Obestatin alleviates subarachnoid haemorrhage-induced oxidative injury in rats via its anti-apoptotic and antioxidant effects

Impact of Fennel Essential Oil as an Antibiotic Alternative in Rabbit Diet on Antioxidant Enzymes Levels, Growth Performance, and Meat Quality

In the current study, fennel essential oil was used as an antibiotic alternative compared to gentamycin for enhancing the expression of apoptosis genes and antioxidant enzymes in weaned rabbits as well as meat quality and growth performance. The gene expression of the cell lymphoma 2 (BAX and BCL2), caspase3 (CASP3), and glutathione peroxidase (GPX1) were estimated in the liver tissue using qRT-PCR. A total of 45 Moshtohor weaned male rabbits aged four weeks were randomly allocated to control, T1, and T2 treatment groups; each consisted of 15 weaned male rabbits with five replicates. Rabbits in the T1 and T2 groups were orally supplied with 1 mL fennel oil and 1 mL gentamycin, respectively. Weaned rabbits under different treatments showed increased body weight (BW) at 8 and 12 weeks of age and average daily gain (ADG) at 4-8 and 4-12 weeks of age compared to the control group. Compared to the controls, the weaned rabbits supplemented with fennel oil and gentamycin had lower total cholesterol, triglyceride, and MDA. In addition, villus length, mRNA of BAX, BCL2, Casp3, and GPX were increased in the different treatments compared to the control. Furthermore, the meat of these rabbits was less tender, had a lower aerobic plate count (APC), pH, and was brighter and redder in color than the control. Under the conditions of the present study, the supplementation of weaned Moshtohor rabbits with fennel oil as a natural alternative for gentamycin enhanced feed conversion and daily gain through enhancing villus length and mucus thickness. Additionally, fennel essential oil reduces oxidative stress by increasing the antioxidant enzymes.

Clinical Prognosis for SAH Consistent with Redox Imbalance and Lipid Peroxidation

Subarachnoid hemorrhage (SAH) accounts for 3% of all strokes. As more and more data indicates the role of oxidative stress in acute brain damage caused by SAH, an attempt was made to correlate the clinical status of patients with systemic level of antioxidants and lipid peroxidation products. The hemorrhage was diagnosed with brain computed tomography (CT) and aneurysm with angio-CT and angiography, while the vasospasm was monitored with transcranial Doppler. Plasma glutathione peroxidase activity (GSH-Px) and vitamin A, E, and C levels were determined spectrophotometrically and by HPLC, respectively. The levels of polyunsaturated fatty acids (PUFAs) cyclization products were determined by GC–MS, while F₂-isoprostanes and neuroprostanes (NP) were determined by LC–MS. SAH was accompanied by changes in antioxidant capacity in blood plasma, including initially (day 1) an increase in GSH-Px activity, followed by its decrease and a progressive decrease in glutathione (GSH) levels and vitamins A, E, and C. On the other hand, levels of PUFAs cyclization products, F₂-isoprostanes, and neuroprostanes were highest on day 1 (two and eight times higher, respectively) and decreased over time. The levels of 4-HNE (4-hydroxynonenal), 4-ONE (4-oxononenal), and MDA (malondialdehyde) changed similarly. In contrast, the 4-HHE (4-hydroxyhexenal) level reduced after SAH increased significantly after a week. It was found that the deterioration of the overall clinical and neurological condition of SAH patients due to cerebral edema, intracranial hemorrhage, or vasoconstriction corresponded to reduced antioxidant defense and, as a consequence, increased lipid peroxidation and slower observed changes in regression. It can be concluded that monitoring the level of lipid peroxidation products (neuroprostanes, 4-ONE, and MDA) can support the monitoring of the clinical status of patients, especially with regard to the assessment of vasospasm.

