Resveratrol, a polyphenolic phytoalexin protects against cyclosporine-induced nephrotoxicity through nitric oxide dependent mechanism

Natural Reno-Protective Agents against Cyclosporine A-Induced Nephrotoxicity: An Overview

CA (cyclosporine A) is a powerful immunosuppressing agent that is commonly utilized for treating various autoimmune illnesses and in transplantation surgery. However, its usage has been significantly restricted because of its unwanted effects, including nephrotoxicity. The pathophysiology of CA-induced kidney injury involves inflammation, apoptosis, tubular injury, oxidative stress, and vascular injury. Despite the fact that exact mechanism accountable for CA's effects is inadequately understood, ROS (reactive oxygen species) involvement has been widely proposed. At present, there are no efficient methods or drugs for treating CA-caused kidney damage. It is noteworthy that diverse natural products have been investigated both in vivo and in-vitro for their possible preventive potential in CA-produced nephrotoxicity. Various extracts and natural metabolites have been found to possess a remarkable potential for restoring CA-produced renal damage and oxidative stress alterations via their anti-apoptosis, anti-inflammatory, and antioxidative potentials. The present article reviews the reported studies that assess the protective capacity of natural products, as well as dietary regimens, in relation to CA-induced nephrotoxicity. Thus, the present study presents novel ideas for designing and developing more efficient prophylactic or remedial strategies versus CA passive influences.

Resveratrol and lycopene ameliorate contrast-induced nephropathy in a rabbit model

Oxidative stress appears to possess a central role in CIN pathophysiology. Resveratrol (Res) and lycopene (Lyc) are strong natural antioxidants evaluated in a limited number of CIN animal studies in vivo. The aim of the study was to evaluate the potential renoprotective effects of Res/Lyc in a CIN rabbit model. Twenty-four adult male New Zealand white rabbits were equally assigned into four groups: control (saline), CIN (intravenous iopromide; 7.5 g iodine/kg), Res + CIN (per os Res; 5 mg/kg), and Lyc + CIN (per os Lyc; 4 mg/kg). Serum Cr (sCr); symmetric/asymmetric dimethylarginine (SDMA/ADMA); oxidative stress biomarkers: malondialdehyde; total antioxidant capacity; catalase; glutathione) were evaluated in blood samples at three time points: right after (0 h); 24 h; 48 h after iopromide/saline administration. CD20⁺/CD3⁺ lymphocytes were determined (48 h). All animals were sacrificed at 48 h and both kidneys collected. Oxidative stress biomarkers were measured in renal tissue. sCr and SDMA/ADMA levels increased significantly in CIN compared to all groups. Oxidative stress secondary to CIN in blood/kidneys was suppressed by Res/Lyc. B and T lymphocytes decreased significantly in CIN compared to all groups. The present study provides emerging evidence that Res/Lyc ameliorate CIN by modulating oxidant/antioxidant balance in blood/renal tissue and by inhibiting vasoconstriction/blood cytotoxicity.

Polyphenols and Novel Insights Into Post-kidney Transplant Complications and Cardiovascular Disease: A Narrative Review

Kidney transplantation is the preferred treatment for end-stage kidney disease. It is, however, not devoid of complications. Delayed graft function related to ischemia-reperfusion injury (IRI), calcineurin inhibitor (CNI) nephrotoxicity, diabetes, and a particularly high-rate cardiovascular disease (CVD) risk, represent important complications following kidney transplantation. Oxidative stress and chronic low-grade inflammation are mechanisms of disease incompletely abrogated in stable kidney transplant recipient (KTR), contributing to the occurrence of these complications. Polyphenols, bioactive compounds with recognized antioxidant and anti-inflammatory properties have been strongly associated with prevention of CVD in the general population and have been shown to decrease IRI and antagonize CNI nephrotoxicity in animal experimental models, therefore they may have a role in prevention of complications in KTR. This narrative review aims to summarize and discuss current evidence on different polyphenols for prevention of complications, particularly prevention of CVD in KTR, pointing toward the need of further studies with potential clinical impact.

The protective effect of resveratrol against cyclosporine A-induced oxidative stress and hepatotoxicity

The immunosuppressive agent cyclosporine A (CsA) has hepatotoxic potential. Increased reactive oxygen species (ROS) formation is among the causes leading to hepatotoxicity. This study aimed to investigate the effect of resveratrol (RES) on CsA-induced oxidative stress and hepatotoxicity in rats. Rats were treated with RES (10 mg/kg/day; i.p.) for 14 days. CsA (25 mg/kg/day; s.c.) was given during the last seven days together with RES. Serum alanine aminotransferase and aspartate aminotransferase activities together with hepatic histopathological examinations were performed. ROS, thiobarbituric acid reactive substances (TBARS), advanced oxidation protein products (AOPPs), ferric reducing antioxidant power, and glutathione levels as well as superoxide dismutase, and glutathione peroxidase activities were measured in the liver tissue. RES ameliorated histopathological changes and decreased hepatic ROS, TBARS, and AOPP levels significantly. However, antioxidant parameters did not change in CsA-treated rats. Our results indicate that RES treatment may be effective in decreasing CsA-induced oxidative stress and hepatotoxicity.

Novel Chalcone BDD-39 Mitigated Diabetic Nephropathy through the Activation of Nrf2/ARE Signaling

BACKGROUND

In this study, we investigated the Nrf2/ARE signaling pathway activating capacity of Biphenyl Diester Derivative-39 (BDD-39) in diabetic nephropathy in order to elucidate the mechanism surrounding its antidiabetic potential.

OBJECTIVES

Protein expressions of Nrf2, HO-1, NQO-1 and biomarkers of kidney fibrosis were executed after which mRNA levels of Nrf2, HO-1 and NQO-1 were estimated after creating the models following BBD-39 treatment.

METHODS

Type 2 diabetes model was established in mice with high-fat diet feeding combined with streptozocin intraperitoneal administration. The diabetic mice were then treated with BDD-39 (15, 45mg· kg-1· d-1, ig) or a positive control drug resveratrol (45mg· kg-1·d-1, ig) for 8 weeks. Staining techniques were used to investigate collagen deposition in the glomerulus of the renal cortex and also to investigate the expression and localization of Nrf2 and extracellular matrix (ECM) proteins (collagen IV and laminin) in vitro and in vivo. Furthermore, we studied the mechanism of action of BDD-39 using RNA-mediated Nrf2 silencing technique in mouse SV40 glomerular mesangial cells (SV40 GM cells).

RESULTS

We found that BDD-39 activates Nrf2/ARE signaling pathway, promotes Nrf2 nuclear translocation (Nrf2nuc/Nrf2cyt) and modulate prominent biomarkers of kidney fibrosis at the protein level. However, BDD-39 could not activate Nrf2/ARE signaling in RNA-mediated Nrf2-silenced HG-cultured SV40 GM cells.

CONCLUSION

Taken together, this study demonstrates for the first time that BDD-39 ameliorates experimental DN through attenuation of renal fibrosis progression and modulation of Nrf2/ARE signaling pathway.

Herbal antioxidants in dialysis patients: a review of potential mechanisms and medical implications

The consumption of exogenous antioxidants isolated from herbal extracts has shown beneficial effects on ameliorating dialysis-related complications through debilitating oxidative stress and inflammatory process. Many clinical studies available in public databases have reported the improved consequences of dialysis in patients supplemented with herbal antioxidants. Exploration of such data offers great possibilities for gaining insights into the potential mechanisms and medical implications of herbal antioxidants. In this work, the mechanisms and implications of some famous bioactive substances including silymarin, curcumin, resveratrol, emodin, and quercetin on the consequences of dialysis in chronic kidney disease (CKD) patients were explored. The protective features of silymarin are due to the flavonoid complex silybin. Curcumin is an active element from the root of curcuma longa with extensive beneficial properties, including antioxidant, anti-inflammatory activity, and inhibitory effects on cell apoptosis. Resveratrol can reduce the oxidative stress by neutralization of free radicals. Emodin is known as a natural anthraquinone derivative isolated from Chinese herbs. Finally, quercetin has been reported to exhibit several properties including antioxidant, anti-diabetic, analgesic, antihistaminic, antiviral, cholesterol reducer, and renal hemodynamic modulator. However, potential mechanisms and medical implications of the aforementioned herbal antioxidants seem to be more complicated, that is, more studies are required in this field.

