Erdosteine prevents bleomycin-induced pulmonary fibrosis in rats

Multifaceted Beneficial Effects of Erdosteine: More than a Mucolytic Agent

Erdosteine is a drug approved for the treatment of acute and chronic pulmonary diseases, originally developed as a mucolytic agent. It belongs to the thiol-based family of drugs that are known to also possess potentially important antioxidant and anti-inflammatory properties, and exhibit antibacterial activity against a variety of medically important bacterial species. Erdosteine is a prodrug that is metabolized to the ring-opening compound metabolite M1 (MET 1), which has mucolytic properties. Experimental studies have documented that erdosteine prevents or reduces lung tissue damage induced by oxidative stress and, in particular, that Met 1 also regulates reactive oxygen species production. The RESTORE study, which has been the only trial that investigated the effects of a thiol-based drug in chronic obstructive pulmonary disease (COPD) frequent exacerbators, documented that erdosteine significantly reduces the risk of acute exacerbations of COPD (AECOPDs), shortens their course, and also decreases the risk of hospitalization from COPD. The preventive action of erdosteine on AECOPDs was not affected by the presence or absence of inhaled corticosteroids (ICSs) or blood eosinophil count. These findings clearly contrast with the Global Initiative for Chronic Obstructive Lung Disease strategy’s approach to use erdosteine only in those COPD patients not treated simultaneously with an ICS. Furthermore, they support the possibility of using erdosteine in a step-down approach that in COPD is characterized by the withdrawal of the ICS.

Chrysin mitigates bleomycin-induced pulmonary fibrosis in rats through regulating inflammation, oxidative stress, and hypoxia

Pulmonary fibrosis is a chronic condition characterized by fibroblast proliferation, and the infiltration of inflammatory cells that can initiate local tissue hypoxia. In this study the effect of chrysin (50 mg/kg/orally) in a model of bleomycin (BLM)-induced pulmonary fibrosis was studied. Chrysin managed to decrease mortality rate associated with BLM instillation and it managed to improve lung architecture and lung fibrosis by decreasing hydroxyproline content and transforming growth factor-β1 (TGF-β1) protein expression. Chrysin showed anti-inflammatory effect displayed by the decrease in inflammatory cells infiltrates, the decline in permeability of the alveolar/capillary barrier and the reduction in lactate dehydrogenase (LDH) activity. Chrysin demonstrated potent antioxidant effect by decreasing lipid peroxidation, increasing antioxidant defense mechanisms by increasing superoxide dismutase (SOD) activity and reduced glutathione (GSH) content. Additionally, the effect of chrysin on nitric oxide (NOx) content was assessed, where chrysin decreased NOx, increased the protein expression of endothelial nitric oxide synthase (eNOS), and decreased inducible nitric oxide synthase (iNOS) protein expression. Chrysin also succeeded in decreasing thioredoxin-interacting protein (TXNIP), the negative regulator of thioredoxin system, showing potent antioxidant effect. Finally, both tissue and bronchoalveolar lavage fluid contents of hypoxia inducible factor one alpha (HIF1α) were decreased by chrysin indicating that chrysin decreased local tissue hypoxia. In conclusion, this study exposed a possible proof that chrysin could mitigate pulmonary fibrosis induced by BLM through its anti-inflammatory, antioxidant, antifibrotic effects and its effect in alleviating hypoxia.

Zingerone ameliorates oxidative stress and inflammation in bleomycin-induced pulmonary fibrosis: modulation of the expression of TGF-β1 and iNOS

