Phoenixin 14 ameloriates pancreatic injury in streptozotocin-induced diabetic rats by alleviating oxidative burden.

Phoenixin-14 (PNX) is a neuropeptide that has been shown to prevent oxidative damage and stimulates insulin secretion. We investigated the effects of PNX on pancreatic injury induced by streptozotocin (STZ), and nicotinamide (NAD). Male Sprague-Dawley rats, in control (C) and diabetic (STZ) groups, were treated with either saline, or PNX (0.45 nmol/kg, or 45 nmol/kg) daily for 3 days 1 week after STZ injection. Fasting blood glucose (FBG) and gastric emptying rate (GER) were measured. Tissue and blood samples were collected. PNX treatments prevented pancreatic damage and ß cell loss. Increased luminol and lucigenin levels in the pancreas, ileum and liver tissues of STZ groups were alleviated by PNX treatment in pancreatic and ileal tissues. PNX0.45 decreased FBG without any change in insulin blood level and pancreatic mRNA. GER increased in all diabetic rats while PNX0.45 delayed GER only in the C group. PNX diminishes pancreatic damage and lowers FBG by reducing oxidative load.

Nesfatin-1 treatment preserves antioxidant status and attenuates renal fibrosis in rats with unilateral ureteral obstruction.

BACKGROUND: Nesfatin-1 (NES-1), an anorexigenic peptide, was reported to have anti-inflammatory and anti-apoptotic actions in several inflammation models. METHODS: To elucidate potential renoprotective effects of NES-1, unilateral ureteral obstruction (UUO) was induced in male Sprague Dawley rats by ligating left ureters. The rats were injected intraperitoneally with either saline (SL) or NES-1 (10 µg/kg/day) for 7 or 14 days (n = 8 in each group). On the 7th or 14th day, obstructed kidneys were removed for the isolation of leucocytes for flow-cytometric analysis and the assessments of biochemical and histopathological changes. RESULTS: Opposite to glutathione levels, renal myeloperoxidase activity in the SL-treated UUO group was significantly increased compared with the sham-operated group, while NES-1 treatment abolished the elevation. The percentages of CD8+/CD4+ T-lymphocytes infiltrating the obstructed kidneys were increased in the SL-treated groups but treatment with NES-1 did not prevent lymphocyte infiltration. Elevated tumour necrosis factor-alpha (TNF-α) levels in SL-treated UUO group were decreased with NES-1. Although total degeneration scores were similarly increased in all UUO groups, tubular dilatation scores were significantly increased in UUO groups and lowered by NES-1 only in the 7-day treated group. Elevated interstitial fibrosis scores in the SL-treated groups were decreased in both 7- and 14-day NES-1 treated groups, while alpha-smooth muscle actin (α-SMA) and apoptosis scores were depressed in both NES-1 treated groups. CONCLUSION: The present data demonstrate that UUO-induced renal fibrosis is ameliorated by NES-1, which appears to involve the inhibition of neutrophil infiltration and thereby amelioration of oxidative stress and inflammation. These data suggest that NES-1 may have a regulatory role in protecting the kidneys against obstruction-induced renal injury.

The gastroprotective effect of obestatin on indomethacin-induced acute ulcer is mediated by a vagovagal mechanism.

In order to investigate the role of the vagus nerve in the possible gastroprotective effect of obestatin on the indomethacin-induced acute oxidative gastric injury, Sprague-Dawley rats of both sexes were injected subcutaneously with indomethacin (25 mg/kg, 5% NaHCO3) followed by obestatin (10, 30 or 100 µg/kg). In other sets of rats, surgical vagotomy (Vx) or selective degeneration of vagal afferent fibers by perivagal capsaicin was performed before the injections of indomethacin or indomethacin + obestatin (30 µg/kg). Gastric serosal blood flow was measured, and 4 h after ulcer induction gastric tissue samples were taken for histological and biochemical assays. Obestatin reduced the severity of indomethacin-induced acute ulcer via the reversal of reactive hyperemia, by inhibiting ulcer-induced neutrophil infiltration and lipid peroxidation along with the replenishment of glutathione (GSH) stores, whereas Vx abolished the inhibitory effect of obestatin on blood flow and lipid peroxidation, and worsened the severity of ulcer. On the other hand, serosal blood flow was even amplified by the selective denervation of the capsaicin-sensitive vagal afferent fibers, but obestatin-induced reduction in ulcer severity was not altered. In conclusion, the gastroprotective effect of obestatin on indomethacin-induced ulcer appears to involve the activation of the vagovagal pathway.

Protective effect of ferulic acid on cisplatin induced nephrotoxicity in rats.