Paradoxical Effect of Grape Pomace Extract on Cisplatin-Induced Acute Kidney Injury in Rats

Cisplatin is one of the most used drugs in the therapy of different types of cancer. However, its use is limited by nephrotoxicity. This study investigated the effects of a commercially available grape pomace extract (GE) from Vitis vinifera on cisplatin-induced kidney toxicity in rats. Sixty-four male Wistar albino rats were randomly divided into eight groups. Groups 1–3 were controls, receiving 0.9% saline and doses 1 and 2 of GE respectively. Cisplatin was given to groups 4–8. Two groups received pretreatment with GE, while another two groups received pre- and post-treatment with GE. Blood samples were collected and all animals sacrificed. Kidneys were harvested for histopathological analysis. GE significantly increased blood creatinine and urea levels, the severity of kidney histopathological damage, and mortality in all cisplatin groups, except for group 7 which received pre- and post-treatment with a low dose of GE. Renal toxicity was determined by mortality and severe histopathological renal lesions. Additionally, the serum total antioxidant capacity (TAC) was not significantly modified in the treated groups compared to the control. These results indicate that the GE did not have a protective effect on cisplatin-induced nephrotoxicity; on the contrary, GE accentuated the toxic effect of cisplatin.

Resveratrol ameliorates the cyclosporine-induced vascular and renal impairments: possible impact of the modulation of renin–angiotensin system

Cyclosporine, an immunosuppressive drug, exhibits a toxic effect on renal and vascular systems. The present study investigated whether resveratrol treatment alleviates renal and vascular injury induced by cyclosporine. Cyclosporine (25 mg/kg per day, s.c.) was given for 7 days to rats either alone or in combination with resveratrol (10 mg/kg per day, i.p.). Relaxation and contraction responses of aorta were examined. Serum levels of blood urea nitrogen, creatinine, angiotensin II, and angiotensin 1-7 were measured. Histopathological examinations as well as immunostaining for 4-hydroxynonenal and nitrotyrosine were performed in the kidney. RNA expressions of renin–angiotensin system components were also measured in renal and aortic tissues. Cyclosporine decreased the endothelium-dependent relaxation and increased vascular contraction in the aorta. It caused renal tubular degeneration and increased immunostaining for 4-hydroxynonenal, an oxidative stress marker. Cyclosporine also caused upregulations of the vasoconstrictive renin–angiotensin system components in renal (angiotensin-converting enzyme) and aortic (angiotensin II type 1 receptor) tissues. Resveratrol co-treatment prevented the cyclosporine-related deteriorations. Moreover, it induced the expressions of vasodilatory effective angiotensin-converting enzyme 2 and angiotensin II type 2 receptor in aorta and kidney, respectively. We conclude that resveratrol may be effective in preventing cyclosporine-induced renal tubular degeneration and vascular dysfunction at least in part by modulating the renin–angiotensin system.

Recovery Of Bone And Muscle Mass In Patients With Chronic Kidney Disease And Iron Overload On Hemodialysis And Taking Combined Supplementation With Curcumin And Resveratrol

Introduction

Malnutrition is common in haemodialysis patients and closely related to morbidity and mortality. We evaluated the effect of twelve weeks of supplementation with resveratrol and curcumin on recovery of bone and muscle mass and protein oxidation, lipid peroxidation on patients with chronic kidney disease and iron overload undergoing hemodialysis, we performed a randomized, double-blind, placebo-controlled trial.

Methods

We included a total of 40 patients, were randomly assigned to two groups, 20 to the group with antioxidant supplementation (Resveratrol + Curcumin) (Group A), treated with a daily oral dose of 500 mg of Resveratrol and 500 mg of Curcumin, and 20 to the control group treated with placebo (Group B).

Results

Significant differences were found in the body composition of the patients between both groups. There was a significant difference in Body Mass Index (BMI) values (p = 0.002), fat percentage (p = 0.007), muscle mass (p = 0.01) bone mass (p = 0.01), as well as in the score of the subjective global evaluation (p = 0.03). Also differences were found between the basal and final serum levels of Triglycerides (TG) (p = 0.01), VLDL (p = 0.003). A significant decrease in the levels of serum ferritin (2003.69 ± 518.73 vs 1795.65 ± 519.00 ng/mL; p = 0.04). Nor were significant differences observed between the baseline and the final Thiobarbituric Acid Reactive Substances (TBARS) values (70.45 ± 69.21 vs 50.19 ± 32.62, p = 0.24). The same results was obtained for carbonyl values (2.67 ± 0.75 vs 2.50 ± 0.85; p = 0.50).

Discussion

The present study is the first assay on patients with chronic kidney disease and iron overload that demonstrates the beneficial effects of combined supplementation with Curcumin and Resveratrol on muscle and bone mass. There was a significant decrease in circulating levels of ferritin, to finding that remarkably novel.

Antioxidant Supplementation in Renal Replacement Therapy Patients: Is There Evidence?

The disruption of balance between production of reactive oxygen species and antioxidant systems in favor of the oxidants is termed oxidative stress (OS). To counteract the damaging effects of prooxidant free radicals, all aerobic organisms have antioxidant defense mechanisms that are aimed at neutralizing the circulating oxidants and repair the resulting injuries. Antioxidants are either endogenous (the natural defense mechanisms produced by the human body) or exogenous, found in supplements and foods. OS is present at the early stages of chronic kidney disease, augments progressively with renal function deterioration, and is further exacerbated by renal replacement therapy. End-stage renal disease patients, on hemodialysis (HD) or peritoneal dialysis (PD), suffer from accelerated OS, which has been associated with increased risk for mortality and cardiovascular disease. During HD sessions, the bioincompatibility of dialyzers and dialysate trigger activation of white blood cells and formation of free radicals, while a significant loss of antioxidants is also present. In PD, the bioincompatibility of solutions, including high osmolality, elevated lactate levels, low pH, and accumulation of advanced glycation end-products trigger formation of prooxidants, while there is significant loss of vitamins in the ultrafiltrate. A number of exogenous antioxidants have been suggested to ameliorate OS in dialysis patients. Vitamins B, C, D, and E, coenzyme Q10, L-carnitine, a-lipoic acid, curcumin, green tea, flavonoids, polyphenols, omega-3 polyunsaturated fatty acids, statins, trace elements, and N-acetylcysteine have been studied as exogenous antioxidant supplements in both PD and HD patients.

Allicin ameliorates kidney function and urinary bladder sensitivity in cyclosporine A-treated rats

Cyclosporine-A (CsA) is an immunosuppressive drug which has been used to prevent rejection after organ transplantation and to treat certain autoimmune diseases. However, its therapeutic use is limited by nephrotoxicity. In this study, the modulator effect of allicin on the oxidative nephrotoxicity of CsA in rats was investigated. Furthermore, the effect of allicin on CsA-induced hypersensitivity of urinary bladder rings to acetylcholine (ACh) was estimated. Rats were divided into three groups, control, CsA (15 mg/kg, subcutaneously), and CsA/allicin (50 mg/kg, orally). At the end of the study, all rats were killed and then blood, urine samples, and kidneys were taken. CsA administration caused a severe nephrotoxicity which was evidenced by elevated kidney/body weight ratio, serum creatinine (Cr), blood urea nitrogen, lactate dehydrogenase, and urinary protein with a concomitant reduction in serum albumin and Cr clearance as compared with control. A significant increase in renal contents of malondialdehyde, myeloperoxidase, and tumor necrosis factor-alpha with a significant decrease in renal reduced glutathione, superoxide dismutase activities, and nitric oxide (NOx) content was detected upon CsA administration. Exposure to CsA increased the sensitivity of isolated urinary bladder rings to ACh. Histological analysis revealed that CsA caused tubular necrosis and moderate diffuse tubular atrophy. Allicin protected kidney tissue against the oxidative damage and the nephrotoxic effect of CsA and significantly reduced the responses of isolated bladder rings to ACh. Our study indicates that allicin administration has the potential to protect against CsA-induced renal injury by reducing oxidative stress and inflammation and restoring NOx level.