Efficacy of two adjuvant systems to promote humoral immunity to the pre-proghrelin peptide obestatin in pigs: consequences for the growth of piglets to weaning

The poor antigenicity of peptide antigens demands the selection of effective adjuvants to induce humoral immunity. The peptides obestatin and ghrelin from the pro-hormone pre-proghrelin were initially identified as antagonistic in regulating feeding behaviour, with obestatin being suppressive. The efficacy of two adjuvant systems, DEAE with the oil polysorbate emulsion of BP85:Span80 and the surfactant-oil system Montanide (ISA 50v) were therefore assessed with an obestatin-ovalbumin conjugate injected into late pregnant sows. This enabled the supply of antibodies directed against obestatin to newborn piglets through colostrum with the objective of promoting ghrelin secretion and therefore increasing feeding behaviour. Pregnant Landrace × Large White sows (n = 28) were immunised with 0.5 mg obestatin-ovalbumin in 2 mL DEAE:BP85:Span80 (DEAE; n = 14) or with 2 mL Montanide (ISA 50v: n = 14) as adjuvants at days 91 and 105 of gestation. After farrowing, piglets remained with their mothers during the lactation period and were weighed after weaning at Day 28. Antibody titres (unitless) in colostrum were assessed by ELISA as 5543 ± 2388 and 3139 ± 1151 for the DEAE and Montanide adjuvants respectively. These were associated with total IgG of 67.7 ± 3 and 82.3 ± 4.8 mg/mL respectively (P = 0.018). Piglet plasma titres were 5100 ± 1576 and 5762 ± 1688 for DEAE and Montanide respectively at Day 5 postpartum. These titres were still detectable through to Day 28 (titres of 1213 ± 389 and 665 ± 203 respectively (P = 0.176). However, sow colostral antibody titres were not related to piglet antibody concentrations on D5 (r = –0.225, P = 0.341). Sow plasma antibody titres were not related to titres at Day 28 in piglets across treatments (r = 0.198, P = 0.402). The concentration of ghrelin in colostrum was 672 ± 78 and 666 ± 39 pg/mL for the DEAE and Montanide groups, respectively, leading to piglet plasma concentrations on Day 5 of 1105 ± 164 and 530 ± 84 pg/mL (P = 0.002). Animals grew from birthweights of 1.7 ± 0.1 and 1.8 ± 0.1 (P = 0.993) to 7.7 ± 1.2 and 7.8 ± 1.0 kg (P = 0.295) at weaning, representing growth rates of 200.5 ± 52.9 and 225.5 ± 53.4 g/day (P = 0.181). There was a significant negative correlation between piglet D28 antibody titre and growth rate to weaning with the Montanide adjuvant (r = 0.116, P = 0.035) but not for the DEAE (r = –0.118, P = 0.411). Although both adjuvants were capable of generating high antibody titres, the DEAE dextran was likely to be the most effective adjuvant to induce a humoral immune response to develop further with a commercial vaccine.

Obestatin inhibits apoptosis and astrogliosis of hippocampal neurons following global cerebral ischemia reperfusion via antioxidant and anti-inflammatory mechanisms

Objective(s):

Obestatin is a newly discovered peptide with antioxidant activities in different animal models. Recent studies have shown that Obestatin inhibits apoptosis following cardiac ischemia/reperfusion injury. Brain ischemia/reperfusion induces irreversible damage especially in the hippocampus area. This study aimed at examining the protective impact of Obestatin on apoptosis, protein expression and reactive astrogliosis level in hippocampal CA1 region of rat following transient global cerebral ischemia.

Materials and Methods:

Forty-eight male Wistar rats were randomly assigned into 4 groups (sham, ischemia/reperfusion, ischemia/reperfusion+ Obestatin 1, and 5 µg/kg, n=12). Ischemia induced occlusion of both common carotid arteries for 20 min. Obestatin 1 and 5 µg/kg were injected intraperitoneally at the beginning of reperfusion period and 24 and 48 hr after reperfusion. Assessment of the antioxidant enzymes and tumor necrosis factor alpha (TNF-α) was performed by ELISA method. Caspase-3 and glial fibrillary acidic protein (GFAP) proteins expression levels were evaluated by immunohistochemical staining 7 days after ischemia.

