End Of Experimental Protocol Research Articles

Administration of mitochondrial fusion promoter during ischemia and at the onset of reperfusion exert neuroprotective effects in rats with cardiac ischemia/reperfusion injury

AbstractBackgroundAcute myocardial infarction (AMI) is one of the fetal cardiovascular diseases and a leading cause of death (1, 2). Our previous study demonstrated that pretreatment of mitochondrial fusion promoter (M1) provided neuroprotective effects on the brain following cardiac ischemia/reperfusion (I/R) injury (3). However, the effects of M1 given during ischemia and M1 given at the onset of reperfusion on brain pathologies following cardiac I/R have never been investigated.MethodSixteen male Wistar rats were randomly divided into either a sham‐operation (n = 8) or cardiac I/R (n = 24). In the cardiac I/R group, rats were then randomly divided into 3 subgroups, including the I/R operation with vehicle (0.9% sodium chloride solution for 15 minutes before I/R protocol, intravenous (i.v.) injection), the I/R operation with M1 administration during cardiac ischemia (2 mg/kg, 15 minutes after left anterior descending (LAD) coronary artery ligation, i.v. injection), and the I/R operation with M1 administration at the onset of reperfusion group (2 mg/kg at the beginning of reperfusion, i.v. injection). At the end of experimental protocol, rats were sacrificed and brains were obtained for further molecular investigation.ResultThe results demonstrated that cardiac I/R increased brain inflammation, caused microglial dysmorphology, caused brain mitochondrial dysfunction, increased tau hyperphosphorylation, and increased brain apoptosis (p<0.05, Figure 1). M1 given during ischemia and M1 given at the onset of reperfusion effectively attenuated brain pathologies following cardiac I/R by preserving microglial morphology, improving brain mitochondrial function, decreasing tau hyperphosphorylation, and decreasing brain apoptosis (p<0.05, Figure 1). Interestingly, M1 given during ischemia had better efficacy to suppressing brain inflammation, when compared to M1 given at the onset of reperfusion apoptosis (p<0.05, Figure 1).ConclusionThese findings suggest the administration of mitochondrial fusion promoter effectively decreased brain pathologies following cardiac I/R. The administration of mitochondrial fusion promoter during ischemia had greater suppression on brain inflammation than administration at the onset of reperfusion. The novel findings obtained from the present study provided the therapeutic strategies which can be translated into clinical settings for cardiac I/R injury.

MAC28 Attenuates Neurodegeneration and Restores Cognitive Function via Reducing Peripheral Insulin Resistance, Neuroinflammation, Brain Oxidative Stress, Amyloid‐β Deposition, and Loss of Dendritic Spines in High‐Fat Diet‐induced Obese Rats

AbstractBackgroundLong‐term high‐fat diet (HFD) consumption induces not only peripheral insulin resistance with low‐grade systemic inflammation, but also neuroinflammation and subsequent brain pathologies including neurodegeneration, which can lead to cognitive impairment (1). MAC28, a novel mono‐carbonyl analogue of curcumin, was recently identified as a novel MD‐2 inhibitor, and has been shown to attenuate systemic inflammation (2). However, the effects of MAC 28 on the neuroinflammation, neurodegeneration and cognitive function in the HFD‐induced obese rats have never been studied.MethodMale Wistar rats were fed either a normal diet (ND; n = 8) or HFD (n = 40) for 16 weeks. At week 13, ND‐fed rats were orally administered a vehicle for 4 weeks, while HFD‐fed rats were randomly divided into 5 groups (n = 8/group). Each subgroup was orally administrated either vehicle, 10mg/kg/day of MAC 28, 20mg/kg/day of MAC 28, 40mg/kg/day of MAC 28 or 300 mg/kg/day of metformin for 4 weeks. At the end of experimental protocol, the novel object location (NOL) test was examined in each rat. Brains were rapidly removed to determine brain TLR4‐MD‐2 signaling pathway, inflammatory cytokines, brain oxidative stress, dendritic spine density, amyloid and tau pathology.ResultHFD‐fed rats developed obesity with peripheral insulin resistance. Neuroinflammation was observed in HFD‐fed rats, as evidenced by increased expressions of hippocampal MD‐2, TLR4 and TNF‐α levels. In addition, HFD‐fed rats not only increased the levels of brain MDA, hippocampal amyloid‐β/APP ratio, but also reduced hippocampal dendritic spine density, resulting in cognitive decline. Although all doses of MAC 28 and metformin attenuated peripheral insulin resistance, brain pathologies and cognitive impairment, MAC 28 (20mg/kg/day and 40mg/kg/day) and metformin had the highest efficacy in attenuating peripheral insulin resistance, brain inflammation, brain oxidative stress, amyloid‐β deposition and improving dendritic spines, resulting in restoring cognitive function (P < 0.05, Figure 1).ConclusionThese findings suggest that an obvious neuroprotective effect of MD‐2 inhibitor may be the potential strategy for attenuating neurodegenerative disorders in the obese‐insulin resistant condition.