Oxidant Mechanisms in Renal Injury and Disease

SIGNIFICANCE

A common link between all forms of acute and chronic kidney injuries, regardless of species, is enhanced generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS) during injury/disease progression. While low levels of ROS and RNS are required for prosurvival signaling, cell proliferation and growth, and vasoreactivity regulation, an imbalance of ROS and RNS generation and elimination leads to inflammation, cell death, tissue damage, and disease/injury progression.

RECENT ADVANCES

Many aspects of renal oxidative stress still require investigation, including clarification of the mechanisms which prompt ROS/RNS generation and subsequent renal damage. However, we currently have a basic understanding of the major features of oxidative stress pathology and its link to kidney injury/disease, which this review summarizes.

CRITICAL ISSUES

The review summarizes the critical sources of oxidative stress in the kidney during injury/disease, including generation of ROS and RNS from mitochondria, NADPH oxidase, and inducible nitric oxide synthase. The review next summarizes the renal antioxidant systems that protect against oxidative stress, including superoxide dismutase and catalase, the glutathione and thioredoxin systems, and others. Next, we describe how oxidative stress affects kidney function and promotes damage in every nephron segment, including the renal vessels, glomeruli, and tubules.

FUTURE DIRECTIONS

Despite the limited success associated with the application of antioxidants for treatment of kidney injury/disease thus far, preventing the generation and accumulation of ROS and RNS provides an ideal target for potential therapeutic treatments. The review discusses the shortcomings of antioxidant treatments previously used and the potential promise of new ones. Antioxid. Redox Signal. 25, 119-146.

High-mobility group box 1 is a novel deacetylation target of Sirtuin1

High mobility group box 1 (HMGB1) undergoes acetylation, nuclear-to-cytoplasmic translocation and release from stressed kidneys, unleashing a signaling cascade of events leading to systemic inflammation. Here we tested whether the deacetylase activity of Sirtuin1 (SIRT1) participates in regulating nuclear retention of HMGB1 to ultimately modulate damage signaling initiated by HMGB1 secretion during stress. When immunoprecipitated acetylated HMGB1 was incubated with SIRT1, HMGB1 acetylation decreased by 57%. Proteomic analysis showed that SIRT1 deacetylates HMGB1 at four lysine residues (55, 88, 90 and 177) within the pro-inflammatory and nuclear localization signal domains of HMGB1. Genetic ablation or pharmacological inhibition of SIRT1 in endothelial cells increased HMGB1 acetylation and translocation. In vivo, deletion of SIRT1 reduced nuclear HMGB1 while increasing its acetylation and release into circulation during basal and ischemic conditions causing increased renal damage. Conversely, resveratrol pretreatment led to decreased HMGB1 acetylation, its nuclear retention, decreased systemic release and reduced tubular damage. Thus, a vicious cycle is set into motion in which the inflammation-induced repression of SIRT1 disables deacetylation of HMGB1, facilitates its nuclear-to-cytoplasmic translocation and systemic release, thereby maintaining inflammation.

Cyclosporine and herbal supplement interactions

Cyclosporine (CyA) is a well-known immunosuppressant with a narrow therapeutic window. Its bioavailability is affected by many other traditional drugs and herbal extracts. Cytochrome P-450 isoenzymes CYP3A4 and CYP3A5 and protein P-glycoprotein (P-gp) are involved in CyA bioavailability. Interactions of CyA with herbal extracts are not well known, but, given their increased concomitant use, it is important to know which extracts, many of which are commonly self-prescribed, can affect CyA blood concentrations. Decreased CyA blood concentration has been shown with St John's wort in case reports and, in vivo animal studies, with ginger, liquorice, scutellariae radix, and quercetin. Increased CyA concentration has been reported in patients with grapefruit juice, chamomile, or berberine, and with cannabidiol or resveratrol in animal studies. Effects of Echinacea and Serenoa repens on CyA levels have not been shown consistently, but concomitant use should be avoided. Although findings from animal studies cannot be directly translated into humans, avoiding concomitant use of herbal extracts is prudent until human clinical studies have ruled out any possible interaction. Clinicians should interview their patients carefully about their use of herbal supplements before CyA administration, and those receiving CyA should be warned about possible interactions between herbal preparations and CyA.

Renal protective effects of resveratrol

Resveratrol (3,5,4′-trihydroxystilbene), a natural polyphenolic compound found in grapes and red wine, is reported to have beneficial effects on cardiovascular diseases, including renal diseases. These beneficial effects are thought to be due to this compound's antioxidative properties: resveratrol is known to be a robust scavenger of reactive oxygen species (ROS). In addition to scavenging ROS, resveratrol may have numerous protective effects against age-related disorders, including renal diseases, through the activation of SIRT1. SIRT1, an NAD⁺-dependent deacetylase, was identified as one of the molecules through which calorie restriction extends the lifespan or delays age-related diseases, and this protein may regulate multiple cellular functions, including apoptosis, mitochondrial biogenesis, inflammation, glucose/lipid metabolism, autophagy, and adaptations to cellular stress, through the deacetylation of target proteins. Previous reports have shown that resveratrol can ameliorate several types of renal injury, such as diabetic nephropathy, drug-induced injury, aldosterone-induced injury, ischemia-reperfusion injury, sepsis-related injury, and unilateral ureteral obstruction, in animal models through its antioxidant effect or SIRT1 activation. Therefore, resveratrol may be a useful supplemental treatment for preventing renal injury.

Sildenafil protects against nitric oxide deficiency-related nephrotoxicity in cyclosporine A treated rats

Cyclosporine A (CsA) is the most widely used immunosuppressant in organ transplant surgery and in treatment of autoimmune disease. Nevertheless, animal and clinical studies have demonstrated that nephrotoxicity is the major adverse effect limiting the prolonged CsA therapeutic use. The present study aimed to investigate possible protective effect of sildenafil, a phoshodiestrase-5 inhibitor, on CsA-induced nephrotoxicity and various mechanism(s) underlies this effect. Male Wistar rats were administered CsA (20 mg/kg/day, s.c.) for 21 days alone or in combination with sildenafil (5 mg/kg/day, p.o.). Sildenafil exhibited nephroprotective effects as evidenced by significant decrease in serum creatinine and urea levels, spot urine albumin-creatinine ratio, as well as renal level of malondialdehyde, with a concurrent increase in renal levels of reduced glutathione and nitric oxide along with catalase activity compared to CsA-treated rats. [corrected]. Additionally, immunohistochemical analysis demonstrated that sildenafil treatment markedly reduced inducible nitric oxide synthase, tumor necrosis factor-alpha, and caspase-3 expressions, while expression of endothelial nitric oxide synthase was prominently enhanced. The protective effects of sildenafil were confirmed by renal histopathological examination. Pretreatment with l-nitro-arginine methyl ester (10 mg/kg/day, i.p.), a non-selective nitric oxide synthase inhibitor, reversed the protection afforded by sildenafil. Taken together, the current study highlighted the renoprotective effects of sildenafil against CsA-induced nephrotoxicity in rats, which might be mediated, in part, through nitric oxide pathway as well as antioxidant, anti-inflammatory, and anti-apoptotic activities.

