Anti-apoptotic and anti-oxidant effects of grape seed proanthocyanidin extract in preventing cyclosporine A-induced nephropathy

Aim: Although the pathogenesis of cyclosporine (CsA) nephropathy is not completely understood, it is attributed to oxidative damage and apoptosis. Grape seed proanthocyanidin extract (GSPE) is a molecule with anti‐oxidant and anti‐apoptotic properties. Our aim was to demonstrate the effects of GSPE in preventing CsA nephropathy. Methods: Twenty‐four Sprague–Dawley rats were divided into four groups. The control, GSPE, CsA and CsA+GSPE groups were given 1 mL olive oil, 100 mg/kg GSPE, 25 mg/kg CsA and 100 mg/kg GSPE+25 mg/kg CsA, respectively. On day 21, blood samples were taken for blood urea nitrogen (BUN), creatinine and CsA levels, and renal tissue was used for total oxidant system (TOS), total anti‐oxidant system (TAS), oxidative stress index (OSI) and malondialdehyde (MDA) measurements. In addition to renal histopathology, apoptosis staining was performed on renal tissue. Results: The BUN, creatinine, TOS, OSI, MDA, histopathological score, and apoptotic index exhibited increases in the CsA group. In the CsA+GSPE group, however, BUN, creatinine, OSI, MDA, renal histopathological score and apoptotic index (AI) decreased and TAS levels increased. In addition, there was no difference between the CsA and CsA+GSPE groups with regard to CsA levels. Conclusion: We demonstrated that GSPE prevents CsA nephropathy and that this effect is achieved by anti‐apoptotic and anti‐oxidant activity. We also achieved a significant recovery in kidney functions without affecting CsA plasma levels.     

Experimentally induced hyperthyroidism influences oxidant and antioxidant status and impairs male gonadal functions in adult rats

The objective of the present experiment was to study the effect of hyperthyroidism on male gonadal functions and oxidant/antioxidant biomarkers in testis of adult rats. Induction of hyperthyroidism by L‐thyroxine (L‐T4, 300 μg kg^‐1 body weight) treatment once daily for 3 or 8 weeks caused a decrease in body weight gain as well as in absolute genital sex organs weight. The epididymal sperm counts and their motility were significantly decreased in a time‐dependent manner following L‐T4 treatment. Significant decline in serum levels of luteinising hormone, follicle stimulating hormone and testosterone along with significant increase in serum estradiol level was observed in hyperthyroid rats compared with euthyroid ones. Significant increase in malondialdehyde and nitric oxide concentration associated with significant decrease in superoxide dismutase and catalase activity was also noticed following hyperthyroidism induction. Both reduced glutathione content and glutathione peroxidase activity were increased in hyperthyroid rats compared with control rats. Marked histopathological alterations were observed in testicular section of hyperthyroid rats. These results provide evidence that hypermetabolic state induced by excess level of thyroid hormones may be a causative factor for the impairment of testicular physiology as a consequence of oxidative stress.     

盐酸多奈哌齐对血管性痴呆患者精神状态和日常生活活动能力的影响

目的探讨盐酸多奈哌齐治疗血管性痴呆对患者精神状态和日常生活活动能力的影响。方法将笔者所在医院2009年12月～2010年5月收治的血管性痴呆患者56例,采用盐酸多奈哌齐治疗,观察治疗前后患者精神状态和日常生活活动能力的变化。结果采用简易智能精神状态检查量表和日常生活活动能力量表对患者的精神状态和日常生活活动能力进行评价,治疗后MMSE和ADL评分均明显改善,与治疗前比较差异均有统计学意义（P〈0.05）。结论盐酸多奈哌齐治疗血管性痴呆能明显改善患者的精神状态和日常生活活动能力,值得临床关注。     

Supplementation of the dilution medium after thawing with reduced glutathione improves function and the in vitro fertilizing ability of frozen-thawed bull spermatozoa

In this study, we evaluated the effects of glutathione (l-gamma-glutamyl-l-cysteinylglycine; GSH) supplementation of the thawing extender on bull semen parameters to compensate for the decrease in GSH content observed during sperm freezing. To address these questions fully, we used a set of functional sperm tests. These included tests of sperm motility assayed by computer-assisted semen analysis, membrane lipid packing disorder, spontaneous acrosome reaction, free radical production [reactive oxygen species (ROS) generation], sperm chromatin condensation, DNA fragmentation by terminal deoxynucleotidyltransferase-mediated dUTP nick-end labelling and acridine orange staining measured by flow cytometry. Finally, the in vitro penetrability of in vitro matured oocytes and the in vitro production of embryos were evaluated. The main findings emerging from this study were that addition of GSH to the thawing medium resulted in: (i) a higher number of non-capacitated viable spermatozoa; (ii) a reduction in ROS generation; (iii) lower chromatin condensation; (iv) lower DNA fragmentation; (v) higher oocyte penetration rate in vitro and (vi) higher in vitro embryo production compared with control group. Nevertheless, GSH had no significant effect on motion parameters or the occurrence of the spontaneous acrosome reaction. Addition of GSH to the thawing extender could be of significant benefit in improving the function and fertilizing capacity of frozen bull spermatozoa.     