Blocking myeloid differentiation factor 2 improves cognitive function via reducing microglia activation, neuroinflammation, brain mitochondrial dysfunction and dendritic spine loss in obese insulin‐resistant rats

Chronic high fat diet (HFD) consumption induces not only low-grade systemic inflammation and obese-insulin resistance, but also initiates neuroinflammation via activating myeloid differentiation factor 2 (MD-2)/toll-like receptor 4 (TLR4) complex, resulting in brain pathologies and cognitive impairment. Recently, MD-2 inhibitor (L6H21) has been shown to alleviate systemic inflammation. However, the effect of L6H21 on the cognitive function and brain pathologies of HFD-induced obese insulin-resistant condition has not been investigated. Male Wistar rats were fed either a normal diet (ND; n=8) or HFD (n=40) for 16 weeks. After 12th week of dietary periods, HFD-fed rats were divided into 5 groups (n=8/group). Each group was orally administered either vehicle, 10 mg/kg/day of L6H21, 20 mg/kg/day of L6H21, 40 mg/kg/day of L6H21, or 300 mg/kg/day of metformin for 4 weeks. For ND-fed rats, animals were orally administered vehicle for 4 weeks. At the end of experimental protocol, the novel object location (NOL) test was examined in each animal. Then, blood was collected before animals were sacrificed. Brains were rapidly removed to determine microglial activity, dendritic spine density, inflammatory cytokines, mitochondrial function, and insulin signaling. HFD-fed rats showed peripheral and brain insulin resistance, as indicated by impaired glucose tolerance and reduced brain insulin receptor substrate (IRS) level. In addition, HFD-fed rats developed brain pathologies, and cognitive impairment, as indicated by increased brain TNF-α level, increased microglial hyperactivity, increased mitochondrial reactive oxygen species (ROS), increased Bax/Bcl2 level, reduced dendritic spine density, and reduced preference indexes of NOL phase. Although L6H21 (20mg/kg/day, 40 mg/kg/day) and metformin alleviated HFD-induced brain pathologies and cognitive impairment, L6H21 at 40mg/kg/day and metformin had the highest efficacy for the neuroprotection in obese insulin-resistant rats through inhibiting neuroinflammation, oxidative stress, microglial activation, neuronal apoptosis and improving dendritic spine density, resulting in restoring cognitive function (p<0.05, Figure 1). These findings suggest that MD-2 inhibitor may be the other drug of choice for improving brain function in the obese-insulin resistant condition.

Melatonin, metformin, and ranolazine equally improved cognitive function in rats with doxorubicin‐induced chemobrain

Doxorubicin (Dox), the common therapeutic regimen for breast cancer treatment, has been shown the toxicity to the brain, known as "chemotherapy-induced cognitive impairment or chemobrain". However, the mechanisms of doxorubicin-induced chemobrain are not fully understood. Melatonin, metformin, and ranolazine have been shown the neuroprotective effects on mitochondrial function and cognition in several pathological conditions. However, the effects of melatonin, metformin, and ranolazine on peripheral oxidative stress, brain mitochondrial function, synaptic plasticity, and cognitive function in Dox-induced chemobrain has never been investigated. Forty male Wistar rats were randomly divided into two groups including control group (0.9% NSS, intraperitoneal (i.p.) injection, n=8) and Dox-treated group (3 mg/kg for 6 doses, i.p. injection, n=32). All Dox-treated rats were randomly divided into four subgroups (n=8/ subgroup) to receive either vehicle (0.9% NSS, daily oral gavage feeding), melatonin (10 mg/kg/day, oral gavage feeding), metformin (250 mg/kg/day, oral gavage feeding), or ranolazine (305 mg/kg/day, oral gavage feeding). Each drug was continuously given by starting at the 1st day of Dox for 30 days. At the end of experimental protocol, cognitive function was tested, and brains were obtained for further molecular investigation. Dox-treated rats significantly increased peripheral oxidative stress as indicated by increased serum malondialdehyde level, which were equally decreased by treatment with melatonin, metformin, and ranolazine (p<0.05, Figure 1). Moreover, brain mitochondrial dysfunction was demonstrated by increasing brain mitochondrial ROS production, membrane potential change, and swelling (p<0.05, Figure 1). These parameters were equally attenuated by all treatments. Consistently, Dox-treated rats showed synaptic dysplasticity, as indicated by decreasing dendritic spine density, which was attenuated by all treatments. Interestingly, melatonin, metformin, and ranolazine improved cognitive function in Dox-treated rats by increasing preference index of object in novel location and novel object in novel object location and recognition test (p<0.05, Figure 1). These findings suggest that melatonin, metformin, and ranolazine effectively ameliorate cognitive decline in rats with Dox-induced chemobrain. The novel findings obtained from the present study provides the therapeutic strategies which can be translated into clinical settings for better preventing chemobrain in the future.