Dendrobium moniliforme Attenuates High-Fat Diet-Induced Renal Damage in Mice through the Regulation of Lipid-Induced Oxidative Stress

Obesity is an important and preventable risk factor for renal disease. The administration of an antioxidant with a lipid-lowering effect is an important therapeutic approach for kidney disease in obese patients. The present study was conducted to examine whether methanolic extract of Dendrobium moniliforme (DM), one of the most famous traditional medicines used in many parts of the world, has an antioxidant effect in vitro and an ameliorative effect on high-fat diet (HFD)-induced alterations such as renal dysfunction and lipid accumulation in vivo. The 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity of DM extract (IC50 = 29.6 μg/mL) was increased in a dose-dependent manner. The LLC-PK1 kidney cell damage induced by oxidative stress was significantly inhibited by the treatments with DM extract. In the animal study, DM extract (200 mg/kg) was orally administered every day for nine weeks to HFD-fed mice, and its effect was compared with that of metformin. The administration of DM extract decreased the elevated serum glucose, total cholesterol concentration and renal lipid accumulation in HFD-fed mice. It also ameliorated renal dysfunction biomarkers including serum creatinine and renal collagen IV deposition. Taken together, these results provide important evidence that DM extract exhibits a pleiotropic effect on obesity induced parameters and exerted a renoprotective effect in HFD-fed mice.

Grape seed and skin extract mitigates garlic-induced oxidative stress in rat liver

Garlic is a commonly used spice in folk medicine that can exert adverse health effects when given at a high dose. Grape seed and skin extract (GSSE) exhibits a variety of beneficial effects even at a high dose. In the present study we evaluated the toxicity of high-dose garlic treatment on liver and the protective effect of GSSE. Rats were intraperitoneally administered either with garlic extract (5 g·(kg body weight)–1) or GSSE (500 mg·(kg body weight)–1) or a combination of garlic and GSSE at the same doses daily for 1 month. Plasma and hepatic levels of cholesterol, triacylglycerol, and transaminases and liver antioxidant status were evaluated. Data showed that a high garlic dose induced liver toxicity and a pro-oxidative status characterized by increased malondialdehyde and decreased antioxidant enzyme activities as catalase, peroxidase, and superoxide dismutase. Garlic increased intracellular H2O2but decreased free iron and Ca2+. GSSE alone or in co-treatment with garlic had the reverse effect and counteracted almost all garlic-induced deleterious impacts to near control levels. In conclusion, a high garlic dose induced a pro-oxidative state characterized by the Fenton reaction between H2O2and free iron, inducing Ca2+depletion, while GSSE exerted antioxidant properties and Ca2+repletion.

Cosupplementation with a synthetic, lipid-soluble polyphenol and vitamin C inhibits oxidative damage and improves vascular function yet does not inhibit acute renal injury in an animal model of rhabdomyolysis

We investigated whether cosupplementation with synthetic tetra-tert-butyl bisphenol (BP) and vitamin C (Vit C) ameliorated oxidative stress and acute kidney injury (AKI) in an animal model of acute rhabdomyolysis (RM). Rats were divided into groups: Sham and Control (normal chow), and BP (receiving 0.12% w/w BP in the diet; 4 weeks) with or without Vit C (100mg/kg ascorbate in PBS ip at 72, 48, and 24h before RM induction). All animals (except the Sham) were treated with 50% v/v glycerol/PBS (6 mL/kg injected into the hind leg) to induce RM. After 24h, urine, plasma, kidneys, and aortae were harvested. Lipid oxidation (assessed as cholesteryl ester hydroperoxides and hydroxides and F(2)-isoprostanes accumulation) increased in the kidney and plasma and this was coupled with decreased aortic levels of cyclic guanylylmonophosphate (cGMP). In renal tissues, RM stimulated glutathione peroxidase (GPx)-4, superoxide dismutase (SOD)-1/2 and nuclear factor kappa-beta (NFκβ) gene expression and promoted AKI as judged by formation of tubular casts, damaged epithelia, and increased urinary levels of total protein, kidney-injury molecule-1 (KIM-1), and clusterin. Supplementation with BP±Vit C inhibited the two indices of lipid oxidation, down-regulated GPx-4, SOD1/2, and NF-κβ gene responses and restored aortic cGMP, yet renal dysfunction and altered kidney morphology persisted. By contrast, supplementation with Vit C alone inhibited oxidative stress and diminished cast formation and proteinuria, while other plasma and urinary markers of AKI remained elevated. These data indicate that lipid- and water-soluble antioxidants may differ in terms of their therapeutic impact on RM-induced renal dysfunction.

Evaluation of renal protective effects of the green-tea (EGCG) and red grape resveratrol: role of oxidative stress and inflammatory cytokines

Epigallocatechin-gallate (EGCG) and resveratrol (RSVL) are two of the most promising natural medicines. We verified their capacity to ameliorate cisplatin (CP)-induced disruption of renal glomerular filtration rate (GFR) in rats, and sought the mediatory involvement of lipid peroxidation (malondialdehyde [MDA]-level) and inflammatory cytokine (TNF-α) therein. CP (10 mg kg⁻¹), a single i.p. dose, disrupted GFR (11-fold-rise in proteinuria, 2-5-fold rise in serum creatinine/urea levels) after 7 days, and killed all animals after 10 days. Kidney-homogenates from CP-treated rats displayed higher MDA and TNF-α, but lower reduced-glutathione (GSH) levels. Rats treated with EGCG (50 mg kg⁻¹, but not 25 mg kg⁻¹) had no fatalities and showed significantly-recovered GFR; while their kidney-homogenates had markedly reduced MDA, TNF-α and enhanced GSH levels at 7 days. Conversely, RSVL or quercetin (25, 50 mg kg⁻¹) neither improved GFR nor reduced (MDA)/TNF-α levels after 7 days. Resuming treatment with 50 mg kg⁻¹ for 10 days rescued only 25% of animals (p > 0.05). Correlation studies showed a significant association between creatinine level, and each of MDA (r = 0.91), GSH (r = -0.87), and TNF-α (0.91). The study showed for the first time that EGCG, unlike RSVL, can protect against CP-induced nephrotoxicity. At the molecular level, CP triggers a high level of oxidative stress and systemic inflammation, events that were all abrogated with EGCG; better than RSVL or quercetin.

Cardioprotective effect of resveratrol on lipopolysaccharide-induced oxidative stress in rat

Lipopolysaccharide (LPS) is a glycolipid component of the cell wall of Gram-negative bacteria, which induces a deleterious effect on several organs, including the heart, eventually leading to septic shock and death. Endotoxemia-induced cardiotoxicity is characterized by disturbed intracellular redox balance, excessive reactive oxygen species (ROS) accumulation, inducing DNA, protein, and membrane lipid damage. Resveratrol (trans-3,5,4' trihydroxystilbene; RVT) is a phytoalexin polyphenol that exhibits antioxidant and -inflammatory properties. We investigated the putative effect of a subacute treatment with this natural compound on LPS-induced cardiotoxicity in the rat. We found that resveratrol counteracted LPS-induced lipoperoxidation and decreased superoxide dismutase (SOD) activity, but had no effect on the LPS-induced decrease in catalase (CAT) nor on the increase in peroxidase (POD) activity. Resveratrol also reversed LPS-induced myocardial nitric oxide (NO) elevation. More important, LPS-induced iron depletion from plasma to the myocardial compartment was abolished upon resveratrol treatment. All these data suggest that resveratrol is capable of alleviating LPS-induced cardiotoxicity, and that its mode of action may involve iron-shuttling proteins.

