restored to near normal levels by ligustrazine at 100mg/kg. In conclusion, ligustrazine has dose dependent protective effects against cisplatin-induced renal tubular toxicity.

Protective effect of ligustrazine on accelerated anti-glomerular basement membrane antibody nephritis in rats is based on its antioxidant properties.

Ligustrazine has a renoprotective effect against nephritis. In this study, we further characterized the renoprotective properties of ligustrazine in an experimental model using accelerated anti-glomerular basement membrane antibody (AGBM-Ab). Ligustrazine was given i.p. once daily at 50, 100 mg/kg for 15 days after singly giving i.v. of rabbit anti-rat glomerular basement membrane serum, and showed dose-dependent inhibition the elevation of urinary protein, serum creatinine and blood urea nitrogen as well as the development of glomerular histological changes. Ligustrazine (50 mg/kg) had no affect on glutathione (GSH) content, glutathione peroxidase and catalase activities, but decreased the malondialdehyde (MDA) content and increased superoxide dismutase (SOD) activity in nephritis induced by AGBM-Ab. Ligustrazine (100 mg/kg) significantly decreased MDA content while significantly increased GSH content and SOD, glutathione peroxidase, catalase activities of kidney tissues in the rats treated with AGBM-Ab alone. In conclusion, our results show that ligustrazine has protective activity against accelerated AGBM-Ab nephritis, and its renoprotective effect may be due to its antioxidant properties and inhibition reactive oxygen species (ROS).

Differential effects of dihydropyridine calcium antagonists on doxorubicin-induced nephrotoxicity in rats.

The aim of this study was to compare the roles of dihydropyridine calcium antagonists nifedipine, nitrendipine, amlodipine on doxorubicin (DXR)-induced nephrotoxicity in rats using biochemical, histopathological and immunohistochemical approaches. Male Sprague-Dawley rats were randomly divided into five experimental groups: control; DXR; DXR+nifedipine (15 mg/kg); DXR+nitrendipine (10 mg/kg); DXR+amlodipine (5 mg/kg). Results showed that treatment with DXR alone caused significant changes in the levels of urinary protein, serum creatinine (SCr), and blood urea nitrogen (BUN). Co-administration with amlodipine effectively reversed the effect of DXR on these parameters. In contrast, nifedipine and nitrendipine either had no effect or worsened DXR induced changes in the levels of urinary protein, SCr and BUN. Furthermore, DXR treatment caused significant increases in the levels of malondialdehyde (MDA), nitric oxide (NO), nitric oxide synthase (NOS) and significant decreases in the levels of reduced glutathione (GSH), glutathione-S-transferase (GST), and superoxide dismutase (SOD). These effects were significantly reduced by co-administration with amlodipine but not affected by nifedipine and worsened by nitrendipine. In addition to the biochemical changes, histopathological studies showed that DXR caused significant structural damages in the kidneys. Glomerular cell apoptosis, a decrease in Bcl-2 expression and an increase in Bax expression were observed in all rats treated with DXR. Co-administration with amlodipine effectively reversed the effect of DXR while nifedipine and nitrendipine had no effect. In conclusion, this study clearly indicated that amlodipine protected against DXR-induced nephrotoxicity while nifedipine and nitrendipine had no effect.