Hepatic susceptibility to oxidative damage after repeated concomitant exposure to aspartame and aflatoxin B1 in rats

The potential interactions among food additives/contaminants and the consequences to biological systems is a topic that is rarely addressed in scientific literature. Thus, the current study investigated if the combined administration of ASP and AFB1 would impair hepatic and renal oxidative status. Male Wistar rats received during 14 days once a day ASP (75 mg/Kg) and/or AFB1 (250 µg/Kg) through intragastric route. At the end of experimental protocol, samples of liver and kidneys were collected for assessing biochemical markers of oxidative status. In the hepatic tissue, the treatment with a single substance (ASP or AFB1) caused an increase in TBARS levels, and a reduction in non-enzymatic antioxidant defenses (Vit C and NPSH levels and FRAP test). In the kidneys, TBARS levels were increased only in the group that received ASP + AFB1. The association reduced NPSH content, while the treatment with AFB1 reduced the FRAP levels. GST and CAT activities were increased in all treatments. Overall, ASP and AFB1 association presented higher toxic effects to the tissues. To the best of our knowledge, this is the first study demonstrating that the associated use of both ASP and AFB1 induces more extensive injuries in comparison to the effects caused by each one alone. Therefore, these data demonstrated that concomitant exposure to ASP and AFB1 potentiated their oxidative damage in hepatic tissue, suggesting that this organ is particularly sensitive to the toxic action induced by these substances.

Short and long-term effects of high-intensity interval training applied alone or with whole-body cryostimulation on glucose homeostasis and myokine levels in overweight to obese subjects.

Background: COVID-19 pandemic has exacerbated the problem of physical inactivity and weight gain. Consequently, new strategies to counteract weight gain are being sought. Because of their accessibility, interval training and cold therapy are the most popular such strategies. We here aimed to examine the effect of 6 units of high-intensity interval training (HIIT), applied alone or in combination with 10 sessions of whole-body cryotherapy (WBC; 3 min at -110 ∘C per session) on incretins, myokines, and adipokines levels. Materials and methods: The study involved 65 subjects (body mass index of approximately 30 kg•m-2). The subjects were randomly divided into training group (TR; n = 27) and training supported by WBC group (TR-WBC; n = 38). Blood samples were collected before, immediately following, and 4 weeks after the intervention. Results: Fibroblast growth factor 21 (FGF21) levels significantly increased (p = 0.03) and adiponectin levels increased in the TR group (p = 0.05) compared with those recorded in TR-WBC group 24 h after the end of experimental protocol. Beneficial changes in the lipid profile (p = 0.07), a significant drop in visfatin levels (p < 0.05), and the improvement in β-cell function (HOMA-B; p = 0.02) were also observed in the TR group in the same time point of study. While TR-WBC did not induce similar changes, it ameliorated blood glucose levels (p = 0.03). Changes induced by both interventions were only sustained for 4 weeks after treatment. Conclusion: Collectively, HIIT, alone and in combination with WBC, positively affects metabolic indicators, albeit, most likely, different mechanisms drive the beneficial effects of different treatments.