The effects of immunosuppressants on vascular function, systemic oxidative stress and inflammation in rats

Immunosuppressants have been associated with increased cardiovascular disease risk. We determined the effects of calcineurin and mammalian target of rapamycin (mTOR) inhibitor administration on endothelial dysfunction and associated inflammation and oxidative stress in adult rats. Cyclosporine A (low and high dose), sirolimus, tacrolimus, everolimus and placebo were administered to 8-week-old male Wistar rats for 10 consecutive days. Aortic vascular endothelial and smooth muscle function were assessed ex vivo in organ baths. Maximal aortic contraction to noradrenaline in sirolimus-treated rats was significantly greater than cyclosporine groups, everolimus and placebo, whereas endothelial-dependent relaxation was significantly impaired with cyclosporine and tacrolimus compared with everolimus. Endothelial-independent relaxation was impaired in tacrolimus-treated rats compared with low dose cyclosporine, everolimus and sirolimus. Sirolimus was associated with a reduction in plasma interleukin (IL)-1β and tumour necrosis factor (TNF)-α and higher levels of catalase and total antioxidant status. In nontransplanted rats, vascular dysfunction was evident following administration of cyclosporine A, sirolimus and tacrolimus, whereas everolimus did not compromise aortic endothelial or smooth muscle function. At the doses administered in this model, the immunosuppressants exerted varying effects on vascular function.     

Effects of antioxidant supplementation on blood cyclosporin A and glomerular filtration rate in renal transplant recipients.

BACKGROUND: Transplant recipients have elevated oxidative stress, which has prompted suggestions that supplementary antioxidants may be beneficial. However, only a small number of clinical trials have investigated antioxidant supplementation in transplant recipients, with very few data on their effects on patients' immunosuppressive therapy. METHODS: A randomized placebo-controlled single-blind crossover trial was conducted in 10 renal transplant recipients (RTRs) taking cyclosporin A (CsA) as part of their immunosuppressive therapy. Each phase of the trial lasted 6 months, with a 6 month wash-out period in between. During one of the phases, patients consumed a tablet twice per day which delivered 400 IU/day of vitamin E, 500 mg/day of vitamin C and 6 mg/day of beta-carotene. RESULTS: During antioxidant supplementation, there was no change in CsA dose. Antioxidant supplementation resulted in a significant decrease (P<0.05) in blood trough CsA by 24% (mean+/-SD, pre- 127.3+/-38.9, post- 97.2+/-30.7 microg/ml) compared with no change while taking the placebo (pre- 132.2+/-50.6, post- 138.6+/-56.0 microg/ml). The glomerular filtration rate was significantly (P<0.05) improved by 12% during antioxidant supplementation (pre- 66.9+/-20.7, post- 75.0+/-20.1 ml/min/1.72 m2), with no change during the placebo phase (pre- 66.8+/-11.8, post- 66.7+/-16.1 ml/min/1.72 m2). There were no significant differences (P>0.05) in markers of oxidative stress (malondialdehyde, susceptibility of plasma to oxidation) or plasma antioxidant enzymes. CONCLUSION: In CsA-treated RTRs, antioxidant supplementation decreased blood CsA, which may affect adequacy of immunosuppression.     

Advanced Oxidation Protein Products Induce Vascular Calcification by Promoting Osteoblastic Trans-Differentiation of Smooth Muscle Cells via Oxidative Stress and ERK Pathway

Vascular calcification is an actively regulated process similar to bone formation. Advanced oxidation protein products (AOPPs) have been demonstrated to be novel markers of oxidant-mediated protein damage. The present study investigated the role of AOPPs in inducing osteoblastic trans-differentiation and calcification of smooth muscle cells in vitro. We found that AOPPs directly increased the calcium deposition and expression of core binding factor-α1 (CBF-α1) and osteopontin (OPN) and significantly decreased SM-α-actin expression in human aortic smooth muscle cells (HASMCs). AOPPs increased intracellular oxidative stress, which was inhibited by vitamin E. Vitamin E also inhibited AOPP-induced calcium content and osteoblast differentiation of HASMCs. Furthermore, the inhibitor of ERK significantly suppressed the effects of AOPPs on calcification and osteoblast marker expression. These findings suggest that AOPPs induce vascular calcification by promoting osteoblast differentiation of smooth muscle cells via oxidative stress and ERK pathway.     

