Amelioration of streptozotocin-induced diabetic nephropathy by melatonin, quercetin, and resveratrol in rats

The role of oxygen radicals are known for the pathogenesis of kidney damage. The aim of the present study was to investigate the antioxidative effects of melatonin, quercetin, and resveratrol on streptozotocin (STZ)-induced diabetic nephropathy in rats. A total of 35 male Wistar rats were divided into 5 groups as follows: control, diabetes mellitus (DM), DM + melatonin, DM + quercetin, and DM + resveratrol. All the injections started on the same day of single-dose STZ injection and continued for 30 days. At the end of this period, kidneys were removed and processed for routine histological procedures. Biochemical parameters and morphological changes were examined. In DM group, blood glucose levels were significantly increased, whereas body weights were decreased compared with the control group. Significant increases in blood urea nitrogen and tissue malondialdehyde (MDA) levels and decreases in superoxide dismutase and catalase activities were detected in DM group. Administration of melatonin, quercetin, and resveratrol significantly reduced these values. Melatonin was more efficient in reducing MDA levels than other antioxidants ( p < 0.05). STZ-induced histopathological alterations including epithelial desquamation, swelling, intracytoplasmic vacuolization, brush border loss and peritubular infiltration. Additionally, basement membrane thickening and sclerotic changes were observed in glomerulus. Transforming growth factor-β1 positive cells were also increased. Melatonin, quercetin, and resveratrol significantly reduced these histopathological changes. Our results indicate that melatonin, quercetin, and resveratrol might be helpful in reducing diabetes-induced renal damage

Effect of a facemask leak on aerosol delivery from a pMDI-spacer system

The objective of this investigation was to study the relation between size and position of a mask leak on spacer output and lung dose. An upper-airway model (SAINT model, Erasmus MC) was connected to a breathing simulator. Facemasks with leaks ranging between 0 and 1.5 cm(2) were examined. Leaks were located close to the nose or close to the chin. During simulated breathing, 200 microg budesonide (Pulmicort, AstraZeneca) was delivered to the model via NebuChamber (AstraZeneca) with facemask. Spacer output and lung dose were measured by placing a filter between spacer and facemask or between model and breathing simulator, respectively. Budesonide trapped on the filter was quantified by means of HPLC, and expressed as percentage of the nominal dose. Mean spacer output doses for the nose position were 50, 38, 28, 12, 10, 6, and 0%, and for the chin position were 50, 40, 31, 11, 9, 4, and 0% for leaks of 0, 0.05, 0.1, 0.16, 0.2, 0.3, and larger than 0.4 cm(2), respectively. Mean lung doses for the nose position were 10, 8, 6, 3, 3, 1, 0, 0, 0, and 0%, and for the chin position were 10, 9, 8, 6, 6, 5, 1, 1, 0, and 0% for leaks of 0, 0.05, 0.1, 0.16, 0.2, 0.3, 0.4, 0.5, 1, and 1.5 cm(2). Efficiency of a pMDI-spacer facemask strongly depends on the size of a facemask leak. Spacer output did not depend on the position of the leak. Lung dose was higher for leaks near the chin than for leaks near the nose.

Therapeutic effects of melatonin and quercetin in improvement of hepatic steatosis in rats through supression of oxidative damage

BACKGROUND

Non-alcoholic steatohepatitis, a cause of cirrhosis, is characterized by fatty infiltration of the liver, inflammation, hepatocellular damage and fibrosis. The aim of the present study was to investigate the effects of melatonin and quercetin on CCl4-induced steatosis characterized by fatty infiltration of the liver, inflammation, hepatocellular damage and fibrosis.

METHODS

Rats were divided into 5 groups: Ethanol, Olive oil, CCl4, CCl4+Melatonin (CCl4+Mel), CCl4+Quercetin. Rats were sacrificed and livers were removed for being evaluated by histopathological, immunohistochemical and biochemical methods.