Proprotein convertase subtilisin/kexin type 9 inhibitor exerts greater efficacy than atorvastatin on ameliorating cognitive impairment in high‐fat diet–induced obesity

AbstractBackgroundLong‐term consumption of a high‐fat diet (HFD) caused not only obesity with dyslipidemia but also caused brain pathologies which resulted in cognitive impairment. Atorvastatin, a recommended first‐line lipid‐lowering drug, had beneficial effects on metabolic control and mitigated brain pathologies in several models. However, the long‐term use of statin had many side effects which may result in discontinuation of statins for therapeutic treatment. Recently, proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor was approved as an effectively therapeutic drug for lowering cholesterol level. PCSK9 inhibitor decreases low‐density lipoprotein receptor (LDLR) degradation, and consequently lowers of LDL levels in the circulation. However, there were only few studies that reported the effect of PCSK9 inhibitor on brain functions. In addition, the comparative effects of atorvastatin and PCSK9 inhibitor on brain functions and cognitive function in HFD‐induced obesity have not been elucidated. We hypothesize that PCSK9 inhibitor has greater effect than atorvastatin on improving brain function and cognitive function in HFD‐induced obesity.MethodTwenty Female Wistar rats were fed with either a normal diet (ND) or HFD for 15 weeks. At week 13, ND rats were given normal saline, and HFD rats were divided into two subgroups to receive either normal saline, atorvastatin (40 mg/kg/day) or PCSK9 inhibitor (4 mg/kg/day) for 3 weeks. At the end of experimental protocol, metabolic parameters, brain function, and cognitive function were determined.ResultHFD‐fed rats developed obesity, dyslipidemia and insulin resistance. An increase in PCSK9 level, LDLR degradation, oxidative stress, blood brain barrier breakdown, microglial hyperactivation, synaptic dysplasticity, apoptosis, Alzheimer’s‐related proteins production in hippocampus, and cognitive decline were observed in HFD‐fed rats. Atorvastatin and PCSK9 inhibitor equally attenuated Alzheimer’s‐related proteins production and apoptosis in hippocampus of HFD‐fed rats. Interestingly, PCSK9 inhibitor had greater efficacy than atorvastatin on the amelioration of hippocampal oxidative stress level, blood brain barrier breakdown, microglial hyperactivation, synaptic dysplasticity and cognitive decline in HFD‐fed rats. Furthermore, PCSK9 inhibitor, but not atorvastatin, decreased the hippocampal PCSK9 and increased LDLR expression in HFD‐fed rats (p&lt;0.05, Figure 1).ConclusionPCSK9 inhibitor exerted greater efficacy than atorvastatin in improving metabolic and brain function in HFD‐induced obesity.

The Long-Term Effects of Ethanol and Corticosterone on the Mood-Related Behaviours and the Balance Between Mature BDNF and proBDNF in Mice.

In this study, we aimed to establish the effects of chronic corticosterone (CORT) and ethanol administration on mood-related behaviour and the levels of mature brain-derived neurotrophic factor (mBDNF) and its precursor protein proBDNF in mice. C57BL6 male and female mice received drinking water (n = 22), 1% ethanol in drinking water (n = 16) or 100μg/ml corticosterone in drinking water (containing 1% ethanol, n = 18) for 4.5weeks. At the end of experimental protocol, the open field test (OFT) and elevated plus maze test were performed. Brain and adrenal tissues were collected and mBDNF and proBDNF were measured by ELISA assays. We found that the mice fed with corticosterone and ethanol developed anxiety-like behaviours as evidenced by reduced time in the central zone in the OFT compared with the control group. Both proBDNF and mBDNF were significantly decreased in the corticosterone and ethanol groups compared with the control group in the prefrontal cortex, hippocampus, hypothalamus and adrenal. The ratio of proBDNF/mBDNF in prefrontal cortex in the corticosterone group was increased compared with the ethanol group. Our data suggest that the ratio of proBDNF/mBDNF is differentially regulated in different tissues. Ethanol and corticosterone downregulate both mBDNF and proBDNF and alter the balance of proBDNF/mBDNF in some tissues. In conclusion, the ethanol and corticosterone may cause abnormal regulation of mBDNF and proBDNF which may lead to mood disorders.