Idiopathic pulmonary fibrosis (IPF) is an interstitial lung disease with limited treatment options. Zingerone found in ginger (Zingiber officinale L.) has many pharmacological effects, especially antiinflammatory and antioxidant activity. However, the effect of zingerone on pulmonary fibrosis (PF) is not fully known. The aim of this study was to investigate the effect of zingerone on bleomycin (BLM)-induced PF and its underlying mechanisms. Wistar-albino rats were given single dose of BLM (5 mg/kg, intratracheal) or vehicle (saline). In treatment groups, zingerone (50 and 100 mg/kg, p.o.) was administered orally for 14 days after BLM administration. Rats and lung tissue were weighed to determine lung index. Antioxidant, antiinflammatory effects, and hydroxyproline content of zingerone were determined by ELISA method. Pulmonary inflammation, collagen deposition, and fibrosis score were determined with Hematoxylin-Eosin (HxE) and Masson's trichrome staining. Transforming growth factor-beta 1 (TGF-β1) and inducible nitric oxide synthase (iNOS) expressions were detected immunohistochemically. BLM administration increased lipid peroxidation (MDA) and decreased superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity. In addition, BLM caused increased levels of tumor necrosis factor alpha (TNF-α) and interleukin-1β (IL-1β) in bronchoalveolar lavage fluid (BALF) and accumulation of collagen bundles. Zingerone administration decreased collagen accumulation, TNF-α and IL-1β levels, MDA level, TGF-β1, and iNOS expression and increased SOD and GPx activity. Histopathological findings supported the results. These results show that zingerone (50 and 100 mg/kg) at both doses significantly contributes to healing of PF by improving inflammation, oxidative stress, and histopathological alterations and by affecting TGF-β1 and iNOS signaling pathways.

Amifostine Analog, DRDE-30, Attenuates Bleomycin-Induced Pulmonary Fibrosis in Mice

Bleomycin (BLM) is an effective curative option in the management of several malignancies including pleural effusions; but pulmonary toxicity, comprising of pneumonitis and fibrosis, poses challenge in its use as a front-line chemotherapeutic. Although Amifostine has been found to protect lungs from the toxic effects of radiation and BLM, its application is limited due to associated toxicity and unfavorable route of administration. Therefore, there is a need for selective, potent, and safe anti-fibrotic drugs. The current study was undertaken to assess the protective effects of DRDE-30, an analog of Amifostine, on BLM-induced lung injury in C57BL/6 mice. Whole body micro- computed tomography (CT) was used to non-invasively observe tissue damage, while broncheo-alveolar lavage fluid (BALF) and lung tissues were assessed for oxidative damage, inflammation and fibrosis. Changes in the lung density revealed by micro-CT suggested protection against BLM-induced lung injury by DRDE-30, which correlated well with changes in lung morphology and histopathology. DRDE-30 significantly blunted BLM-induced oxidative stress, inflammation and fibrosis in the lungs evidenced by reduced oxidative damage, endothelial barrier dysfunction, Myeloperoxidase (MPO) activity, pro-inflammatory cytokine release and protection of tissue architecture, that could be linked to enhanced anti-oxidant defense system and suppression of redox-sensitive pro-inflammatory signaling cascades. DRDE-30 decreased the BLM-induced augmentation in BALF TGF-β and lung hydroxyproline levels, as well as reduced the expression of the mesenchymal marker α-smooth muscle actin (α-SMA), suggesting the suppression of epithelial to mesenchymal transition (EMT) as one of its anti-fibrotic effects. The results demonstrate that the Amifostine analog, DRDE-30, ameliorates the oxidative injury and lung fibrosis induced by BLM and strengthen its potential use as an adjuvant in alleviating the side effects of BLM.

Effects of Ginkgo biloba on plasma oxidant injury induced by bleomycin in rats

Bleomycin is an anti-neoplastic agent and its clinical usage is limited by its toxicity, which is mostly induced by oxygen radicals. The aim of this study was to investigate the effect of Ginkgo biloba on plasma indices of oxidants induced by bleomycin in rats.

Male Sprague-Dawley rats were divided into five groups: none medicated or 0.9% NaCl injected or only Ginkgo biloba (orally, 100 mg/kg per day for 14 days) or only a single dose of bleomycin (intratracheal, 2.5 U/kg) or Gingko biloba and bleomycin-treated groups. After 14 days, blood was taken before the rats were sacrificed. The plasma was removed and stored at −85°C until the study day. Plasma superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and xanthine oxidase (XO) enzyme activities with malondialdehyde and nitric oxide (NO) levels were studied.