Toxicodynamic effects of ciclosporin are reflected by metabolite profiles in the urine of healthy individuals after a single dose

WHAT IS ALREADY KNOWN ABOUT THE SUBJECT * Ciclosporin's nephrotoxicity initially targets the proximal tubule and is, at least in part, driven by increased formation of oxygen radicals. * (1)H-nuclear magnetic resonance spectroscopy (NMR)- and mass spectrometry (MS)-based biochemical profiling (metabolomics) allows for the sensitive detection of metabolite pattern changes in urine. * In systematic studies in rats we showed that ciclosporin caused urine metabolite pattern changes typical for proximal tubule damage and that these pattern changes seemed to be more sensitive than established clinical kidney function markers such as serum creatinine concentrations. WHAT THIS PAPER ADDS * This study showed that urine metabolite pattern changes as assessed by (1)H-NMR and HPLC-MS are sensitive enough to detect the effect of ciclosporin as early as 4 h after a single oral dose. * In our previous rat studies, changes in urine metabolite pattern in response to ciclosporin translated into healthy humans, indicating the involvement of the same toxicodynamic mechanisms. * The results provide proof of concept for further development of this combination molecular marker strategy into diagnostic tools for the detection and monitoring of drug nephrotoxicity. AIMS The immunosuppressant ciclosporin is an efficient prophylaxis against transplant organ rejection but its clinical use is limited by its nephrotoxicity. Our previous systematic studies in the rat indicated urine metabolite pattern changes to be sensitive indicators of the negative effects of ciclosporin on the kidney. To translate these results, we conducted an open label, placebo-controlled, crossover study assessing the time-dependent toxicodynamic effects of a single oral ciclosporin dose (5 mg kg(-1)) on the kidney in 13 healthy individuals. METHODS In plasma and urine samples, ciclosporin and 15-F(2t)-isoprostane concentrations were assessed using HPLC-MS and metabolite profiles using (1)H-NMR spectroscopy. RESULTS The maximum ciclosporin concentrations were 1489 +/- 425 ng ml(-1) (blood) and 2629 +/- 1308 ng ml(-1) (urine). The increase in urinary 15-F(2t)-isoprostane observed 4 h after administration of ciclosporin indicated an increase in oxidative stress. 15-F(2t)-isoprostane concentrations were on average 2.9-fold higher after ciclosporin than after placebo (59.8 +/- 31.2 vs. 20.9 +/- 19.9 pg mg(-1) creatinine, P < 0.02). While there were no conclusive changes in plasma 15-F(2t)-isoprostane concentrations or metabolite patterns, non-targeted metabolome analysis using principal components analysis and partial least square fit analysis revealed significant changes in urine metabolites typically associated with negative effects on proximal tubule cells. The major metabolites that differed between the 4 h urine samples after ciclosporin and placebo were citrate, hippurate, lactate, TMAO, creatinine and phenylalanine. CONCLUSION Changes in urine metabolite patterns as a molecular marker are sufficiently sensitive for the detection of the negative effects of ciclosporin on the kidney after a single oral dose.

Protective effect of resveratrol against lipopolysaccharide-induced oxidative stress in rat brain

PRIMARY OBJECTIVE

To study the protective effect of resveratrol on endotoxemia-induced neurotoxicity.

METHODS

Rats were pre-treated during 7 days with 20 mg kg(-1) body weight (b.w.) resveratrol and challenged with a single dose of lipopolysaccharide (LPS: 8 mg kg(-1) b.w.) for 24 hours. Brains were harvested to determine LPS-induced lipoperoxidation level, antioxidant enzyme activities, nitric monoxide (NO) and iron distribution as well as the impact of resveratrol on these parameters.

RESULTS

Resveratrol counteracted LPS-induced brain malondialdehyde (MDA) level and antioxidant enzyme activities depletion as superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD). Resveratrol also reversed LPS-induced brain and plasma NO elevation as well as iron sequestration from plasma to brain compartment.

CONCLUSION

The data suggest that resveratrol is capable of alleviating LPS-induced neurotoxicity by a mechanism that may involve iron shuttling proteins.

Resveratrol, a red wine polyphenol, attenuates lipopolysaccharide-induced oxidative stress in rat liver

Lipopolysaccharide (LPS) is a glycolipid component of the cell wall of gram-negative bacteria inducing deleterious effects on several organs including the liver and eventually leading to septic shock and death. Endotoxemia-induced hepatotoxicity is characterized by disturbed intracellular redox balance, excessive reactive oxygen species (ROS) accumulation inducing DNA, proteins and membrane lipid damages. Resveratrol (trans-3,5,4' trihydroxystilbene) is a phytoalexin polyphenol exhibiting antioxidant and anti-inflammatory properties. In this study, we investigated the effect of subacute pre-treatment with this natural compound on LPS-induced hepatotoxicity in rat. Resveratrol counteracted LPS-induced lipoperoxidation and depletion of antioxidant enzyme activities as superoxide dismutase (SOD) and catalase (CAT) but slightly glutathione peroxidase (GPx) activity. The polyphenol also abrogated LPS-induced liver and plasma nitric oxide (NO) elevation and attenuated endotoxemia-induced hepatic tissue injury. Importantly resveratrol treatment abolished LPS-induced iron sequestration from plasma to liver compartment. Our data suggest that resveratrol is capable of alleviating LPS-induced hepatotoxicity and that its mode of action may involve differential iron compartmentalization via iron shuttling proteins.

Prevention of lipopolysaccharide-induced mouse lethality by resveratrol

The present study was undertaken to determine whether subacute treatment with resveratrol (RVT) protects mice against lipopolysaccharide (LPS)-induced oxidative stress and mortality as well as the mechanism involved in such protection. Mice were divided into three groups: control, LPS and LPS+RVT. Animals were pre-treated with RVT during 7 days. The survival rate was monitored over 48 h after LPS administration. Survival animals were sacrificed, their kidney, liver and brain homogenized for malondialdehyde (MDA), catalase (CAT) activity, free iron and nitric oxide (NO) determination. Plasma was also processed for transaminases, creatinine, urea, NO and iron measurement. Pre-treatment with resveratrol greatly improved the survival rate of LPS-treated mice. Resveratrol counteracted LPS-induced tissue lipoperoxidation and catalase activity depletion. The polyphenol abrogated LPS-induced liver and kidney dysfunction as increased creatinine and urea as well as transaminases activities. In addition, pre-treatment with resveratrol abrogated LPS-induced tissues and plasma NO elevation and iron sequestration from plasma to tissue compartment. These data suggest that resveratrol prevents LPS-induced lethality and that its mode of action may involve differential iron deposition via iron shuttling proteins.

Preparation, characterization and in silico modeling of biodegradable nanoparticles containing cyclosporine A and coenzyme Q10

Combination therapy will soon become a reality, particularly for those patients requiring poly-therapy to treat co-existing disease states. This becomes all the more important with the increasing cost, time and complexity of the drug discovery process prompting one to look at new delivery systems to increase the efficacy, safety and patient compliance of existing drugs. Along this line, we attempted to design nano-scale systems for simultaneous encapsulation of cyclosporine A (CsA) and coenzyme Q10 (CoQ10) and model their encapsulation and release kinetics. The in vitro characterization of the co-encapsulated nanoparticles revealed that the surfactant nature, concentration, external phase volume, droplet size reduction method and drug loading concentration can all influence the overall performance of the nanoparticles. The semi-quantitative solubility study indicates the strong influence of CoQ10 on CsA entrapment which was thought to be due to an increase in the lipophilicity of the overall system. The in vitro dissolution profile indicates the influence of CoQ10 on CsA release (64%) to that of individual particles of CsA, where the release is faster and higher (86%) on 18th day. The attempts to model the encapsulation and release kinetics were successful, offering a possibility to use such models leading to high throughput screening of drugs and their nature, alone or in combination for a particular polymer, if chi-parameters are understood.