RESULTS

In CCI4 group, vacuolization, vascular congestion, haemorrhage, necrosis, and inflammatory infiltration were identified. The mean tissue MDA level was increased, whereas GSH level and SOD and CAT activities were decreased in comparison with ethanol and olive oil groups. MDA levels were decreased in CCI4+Quercetin and CCI4+Mel groups versus CCI4 group. CAT activity of CCI4+Mel group was higher than that of CCI4 and CCI4+Quercetin groups. The mean tissue GSH level of CCI4+Mel group versus CCI4 group was significantly increased.

CONCLUSIONS

By the means of histopathological examination, we suggest that both agents are beneficial against necrotic and apoptotic cell death during steatosis. Thus, melatonin and quercetin might be beneficial in the improvement of hepatic steatosis by supporting conventional therapy in humans (Tab. 1, Fig. 5, Ref. 53).

The protective effect of melatonin in lungs of newborn rats exposed to maternal nicotine

We investigated possible healing effects of melatonin (MEL) on biochemical and histological changes in the lungs of rat offspring caused by exposure to nicotine (NT) in utero. Pregnant rats were divided randomly into five groups. The SP group was treated with physiological saline. The EA group was treated with ethyl alcohol. The MEL group was treated with MEL. The NT group was treated with NT. The NT + MEL group was treated with NT and MEL. At the end of the study, the biochemistry and histopathology of lung tissue of the offspring were examined. Reduced alveolar development and increased numbers of alveolar macrophages and mast cells were observed in the NT group compared to the SP, EA and MEL groups. We also found increased malondialdehyde (MDA) levels and decreased total glutathione (GSH) levels in the NT group. Application of MEL ameliorated the histological and biochemical damage caused by NT. The number of alveoli was greater in the NT + MEL group than in the NT group. Also, the increased numbers of alveolar macrophages and mast cells resulting from exposure to NT were decreased following MEL treatment. We found that MEL caused a significant decrease in the level of MDA. Maternal exposure to NT caused significant structural and biochemical changes in the lungs of the offspring and administration of MEL ameliorated the changes.

The effects of pentoxifylline and caffeic acid phenethyl ester in the treatment of d-galactosamine-induced acute hepatitis in rats

The aim of this study was to investigate histological changes in hepatic tissue and effects of pentoxifylline (PTX) and caffeic acid phenethyl ester (CAPE) on these changes using histochemical and biochemical methods in rats, in which hepatitis was established by D-galactosamine (D-GAL). Rats were divided into five groups as follows: control group, D-GAL (24 h) group, D-GAL group, d-GAL + PTX group, and D-GAL + CAPE group. In histological evaluations, the control group showed normal appearance of the liver cells. However in the d-GAL groups, focal areas consisting of inflammatory, necrotic, and apoptotic cells were detected in parenchyma. Glycogen loss was observed in the hepatocytes localized at the periphery of lobule. It was found that number of mast cells of portal areas were significantly higher in D-GAL groups compared with other groups (p = 0.0001). In addition, the number of cells with positive staining by Ki-67 and caspase-3 were significantly increased in GAL groups compared with the control group (p = 0.0001). In biochemical analysis, there was an increase in malondialdehyde and myeloperoxidase levels, while a decrease was observed in glutathione level and glutathione peroxidase activity in groups treated with d-GAL compared with the control group. On the other hand, it was seen that, in the groups treated with D-GAL, histological and biochemical injuries in the liver were reduced by administration of PTX and CAPE. In this study, we demonstrated the ameliorative effects of PTX and CAPE on D-GAL-induced liver injury.

Combined usage of estrogen and melatonin restores bladder contractility and reduces kidney and bladder damage in ovariectomized and pinealectomized rat

OBJECTIVE

The incidence of urinary bladder disturbances and renal structural changes and functional decline are found to increase with age.

METHODS

We investigated the effect of melatonin treatment in addition to estrogen replacement therapy in pinealectomized (Px) and ovariectomized (Ovx) rats. 56 female Wistar rats were divided into seven groups, each containing eight animals: Sham, (Ovx), (Px), Px+Ovx, Px+Ovx receiving estrogen (Px+Ovx+E), Px+Ovx receiving melatonin (Px+Ovx+M) and Px+Ovx estrogen and melatonin supplemented (Px+Ovx+EM) group (EM group). We evaluated reduced glutathione (GSH) levels and malondialdehyde (MDA) levels. The mean collagen fiber (CF)/smooth muscle (SM) ratio in the bladder wall and structure of the kidney were examined histolologically. We also recorded response of the bladder contractility to acetylcholine (Ach).

