Acetaminophen induced renal injury via oxidative stress and TNF-alpha production: therapeutic potential of arjunolic acid

Acetaminophen increases the risk of arsenic-mediated development of hepatic damage in rats by enhancing redox-signaling mechanism

We evaluated whether the commonly used analgesic-antipyretic drug acetaminophen can modify the arsenic-induced hepatic oxidative stress and also whether withdrawal of acetaminophen administration during the course of long-term arsenic exposure can increase susceptibility of liver to arsenic toxicity. Acetaminophen was co-administered orally to rats for 3 days following 28 days of arsenic pre-exposure (Phase-I) and thereafter, acetaminophen was withdrawn, but arsenic exposure was continued for another 28 days (Phase-II). Arsenic increased lipid peroxidation and reactive oxygen species (ROS) generation, depleted glutathione (GSH), and decreased superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), and glutathione reductase (GR) activities. Acetaminophen caused exacerbation of arsenic-mediated lipid peroxidation and ROS generation and further enhancement of serum alanine aminotransferase and aspartate aminotransferase activities. In Phase-I, acetaminophen caused further GSH depletion and reduction in SOD, catalase, GPx and GR activities, but in Phase-II, only GPx and GR activities were more affected. Arsenic did not alter basal and inducible nitric oxide synthase (iNOS)-mediated NO production, but decreased constitutive NOS (cNOS)-mediated NO release. Arsenic reduced expression of endothelial NOS (eNOS) and iNOS genes. Acetaminophen up-regulated eNOS and iNOS expression and NO production in Phase-I, but reversed these effects in Phase-II. Results reveal that acetaminophen increased the risk of arsenic-mediated hepatic oxidative damage. Withdrawal of acetaminophen administration also increased susceptibility of liver to hepatotoxicity. Both ROS and NO appeared to mediate lipid peroxidation in Phase-I, whereas only ROS appeared responsible for peroxidative damage in Phase-II.

Hepatoprotective effect of Caesalpinia gilliesii and Cajanus cajan proteins against acetoaminophen overdose-induced hepatic damage

This study aims to evaluate two proteins derived from the seeds of the plants Cajanus cajan (Leguminosae) and Caesalpinia gilliesii (Leguminosae) for their abilities to ameliorate the toxic effects of chronic doses of acetoaminphen (APAP) through the determination of certain biochemical parameters including liver marker enzymes: alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and total bilirubin. Also, total protein content and hepatic marker enzyme, lactate dehydrogenase were studied. Moreover, liver antioxidants, glutathione (GSH), nitric oxide, and lipid peroxides were determined in this study. Hepatic adenosine triphosphatase (ATPase), adenylate energy charge (ATP, adenosine diphosphate, adenosine monophosphate, and inorganic phosphate), and phosphate potential, serum interleukin-6, tumor necrosis factor-α, and myeloperoxidase were also examined in the present study. On the other hand, histopathological examination of intoxicated and liver treated with both proteins was taken into consideration. The present results show disturbances in all biochemical parameters and hepatic toxicity signs including mild vascular congestion, moderate inflammatory changes with moderate congested sinusoids, moderate nuclear changes (pyknosis), moderate centrilobular necrosis, fatty changes, nuclear pyknosis vascular congestion, and change in fatty centrilobular necrosis liver. Improvement in all biochemical parameters studied was noticed as a result of treatment intoxicated liver with C. gilliesii and C. cajan proteins either paracetamol with or post paracetamol treatment. These results were documented by the amelioration signs in rat's hepatic architecture. Thus, both plant protein extracts can upregulate and counteract the inflammatory process, minimize damage of the liver, delay disease progression, and reduce its complications.

Multifunctional pentacyclic triterpenoids as adjuvants in cancer chemotherapy: a review

The protective adjuvants in chemotherapy.

Therapeutic and protective effects of Caesalpinia gilliesii and Cajanus cajan proteins against acetaminophen overdose-induced renal damage

The present work aims to evaluate the protective and ameliorative effects of two plant-derived proteins obtained from the seeds of Cajanus cajan and Caesalpinia gilliesii(Leguminosae) against the toxic effects of acetaminophen in kidney after chronic dose through determination of certain biochemical markers including total urea, creatinine, and kidney marker enzyme, that is, glyceraldehyde-3-phosphate dehydrogenase (GAPDH). In addition histopathological examination of intoxicated and treated kidney with both proteins was performed. The present results show a significant increase in serum total urea and creatinine, while significant decrease in GAPDH. Improvement in all biochemical parameters studied was demonstrated, which was documented by the amelioration signs in rats kidney architecture. Thus, both plant protein extracts can counteract the nephrotoxic process, minimize damage to the kidney, delay disease progression, and reduce its complications.

