Effect of grape seed extract on puromycin-aminonucleoside-induced nephrosis in rats

Renoprotective potential of Macrothelypteris torresiana via ameliorating oxidative stress and proinflammatory cytokines

ETHNOPHARMACOLOGICAL RELEVANCE

Macrothelypteris torresiana is traditionally used in Chinese folk medicine for the treatment of edema for patients suffering from kidney/bladder problems due to its satisfactory therapeutic effectiveness.

AIM OF THE STUDY

The aim of this study was to investigate the renoprotective nature of the total polyphenols fraction from Macrothelypteris torresiana (PMT).

MATERIALS AND METHODS

The biochemical criterions of plasma and kidney tissues were evaluated to study the effects of PMT on puromycin aminonucleoside-induced chronic nephrotic syndrome (NS) in hyperlipidemic mice.

RESULTS

In this study, the NS and hyperlipidemia were ameliorated after 9 weeks administration of PMT. Besides, PMT was able to modulate the level of renal oxidative stress and vascular endothelial growth factor-nitric oxide (VEGF-NO) pathway.

CONCLUSIONS

It represented a potential resource of PMT for the treatment of NS involved in metabolic syndrome.

Grape seed extract treatment reduces hepatic ischemia-reperfusion injury in rats

This study was designed to determine the possible protective effect of grape seed extract (GSE), a widely used antioxidant dietary supplement, on hepatic ischemia/reperfusion (I/R) injury. Wistar albino rats were subjected to 45 min of hepatic ischemia, followed by a 60 min reperfusion period. GSE was administered in a dose of 50 mg/kg/day orally for 15 days before I/R injury and repeated before the reperfusion period. Liver samples were taken for histological examination or determination of hepatic malondialdehyde (MDA), glutathione (GSH) and myeloperoxidase (MPO) activity. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were determined to assess liver functions. Lactate dehydrogenase (LDH) and cytokines (TNF-alpha and IL-1 beta) were also assayed in serum samples for the evaluation of generalized tissue damage. Ischemia/reperfusion caused a significant decrease in hepatic GSH, and significant increases in MDA level, and MPO activity. Serum AST and ALT levels, as well as LDH activity and plasma TNF-alpha and IL-1beta levels were also elevated in the I/R group. Treatment with GSE reversed all these biochemical parameters as well as histological alterations induced by I/R. In conclusion, GSE reduced I/R-induced organ injury through its ability to balance the oxidant-antioxidant status, to inhibit neutrophil infiltration and to regulate the release of inflammatory mediators.

Grape seed extract reduces oxidative stress and fibrosis in experimental biliary obstruction

BACKGROUND AND AIM

The aim of this study was to assess the protective effect of grape seed extract (GSE) against oxidative liver injury and fibrosis induced by biliary obstruction in rats.

METHODS

Wistar albino rats were divided into four groups; control (C), GSE-treated, bile duct ligated (BDL), and BDL and GSE-treated (BDL + GSE) groups. GSE was administered at a dose of 50 mg/kg a day orally for 28 days. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) levels were determined to assess liver function and tissue damage, respectively. Tumor necrosis factor-alpha (TNF-alpha) and antioxidant capacity (AOC) were assayed in plasma samples. Liver tissues were taken for determination of the hepatic malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity and collagen content. Production of reactive oxidants was monitored by chemiluminescence (CL) assay.

RESULTS

Serum AST, ALT, LDH and plasma TNF-alpha were elevated in the BDL group as compared to the control group and were significantly decreased with GSE treatment. Plasma AOC and hepatic GSH level, depressed by BDL, was elevated back to the control level in the GSE-treated BDL group. Increases in tissue MDA level, MPO activity and collagen content due to BDL were also attenuated by GSE treatment. Furthermore, luminol and lucigenin CL values in the BDL group increased dramatically compared to the control and were reduced by GSE treatment.

DISCUSSION

These results suggest that GSE protects the liver from oxidative damage following bile duct ligation in rats. This effect possibly involves the inhibition of neutrophil infiltration and lipid peroxidation; thus, restoration of oxidant and antioxidant status in the tissue.

Antioxidant capacity of 55 medicinal herbs traditionally used to treat the urinary system: a comparison using a sequential three-solvent extraction process

BACKGROUND

The prevalence of chronic renal disease exceeds 10% in industrialized societies. Oxidative damage is thought to be one of the main mechanisms involved in nearly all chronic renal pathologies.

OBJECTIVE

We aimed to use the oxygen radical absorbance capacity (ORAC) method and a sequential multisolvent extraction process to compare the in vitro antioxidant capacity of 55 medicinal herbs and prioritize them for in vivo studies investigating the value of herbal therapies in the treatment of renal disorders.

METHODS

The herbs were chosen on the basis of their traditional use in kidney or urinary system disorders, or because they have attracted the attention of recent investigations into renal pathologies. The three solvents used for extraction were ethyl acetate, methanol, and 50% aqueous methanol. Silybum marianum (milk thistle) seed and Camellia sinensis (tea) leaf, both known to possess high antioxidant capacity, were included for comparison.

RESULTS

Twelve of the 55 herbs were comparable to or exceeded ORAC levels of milk thistle seed or tea leaf. The highest radical-scavenging activity was found in Olea europaea (olive leaf), Cimicifuga racemosa (black cohosh), Rheum palmatum (rhubarb), Glycyrrhiza glabra (licorice), and Scutellaria lateriflora (Virginia skullcap).

CONCLUSIONS

The antioxidant capacity of many of the herbs studied may, at least in part, be responsible for their reputation as being protective of organs of the urinary system. Overall, the combined ORAC values for the methanol and aqueous methanol extracts comprised 84% of the total ORAC value. Sequential extraction with solvents of different polarities may be necessary to fully extract the antioxidant principles from medicinal plants.