Effects of Nicorandil and Chronic Physical Exercise on Glycemia in Diabetic Rats Induced by Streptozotocin

Diabetes is a chronic metabolic disease characterized by persistent hyperglycemia caused by a decrease or deficiency of insulin secretion and/or peripheral insulin resistance. Regular physical exercise could improves glucose metabolism and insulin sensitivity, which is essential for preventing diabetic complications. Moreover, there is evidence that the opening of ATP sensitive potassium (KATP) channels contributes to cytoprotective effects under metabolic stress, therefore KATP channels could be a therapeutic target in this disease. Thus, the purpose of this study was to assess the impact of the potential effects of nicorandil (KATP channel opener) after a chronic exercise training program on levels glicemic in diabetic rats.Male Wistar rats (23–25 days old) were randomly divided into six groups, among them: sedentary control, trained control, sedentary diabetic, trained diabetic, sedentary diabetic plus nicorandil, trained diabetic plus nicorandil. Diabetes was induced by a single streptozotocin injection (100 mg/kg body weight), animals with fasting blood glucose levels ≥ 250 mg/dL were considered as diabetic. Training comprised 8 weeks of treadmill running (30 minutes daily, 5 days/week); at week 4, nicorandil (3 mg/kg) was administered for to 4 weeks. Fasting blood glucose (FBG) level was recorded every week for 8 consecutive weeks. At the end of experimental protocol, insulin tolerance test (ITT) was evaluated in all groups, rats received a application of insulin (0.75UI/kg body weight), with blood samples drawn after 0, 30, 60, 90 and 120 min postinjection. Blood glucose response to ITT was calculated as area under the curve (AUC‐ITT) of the blood glucose excursion along 120 minutes after intra‐peritoneal insulin injection and correlated with the corresponding fasting values according to the trapezoidal method.Treatment with nicorandil and the chronic exercise exerted remarkable effects on hyperglycemic status in diabetic rats by decreases FBG levels (47.51± 10.2 %) and inducing significant increases in the insulin sensitivity (P&lt; 0.05) compared with sedentary diabetic rats and trained diabetic rats. Our results suggest than opening KATP channels by nicorandil mediates potential benefits the chronic physical exercise on glycemic in diabetes.Support or Funding InformationWe thank Universidad de Guanajuato, Campus León. We acknowledge the financing PRODEP (Programa para el Desarrollo Profesional Docente en Educación Superior, ESD (511‐6/18‐8876).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Effects of sympathectomy on cardiac remodeling in a doxorrubicin-induced dilated cardiomyopathy model

Introduction: The main cause of cardiac transplantation is dilated cardiomyopathy (DCM), in which there are ventricular dilation and systolic dysfunction, leading to congestive heart failure. Ventricular remodeling involves activation of the sympathetic nervous and renin-angiotensin- aldosterone systems. As such, classic treatments include angiotensin-converting enzyme inhibitors (ACEI), beta-blockers and mineralocorticoid receptor antagonists. Once such treatments only delay the development of the disease, it is important to look for better therapeutic options. Experimental models demonstrated the benefits of sympathetic blockade on preserving ventricular function and preventing left ventricle remodeling after myocardial infarction. Objective: We evaluated the influence of bilateral thoracic sympathectomy on left ventricle remodeling and function in a rat model of doxorubicin induced DCM. Methodology: Animals were randomly divided into 4 groups of 7 rats each. DCM only, bilateral sympathectomy (BS) with DCM, ACEI with DCM and also a negative control group (SHAM). DCM was inducted in the experimental groups through weekly intraperitoneal injection of doxorubicin. Fifteen days after the beginning of DCM induction, bilateral sympathectomy was performed by chemical sclerosis of stellate ganglion with ethanol in the BS group. From this same time point until the end of experimental protocol, animals of the ACEI group received daily, through water ingestion, a enalapril maleate dilution. Ten weeks later, left ventricular function was evaluated with the use of a microtip pressureconductance catheter. Also, extracellular fibrosis were evaluated and BCL-2 expression on myocardial tissue were quantified. Partial Results: DCM group showed an increased left ventricular (LV) end-diastolic volume in relation to Sham group(p=0.034). Also, a significant decrease was observed in LV ejection fraction in DCM group, while bilateral sympathectomy were able to preserve this parameter (p=0,001). Furthermore, both treated groups showed an increased LV stroke work compared to DCM group (p=0,002). Myocardial extracellular fibrosis were more present in control group, whereas both BS and ACE inhibitor treatments reduced the areas of fibrotic tissue (p&lt;0,0001), which can be associated with increased expression of anti-apoptotic BCL-2 in treated groups (p=0,0004). Discussion and Conclusion: Sympathetic blockade was able to suppress myocardial tissue fibrosis, most likely due to increasing anti-apoptotic BCL-2 expression. Moreover, LV function was maintained as observed through LV ejection fraction,stroke work and cardiac efficiency levels. Although ACE inhibitor was also able to inhibit extracellular fibrosis and increase BCL- 2 expression, cardiac function has not been preserved as in BS group. Therefore, we conclude that BS was able to decrease myocardial tissue deterioration and also to preserve LV in a doxorubicin model of DCM in rats. Keywords: Sympathectomy; Cardiomyopathy; Cardiac transplantation; Doxorubicin.