Resveratrol increases iodide trapping in the rat thyroid cell line FRTL-5

BACKGROUND

Resveratrol, a polyphenol found in grapes, exhibits several beneficial health effects by its antioxidant, antiinflammatory, and chemopreventive properties. The aim of the present study was to determine the effect of resveratrol on iodide trapping and efflux as well as its mode of action using FRTL-5 cells, having in mind the pivotal role of the natrium iodide symporter (NIS) in the treatment of differentiated thyroid cancers.

METHODS

Cells were treated with resveratrol for various times and doses, in the presence or absence of thyrotropin (TSH). Iodide trapping, iodide efflux, rat NIS (rNIS) protein expression, and cyclic AMP (cAMP) production were evaluated.

RESULTS

Resveratrol increased iodide trapping in a time-dependent (optimal 6 hours) and dose-dependent (100 microM) way in the presence of TSH. It showed an additive effect when concomitantly added with an optimal dose of TSH. Resveratrol (50 microM) increased (threefold) rNIS protein expression. In TSH-deprived cells, resveratrol also provoked an increase in rNIS protein (>3-fold in 6 hours) with an optimum at 40 microM. Resveratrol did not inhibit iodide efflux from FRTL-5 cells. It neither increased intracellular cAMP nor induced the arborization of living cells, two TSH-induced effects. A non-cAMP mode of action is highly suspected.

CONCLUSIONS

Resveratrol increases iodide trapping in FRTL-5 cells, increasing iodide influx and rNIS protein level even in the absence of TSH. It has an additive effect with TSH. Consequently, resveratrol could be a promising molecule for radioiodide therapy in follicular and papillary differentiated thyroid carcinoma in association with recombinant human TSH.

S-allylcysteine attenuates renal injury by altering the expressions of iNOS and matrix metallo proteinase-2 during cyclosporine-induced nephrotoxicity in Wistar rats

Cyclosporine A (CsA) is the first choice immunosuppressant used for the prevention of allograft rejection in solid organ transplantation and immune-mediated diseases. Reactive oxygen species-induced oxidative stress and lipid peroxidation are implicated in the pathophysiology of CsA-induced renal injury. In this work, we have studied the effect of a garlic-derived compound, S-allylcysteine (SAC) on CsA-induced nephrotoxicity. CsA-induced nephrotoxicity was assessed in terms of increased activities of serum marker enzymes and levels of kidney markers. CsA administration induced significant elevation in lipid peroxidation along with abnormal levels of enzymic and non-enzymic antioxidants in the kidneys of the rats. SAC administration improved renal function by bringing about a significant decrease in peroxidative levels and increase in antioxidant status. Elevated expressions of inducible nitric oxide synthase (iNOS) and nuclear factor kappa B (NF-kappaB) due to CsA administration were reduced by SAC treatment. An increase in the expression of matrix metalloproteinase-2 (MMP-2) was evident in CsA-induced groups of rats, which was moderately reduced in SAC treated rats. An increase in the levels of serum constituent's urea, uric acid and creatinine was observed in the CsA-induced rats, which was reduced upon treatment with SAC. These results indicate that SAC has a protective action against CsA-induced nephrotoxicity which is also supported by histopathological studies. A comparative study of the antioxidant vitamin C and SAC is more valuable to assess the efficacy of the drug that can be used for the treatment of nephrotoxicity.

Protective effect of resveratrol on acute endotoxemia-induced nephrotoxicity in rat through nitric oxide independent mechanism

Lipopolysaccharide (LPS) is a glycolipid component of the cell wall of gram negative bacteria inducing deleterious effects on the kidney. Endotoxemia-induced nephrotoxicity is characterized by disturbed intracellular redox balance and reactive oxygen species (ROS) accumulation leading to DNA, proteins and membrane lipid damages. Resveratrol (trans-3,5,4'-trihydroxystilbene) is a polyphenol displaying antioxidant and anti-inflammatory properties. This study investigated its effects on LPS-induced nephrotoxicity in rats. Resveratrol counteracted all LPS-induced changes in renal haemodynamic parameters. In the kidney resveratrol abrogated LPS-induced lipoperoxidation and antioxidant enzyme activities depletion as superoxide dismutase (SOD) and catalase (CAT) but not peroxidase (POD) activity. LPS increased plasma and urine nitric oxide (NO) level and resveratrol reversed them. More importantly, LPS-induced iron mobilization from plasma to kidney, which was also abolished by resveratrol treatment. All these results suggest that resveratrol exerted strong antioxidant properties against LPS-induced nephrotoxicity and that its mode of action seemed to involve iron shuttling proteins.

Resveratrol attenuates oxidative stress and histological alterations induced by liver ischemia/reperfusion in rats

AIM: To investigate the effects of resveratrol on liver ischemia/reperfusion (I/R) injury in rats.

METHODS: A total of 40 male Sprague-Dawley rats weighing 240-290 g were randomized into four groups of ten: (1) controls: data from unmanipulated animals; (2) sham group: rats subjected to the surgical procedure, except for liver I/R, and given saline; (3) I/R group: rats underwent liver ischemia for 45 min followed by reperfusion for 45 min; (4) I-R/Resveratrol group: rats pretreated with resveratrol (10 μmol/L, iv). Liver tissues were obtained to determine antioxidant enzyme levels and for biochemical and histological evaluation.

RESULTS: Plasma aminotransferase activities were higher in the I/R group than in the I-R/Resveratrol group. Malondialdehyde levels and the hepatic injury score decreased, while superoxide dismutase, catalase, and glutathione peroxidase levels increased in group 4 compared to group 3. In group 4, histopathological changes were significantly attenuated in resveratrol-treated livers.

CONCLUSION: These results suggest that resveratrol has protective effects against hepatic I/R injury, and is a potential therapeutic drug for ischemia reperfusion-related liver injury.

Effect of melatonin, curcumin, quercetin, and resveratrol on acute ferric nitrilotriacetate (Fe-NTA)-induced renal oxidative damage in rats

The influence of melatonin, curcumin, quercetin, and resveratrol pretreatment on ferric nitrilotriacetate (Fe-NTA)-induced oxidative renal damage was studied. Male Wistar rats were treated orally once daily for 3 days with melatonin (10 mg/kg), curcumin (50 mg/kg), quercetin (15 mg/kg), and resveratrol (10 mg/kg). One hour after the last dose of antioxidants, a single dose of Fe-NTA was administered (8 mg of Fe/kg body weight, i.p.) to pre-treated animals. Twenty-four hours after Fe-NTA administration, the lipid peroxidation (LP), reduced glutathione (GSH), catalase (CAT), and glutathione peroxidase (GSH-Px) were estimated in kidney homogenates. Iron, zinc, and copper concentrations were estimated in kidney tissue. Administration of Fe-NTA to rats induced renal LP (170%, P < 0.001) and inhibited catalase (78%, P < 0.05) in the kidney. The oral pretreatment with melatonin, curcumin, quercetin, and resveratrol each one was effective in decreasing the Fe-NTA-induced LP (P < 0.001); however, it did not influence the FeNTA-induced inhibition of renal CAT activity. No changes were found in renal GSH level and GSH-Px activity compared to control animals. The pretreatment with antioxidants did not affect the increase in renal iron content, blood urea nitrogen/creatinine ratio, and relative kidney weight of FeNTA-intoxicated rats. The results indicate that the pretreatment with natural antioxidants, curcumin, melatonin, quercetin, and resveratrol, significantly and equally suppressed lipid peroxidation induced by Fe-NTA but had no effect on other markers of FeNTA nephrotoxicity and iron deposition in kidneys.