An update on oxidative stress-mediated organ pathophysiology

Exposure to environmental pollutants and drugs can result in pathophysiological situations in the body. Research in this area is essential as the knowledge on cellular survival and death would help in designing effective therapeutic strategies that are needed for the maintenance of the normal physiological functions of the body. In this regard, naturally occurring bio-molecules can be considered as potential therapeutic targets as they are normally available in commonly consumed foodstuffs and are thought to have minimum side effects. This review article describes the detailed mechanisms of oxidative stress-mediated organ pathophysiology and the ultimate fate of the cells either to survive or to undergo necrotic or apoptotic death. The mechanisms underlying the beneficial role of a number of naturally occurring bioactive molecules in oxidative stress-mediated organ pathophysiology have also been included in the review. The review provides useful information about the recent progress in understanding the mechanism(s) of various types of organ pathophysiology, the complex cross-talk between these pathways, as well as their modulation in stressed conditions. Additionally, it suggests possible therapeutic applications of a number of naturally occurring bioactive molecules in conditions involving oxidative stress.

A screen for apoptotic synergism between clinical relevant nephrotoxicant and the cytokine TNF-α

Nephrotoxicity remains one of the main reasons for post-market drug withdrawal. Tumour necrosis factor α (TNF-α) secretion has been shown to underlie the nephrotoxicity induced by some of these drugs. Yet, there is currently no reliable and sensitive in vitro assay available to screen for nephrotoxicants of which toxicity largely depends on TNF-α secretion. Therefore, we developed and applied a sensitive fluorescence-based in vitro assay for TNF-α-mediated nephrotoxicity screening using mouse immortalized proximal tubular epithelial cells (IM-PTECs). Our assay allows rapid evaluation of TNF-α-mediated toxicant-induced apoptosis and necrosis using fixed endpoint and live cell measurements. To evaluate our assay, sixteen nephrotoxicants and two control non-nephrotoxicants were used. Out of the sixteen nephrotoxicants, eight induced cell death, of which five induced apoptosis as well as necrosis. Moreover, TNF-α significantly enhanced apoptotic cell death induced by cisplatin, cyclosporine A, tacrolimus and azidothymidine. These nephrotoxicants are known to induce inflammation in vivo which has been linked to an enhancement of nephrotoxicity for cisplatin, cyclosporine A and tacrolimus, confirming the functionality of our assay. Overall, our assay allows rapid and sensitive measurement of apoptosis and necrosis induced by a combination of nephrotoxicants and inflammatory components such as TNF-α and can be used as an alternative assay for nephrotoxicity prediction in vitro.

Mechanism of the protective action of taurine in toxin and drug induced organ pathophysiology and diabetic complications: a review

Taurine (2-aminoethanesulfonic acid), a conditionally essential amino acid, is found in large concentrations in all mammalian tissues and is particularly abundant in aquatic foods. Taurine exhibits membrane stabilizing, osmoregulatory and cytoprotective effects, antioxidative properties, regulates intracellular Ca(2+) concentration, modulates ion movement and neurotransmitters, reduce the levels of pro-inflammatory cytokines in various organs and controls blood pressure. Recently, emerging evidence from the literature shows the effectiveness of taurine as a protective agent against several environmental toxins and drug-induced multiple organ injuries as the outcome of hepatotoxicity, nephrotoxicity, neurotoxicity, testicular toxicity and cardiotoxicity in several animal models. Besides, taurine is also effective in combating diabetes and its associated complications, including cardiomyopathy, nephropathy, neuropathy, retinopathy and atherosclerosis. These beneficial effects appear to be due to the multiple actions of taurine on cellular functions. This review summarizes the mechanism of the prophylactic role of taurine against several environmental toxins and drug-induced organ pathophysiology and diabetes.

Oxidative stress: the mitochondria-dependent and mitochondria-independent pathways of apoptosis

Oxidative stress basically defines a condition in which prooxidant-antioxidant balance in the cell is disturbed; cellular biomolecules undergo severe oxidative damage, ultimately compromising cells viability. In recent years, a number of studies have shown that oxidative stress could cause cellular apoptosis via both the mitochondria-dependent and mitochondria-independent pathways. Since these pathways are directly related to the survival or death of various cell types in normal as well as pathophysiological situations, a clear picture of these pathways for various active molecules in their biological functions would help designing novel therapeutic strategy. This review highlights the basic mechanisms of ROS production and their sites of formation; detail mechanism of both mitochondria-dependent and mitochondria-independent pathways of apoptosis as well as their regulation by ROS. Emphasis has been given on the redox-sensitive ASK1 signalosome and its downstream JNK pathway. This review also describes the involvement of oxidative stress under various environmental toxin- and drug-induced organ pathophysiology and diabetes-mediated apoptosis. We believe that this review would provide useful information about the most recent progress in understanding the mechanism of oxidative stress-mediated regulation of apoptotic pathways. It will also help to figure out the complex cross-talks between these pathways and their modulations by oxidative stress. The literature will also shed a light on the blind alleys of this field to be explored. Finally, readers would know about the ROS-regulated and apoptosis-mediated organ pathophysiology which might help to find their probable remedies in future.