The levels of malondialdehyde and NO with activity of XO were higher in plasma of bleomycin group than the other groups (P B/0.05). The activities of SOD and GSH-Px were increased in the bleomycin plus Gingko biloba group in comparison with the bleomycin group (P B/0.05). There was a positive correlation between malondialdehyde and NO levels in the bleomycin group (r-/0.859, P B/0.05). There were positive correlations between SOD and GSH-Px activities (r-/0.760, P B/0.05) and between XO activity and malondialdehyde level (r-/0.822, P B/0.05) in the bleomycin plus Gingko biloba group.

In conclusion, it was thought that bleomycin induced oxidative stress can be prevented by Gingko biloba treatment via high anti-oxidant enzyme activity together with decreased radical production from XO.

Protective effects of erdosteine on rotenone-induced oxidant injury in liver tissue

Rotenone, an insecticide of botanical origin, causes toxicity through inhibition of complex I of the respiratory chain in mitochondria. This study was undertaken to determine whether rotenone-induced liver oxidant injury is prevented by erdosteine, a mucolytic agent showing antioxidant properties. There were four groups of Male Wistar Albino rats: group one was untreated as control; the other groups were treated with erdosteine (50 mg/kg per day, orally), rotenone (2.5 mg/mL once and 1 mL/kg per day for 60 days, i.p.) or rotenone plus erdosteine, respectively. Rotenone treatment without erdosteine increased xanthine oxidase (XO) enzyme activity and also increased lipid peroxidation in liver tissue P < 0.05). The rats treated with rotenone plus erdosteine produced a significant decrease in lipid peroxidation and XO activities in comparison with rotenone group PB/0.05). Erdosteine treatment with rotenone led to an increase in catalase (CAT) and superoxide dismutase (SOD) activities in comparison with the rotenone group PB/0.05). There was no significant difference in nitric oxide (NO) level between groups. There were negative correlations between CAT activity and malondialdehyde (MDA) level (r= -0.934, P <0.05) with between CAT and SOD activities (r= -0.714, P <0.05), and a positive correlation between SOD activity and MDA level (r= 0.828, P <0.05) in rotenone group. In the rotenone plus erdosteine group, there was a negative correlation between XO activity and NO level in liver tissue (r= -0.833, P -0.05). In the light of these findings, erdosteine may be a protective agent for rotenone-induced liver oxidative injury in rats.

Evaluating the Ameliorative Potential of Quercetin against the Bleomycin-Induced Pulmonary Fibrosis in Wistar Rats

The current study deals with the effect of a dietary flavanoid quercetin on fibrotic lung tissue in rats. Bleomycin was administered by single intratracheal instillation to Wistar rats to induce lung fibrosis. The pathologies associated with this included significantly reduced antioxidant capacity, ultimately leading to protracted inflammation of the lung tissue. The hallmark of this induced fibrosis condition was an excessive collagen deposition in peribronchial and perialveolar regions of the lung. Oral quercetin treatment over a period of twenty days resulted in significant reversal of the pathologies. The antioxidant defense in lung tissue was revived. Moreover, activity of the collagenase MMP-7, which was high in fibrotic tissue, was seen restored after quercetin administration. Trichome staining of lung tissue sections showed high collagen deposition in fibrotic rats, which may be a direct result of increased mobilization of collagen by MMP-7. This was appreciably reduced in quercetin treated animals. These results point towards an important protective role of quercetin against idiopathic lung fibrosis, which remains a widely prevalent yet incurable condition in the present times.

Evaluating the inhibitory potential of sulindac against the bleomycin-induced pulmonary fibrosis in wistar rats

The present study examined the protective effect of sulindac on bleomycin-induced lung fibrosis in rats. Animals were divided into saline group, bleomycin group (single intra-tracheal instillation of bleomycin) and bleomycin+sulindac (orally from day 1 to day 20). Bleomycin administration reduced the body weight, altered antioxidant status (such as superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione) while it increased the lung weight, hydroxyproline content, collagen deposition and lipid peroxidation. However, simultaneous administration of sulindac improved the body weight, antioxidant status and decreased the collagen deposition in lungs. Moreover, the levels of inflammatory cytokine tumour necrosis factor-α increased in bleomycin-induced group, whereas, on treatment with sulindac the levels of tumour necrosis factor-α were found reduced. Finally, histological evidence also supported the ability of sulindac to inhibit bleomycin-induced lung fibrosis. The results of the present study indicate that sulindac can be used as an agent against bleomycin-induced pulmonary fibrosis.