RESULTS

Px and Ovx groups showed statistically significant reductions of antioxidant defenses, impaired Ach-evoked contraction, histological changes compared with the control group. Also, these changes were prominent in Px+Ovx group compared with all other groups. Both estrogen and melatonin reversed these changes however best restoration was observed in the EM group.

CONCLUSIONS

Px performed in addition to Ovx led to a distinct increase in oxidative damage in bladder and renal tissue and deteriorate of the detrussor function. Either estradiol or melatonin replacement alone or in combination prevents significant alterations of tissue histology and bladder contractility following Ovx and Px. Thus, combination treatment appears to be the best method to restore both contractility and histomorphology of bladder and kidney tissues after Ovx and Px (Tab. 3, Fig. 4, Ref. 44).

Hydrogel-Integrated Heart-on-a-Chip Platform for Assessment of Myocardial Ischemia Markers

Organ-on-a-chip platform scans offer a controllable environment and a physiological similarity to mimic human pathophysiology. In this study, a single-channel PDMS microchip was fabricated, characterized, and optimized to obtain a heart-on-a-chip platform, which is integrated with a hydrogel scaffold suitable for cardiomyocyte growth inside its channel. Single-channel chips with a size of 20 × 12 mm and a channel height ranging from 60 to 100 μm were produced using photolithography and soft lithography techniques. A gelatin-embedded alginate network-based hydrogel was further augmented with 3% (v/v) collagen type I. Pore sizes were in the range of 74-153 μm for H9C2 implantation and biomimicry. The hydrogels are characterized both on PDMS surfaces and in capillaries. The primary feature distinguishing this study from previous microchip studies is that it mimics the cell microenvironment much better using different hydrogel formulations instead of creating a 2D cell culture by passing fluids, such as fibronectin, for cell adhesion. Instead of using complex microchip designs, the chip system we created intends to provide a physiologically relevant copy by using a 3D cell culture to its advantage and a simple, single-channel architecture. The microchip study was combined with cardiomyocytes to create the heart-on-a-chip system and tested under normoxic and hypoxic conditions to create a myocardial ischemia model inside this channel. As a result, this heart-on-a-chip platform was shown to be utilized for the detection of several small-size biomarkers such as adenosine, ADP, lactic acid, l-isoleucine, l-glutamic acid, and oxidized glutathione via LC-MS/MS from control conditions and a myocardial ischemia model. Cell-embedded and hydrogel matrix-supported versions of this heart-on-a-chip system were successfully prepared and shown to provide powerful outputs with myocardial ischemia markers. In light of this research, these outputs aim to develop simple and biologically effective organ-on-a-chip systems for future research.

Modulation of DMBA-induced biochemical changes by organoselenium compounds in blood of rats

The protective role of two synthetic organoselenium compounds 1-isopropyl-3-methylbenzimidazole-2-selenone (SeI) and 1, 3-di-p-methoxybenzylpyrimidine-2-selenone (Sell) was examined against the 7,12-dimethylbenz[a]anthracene (DMBA)-induced changes in biochemical parameters in blood of rats. Albino Winstar rats (150-200 g body wt) were treated with single dose of DMBA (50 mg/kg body wt) and organoselenium compounds (25 micromol/kg) for 4 weeks at two days internal. Blood was taken from the anaesthetized rats ventricle from their hearts for biochemical analysis. Administration of DMBA resulted in elevation of urea, uric acid and creatinine levels as well as AST, ALT and LDH activities and decrease in levels of total proteins, albumin and globulin. SeI and SeII caused a significant (p<0.05) decrease in urea, uric acid and creatinine levels and alanine aminotransferase (ALT); aspartate aminotransferase; (AST) and lactate dehydrogenase (LDH) activities and significantly increased the levels of total protein and albumin (p<0.05). These organoselenium compounds are likely to be beneficial in human health.