This study aims to determine the potential protective effects of ferulic acid against cisplatin-induced nephrotoxicity and to compare its effect with curcumin, a well-known protective agent against cisplatin- induced toxicity in rats. Administration of cisplatin resulted in high BUN (Blood Urea Nitrogen), creatinine, MDA (Malondialdehyde), MPO (Myeloperoxidase), TOS (Total Oxidative Status), PtNT (Protein Nitrotyrosine) levels (p<0.05). Histological observations showed abnormal morphology of kidney; in addition with appearance of TUNEL positive cells indicating apoptosis in cisplatin administered group. HO-1 (Heme Oxygenase-1) levels measured by RT-PCR (Real Time Polymerase Chain Reaction), and TAS (Total Antioxidative Status) revealed antioxidant depletion due to cisplatin toxicity in animals (p<0.05). All parameters showed improvement in groups treated with ferulic acid (p<0.05). Ferulic acid treatment was found significant in preventing oxidative stress, increasing antioxidative status and regaining histological parameters to normal, indicating nephroprotective and antioxidant effects of this phenolic compound.

Functional and structural changes of the urinary bladder following spinal cord injury; treatment with alpha lipoic acid.

BACKGROUND & AIM: Alpha lipoic acid (LA) was shown to exert neuroprotection in trauma-induced spinal cord injury (SCI), which is frequently associated with urinary bladder complaints in patients with SCI. Accordingly, the protective effects of LA on biochemical and histological changes in bladder as well as functional studies were assessed. METHODS: Wistar albino rats were divided as control, SCI, and LA (50 mg/kg/day, ip) treated SCI groups (SCI+LA). The standard weight-drop (100 g/cm force at T10) method was used to induce a moderately severe SCI. One week after the injury, neurological examination was performed and the rats were decapitated. Bladder samples were taken for histological examination, functional (isolated tissue bath) studies, and for the measurement of biochemical parameters (malondialdehyde, MDA; gluthathione, GSH; nerve growth factor, NGF; caspase-3, luminol and lucigenin chemiluminescences). RESULTS: SCI caused a significant (P < 0.001) increase in the detrusor muscle thickness. It increased the contractility responses to carbachol and relaxation responses to papaverine (P < 0.05-0.001). There were also significant alterations in MDA, caspase-3, luminol, and lucigenin chemiluminescences with concomitant decreases in NGF and GSH (P < 0.05). LA treatment reversed histological and functional (contraction and relaxation responses) changes induced by SCI (P < 0.05-0.001), but no significant recovery was observed in the impaired neurological functions. CONCLUSION: These results indicate that LA have a beneficial effect in improving the bladder tonus via its antioxidant and anti-inflammatory actions following SCI.

Estrogen receptor agonists alleviate cardiac and renal oxidative injury in rats with renovascular hypertension.

Although endogenous estrogen is known to offer cardiac and vascular protection, the involvement of estrogen receptors in mediating the protective effect of estrogen on hypertension-induced cardiovascular and renal injury is not fully explained. We aimed to investigate the effects of estrogen receptor (ER) agonists on oxidative injury, cardiovascular and renal functions of rats with renovascular hypertension (RVH). Female Sprague-Dawley rats were randomly divided as control and RVH groups, and RVH groups had either ovariectomy (OVX) or sham-OVX. Sham-OVX-RVH and OVX-RVH groups received either ERß agonist diarylpropiolnitrile (1 mg/kg/day) or ERα agonist propyl pyrazole triol (1 mg/kg/day) for 6 weeks starting at the third week following the surgery. At the end of the 9(th) week, systolic blood pressures were recorded, cardiac functions were determined, and the contraction/relaxation responses of aortic rings were obtained. Serum creatinine levels, tissue malondialdehyde, glutathione, superoxide dismutase, catalase levels, and myeloperoxidase activity in heart and kidney samples were analyzed, and Na(+), K(+)-ATPase activity was measured in kidney samples. In both sham-OVX and OVX rats, both agonists reduced blood pressure and reversed the impaired contractile performance of the heart, while ERß agonist improved renal functions in both the OVX and non-OVX rats. Both agonists reduced neutrophil infiltration, lipid peroxidation, and elevated antioxidant levels in the heart, but a more ERß-mediated protective effect was observed in the kidney. Our data suggest that activation of ERß might play a role in preserving the function of the stenotic kidney and delaying the progression of renal injury, while both receptors mediate similar cardioprotective effects.

Intravesical hyaluronic acid treatment improves bacterial cystitis and reduces cystitis-induced hypercontractility in rats.