The effect of two different speed endurance training protocols on a multiple shuttle run performance in young elite male soccer players

ABSTRACTThere is not enough evidence on the impact of different speed endurance training regimes on footballers’ ability to perform multiple shuttle run performance. This study examined the effect of 4 weeks of speed endurance maintenance (SEM) and speed endurance production (SEP) training on the 5-meter multiple shuttle run test (5-m MST) performance in young elite soccer players. A parallel two-groups, longitudinal design was used. Fifteen players were divided to either SEM (8 repetitions of 20-s all-out sprint interspersed with 40 s of recovery) or SEP (8 repetitions of 20-s all-out bout interspersed with 120 s of recovery) training group. SEM improved the ability to tolerate fatigue and maintained the performance development during the 5-m MST while SEP increased only the 1st sprint showing, simultaneously, an increased fatigue index and performance decrement. The selection of which training regimes to prioritize should be based on the players’ characteristics and individual game requirementsAbbreviations: SEP: Speed Endurance Production; SEM: Speed Endurance Maintenance; PRE: Baseline; POST: End of experimental protocol; 5-m MST: 5-meters Multiple Shuttle Run Test; TD: Total Distance; FI: Fatigue Index; MSTdec: Percentage Decrement Score; BMI: Body Mass Index

Decreased microglial activation through gut-brain axis by prebiotics, probiotics, or synbiotics effectively restored cognitive function in obese-insulin resistant rats

BackgroundChronic high-fat diet (HFD) consumption caused not only obese-insulin resistance, but also cognitive decline and microglial hyperactivity. Modified gut microbiota by prebiotics and probiotics improved obese-insulin resistance. However, the effects of prebiotics, probiotics, and synbiotics on cognition and microglial activity in an obese-insulin resistant condition have not yet been investigated. We aimed to evaluate the effect of prebiotic (Xyloolidosaccharide), probiotic (Lactobacillus paracasei HII01), or synbiotics in male obese-insulin resistant rats induced by a HFD.MethodsMale Wistar rats were fed with either a normal diet or a HFD for 12 weeks. At week 13, the rats in each dietary group were randomly divided into four subgroups including vehicle group, prebiotics group, probiotics group, and synbiotics group. Rats received their assigned intervention for an additional 12 weeks. At the end of experimental protocol, the cognitive functioning of each rat was investigated; blood and brain samples were collected to determine metabolic parameters and investigate brain pathology.ResultsWe found that chronic HFD consumption leads to gut and systemic inflammation and impaired peripheral insulin sensitivity, which were improved by all treatments. Prebiotics, probiotics, or synbiotics also improved hippocampal plasticity and attenuated brain mitochondrial dysfunction in HFD-fed rats. Interestingly, hippocampal oxidative stress and apoptosis were significantly decreased in HFD-fed rats with all therapies, which also decreased microglial activation, leading to restored cognitive function.ConclusionsThese findings suggest that consumption of prebiotics, probiotics, and synbiotics restored cognition in obese-insulin resistant subjects through gut-brain axis, leading to improved hippocampal plasticity, brain mitochondrial function, and decreased microglial activation.

Hypercaloric Diet Establishes Erectile Dysfunction in Rat: Mechanisms Underlying the Endothelial Damage.

Obesity is characterized by an excessive increase in body mass, leading to endothelial damage that may favor the development of erectile dysfunction (ED). ED is defined as the inability to achieve or maintain a penile erection long enough to have a sexual intercourse. In this context, different ED models were developed, however the high price of special animals or the long period to establish the disease has limited studies in this field. Therefore, this study proposed to establish and characterize a novel model of ED in rats associated to a hypercaloric diet consumption. Animals were randomly divided into control group (CG), which received a standard diet, and obese group (OG), fed with a hypercaloric diet during 8 weeks. Rat's erectile function was evaluated in vivo and in vitro. Food and caloric intake of OG were reduced compared to CG, due to an increased diet energy efficiency. However, OG presented an increased body mass, inguinal, retroperitoneal and epididymal adipose tissues, as well as body adiposity index at the end of experimental protocol. In erectile function analysis, there was a decrease in the number and the latency of penile erections in OG. Additionally, the contractile reactivity of corpus cavernosum was increased in OG, favoring penile detumescence and related to a reduced nitric oxide bioavailability and an increased in contractile prostaglandins levels as a consequence of endothelial damage. Moreover, the endothelium-relaxation reactivity of corpus cavernosum was attenuated in OG associated to the oxidative stress. Thus, it was provided a model for advances in sexual dysfunction field and drug discovery for ED treatment.