Arjunolic acid: a new multifunctional therapeutic promise of alternative medicine

IMPORTANCE OF THE FIELD

In recent years, a number of studies describing the effective therapeutic strategies of medicinal plants and their active constituents in traditional medicine have been reported. Indeed, tremendous demand for the development and implementation of these plant derived biomolecules in complementary and alternative medicine is increasing and appear to be promising candidates for pharmaceutical industrial research. These new molecules, especially those from natural resources, are considered as potential therapeutic targets, because they are derived from commonly consumed foodstuff and are considered to be safe for humans.

AREAS COVERED IN THIS REVIEW

This review highlights the beneficial role of arjunolic acid, a naturally occurring chiral triterpenoid saponin, in various organ pathophysiology and the underlying mechanism of its protective action. Studies on the biochemistry and pharmacology suggest the potential use of arjunolic acid as a novel promising therapeutic strategy.

WHAT THE READERS WILL GAIN

The multifunctional therapeutic application of arjunolic acid has already been documented by its various biological functions including antioxidant, anti-fungal, anti-bacterial, anticholinesterase, antitumor, antiasthmatic, wound healing and insect growth inhibitor activities. The scientific basis behind its therapeutic application as a cardioprotective agent in traditional medicine is justified by its ability to prevent myocardial necrosis and apoptosis, platelet aggregation, coagulation and lowering of blood pressure, heart rate, as well as cholesterol levels. Its antioxidant property coupled with metal chelating property (by its two hydroxyl groups) protects different organs from metal and drug-induced organ pathophysiology. Arjunolic acid also plays a beneficial role in the pathogenesis of diabetes and its associated complications. The mechanism of cytoprotection of arjunolic acid, at least in part, results from the detoxification of reactive oxygen species (ROS) produced in the respective pathophysiology. In addition to its other biological functions, it also possesses vibrant insecticidal properties and it has the potential to be used as a structural molecular framework for the design of molecular receptors in the general area of supramolecular chemistry and nanochemistry. Esters of arjunolic acid function as organogelators which has wide application in designing thermochromic switches and sensor devices. Arjunolic acid derived crown ether is an attractive candidate for the design of molecular receptors, biomimetics and supramolecular systems capable of performing some biological functions.

HOME MESSAGE

This review would provide useful information about the recent progress of natural product research in the domain of clinical science. This review also aims to untie the multifunctional therapeutic application of arjunolic acid, a nanometer-long naturally occurring chiral triterpenoid biomolecule.

Ameliorative potential of whey protein hydrolysate against paracetamol-induced oxidative stress

The aim of the present study was to validate the antioxidant effect of whey protein hydrolysate (WPH) using a small animal model. Paracetamol is common drug that is safe at therapeutic levels; however, an overdose causes oxidative stress, which may lead to potential hepatic and renal necrosis. The protective effect of WPH against paracetamol-induced hepato-nephrotoxicity in mice was investigated in this study. The WPH was prepared by hydrolyzing ultrafiltered retentate of mozzarella cheese whey with commercial food-grade alcalase; the resulting WPH had substantial in vitro antioxidant activity. Male albino mice were treated with WPH for 4 d [intraperitoneally at 4 mg/kg of body weight (BW) per day or orally at 8 mg/kg of BW per day] before or after oral administration of paracetamol (300 mg/kg of BW) for 2 d. Two control groups were used; the negative control mice were administered water only; the paracetamol group was administered paracetamol at 300 mg/kg of BW but received no WPH. Levels of different marker enzymes (glutamate pyruvate transaminase and alkaline phosphatase), creatinine, and blood urea nitrogen were measured in the experimental animal blood sera. The WPH successfully mitigated the increase in the concentration of oxidative biomarkers such as glutathione pyruvate transaminase, alkaline phosphatase, and creatinine, and restored the level of blood urea nitrogen to normal in sera of mice in which oxidative stress was induced with an overdose of paracetamol. Furthermore, the indices of different antioxidant enzymes, such as catalase, superoxide dismutase, and glutathione peroxidase, and lipid peroxidation end-products were determined in liver homogenate. The mice that were given WPH, either intraperitoneally or orally, showed increased activities of antioxidant enzymes and a reduction in thiobarbituric acid reactive substances (TBARS) compared with the paracetamol control group. The protective effect of WPH was less when administered orally than intraperitoneally. We concluded that WPH is the potential protector against paracetamol-induced hepato-nephrotoxicity and can be effectively used in health-promoting foods as a biofunctional ingredient.