Results:

Based on the result of the current study, lower superoxide dismutase (SOD) and glutathione (GSH) (P<0.05) and higher malondialdehyde (MDA) and TNF-α levels were observed in the ischemia group than those of the sham group (P<0.01). Obestatin treatment could increase both SOD and GSH (P<0.05) and reduce MDA and TNF-α (P<0.05) versus the ischemia group. Moreover, obestatin could significantly decrease caspase-3 and GFAP positive cells in the CA1 region of hippocampus (P<0.01).

Conclusion:

Obestatin exerts protective effects against ischemia injury by inhibition of astrocytes activation and decreases neuronal cell apoptosis via its antioxidant properties.

Obestatin improve spatial memory impairment in a rat model of fetal alcohol spectrum disorders via inhibiting apoptosis and neuroinflammation

Clinical and experimental evidence have demonstrated that, use of alcohol during pregnancy can interrupt brain development. Alcohol-induced neurocognitive deficits in offspring's are involved with activation of oxidative-inflammatory cascade joined with extensive apoptotic neurodegeneration in different brain regions such as hippocampus. Obestatin is a newly discovered peptide with anti-inflammatory, antioxidant, activities in different animal models. In this study, we aimed to evaluate the protective effects of obestatin on alcohol-induced neuronal apoptosis and neuroinflammation in rat pups with postnatal ethanol exposure. Through intragastric intubation, ethanol (5/27 g/kg/day) was administered in male Wistar rat pups on postnatal days 2-10 (third trimester in humans). The animals received Obestatin (1 and 5 μg/kg, S.C.) on postnatal days 2-10. Thirty-six days after birth, the spatial memory test was performed using Morris water maze test, and then, antioxidant enzymes and TNF-α levels were measured by ELISA assay. The expression level of GFAP and caspase-3 proteins was determined via immunohistochemical staining after the behavioral test. Obestatin significantly improved spatial memory deficits (P < .01), and obestatin treatment could significantly increase glutathione and total superoxide dismutase activity (P < .05), reduce level of malondialdehyde (P < .05) and TNF-α in comparison with the ethanol group (P < .01). It's also reduced caspase-3 level, and decreased GFAP-positive cells in the hippocampus of ethanol-exposed rat pups (P < .01). The result of this study shows the potential involvement of oxidative-inflammatory cascade-mediated apoptotic signaling in cognitive deficits due to postnatal ethanol exposure, the results also indicated the neuroprotective effects of Obestatin on alcohol-related behavioral, biochemical and molecular deficits.

Expression of caspase-3, Bax and Bcl-2 in hippocampus of rats with diabetes and subarachnoid hemorrhage

The expression of caspase-3, Bax and Bcl-2 in hippocampus of rats with diabetes and subarachnoid hemorrhage (SAH) were investigated. Diabetes mellitus model was established by intraperitoneal injection of STZ. On the basis of diabetes mellitus model, SAH animal model was established by injecting fresh autologous femoral artery blood into cerebellomedullary cisten. Rats were divided into blank control group, diabetes control group and diabetes + SAH group. TUNEL method was used to detect cell apoptosis of hippocampus. Expression levels of caspase-3, Bax and Bcl-2 were detected by real-time quantitative reverse transcription PCR and western blot analysis at mRNA and protein levels, respectively. Apoptotic cells were not detected in blank control group and diabetes group, and number of apoptotic cells was the highest in the diabetic SAH group. Expression levels of caspase-3, Bax and Bcl-2 mRNA and protein were significantly higher in diabetes + SAH group than in blank control group and diabetes group. In conclusion, Hippocampal neuron apoptosis was induced by diabetes + SAH and expression levels of caspase-3, Bax and Bcl-2 were also increased. Our study provided experimental basis for further studies of the relationship between SAH and cell apoptosis.