Protective effect of resveratrol in endotoxemia-induced acute phase response in rats

Lipopolysaccharide (LPS), a glycolipid component of the cell wall of gram-negative bacteria can elicit a systemic inflammatory process leading to septic shock and death. Acute phase response is characterized by fever, leucocytosis, thrombocytopenia, altered metabolic responses and redox balance by inducing excessive reactive oxygen species (ROS) generation. Resveratrol (trans-3,5,4' trihydroxystilbene) is a natural polyphenol exhibiting antioxidant and anti-inflammatory properties. We investigated the protective effect of resveratrol on endotoxemia-induced acute phase response in rats. When acutely administered by i.p. route, resveratrol (40 mg/kg b.w.) counteracted the effect of a single injection of LPS (4 mg/kg b.w.) which induced fever, a decrease in white blood cells (WBC) and platelets (PLT) counts. When i.p. administered during 7 days at 20 mg/kg per day (subacute treatment), resveratrol abrogated LPS-induced erythrocytes lipoperoxidation and catalase (CAT) activity depression to control levels. In the plasma compartment, LPS increased malondialdehyde (MDA) via nitric monoxide (NO) elevation and decreased iron level. All these deleterious LPS effects were reversed by a subacute resveratrol pre-treatment via a NO independent way. Resveratrol exhibited potent protective effect on LPS-induced acute phase response in rats.

Resveratrol: is there any effect on healthy subject?

This preliminary study was planned to investigate the effects of resveratrol on oxidative-nitrosative stress markers and on trace element concentrations in blood and on circulatory system parameters in rats. Twenty-five Sprague-Dawley male rats, 10-12 weeks old, with mean body weight of 295 g were used in the study. Administration of resveratrol (0.5 ml/day) was performed in experimental group in 10 days. In control (n = 10) and in experimental groups (n = 15), after 1 week training period, systolic arterial blood pressures and heart rates were recorded daily. At the end of the tenth day, blood samples of control and experimental groups were drawn. Total nitrite, nitrite, nitrate, malondialdehyde, copper, zinc concentrations in plasma, superoxide dismutase, and catalase activities and copper, zinc concentrations in red cell were determined both in control and experimental groups. Alterations in oxidative and nitrosative stress markers, trace element concentrations, and circulatory system parameters in experimental group compared to controls were observed. The results of this study were discussed according to the effect of resveratrol.

Pretreatment effect of resveratrol on streptozotocin-induced diabetes in rats

This study was planned to investigate the pretreatment effect of resveratrol on streptozotocin-induced diabetic rats. The control group consisted of 10 male albino Sprague-Dawley rats, 10-12 weeks of age, weighing approximately 295 g. The first experimental group consisted of 15 albino Sprague-Dawley rats, 10-12 weeks of age, weighing approximately 305 g. This group was administered streptozotocin (55 mg/kg, intraperitoneally). The second experimental group (n = 15) was administered resveratrol (0.5 ml/day) 10 days before streptozotocin induction. A training period was performed for all groups before the experimental procedure, and systolic arterial blood pressures and heart rates were recorded daily. At the end of the 10th day, blood samples of control and experimental groups were drawn. Total nitrite, nitrite, nitrate, malondialdehyde (MDA), copper, and zinc concentrations in plasma were measured both in control and experimental groups. Additionally, superoxide dismutase, catalase activities, and copper and zinc concentrations in red cell were determined in each group. At the end of the study, increases in catalase activity, nitric oxide level, and zinc concentrations and decreases in lipid peroxidation product MDA and copper concentrations were found in the resveratrol-pretreated diabetic group when compared to the diabetic group.

Effects of resveratrol on glycerol-induced renal injury

Glycerol-induced renal lesions can have many causes, including increased oxidative stress and inflammation. Resveratrol, a polyphenolic phytoalexin found in grapes and red wine, is an antioxidant agent with anti-inflammatory effects. In the present study, we investigated the possible protective effect of resveratrol on glycerol-induced nephrotoxicity. Male Wistar rats were injected intramuscularly with 8 ml/kg of either 50% glycerol (n=18), glycerol+resveratrol (n=22), 0.15 M saline (n=14), saline+carboxymethylcellulose (n=10) or saline+resveratrol (n=8). The rats were killed 3 days after the injections, at which time the kidneys were removed for histological and immunohistochemical studies and lipid peroxidation determination. Blood and urine samples were collected in order to quantify sodium and creatinine. The results of the histological and immunohistochemical studies were scored according to the extent of damage and immunostaining, respectively, in the cortical tubulointerstitium. Lipid peroxidation was estimated by measuring malondialdehyde in renal tissue samples collected from control rats and glycerol-injected rats. By postinjection day 3, glycerol-only treated rats presented increases in plasma creatinine levels, as well as in fractional excretion of sodium and potassium (P<0.001). These increases were less pronounced in glycerol+resveratrol-treated rats (P<0.05). Cortical expression of macrophages, lymphocytes, nuclear factor-kappa B, heme oxygenase-1 and nitrotyrosine was greater in glycerol-treated rats than in controls (P<0.001). In addition, the histological findings for glycerol-treated rats were characteristic of acute tubular necrosis. Resveratrol attenuated all of these alterations (P<0.001). We conclude that resveratrol ameliorates glycerol-induced renal injury by suppressing the inflammatory process and by inhibiting lipid peroxidation.

Development of Biodegradable Nanoparticles for Oral Delivery of Ellagic Acid and Evaluation of Their Antioxidant Efficacy Against Cyclosporine A-Induced Nephrotoxicity in Rats

PURPOSE

Ellagic acid (EA), a dietary antioxidant associated with poor biopharmaceutical properties, was encapsulated into poly(lactide-co-glycolide) (PLGA) and polycaprolactone (PCL) nanoparticles to improve oral bioavailability.

MATERIALS AND METHODS

EA-loaded nanoparticles were prepared following emulsion-diffusion-evaporation method employing didodecyldimethyl ammonium bromide (DMAB) and polyvinyl alcohol (PVA) as stabilizers. In vitro release was investigated in phosphate buffer (pH 7.4). The in situ permeation studies were performed in rats. The antioxidant potential of the DMAB-stabilized nanoparticulate formulations was evaluated against cyclosporine A (CyA)-induced nephrotoxicity in rats.

RESULTS

EA-loaded PLGA and PCL nanoparticles have been successfully prepared employing PEG 400 as co-solvent to solubilize EA. The stabilizers influenced the particle size and encapsulation efficiency. DMAB when used as stabilizer to particles of approximately 120 nm and approximately 50% encapsulation, whereas PVA led to approximately 290 nm and approximately 60% encapsulation at 5% initial loading (w/w of polymer). The in vitro release of EA from the nanoparticles followed Higuchi's square root pattern and was faster with PVA-stabilized particles in comparison to those stabilized with DMAB. From the in situ permeation studies in rats, it was evident that intestinal uptake of EA as DMAB-stabilized nanoparticles was significantly higher as compared to the sodium carboxymethyl cellulose suspension and the PVA-stabilized particles. EA and EA nanoparticles were able to prevent the CyA-induced nephrotoxicity in rats as evident by biochemical parameters as well as kidney histopathology.

CONCLUSION

The present study demonstrates the potential of EA nanoparticulate formulations in the prevention of CyA-induced nephrotoxicity at three times lower dose suggesting improved oral bioavailability of EA.