Bioavailability, distribution, and antioxidative effects of selected triterpenes in mice

This study analyzed the content of eight triterpenes (oleanolic acid, ursolic acid, arjunolic acid, asiatic acid, boswellic acid, corosolic acid, madecassic acid, and maslinic acid) in ten vegetables and eight fruits. These compounds at 0.5% were supplied to mice for 4 or 8 weeks. The bioavailability, tissue distribution, and antioxidative protection of these triterpenes were examined. Results showed that triterpenes were detected in eight vegetables and six fruits. Basil and brown mustard contained seven test triterpenes, in the range of 14-102 mg/100 g dry weight. The level of each triterpene in plasma, brain, heart, liver, kidney, colon, and bladder increased as the feeding period was increased from 4 weeks to 8 weeks (P < 0.05). Renal homogenates from mice with triterpene intake had greater antioxidative effects against glucose-induced glutathione loss and malondialdehyde and oxidized glutathione production when compared with those from control groups (P < 0.05). These data support that these triterpenes were absorbed and deposited in their intact forms, which in turn exerted in vivo antioxidative protection.

Arjunolic acid: beneficial role in type 1 diabetes and its associated organ pathophysiology

In this review article, we describe the most recent development of the beneficial effect of arjunolic acid (AA) in reducing type 1 diabetic pathophysiology. Diabetic mellitus is a serious and growing health problem worldwide. Increasing evidence suggest that oxidative stress plays a pivotal role in the pathogenesis of diabetes and its associated complications. Use of antioxidant supplements as a complimentary therapeutic approach in diabetes has, therefore, been seriously considered worldwide. AA, a natural pentacyclic triterpenoid saponin, is well known for various biological functions including antioxidant activity. It could prevent the increased production of ROS, RNS, AGEs, and the 8OHdG/2dG ratio and increase the intracellular antioxidant defence system. Signal transduction studies showed that AA could prevent hyperglycaemia induced activation of MAPKs, PKC, NF-κB signalling cascades and apoptotic cell death. Combining, AA supplements could be regarded as beneficial therapeutics in the treatment of diabetes and its associated complications.

Induction of oxidative stress in kidney

Oxidative stress has a critical role in the pathophysiology of several kidney diseases, and many complications of these diseases are mediated by oxidative stress, oxidative stress-related mediators, and inflammation. Several systemic diseases such as hypertension, diabetes mellitus, and hypercholesterolemia; infection; antibiotics, chemotherapeutics, and radiocontrast agents; and environmental toxins, occupational chemicals, radiation, smoking, as well as alcohol consumption induce oxidative stress in kidney. We searched the literature using PubMed, MEDLINE, and Google scholar with “oxidative stress, reactive oxygen species, oxygen free radicals, kidney, renal injury, nephropathy, nephrotoxicity, and induction”. The literature search included only articles written in English language. Letters or case reports were excluded. Scientific relevance, for clinical studies target populations, and study design, for basic science studies full coverage of main topics, are eligibility criteria for articles used in this paper.

Acute and chronic acetaminophen use and renal disease: a case-control study using pharmacy and medical claims

BACKGROUND

Studies have examined the association between acetaminophen (APAP) use and renal disease; however, their interpretation is limited by a number of methodological issues.

OBJECTIVE

To study the association between acute and chronic prescription-acquired APAP use and renal disease.

METHODS

This was a retrospective case-control study of medical and pharmacy claims of a 10% random sample of the enrollees from the IMS LifeLink Health Plans commercial claims dataset for dates of service from January 1, 1997, through December 31, 2009. Subjects were continuously enrolled and aged 18 years or older. Cases had at least 1 incident claim of renal disease defined by ICD-9-CM codes in the primary diagnosis field. Controls were randomly selected from individuals without evidence of renal disease, liver disease, or asthma in medical claims and matched to cases in a 3-to-1 ratio based on 3 variables (age, gender, and geographic region). APAP exposure, dosage, and duration of use were measured in the 7 and 30 days (acute) and in the 1-year (chronic) look-back periods. Multivariable conditional logistic regression was used to estimate the risk of APAP exposure adjusted for comorbidities, use of other nephrotoxic drugs, and health system factors.