Melastoma malabathricum Linn attenuates complete freund's adjuvant-induced chronic inflammation in Wistar rats via inflammation response.

BackgroundNatural products use for arthritis treatment is gaining importance in the medical worldt. Various studies reports medical importance of Melastoma malabathricum Linn. (MM) (Melastomataceae), also known as “putki,” has a broad range of health benefits, for its free radical scavenging constituents. The current investigation scrutinizes the antioxidant and anti-inflammatory effect of MM against adjuvant-induced arthritis in experimental rats.MethodsHigh-performance thin layer chromatography (HPTLC) was used for estimation of phytochemical-constituents present in the MM extract. Protective effect of MM extract in Wistar rats was estimated using CFA-induced model. The rats were divided into different groups with six rats in each group. All animals received oral administration of MM and indomethacin for 28 days. The body weight and arthritic score were scrutinized at regular intervals. At the end of experimental protocol, the rats were sacrificed, and blood samples were used for antioxidant, hematological parameters, pro-inflammatory and inflammatory mediator, respectively. Histopathological observation was used to evaluate the protective effect of MM extract.Result & discussionCurrent study confirmed the preventive effect of MM against adjuvant-induced paw edema, paw redness and arthritic progression. MM significantly (P < 0.001) modulated the oxidative stress parameters as well as hematological parameter induced by CFA. The result also altered the distorted level of proinflammatory mediators and inflammatory mediator, which further reinforce the implication of MM in CFA induced arthritis. Histological analyses of joints of rats showed a reduction in the synovial hyperplasia and mononuclear infiltration in the MM treated group which provides evidence for the antiarthritic effect of MM.ConclusionFrom above parameters our study states that the MM is capable of restraining the alteration produced via adjuvant-induced arthritis in aminals. The repressing effect of MM could be attributed, at least in part, to antioxidant, hematological and anti-inflammatory effect.Graphical abstractFigure Caption: Melastoma Malabathricum Linn Attenuates Complete Freund’s Adjuvant-Induced Chronic Inflammation in Wistar rats by Inflammation Response

Preventive effect of selenium pretreatment against cisplatin-induced oral mucositis in rats

Objective. The aim of the present study was to investigate the protective role of selenium against cisplatin-induced oral mucositis in rats. Methods. Healthy wistar albino rats (n=21) were randomly divided into three groups: Cisplatin (Cis), cisplatin and selenium (Cis+Se) and control (C). Cisplatin was administered for 3 days to Cis and Cis+Se groups. Cis+Se group received selenium 5 days before cisplatin injection and continued for 11 consecutive days. Malondialdehyde (MDA) levels of the rats were determined before and at the end of experimental protocol. The tongues of rats were harvested for immunuhistochemical examinations. Results. In biochemichal analysis, MDA levels significantly increased in the Cis group ( p =0.018). On the contrary, there was no significant difference between pretreatment and posttreatment MDA levels in Cis+Se group ( p =0.128). In the immunohistochemical examinations of lingual tissues stained with anti-caspase-3, when the Cis and Cis+Se groups were compared, there were significantly more immunopositivity in the Cis group and significantly less immunopositivity in the Cis+Se group ( p <0.05). Conclusions. Selenium might have played a protective role against cisplatin-induced oral mucositis in rats. Further studies are necessary before its clinical use in patients.

Protective Effect of Selenium Against Cisplatin-Induced Ototoxicity in an Experimental Design.