Impact of caffeic acid phenethyl ester treatment on vancomycin-induced pancreatic damage in rats

This study investigates the preventive effect of caffeic acid phenethyl ester (CAPE) on pancreatic damage induced by vancomycin (VCM) in rats. Rats were equally divided into three groups: group I (control), group II (only VCM-treated group) and group III (VCM + CAPE-treated groups). VCM was intraperitoneally administered at a dose of 200 mg kg(-1)twice daily for 7 days. CAPE was administered orally at 10 µM mL(-1) kg(-1) dose once daily for 7 days. The first dose of CAPE administration was performed 24 h prior to VCM injection. Blood and pancreas tissue samples were removed and collected after the study. Serum alkaline phosphatase (ALP), amylase, γ-glutamyl transferase (GGT) and lipase activities were determined. Pancreas tissue samples were evaluated with the light microscope. Group II significantly increased serum ALP, amylase, GGT and lipase activities when compared with the control group. Group III significantly decreased serum ALP, amylase, GGT and lipase activities when compared with group II. In histopathological examination, it has been observed that there was a significant pancreatic damage in group II. CAPE exerted prominent structural protection against VCM-induced pancreatic damage and this effect was statistically significant. CAPE caused a marked reduction in the extent of pancreatic damage. We have concluded that it may play an important role in the VCM-induced pancreatic damage and reduce the pancreatic damage both at the biochemical and histopathological aspects.

Protective effect of dexpanthenol on bleomycin-induced pulmonary fibrosis in rats

Despite extensive studies, there is no effective treatment currently available other than pirfenidone for idiopathic pulmonary fibrosis. A protective effect of pantothenic acid and its derivatives on cell damage produced by oxygen radicals has been reported, but it has not been tested in bleomycin (BLM)--induced pulmonary fibrosis in rats. Therefore, we aimed to investigate the preventive effect of dexpanthenol (Dxp) on pulmonary fibrosis. Thirty-two rats were assigned to four groups as follows: (1) control group, (2) dexpanthenol (Dxp) group; 500 mg/kg Dxp continued intraperitoneally for 14 days, (3) bleomycin (BLM) group; a single intratracheal injection of BLM (2.5 mg/kg body weight in 0.25-ml phosphate buffered saline), and (4) BLM + Dxp-treated group; 500 mg/kg Dxp was administered 1 h before the intratracheal BLM injection and continued for 14 days i.p. The histopathological grades of lung inflammation and collagen deposition, tissue levels of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and myeloperoxidase (MPO) were measured. BLM provoked inflammation and collagen deposition (p < 0.0001), with a marked increase in myeloperoxidase (MPO) activity resembling increased inflammatory activity (p < 0.0001), which was prevented by Dxp (p < 0.0001, p = 0.02). BLM reduced tissue activities of SOD, GPx, and CAT compared to controls (p = 0.01, 0.03, 0.009). MDA was increased with BLM (p = 0.003). SOD (p = 0.001) and MDA (p = 0.016) levels were improved in group 4. The CAT levels in the BLM + Dxp group were close to those in the control group (p > 0.05). We showed that Dxp significantly prevents BLM-induced lung fibrosis in rats. Further studies are required to evaluate the role of Dxp in the treatment of lung fibrosis.