RESULTS

There were 4,724 cases and 14,172 controls with a mean (SD) age of 60.8 (17.8) years, and 52.6% were males; 10.9% of cases and 4.2% of controls had APAP exposure in the 30 days pre-index with mean potential maximum daily dosages of 3,846.5 mg and 3,190.8 mg, respectively. Acute APAP exposure was significantly associated with renal disease, and the risk decreased with longer look-back periods (7 days: adjusted odds ratio [OR] = 1.93, 95% CI = 1.61-2.30); 30 days: OR = 1.71, 95% CI = 1.48-1.97). Cumulative APAP dosage greater than 1 kg and APAP use for longer than 30 days in the pre-index year were not significantly associated with an increased risk of renal disease (both P values = 0.900).

CONCLUSIONS

Acute prescription-acquired APAP use was associated with renal disease, while chronic use was not. Because this study assessed APAP use in pharmacy claims, further research accounting for over-the-counter APAP use is warranted before the safety of chronic APAP consumption can be firmly established.

Montelukast abrogates rhabdomyolysis-induced acute renal failure via rectifying detrimental changes in antioxidant profile and systemic cytokines and apoptotic factors production

In addition to antiasthmatic effect, the cysteinyl leukotriene receptor 1 (CysLT₁) antagonist montelukast shows renoprotective effect during ischemia/reperfusion and cyclosporine-induced renal damage. Here, we proposed that montelukast protects against rhabdomyolysis-induced acute renal failure. Compared with saline-treated rats, at 48 h following the induction of rhabdomyolysis using intramuscular glycerol (10 ml 50% glycerol/kg), significant elevations in serum levels of urea, creatinine, phosphate and acute renal tubular necrosis were observed. This was associated with elevations in serum Fas, interleukin-10, tumor necrotic factor-alpha, and transforming growth factor-beta1 and renal malondialdehyde and nitrite and detrimental reductions in renal catalase and superoxide dismutase activities. The effects of rhabdomyolysis on renal functional, biochemical and structural integrity and the associated changes in cytokines and Fas levels were abolished upon concurrent administration of montelukast (10 mg/kg i.p.) for 3 days (1 day before and 2 days after induction of rhabdomyolysis). Alternatively, administration of the anti-oxidant, α-tocopherol (400 mg/kg i.m.) for 3 days, succeeded in alleviating renal oxidative stress, but had no significant effect on the circulating levels of most cytokines and partially restored kidney functional and structural damage. Serum level of interleukin-6 was not altered by rhabdomyolysis but showed significant elevations in rats treated with montelukast or α-tocopherol. Collectively, motelukast abrogated functional and structural renal damage induced by rhabdomyolysis via ameliorating renal oxidative stress and modulation of systemic cytokines and apoptotic factors production. The results of this work are expected to open new avenues for early prevention of rhabdomyolysis-induced acute renal failure using selective CysLT₁ antagonists such as montelukast.

Reduction of acute hepatic damage induced by acetaminophen after treatment with diphenyl diselenide in mice

In this study, the authors evaluated the ability of diphenyl diselenide (PhSe)(2) to reverse acute hepatic failure induced by acetaminophen (APAP) in mice. The animals received an APAP dose of 600 mg/kg intraperitoneally (i.p.), and then 1 hour later, they received 15.6 mg/kg i.p. of (PhSe)(2). Three hours after (PhSe)(2) administration, the animals were sacrificed and blood and liver samples were collected for analysis. The serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were measured. The levels of reduced glutathione (GSH) and oxidized glutathione (GSSG), thiobarbituric acid-reactive substances (TBARS), 2',7'-dichlorofluorescein (DFC), catalase activity (CAT), and myeloperoxidase (MPO) activity were determined in the liver. A methyl-tetrazolium reduction (MTT) assay was also performed on the liver. Histopathological studies were conducted in all groups. Exposure of animals to APAP induced oxidative stress, increased lipid peroxidation (LPO), and the generation of reactive species, reduced the levels of GSH, and caused an increase in the MPO activity. Treatment with (PhSe)(2) reduced LPO and the formation of reactive species and inhibited the processes of inflammation, reducing the hepatic damage induced by APAP. The results of this study show that (PhSe)(2) is a promising therapeutic option for the treatment of acute hepatic failure.