Obestatin improves oxidative brain damage and memory dysfunction in rats induced with an epileptic seizure

Obestatin was shown to alleviate renal, gastrointestinal and haemorrhage-induced brain injury in rats. In order to investigate the neuroprotective effects of obestatin on seizure-induced oxidative brain injury, an epileptic seizure was induced with a single intraperitoneal (i.p.) dose of pentylenetetrazole (PTZ, 45mg/kg) in male Wistar rats. Thirty minutes before the PTZ injection, rats were treated with either saline or obestatin (1μg/kg, i.p.). Seizure was video-taped and then evaluated by using Racine's scoring (0-5). For the assessment of memory function, passive-avoidance test was performed before seizure induction, which was repeated on the 3rd day of seizure. The rats were decapitated at the 24th or 72nd hour of seizures and brain tissues were obtained for histopathological examination and for measuring levels of malondialdehyde (MDA), glutathione (GSH), reactive oxygen radicals and myeloperoxidase (MPO) activity. Obestatin treatment reduced the average seizure score, decreased the occurrence and duration of generalized tonic-clonic seizures, presenting with a shorter latency to their onset. Increased lipid peroxidation and enhanced generation of oxygen-derived radicals detected at the post-seizure 72nd h were suppressed by the consecutive treatments of obestatin, but no changes were observed by the single obestatin treatment in the 24-h seizure group. Neuronal damage and increased GFAP immunoreactivity, observed in the hippocampal areas and cortex of PTZ-induced rats were alleviated in 3-day obestatin-treated PTZ group. PTZ-induced memory dysfunction was significantly improved in obestatin-treated PTZ group as compared to saline-treated rats. The present data indicate that obestatin ameliorated the severity of PTZ-induced seizures, improved memory dysfunction and reduced neuronal damage by limiting oxidative damage.

Protective effect 3,4-dihydroxyphenylethanol in subarachnoid hemorrhage provoked oxidative neuropathy

Clinical studies have indicated that early brain injury (EBI) following subarachnoid hemorrhage (SAH) is associated with fatal outcomes. Oxidative stress and brain edema are the characteristic pathological events in occurrence EBI following SAH. The present study aimed to examine the effect of 3,4-dihydroxyphenylethanol (DOPET) against SAH-induced EBI, and to demonstrate whether the effect is associated with its potent free radical scavenging property. SAH was induced in rats using an endovascular perforation technique, and 24 h later the rats displayed diminished neurological scores and brain edema. Furthermore, elevated malondialdehyde (an index of lipid peroxidation) and depleted levels of antioxidants were observed in the rat cerebral cortex tissue. Quantitative polymerase chain reaction analysis indicated the upregulated mRNA expression of the apoptotic markers caspase-3 and -9 in the cerebral cortex. Furthermore, the protein expression levels of the proinflammatory cytokines tumor necrosis factor-α, interleukin (IL)-1β and IL-6 were significantly upregulated in SAH-induced rats. By constrast, treatment with DOPET significantly attenuated EBI by reducing brain edema, elevation of antioxidant status, inhibition of apoptosis and inflammation. In this context, DOPET may be a potent agent in the treatment of EBI following SAH, as a result of its free radical scavenging capacity.

Obestatin promotes proliferation and survival of adult hippocampal progenitors and reduces amyloid-β-induced toxicity

The ghrelin gene-derived peptide obestatin promotes survival in different cell types through a yet undefined receptor; however, its potential neuroprotective activities are still unknown. Here, obestatin effects were investigated on proliferation and survival of adult rat hippocampal progenitor cells (AHPs). Obestatin immunoreactivity was found in AHPs; moreover, obestatin binding to AHPs was displaced by the GLP-1R agonist Ex-4 and antagonist Ex-9. Furthermore, obestatin increased cell proliferation and survival in growth factor deprived medium and inhibited apoptosis; these effects were blocked by Ex-9. The underlying mechanisms involved Gαs/cAMP/PKA/CREB signaling, phosphorylation of ERK1/2 and PI3K/Akt, and the PI3K targets GSK-3β/β-catenin and mTOR. Obestatin also counteracted Aβ1-42-induced detrimental effects through inhibition of GSK-3β activity and Tau hyperphosphorylation, main hallmarks of neuronal death in Alzheimer's disease. These findings indicate a novel protective role for obestatin in AHPs and candidate this peptide as potential therapeutic target for increasing neurogenesis and for approaching neurodegenerative disorders.