Comparison of proanthocyanidins in commercial antioxidants: grape seed and pine bark extracts

The major constituents in grape seed and pine bark extracts are proanthocyanidins. To evaluate material available to consumers, select lots were analyzed using high-performance liquid chromatography, gas chromatography/mass spectrometry (GC/MS), liquid chromatography/mass spectrometry (LC/MS), gel permeation chromatography (GPC), and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Atmospheric pressure chemical ionization (APCI) LC/MS was used to identify monomers, dimers, and trimers present. GC/MS analyses led to the identification of ethyl esters of hexadecanoic acid, linoleic acid, and oleic acid, as well as smaller phenolic and terpene components. The GPC molecular weight (MW) distribution indicated components ranging from approximately 162 to approximately 5500 MW (pine bark less than 1180 MW and grape seed approximately 1180 to approximately 5000 MW). MALDI-TOF MS analyses showed that pine bark did not contain oligomers with odd numbers of gallate units and grape seed contained oligomers with both odd and even numbers of gallate. Reflectron MALDI-TOF MS identified oligomers up to a pentamer and heptamer, and linear MALDI-TOF MS showed a mass range nearly double that of reflectron analyses.

Puromycin aminonucleoside induces oxidant-dependent DNA damage in podocytes in vitro and in vivo

A decline in podocyte number correlates with progression to glomerulosclerosis. A mechanism underlying reduced podocyte number is the podocyte's relative inability to proliferate in response to injury. Injury by the podocyte toxin puromycin aminonucleoside (PA) is mediated via reactive oxygen species (ROS). The precise role of ROS in the pathogenesis of PA-induced glomerulosclerosis remains to be determined. We sought to examine whether PA-induced ROS caused podocyte DNA damage, possibly accounting for the podocyte's inability to proliferate in response to PA. In vitro, podocytes were exposed to PA, with or without the radical scavenger 1,3-dimethyl-2-thiourea (DMTU). In vivo, male Sprague-Dawley rats were divided into experimental groups (n = 6/group/time point): PA, PA with DMTU, and control, killed at days 1.5, 3, or 7. DNA damage was measured by DNA precipitation, apurinic/apyrimidinic site, Comet, and 8-hydroxydeoxyguanosine assays. Cell cycle checkpoint protein upregulation (by immunostaining and Western blotting), histopathology, and biochemical parameters were examined. DNA damage was increased in cultured podocytes that received PA, but not PA with DMTU. PA exposure activated specific cell cycle checkpoint proteins, with attenuation by DMTU. DNA repair enzymes were activated, providing evidence for attempted DNA repair. The PA-treated animals developed worse proteinuria and histopathologic disease and exhibited more DNA damage than the DMTU pretreated group. No significant apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling staining. A mechanism underlying the lack of podocyte proliferation following PA-induced injury in vitro and in vivo may be ROS-mediated DNA damage, with upregulation of specific cell cycle checkpoints leading to cell cycle arrest.

Grape Seed Extract Prevents Gentamicin-Induced Nephrotoxicity and Genotoxicity in Bone Marrow Cells of Mice

The protection conferred by grape seed extract against gentamicin-induced nephrotoxicity and bone marrow chromosomal aberrations have been evaluated in adult Swiss albino mice. The activity of reduced glutathione peroxidase (GSH peroxidase), the levels of glutathione (GSH) and lipid peroxidation as malondialdehyde (MDA) in the kidneys homogenates, serum urea and creatinine were measured, and in addition the changes in kidney histology and bone marrow chromosomes were investigated. Gentamicin (80 mg/kg b.wt. intraperitoneally for 2 weeks) induced kidney damage as indicated from a pronounced changes in kidney histology, a significant increase in serum urea and creatinine and MDA content in the kidney homogenate. While the activity of the antioxidant enzyme GSH peroxidase and the level of GSH were significantly decreased. Gentamicin induced genotoxicity indicated by increased the number of aberrant cells and different types of structural chromosomal aberrations (fragment, deletion and ring chromosome) and showed no effect on mitotic activity of the cell. Pretreatment with grape seed extract (7 days) and simultaneously (14 days) with gentamicin significantly protected the kidney tissue by ameliorating its antioxidant activity. Moreover, grape seed extract significantly protected bone marrow chromosomes from gentamicin induced genotoxicity by reducing the total number of aberrant cells, and different types of structural chromosomal aberrations. It could be concluded that grape seed extract acts as a potent antioxidant prevented kidney damage and genotoxicity of bone marrow cells.

Grape seed extract suppresses lipid peroxidation and reduces hypoxic ischemic brain injury in neonatal rats

Oxygen radicals play a crucial role in brain injury. Grape seed extract is a potent anti-oxidant. Does grape seed extract reduce brain injury in the rat pup? Seven-day-old rat pups had the right carotid arteries permanently ligated followed by 2.5 h of hypoxia (8% oxygen). Grape seed extract, 50 mg/kg, or vehicle was administered by i.p. 5 min prior to hypoxia and 4 h after reoxygenation and twice daily for 1 day. Brain damage was evaluated by weight deficit of the right hemisphere at 22 days following hypoxia and by histopathology. Grape seed extract reduced brain weight loss from 20.0+/-4.4% S.E.M. in vehicle pups (n=21) to 3.1+/-1.6% in treated pups (n=20, P<0.01). Grape seed extract improved the histopathologic brain score in cortex, hippocampus and thalamus (P<0.05 versus vehicle). Concentrations of brain 8-isoprostaglandin F2alpha and thiobarbituric acid reacting substances significantly increased due to hypoxic ischemia. Grape seed extract reduced this increase. Treatment with grape seed extract suppresses lipid peroxidation and reduces hypoxic ischemic brain injury in neonatal rat.