D(+) galactosamine induced oxidative and nitrosative stress-mediated renal damage in rats via NF-κB and inducible nitric oxide synthase (iNOS) pathways is ameliorated by a polyphenol xanthone, mangiferin

The present study investigated the possible protective effect of mangiferin against D(+) galactosamine (DGal)-induced nephrotoxicity. DGal intoxication increased reactive oxygen species (ROS), reactive nitrogen species and tumor necrosis factor-α (TNF-α) production and disturbed the antioxidant machineries in the kidney tissue. Mangiferin treatment post to DGal exposure reduced all these DGal-induced adverse effects. Signal transduction studies showed that DGal significantly increased the protein expression of Bax, cytochrome c, caspase 3/9 and inducible nitric oxide synthase (iNOS) in the cytosol and NF-κB in nuclear fraction. The same exposure, on the other hand, reduced the protein expression of Bcl-2 in the cytosol. Mangiferin treatment could, however, reduce the DGal-induced up-regulation of cytochrome c, NF-κB, iNOS, caspase 3/9 and alter the reciprocal regulation of Bcl-2 family proteins. Histological studies also revealed the nephroprotective effect of mangiferin against DGal induced nephrotoxicity. Combining, results suggest that mangiferin protects rat's kidney in DGal-induced oxidative/nitrosative stress and acute nephrotoxicity via its antioxidant activities.

Ameliorative Potential of Quercetin Against Paracetamol-induced Oxidative Stress in Mice Blood

The aim of the present study was to evaluate the ameliorative potential of quercetin (QC) against paracetamol (PCM)-induced oxidative stress and biochemical alterations in mice blood. A total of 36 mice were randomly allocated into six groups, six mice in each. Group I served as healthy controls, while groups II and III were administered with N-acetylcysteine (NAC) and QC alone respectively. Group IV was administered with PCM alone. Groups V and VI were administered with PCM on day 0 followed by NAC and QC, respectively, for 6 consecutive days. On day 7^th blood samples were obtained and subjected for the assays of oxidative stress and serum biochemical panels. Erythrocytic lipid peroxides contents of alone PCM-intoxicated mice were significantly higher, while reduced glutathione contents were found to be significantly lower in comparison with the healthy controls. The activities of antioxidant enzymes were also found to be singnificantly lower in these mice. Additionally, significantly increased activities of serum aspartate transaminase, alanine transaminase and alkaline phosphatase, as well as levels of bilirubin, urea and creatinine were revealed by these mice. Postadministration with QC remarkably alleviated the over production of MDA and improved GSH levels in PCM-intoxicated mice blood. In addition, antioxidant enzymes; glutathione peroxidase, glutathione-S-transferase, superoxide dismutase and catalase activities were also improved significantly in these mice. QC had also considerably ameliorated the altered biochemical parameters toward normalcy. Thus, it can be concluded that QC may constitute a remedy against PCM-induced oxidative stress and reno-hepatic injuries.

Acetaminophen: beyond pain and Fever-relieving

Acetaminophen, also known as APAP or paracetamol, is one of the most widely used analgesics (pain reliever) and antipyretics (fever reducer). According to the U.S. Food and Drug Administration, currently there are 235 approved prescription and over-the-counter drug products containing acetaminophen as an active ingredient. When used as directed, acetaminophen is very safe and effective; however when taken in excess or ingested with alcohol hepatotoxicity and irreversible liver damage can arise. In addition to well known use pain relief and fever reduction, recent laboratory and pre-clinical studies have demonstrated that acetaminophen may also have beneficial effects on blood glucose levels, skeletal muscle function, and potential use as cardioprotective and neuroprotective agents. Extensive laboratory and pre-clinical studies have revealed that these off-label applications may be derived from the ability of acetaminophen to function as an antioxidant. Herein, we will highlight these novel applications of acetaminophen, and attempt, where possible, to highlight how these findings may lead to new directions of inquiry and clinical relevance of other disorders.

Cajanus indicus leaf protein: Beneficial role in experimental organ pathophysiology. A review

The herb, Cajanus indicus L, has been and is popular for its medicinal value in India and other countries for long. The herb is mainly cultivated for the seeds which are used as pulses and are rich in proteins. People of rural India and some neighboring countries use the aqueous extract of the leaves of the herb against poor liver function and recently it has been found that the extract is not only useful against liver damage but also beneficial for renal failure and a number of other pathophysiological conditions. Intraperitoneal administration of the aqueous protein fraction of the leaves has shown hepatoprotective activity in mice. The protein fraction revealed the presence of a 43kDa protein having antioxidant and other protective properties in organ pathophysiology. The purified protein, CI-protein, scavenges free radicals generated by different free radical inducers and helps providing cytoprotection. Amino acid sequence of CI-protein has some structural similarity with plastocyanin, an electron carrier protein in photosynthesis. The protein has also been found to be active against a number of organ dysfunction inducer chemicals and drugs, like carbon tetrachloride, thioacetamide and acetaminophen. Signal transduction studies suggest that CI-protein exerts its protective action by free radical scavenging and antioxidative properties; it activates NF-κB and Akt without any involvement of ERK1/ERK2 and STAT-3 in acetaminophen induced hepatic pathophysiology. Besides, it reduces both drug and toxin induced cytotoxicity by decreasing the formation and/or scavenging of free radicals involving cytochrome P450, taking part in detoxification of xenobiotics.