Treatment with either obestatin or ghrelin attenuates mesenteric ischemia-reperfusion-induced oxidative injury of the ileum and the remote organ lung

To evaluate the effects of exogenous ghrelin or obestatin on intestinal injury and accompanying pulmonary injury, intestinal ischemia-reperfusion (I/R) was induced in rats by obstructing the superior mesenteric artery for 60min, whereas laparotomy was performed in the sham group. At the beginning of the 90-min reperfusion period, the rats were injected with obestatin (100μg/kg), ghrelin (10ng/kg), or saline intravenously (iv). At the end of reperfusion, the blood, ileum, and lung samples were taken for the histological and biochemical assays. In the saline-treated I/R group, the increased serum interleukin (IL)-1β level, high damage scores, and elevated tissue malondialdehyde level and collagen content in both tissues were significantly reduced by obestatin or ghrelin. Increased ileal myeloperoxidase activity of the saline-treated I/R group was reduced by treatment with obestatin or ghrelin, whereas increased pulmonary myeloperoxidase activity was reduced with administration of obestatin. Increased DNA fragmentation in the ileum of the saline-treated I/R group was reduced by both peptides. Elevated luminol-lucigenin chemiluminescence levels and nuclear factor kappa B (NF-κB) messenger RNA (mRNA) expression in the ileum of the saline-treated-I/R group were significantly decreased by obestatin or ghrelin treatment. I/R-induced depletion of the antioxidant glutathione in both ileal and pulmonary tissues was prevented with either obestatin or ghrelin treatment. Administration of either obestatin or ghrelin exerts similar protective effects against I/R-induced ileal and pulmonary injury, thus warranting further investigation for their possible use against ischemic intestinal injury.

Tacrolimus and mycophenolate mofetil associations

Gastrointestinal risk factors after organ transplantation are prevalent, due to the chronic use of immunosuppressant. The immunosuppressive drugs such as tacrolimus/mycophenolate mofetil (TAC/MMF) association are the most commonly used therapy. TAC and MMF have been implicated in gastrotoxicity, but their direct effects, alone and combined, on intestinal cells are not completely elucidated. This study investigated the effect of TAC and MMF alone and combined on human colon carcinoma cells. Our results demonstrated that TAC and MMF individually inhibit clearly cells proliferation, enhanced free radicals, lipid peroxidation production, induced DNA lesions and reduced mitochondrial membrane potential. In this study, we also showed that the two molecules TAC and MMF combined at high concentrations amplified the cell damage. Furthermore, the TAC (5 µM) prevented cell death induced by MMF (half maximal inhibitory concentration (IC50)). Also, MMF (50 µM) induced cytoprotection in HCT116 cells against TAC (IC50) toxicity. Our findings provide additional evidence that oxidative damage is the major contribution of TAC and MMF combined toxicities. In fact, MMF and TAC exert a gastroprotective effect by modulating reactive oxygen species production. These data underscore the pleiotropic effect of TAC and MMF on HCT116 cells that play a preventive and critical role on intestinal function.