Cisplatin is an effective chemotherapeutic agent in the treatment of several types of malignant solid tumors but its clinical use is associated with ototoxicity. In the present study, we investigated the effect of selenium administration on lipid peroxidation (malondialdehyde [MDA]) and cisplatin-induced ototoxicity in rats. Healthy wistar albino rats (n = 21) were randomly divided into 3 groups: control (C), cisplatin (Cis), cisplatin and selenium (Cis+Se). Cisplatin was administered for 3 days to Cis and Cis+Se groups. Cis+Se group received selenium 5 days before cisplatin injection and continued for 11 consecutive days. Hearing thresholds and lipid peroxidation (MDA) levels of the rats were recorded before injections and at the end of experimental protocol. The cochleas of animals were harvested for histologic and immunuhistochemical examinations. In biochemichal analyses, pretreatment with selenium prevented the elevation of MDA levels in Cis+Se group rats. Moreover, animals in Cis+Se group had better hearing threshold levels than animals in cis group. Samples obtained from the animals in Cis group revealed extensive loss of the normal microarchitecture of the organ of Corti. On the other hand, animals in Cis+Se group exhibited a preservation of the morphology of the organ of Corti and outer hair cells. In the immunohistochemical examinations of cochlear tissues stained with anti-caspase-3, a higher degree of immunopositivity was found in the Cis group. When Cis+Se group and Cis group were compared, significantly less immunopositivity occurred in the Cis+Se group (P < 0.05). Thus, it appears that pretreatment with selenium may reduce cisplatin-induced ototoxicity in rats.

Selenium partially prevents cisplatin-induced neurotoxicity: A preliminary study

Cisplatin is an anticancer drug and it has neurotoxic effects. On the other hand, the neuroprotective effect of selenium was observed in previous studies. However, the effect of selenium on cisplatin-induced neurotoxicity has not been studied yet. Therefore, we aimed to investigate whether selenium prevent cisplatin-induced neurotoxicity. Twenty-one male Wistar albino rats were divided into three groups: control (C), cisplatin (CS), cisplatin and selenium (CSE, n=7 in each group). Cisplatin (12mg/kg/day, i.p.) was administered for 3 days to CS and CSE groups. Also, CSE group received via oral gavage 3mg/kg/day (twice-a-day as 1.5mg/kg) selenium 5 days before of cisplatin injection and continued for 11 consecutive days. The same volumes of saline were intraperitoneally and orally administered to C group at same time. At the end of experimental protocol, electrophysiological and histopathological examinations were performed. The nerve conduction velocity, amplitude of compound action potential and number of axon of CS group were significantly lower than the C group. However, the same parameters of CSE group were significantly higher than the CS group. Although, cisplatin has a peripheral neurotoxic effect in rats, this effect was partially prevented by selenium treatment. Thus, it appears that co-administration of selenium and cisplatin may be a useful approach to decrease severity of peripheral neurotoxicity.

Effect of Concomitant Administration of a-tocopherol and ACEI on Cardiovascular Performance and Nucleic Acid Changes in DOCA Hypertensive Rats

Background: Evidence for cardiovascular oxidative stress in animals with hypertension has been accumulated. Antioxidant agents have been used to treat endothelial dysfunction and arterial hypertension. Aim: The aim of present study is to elucidate the effect of concomitant administration of α-tocopherol (antioxidant) and angiotensin converting enzyme inhibitor (ACEI; anti-hyptertensive) on cardiac smooth muscle DNA and RNA changes in DOCA induced hypertension in rats. Methods: 48 male Sprague-Dawley rats were used in this study and were divided into 6 groups (n=8): C control rats; CE control rats received α-tocopherol (60 mg/kg) intragastrically (IG); DOCA rats were made hypertensive by SC injection of DOCA (50 mg/kg once weekly for 4 weeks); DOCA+E; DOCA hypertensive rats received α-tocopherol (60 mg/kg) IG; DOCA+ACEI; DOCA hypertensive rats received ACEI (captopril; 15 mg/kg) IG; and DOCA+E+ACEI; DOCA hypertensive rats received both α-tocopherol and captopril in the same doses as DOCA+E and DOCA+ACEI groups respectively. All IG treatments were given to the animals 6 days weekly for 6 weeks. At the end of experimental protocol, systolic blood pressure (MSP), renal vascular flow velocity (RFV), renal vascular resistance (RVR), myocardial contractility (MC) and heart rate (HR) were measured in rats of all groups. Also, serum sodium (Na + ), potassium (K + ) and total plasma antioxidant capacity (TOC) were measured. DNA and RNA analysis were done for the myocardial tissue homogenate. Results: While DOCA administration in rats produced significant increase in serum Na + , MSP, RVR, and RNA levels; it reduced significantly serum K + , TOC, MC and DNA levels compared with the control group. Concomitant administration of both α-tocopherol and ACEI resulted in significant reduction of serum Na + ,