PT, Martins DT. Anti-inflammatory, antinociceptive, and antipyretic effects of methanol extract of Cariniana rubra stem bark in animal models

Cariniana rubra Miers (Lecythidaceae), popularly known as "jequitibá-vermelho'', is a large Brazilian tree whose bark is used in infusion and decoction for the treatment of inflammatory conditions. This study aims to assess the anti-inflammatory, antinociceptive, and antipyretic effects of Cariniana rubra methanolic stem bark extract (EM Cr) using experimental animals. Anti-inflammatory activity of EM Cr was tested on carrageenan and dextran-induced rat paw edema, carrageenan-induced pleurisy in rats and acetic acid-increase vascular permeability in mice. Antinociceptive and antipyretic activities were evaluated using acetic acid-induced writhing, formalin and hot-plate tests in mice, as well as brewer's yeast-induced pyrexia in rats. The extract inhibitied carrageenan and dextran-induced edema, reduced exudate volume and leukocyte migration on the carrageenan-induced pleurisy and on the vascular permeability increase induced by acetic acid. The EM Cr inhibited nociception on the acetic acid-induced writhing and in the second phase of formalin test, and decreased rectal temperature. It was, however, inactive against thermal nociception.Phytochemical analysis with EM Cr showed the occurrence of saponins, triterpenes, sterols and phenolic compounds. Phytosterols (β-sitosterol, stigmasterol), pentacyclic triterpenes (α- and β-amyrin as a mixture), arjunolic acid, a phytosterol glycoside (sitosterol 3-O-β-D-glucopyranoside), and triterpenoid saponins (28-β-glucopyranosyl-23-O-acetyl arjunolic acid; 3-O-β-glucopyranosyl arjunolic acid and 28-O-[α-L-Rhamnopyranosyl-(1→2)-β-glucopyranosyl]-23- O-acetyl arjunolic acid) were the main identified compounds. It can be presumed that EM Cr caused their effects by inhibiting the liberation and/or action of different inflammatory mediators. These findings support the traditional use of Cariniana rubra preparations to treat inflammation.

Involvement of both intrinsic and extrinsic pathways in hepatoprotection of arjunolic acid against cadmium induced acute damage in vitro

Cadmium (Cd) is one of the ubiquitous environmental pollutants and is responsible for various organ pathophysiology including hepatic disorders. It is extremely toxic even in low concentrations and bioaccumulate in organisms. The present study has been carried out to investigate the cytoprotective role of arjunolic acid (AA), a tri terpenoid saponin, against Cd induced oxidative impairment and cell death in murine hepatocytes. Administration of cadmium (30 μM), in the form of chloride (CdCl(2)) for 2h, significantly enhanced the ALT, ALP and LDH leakage, increased reactive oxygen species (ROS) production, reduced hepatocytes viability and altered the antioxidant status of hepatocytes by reducing intracellular GSH level, anti-oxidant enzymes activity and increasing intracellular GSSG and lipid peroxidation. Evidence for Cd-induced nature of cell death was sought by flow cytometric analysis. Signal transduction studies revealed that Cd markedly increased the levels of caspase-9, -8, -3, Fas and Bid, decreased mitochondrial membrane potential, enhanced cytochrome c release in the cytosol, disturbed the Bcl-2 family protein balance, cleaved PARP protein and ultimately led to apoptotic cell death. Results showed that Cd could trigger both intrinsic and extrinsic apoptotic pathways. In addition, Cd markedly increased NF-κB nuclear translocation in association with IKKα/β phosphorylation and IκBα degradation. Simultaneous treatment with AA (200 μM), however, reduced Cd-induced oxidative stress, attenuated the nuclear translocation of NF-κB and protects the hepatocytes from Cd-induced apoptotic death. Combining, data suggest that Cd-induced hepatic dysfunction and apoptosis might be supported by the ROS formation and mediated via the activation of NF-κB. AA treatment, on the other hand, reduced Cd-induced oxidative stress, attenuated the activation of NF-κB and mitochondrion-dependent and independent apoptotic signaling pathways.