Obestatin improves ischemia/reperfusion-induced renal injury in rats via its antioxidant and anti-apoptotic effects: role of the nitric oxide

Obestatin was shown to have anti-inflammatory effects in several inflammatory models. To elucidate the potential renoprotective effects of obestatin, renal I/R injury was induced in male Sprague Dawley rats by placing a clamp across left renal artery for 60min following a right nephrectomy. Clamp was released and the rats were injected with either saline or obestatin (10, 30, 100μg/kg). In some experiments, obestatin (10μg/kg) was administered with L-NAME (10mg/kg) or L-Nil (0.36mg/kg). Following a 24-h reperfusion, the rats were decapitated to measure serum creatinine and nitrite/nitrate levels, renal malondialdehyde (MDA), glutathione (GSH) levels and myeloperoxidase (MPO) activity and to assess cortical necrosis and apoptosis scores. Obestatin treatment reduced I/R-induced increase in creatinine levels, renal MPO activity and renal MDA levels, while renal GSH levels were significantly increased by obestatin. Histological analysis revealed that severe I/R injury and high apoptosis score in the kidney samples of saline-treated rats were significantly reduced and the cortical/medullary injury was ameliorated by obestatin. Expression of eNOS, which was increased by I/R injury, was further increased by obestatin, while serum NO levels were significantly decreased. iNOS inhibitor L-Nil reduced oxidative renal damage and improved the functional and histopathological parameters. I/R-induced elevation in eNOS expression, which was further increased by obestatin, was depressed by L-NAME and L-Nil treatments. The present data demonstrate that obestatin ameliorates renal I/R-injury by its possible anti-oxidative, anti-inflammatory and anti-apoptotic properties, which appear to involve the suppression of neutrophil accumulation and modulation of NO metabolism.

The protective effects of tacrolimus on rat uteri exposed to ischemia-reperfusion injury: a biochemical and histopathologic evaluation

OBJECTIVE

To evaluate the effects of the immunosuppressant tacrolimus as an antioxidant and analyze the histopathologic changes in rat uteri exposed to experimental ischemia-reperfusion (I/R) injury.

DESIGN

Experimental study.

SETTING

Experimental surgery laboratory in a university.

ANIMAL(S)

Twenty-eight female rats exposed to experimentally induced uterine I/R injury.

INTERVENTION(S)

Group I: control group; group II: uterine I/R injury-induced group; group III: pre-ischemia tacrolimus group; group IV: post-ischemia tacrolimus group.

MAIN OUTCOME MEASURE(S)

Uterine tissue malondialdehyde (MDA) level as a marker of lipid peroxidation and glutathione (GSH) level and superoxide dismutase (SOD) and catalase (CAT) activities as markers of tissue antioxidant capacity; histopathologic examination of all uterine rat tissue.

RESULT(S)

Following aortic I/R injury, MDA levels were significantly increased whereas GSH levels and CAT and SOD activities were found to be decreased compared with control animals. MDA levels were found to recover prominently after the administration of tacrolimus in both groups III and IV. Administration of tacrolimus improved uterine GSH levels and CAT activity in the tacrolimus-treated groups.

CONCLUSION(S)

Our results indicate that tacrolimus reduces oxidative damage in rat uteri exposed to I/R injury induced by distal abdominal aortic occlusion. Histologic evaluation reveals that tacrolimus attenuates the inflammatory response and protects the tissue damage induced by I/R injury.

Obestatin: a new metabolic player in the pancreas and white adipose tissue

Obestatin is a 23 amino acid amidated peptide, member of the preproghrelin gene-derived peptides. Initially, obestatin was reported to exert opposite effects to those of ghrelin on food intake and body weight gain, through interaction with GPR39; however, these findings are still strongly debated and obestatin biological role remains largely unknown. Interestingly, binding of obestatin to the glucagon-like peptide 1 receptor has been recently suggested. Despite being a controversial peptide, recent findings have clearly indicated that obestatin is indeed a multifunctional peptide, exerting a variety of effects, such as stimulation of cell proliferation, survival and differentiation, influence on glucose and lipid metabolism, as well as anti-inflammatory and cardioprotective actions. Its positive effects on glucose and lipid metabolism candidate this peptide as a potential therapeutic tool in pathological conditions such as insulin resistance and diabetes.