Supplementation of IVF medium with melatonin: effect on sperm functionality and in vitro produced bovine embryos

Gamete co‐incubation generates high free radical levels surrounding growing zygotes which may impair subsequent embryo viability. Melatonin eliminates a wide variety of free radicals; hence, we tried to improve in vitro embryo production by adding melatonin to in vitro fertilisation (IVF) media in high (Exp. 1) and low concentrations (Exp. 2), and we evaluated its effect on bull sperm function during IVF co‐incubation time (Exp. 3). In Experiment 1, we supplemented IVF media culture with 0.01, 0.1 and 1 mmol of melatonin, along with a no melatonin control group. In Experiment 2, melatonin levels were reduced to 10, 100 and 1000 nmol, with a no melatonin control group. In Experiment 3, spermatozoa were incubated in IVF media with melatonin (as Exp. 2) and functional parameters were analysed at 0, 4 and 18 h. In Experiment 1, only 1 mmol melatonin showed lesser blastocyst rates than control (C: 23.2 ± 6.7% versus 1 mmol: 2.0 ± 1.7%). In Experiment 2, no statistical differences were found in cleavage percentage, blastocyst percentage and total cell count for any melatonin treatment. In Experiment 3, sperm samples with 1000 nmol melatonin had a significantly higher wobbler (WOB) coefficient, a lower percentage of intact acrosomes, a lower percentage of viable spermatozoa with ROS, greater DNA fragmentation and higher DNA oxidation than controls. Total fluorescence intensity for ROS at 10 nmol melatonin was significantly greater than controls (P < 0.05). IVF media with 1 mmol melatonin is deleterious for embryo development, and in lower concentrations, it modulated sperm functionality, but had no effects on embryo production.     

Assessment of DNA Oxidation and Antioxidant Activity in Hypertensive Patients with Chronic Kidney Disease

The aim of this study was to evaluate the oxidative DNA damage, antioxidant activity, and effects of antihypertensive drugs on oxidative stress in hypertensive patients with different stages of chronic kidney disease (CKD). Fifty-three non-dialyzed hypertensive CKD patients were included by the study. Serum and urinary 8-hydroxydeoxy guanosine (8-OHdG) levels (as a marker of oxidative DNA damage), serum superoxide dismutase (SOD), and glutathione peroxidase (G-Px) activities (as antioxidant enzymes) were measured. SOD activity was higher and G-Px activity was lower in the patient group as compared to control group. Serum and urinary 8-OHdG levels were found to be higher in the patients with proteinuria greater than 3 g/day than those in the patients with proteinuria less than 3 g/day. It has been determined that G-Px activity and urinary 8-OHdG level were lower in the patients treated with angiotensin-converting enzyme (ACE) inhibitor compared to patients treated with calcium channel blocker. The present data show oxidative DNA damage at a higher level in the patients with proteinuria greater than 3 g/day. In comparison to a calcium channel blocker, an ACE inhibitor seems much more protective against oxidative DNA damage in hypertensive patients with different stages of CKD.     

The Role of Angiogenic and Wound Repair Factors During CMV-Accelerated Transplant Vascular Sclerosis in Rat Cardiac Transplants

Human cytomegalovirus (HCMV) accelerates transplant vascular sclerosis (TVS), a consequence of angiogenesis (AG) and wound repair (WR). While HCMV can be localized to TVS lesions, the low number of infected cells suggests a global effect on target tissues. We used microarray analysis followed by real-time-polymerase chain reaction (RT-PCR) in an RCMV-accelerated TVS rat cardiac transplant model to determine whether CMV activates host WR and AG factors. Dysregulated cellular genes in allografts from RCMV-infected recipients were compared to those from uninfected recipients and native hearts. We demonstrated that RCMV upregulates the genes involved in WR and AG, which was highest during the critical time of TVS acceleration (21–28 days). Using a standard in vitro AG assay, virus and serum-free supernatants collected at 48 h postinfection significantly induced endothelial cell (EC) migration, branching and tubule formation compared to supernatants from mock-infected cells. Supernatants from ultraviolet (UV)-inactivated RCMV-infected cells failed to induce AG, indicating that virus replication is required. Upregulation of WR and AG genes occurs during the critical period of CMV-accelerated TVS. Targeting these genes may prevent this process and improve allograft survival.