Modulation of mercury-induced mitochondria-dependent apoptosis by glycine in hepatocytes

Mercury (Hg) is one of the universal environmental pollutants and is responsible for various organ pathophysiology including oxidative stress-induced hepatic disorders. In the present study, we aimed to explore the protective role of glycine in Hg-induced cytotoxicity and cell death in murine hepatocytes. Exposure of mercury (20 μM), in the form HgCl2 for 1 h, significantly enhanced the ALT and ALP leakage, increased reactive oxygen species production, reduced cell viability and distorted the antioxidant status of hepatocytes. Flow cytometric analyses shows that Hg-induced apoptotic death in hepatocytes. Mechanism of this pathophysiology involves reduced mitochondrial membrane potential, variations in Bcl-2/Bad proteins, activation of caspases and cleavage of PARP protein. In addition, Hg distinctly increased NF-κB phosphorylation in association with IKKα phosphorylation and IκBα degradation. Concurrent treatment with glycine (45 mM), however, reduced Hg-induced oxidative stress, attenuated the changes in NF-κB phosphorylation and protects hepatocytes from Hg-induced apoptotic death. Hg also distinctly increased the phosphorylation of p38, JNK and ERK mitogen-activated protein kinase (MAPKs). Glycine treatment suppressed these apoptotic events, signifying its protective role in Hg-induced hepatocyte apoptosis as referred by reduction of p38, JNK and ERK MAPK signaling pathways. Results suggest that glycine can modulate Hg-induced oxidative stress and apoptosis in hepatocytes probably because of its antioxidant activity and functioning via mitochondria-dependent pathways and could be a beneficial agent in oxidative stress-mediated liver diseases.

Effects of acetaminophen on reactive oxygen species and nitric oxide redox signaling in kidney of arsenic-exposed rats

We examined whether acetaminophen could alter renal oxidative stress induced by arsenic; also whether withdrawal of acetaminophen treatment can increase susceptibility of kidney to arsenic toxicity. Acetaminophen (400 and 1600 mg/kg) was co-administered orally to rats for 3 days after preexposure to arsenic (25 ppm) for 28 days (Phase-I) and thereafter, acetaminophen was withdrawn, but arsenic exposure was continued for another 28 days (Phase-II). Acetaminophen enhanced arsenic-induced lipid peroxidation, GSH depletion and ROS production and further decreased superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase activities. Increased peroxidation did not alter kidney weight, but increased serum urea nitrogen and creatinine. Arsenic did not alter basal, iNOS-mediated NO production or iNOS expression. Arsenic decreased cNOS-mediated NO release and eNOS expression in Phase-II. Acetaminophen increased their expressions and NO production in Phase-I. In Phase-II, arsenic-mediated effects on NO remained mostly unaffected with acetaminophen. Results reveal that acetaminophen enhanced the risk of arsenic-mediated oxidative stress in kidney. Discontinuation of acetaminophen administration also increased the susceptibility of kidney to nephrotoxic effect of arsenic. It appeared ROS were primarily responsible for oxidative stress in both the phases. NO may have a minor role in Phase-I, but does not contribute to redox signaling mechanism in Phase-II.

Taurine protects acetaminophen-induced oxidative damage in mice kidney through APAP urinary excretion and CYP2E1 inactivation

Acute exposure of acetaminophen (APAP), a widely used analgesic and antipyretic drug, causes severe renal damage and no specific agent has been reported so far that plays any beneficial role in this organ pathophysiology. In the present study, the protective role of taurine on APAP-induced nephrotoxicity was investigated in mice. In order to induce acute nephrotoxicity, APAP was administered at a single dose of 2g/kg body weight orally to male adult albino mice of Swiss strain. APAP exposure for 24h significantly increased plasma level of blood urea nitrogen (BUN), creatinine, uric acid, TNF-alpha, NO production, urinary gamma-glutamyl transpeptidase (gamma-GT) activity, total urinary protein and urinary glucose level accompanied by a decrease in Na(+)-K(+)-ATPase activity. Moreover, APAP administration significantly increased MDA, protein carbonylation, GSSG level, intracellular ROS production and cytochrome P450 enzyme (CYPP450) activity. The same exposure decreased GSH level, ferric reducing/antioxidant power (FRAP) as well as the activities of antioxidant enzymes indicating that APAP-induced renal damage was mediated through oxidative stress. Besides, APAP exposure significantly reduced mitochondrial membrane potential and induced up-regulation of CYP2E1 in renal tissues although JNK did not play any significant role in this APAP-induced renal pathophysiology. Caspase 9/3 immunoblot and DNA fragmentation analyses showed that APAP-induced renal cell damage was mostly necrotic in nature, although some apoptosis also occurred simultaneously. Taurine treatment both pre and post (150 mg/kg body weight for 3 days, orally) to APAP exposure, however, significantly reduced APAP-induced nephrotoxicity through its antioxidant properties, urinary excretion of APAP and suppression of CYP2E1. Results suggest that taurine might be a potential therapeutic candidate against APAP-induced acute nephrotoxicity.