PLGA nanoparticles for oral delivery of cyclosporine: nephrotoxicity and pharmacokinetic studies in comparison to Sandimmune Neoral

The cyclosporine-loaded poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs) were prepared by the emulsion-diffusion-evaporation method and were optimized for particle size and entrapment efficiency. The optimized particles were 143.3+/-8.7 nm in size with narrow size distribution and 71.9+/-1.7% entrapment efficiency at 20% w/w initial drug loading when prepared with 0.1% w/v of Didodecylmethylammonium bromide (DMAB) as stabilizer. These particulate carriers exhibited controlled in vitro release of cyclosporine for 23 days at a nearly constant rate and showed very good hemocompatibility in vitro. The nanoparticulate formulation showed significantly higher intestinal uptake as compared to Sandimmune Neoral and cyclosporine suspension. The relative bioavailability of nanoparticulate formulation was found to be 119.2% as compared to Sandimmune Neoral. A marked difference in the pharmacokinetic profile between nanoparticulate and Sandimmune Neoral formulations was observed where nanoparticulate formulation showed controlled release of cyclosporine over 5 days, on the other hand, the marketed formulation showed a sharp Cmax with a 3-day release profile. The nanoparticulate formulation exerted significantly lower nephrotoxicity in the rats as compared to Sandimmune Neoral, which was evidenced by lower blood urea nitrogen (BUN), plasma creatinine (PC) and malondialdehyde (MDA) levels in plasma and kidney. The results were further supported by the histopathological changes in kidneys. Together, these results indicate that PLGA NPs have greater potential for oral delivery of cyclosporine.

Role of lipoic acid in reducing the oxidative stress induced by cyclosporine A

BACKGROUND

Cyclosporine A (CsA) is the first choice immunosuppressant universally used for the prevention of allograft rejection in solid organ transplantation and immune-mediated diseases. However, with increasing use, evidence has accumulated that CsA therapy is associated with a variety of side effects, the most important being nephrotoxicity. We investigated the potential role of DL-alpha lipoic acid (LA), a universal antioxidant in combating the oxidative stress induced by CsA.

METHODS

Adult male albino Wistar rats were divided into 4 treatment groups. Two groups received CsA (25 mg/kg body weight, orally for 21 days) to induce nephrotoxicity. One of these groups received LA treatment (20 mg/kg body weight, orally) for 21 days concurrently during CsA administration. A vehicle treated control group and a LA drug control were also included.

RESULTS

CsA-induced nephrotoxicity was assessed in terms of increased activities of serum marker enzymes; alkaline phosphatase, acid phosphatase and lactate dehydrogenase. An apparent rise in the activities of N-acetyl-beta-D-glucosaminidase, beta-glucuronidase and cathepsin D were seen in the renal tissue of CsA given rats, which were reversed upon treatment with LA. CsA administration induced significant elevation in lipid peroxidation along with abnormal levels of enzymic (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione-S-transferase and glucose-6-phosphate dehydrogenase) and non-enzymic antioxidants (glutathione, vitamins C and E) in the rat kidney. LA administration improved renal function, by bringing about a significant decrease in peroxidative levels and increase in antioxidant status.

CONCLUSION

These results indicate that LA has a protective action against CsA nephrotoxicity and suggest that the LA may find clinical application against a variety of toxins where cellular damage is a consequence of reactive oxygen species.

Effect of resveratrol on 3-nitropropionic acid-induced biochemical and behavioural changes: possible neuroprotective mechanisms

Huntington's disease is a progressive, degenerative disease characterized by abnormal body movements called chorea, and a reduction of various mental abilities. 3-Nitropropionic acid, an inhibitor of complex II of the electron transport chain, causes Huntington's disease-like symptoms in rodents. Recently, it has been reported that oxidative stress, which is one of the pathological hallmarks of various neurodegenerative disorders, also plays an important role in the pathogenesis of Huntington's disease. The present study was designed to investigate effects of resveratrol, an antioxidant with cyclooxygenase I inhibitory activity, in the 3-nitropropionic acid-induced model of Huntington's disease. Intraperitoneal administration of 3-nitropropionic acid (20 mg/kg for 4 days) caused significant loss of body weight, a decline in motor function (locomotor activity, movement pattern and vacuous chewing movements) and poor retention of memory. Repeated treatment with resveratrol (5 and 10 mg/kg, orally), once daily for a period of 8 days beginning 4 days prior to 3-nitropropionic acid administration, significantly improved the 3-nitropropionic acid-induced motor and cognitive impairment. Biochemical analysis revealed that systemic 3-nitropropionic acid administration significantly increased lipid peroxidation, nitrite levels, and depleted reduced glutathione levels, and decreased succinate dehydrogenase activity in the brains of rats. The results of the present study indicate that resveratrol (5 and 10 mg/kg, orally) significantly reversed 3-nitropropionic acid-induced motor and cognitive impairment, and that the beneficial effects of resveratrol might be attributed to its antioxidant activity.

Neuroprotection by resveratrol against traumatic brain injury in rats

Oxidative stress after traumatic brain injury may contribute to many of the pathophysiologic changes. Resveratrol, naturally present at high concentration in grape skin, seeds, and red wine, has significant antioxidant properties in a variety of in vitro and in vivo models. In this study, we investigate the effect of resveratrol on oxidative stress after traumatic brain injury in rat model.A total of 54 adult Wistar albino male rats weighing 250-300 g were used. The rats were allocated into three groups. The first group was control (sham-operated) group in which only a craniotomy was performed, the others were trauma and resveratrol groups. A 100 mg/kg single dose of resveratrol, freshly prepared by dissolving in 50% ethanol and diluted in physiological saline (2%), for resveratrol group, and 1 ml ethanol (2%) for trauma group, was administered intraperitoneally immediately after trauma. Weight-drop method was used for achieving head trauma. Then, all groups were separated into three subgroups for biochemical analysis, brain water content and histopathological assessment following trauma. Twenty-four hours after trauma brain water content and malondialdehyde (MDA), glutathione (GSH), nitric oxide (NO), xanthine oxidase (XO) levels of traumatic hemisphere were evaluated. Quantitative histopathological analysis was performed on 14th day postinjury. Trauma caused a significant increase in MDA, XO, NO levels and decrease in GSH level as compared to control group. Resveratrol administration significantly reduced MDA, XO and NO levels, increased GSH level, and also attenuated tissue lesion area. Our results indicate that treatment with resveratrol immediately after traumatic brain injury reduce oxidative stress and lesion volume. Future studies involving different doses and the dose-response relationship could promise better results.

Resveratrol prevents CsA inhibition of proliferation and osteoblastic differentiation of mouse bone marrow-derived mesenchymal stem cells through an ER/NO/cGMP pathway

The purpose of this study was to investigate the in vitro effects of resveratrol (RSVL) and cyclosporin A (CsA) on proliferation and osteoblastic differentiation of mouse bone marrow-derived mesenchymal stem cell (BMSC) cultures. Application of RSVL (10(-8) -10(-6) mol l(-1)) resulted in a dose-dependent increase in [3H]-thymidine incorporation, alkaline phosphatase (ALP) activity and calcium deposition of BMSCs cultures, which was accompanied with the increase of NO production and cGMP content. Concurrent treatment with the estrogen receptor antagonist ICI182,780 (10(-7) mol l(-1)) or the NO synthase inhibitor, Nomega-nitro-L-arginine methyl ester (6 x 10(-3) mol l(-1)) abolished the RSVL (10(-6) mol l(-1))-induced increase in NO production and cGMP content and eliminated the RSVL-induced increase in proliferation and osteoblastic differentiation of BMSCs. In contrast, CsA (10(-6) -10(-5) mol l(-1)) dose-dependently decreased [3H]-thymidine incorporation, ALP activity and calcium deposition of BMSCs cultures, which was accompanied with the reduction of NO production in the conditioned media. Concurrent treatment with RSVL (10(-6) mol l(-1)) significantly reversed the CsA (3 x 10(-6) mol l(-1))-mediated decrease in NO production and restored the proliferation and differentiation potential of BMSCs. Our data suggest that (1) the NO/cGMP pathway may play an important role in both RSVL-induced and CsA-inhibited proliferation and osteoblastic differentiation of mouse BMSCs, and (2) RSVL may act through an ER/NO/cGMP pathway to reverse the inhibitory effect of CsA on BMSC cultures. Taken together, the data suggest that RSVL may prevent osteoporosis induced by CsA.