OBJECTIVE: To investigate the effect of intravesical hyaluronic acid on Escherichia coli-induced cystitis and cystitis-induced hypercontractility in rats. METHODS: Bacterial cystitis was induced in Wistar female rats by intravesical inoculation of E. coli. Isotonic saline was instilled in the control group (n = 6). The rats were either non-treated, treated with gentamycin (4 mg/kg, 5 days) or treated intravesically with hyaluronic acid (0.5 mL, 0.5%). On the eighth day, the bladder tissues were excised for histological examination, and the measurements of myeloperoxidase, superoxide dismutase and catalase activities. Contraction/relaxation responses to carbachol, isoprotrenol and papaverine were studied. RESULTS: Tissue myeloperoxidase activity was increased, but superoxide dismutase and catalase activities were decreased in bacterial cystitis, while hyaluronic acid treatment reversed these changes. In the hyaluronic acid-treated group, healing of the uroepithelium was observed, while decreased inflammatory cell infiltration was obvious in gentamycin-treated group. E. coli-induced cystitis in all rats resulted in increased contraction responses to carbachol compared with controls (P < 0.01). Treatment with hyaluronic acid, but not gentamycin, significantly (P < 0.05) depressed hypercontractility at maximum carbachol concentrations. In all rats with cystitis, papaverine-induced relaxation was increased, whereas isoproterenol-induced relaxation curves were not different between the studied groups. CONCLUSION: Gentamycin treatment, despite its ameliorative effect on inflammation, had no impact on the contractile dysfunction of the injured bladder. Intravesical hyaluronic acid, in addition to its supportive role in the healing of the epithelium, seems to lower the increased threshold for contraction and to reduce oxidative stress. These findings support a potential role for hyaluronic acid in the treatment of bacterial cystitis.

Nesfatin-1 alleviates gastric damage via direct antioxidant mechanisms.

BACKGROUND: Indomethacin is a nonsteroidal anti-inflammatory drug, which is known to produce serious side effects, causing ulcerative lesions. Nesfatin-1, a newly identified anorexigenic peptide, was recently shown to have neuroprotective effects. The aim of the study was to investigate the anti-inflammatory effects of nesfatin-1 on indomethacin-induced gastric ulcer. MATERIALS AND METHODS: After a 24-h starvation period, ulcer was induced in Sprague-Dawley rats by subcutaneous administration of indomethacin (25 mg/kg), whereas control group received vehicle. Fifteen minutes after ulcer induction, rats were treated with either saline or nesfatin-1 (0.1, 0.3, or 1 µg/kg, intraperitoneally). At the fourth hour, all rats were decapitated and their trunk blood was collected for tumor necrosis factor (TNF)-α and interleukin (IL)-6 measurements. Stomach samples were examined microscopically and analyzed for myeloperoxidase (MPO) activity, malondialdehyde (MDA), glutathione (GSH), luminol-, and lucigenin-enhanced chemiluminescence (CL) levels. RESULTS: Ulcer induction increased serum TNF-α; and IL-6 levels, gastric CL and MDA levels and MPO activity but decreased gastric GSH content (P < 0.05-0.001). On the other hand, 0.1 µg/kg dose of nesfatin-1 reduced microscopic and macroscopic damage scores, decreased MPO activity and MDA levels, CL and IL-6 levels, whereas gastric GSH was replenished (P < 0.01). However, indomethacin-induced increase in TNF-α level was abolished at only 1 µg/kg dose of nesfatin-1 (P < 0.01). CONCLUSIONS: Nesfatin-1 alleviated indomethacin-induced gastric injury, suggesting that the anti-inflammatory and gastroprotective effects of nesfatin-1 on oxidative gastric damage could be implemented by supporting the balance in oxidant and antioxidant systems while inhibiting the generation of pro-inflammatory mediators.

Protective effects of melatonin against spinal cord injury induced oxidative damage in rat kidney: A morphological and biochemical study.

Spinal cord injury (SCI) induced oxidative stress affects multiple organ systems including the kidney. We studied the possible protective effects of melatonin on SCI-induced oxidative damage in renal tissues of rats. Wistar albino rats (n = 24) were exposed to SCI and divided into vehicle- or melatonin-treated SCI groups. Melatonin was administred intraperitoneally at a dose of 10 mg/kg for seven days. Renal tissues were investigated by light and electron microscopy. Furthermore, tissue malondialdehyde (MDA) and glutathione (GSH) levels and myeloperoxidase (MPO) and superoxide dismutase (SOD) activities were also determined. In the vehicle-treated SCI group, the renal histology was disturbed compared to controls, whereas the melatonin-treated SCI group showed significantly reduced degeneration of renal tissue as seen by both light and electron microscopy. MDA levels, MPO and SOD activities were increased and GSH levels were decreased in the vehicle-treated SCI group compared to controls. On the other hand, decreased MDA levels and MPO activities and increased GSH levels were observed in the melatonin-treated SCI group compared to vehicle-treated SCI group. These results showed that experimentally induced SCI caused oxidative stress in the rat kidney, whereas melatonin treatment reduced oxidative stress, suggesting that it may be used as a complementary therapy of renal problems occurring following SCI.