Effect of resveratrol on treatment of bleomycin-induced pulmonary fibrosis in rats

Resveratrol has a preventive potential on bleomycin-induced pulmonary fibrosis in prophylactic use; however, it was not studied in the treatment of the fibrosis. This study investigated the role of resveratrol on the treatment of bleomycin-induced pulmonary fibrosis. Intratracheal bleomycin (2.5 mg/kg) was given in fibrosis groups and saline in controls. First dose of resveratrol was given 14 days after bleomycin and continued until sacrifice. On 29th day, fibrosis in lung was estimated by Aschoft's criteria and hydroxyproline content. Bleomycine increased the fibrosis score (3.70 ± 1.04) and hydroxyproline levels (4.99 ± 0.90 mg/g tissue) as compared to control rats (1.02 ± 0.61 and 1.88 ± 0.59 mg/g), respectively. These were reduced to 3.16 ± 1.58 (P = 0.0001) and 3.08 ± 0.73 (P > 0.05), respectively, by resveratrol. Tissue malondialdehyde levels in the bleomycin-treated rats were higher (0.55 ± 0.22 nmol/mg protein) than that of control rats (0.16 ± 0.07; P = 0.0001) and this was reduced to 0.16 ± 0.06 by resveratrol (P = 0.0001). Tissue total antioxidant capacity is reduced (0.027 ± 0.01) by bleomycine administration when compared control rats (0.055 ± 0.012 mmol Trolox Equiv/mg protein; P = 0.0001) and increased to 0.041 ± 0.008 (P = 0.001) by resveratrol. We concluded that resveratrol has some promising potential on the treatment of bleomycin-induced pulmonary fibrosis in rats. However, different doses of the drug should be further studied.

N-Acetyl cysteine and erdosteine treatment in acetaminophen-induced liver damage

OBJECTIVE

This study is aimed to investigate the efficacy of erdosteine usage in acetaminophen-induced liver damage and to compare it with N-acetyl cysteine (NAC) in the treatment and prevention of liver toxicity due to overdose of acetaminophen.

METHODS

The rats were separated into the following six groups of seven rats each: control group; acetaminophen (1 g/kg, orally); acetaminophen (1 g/kg, orally) + erdosteine (150 mg/kg/day, orally); acetaminophen (1 g/kg, orally) + NAC (140 mg/kg loading dose, followed by 70 mg/kg, orally); NAC (140 mg/kg loading dose, followed by 70 mg/kg, orally); erdosteine (150 mg/kg/kg, orally), subsequently. In all the groups, potential liver injuries were evaluated using biochemical and hematological analyses, oxidant-antioxidant parameters and histopathological parameters.

RESULTS

In acetaminophen-treated group, levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total oxidant status (TOS) in the blood, prothrombin time (PT) and international normalized ratio (INR) were significantly increased when compared with controls. However, total antioxidant capacity (TAC) and glutathione (GSH) levels were decreased in group treated with acetaminophen, when compared with control group. Levels of AST, ALT and TOS, PT and INR were decreased in groups treated with NAC and erdosteine after acetaminophen administration, but the levels of TAC and GSH were increased. Histopathological improvements were observed in the groups treated with NAC and erdosteine after acetaminophen administration.

CONCLUSION

The present study demonstrated that, in the prevention of liver damage induced by acetaminophen intoxication, an early treatment with a single dose of erdosteine was beneficial instead of NAC administration.

Protective effects of a bacterially expressed NIF-KGF fusion protein against bleomycin-induced acute lung injury in mice

Current evidence suggests that the keratinocyte growth factor (KGF) and the polymorphonuclear leukocyte may play key roles in the development of lung fibrosis. Here we describe the construction, expression, purification, and identification of a novel NIF (neutrophil inhibitory factor)-KGF mutant fusion protein (NKM). The fusion gene was ligated via a flexible octapeptide hinge and expressed as an insoluble protein in Escherichia coli BL21 (DE3). The fusion protein retained the activities of KGF and NIF, as it inhibited both fibroblast proliferation and leukocyte adhesion. Next, the effects of NKM on bleomycin-induced lung fibrosis in mice were examined. The mice were divided into the following four groups: (i) saline group; (ii) bleomycin group (instilled with 5 mg/kg bleomycin intratracheally); (iii) bleomycin plus dexamethasone (Dex) group (Dex was given intraperitoneally (i.p.) at 1 mg/kg/day 2 days prior to bleomycin instillation and daily after bleomycin instillation until the end of the treatment); and (iv) bleomycin plus NKM group (NKM was given i.p. at 2 mg/kg/day using the same protocol as the Dex group). NKM significantly improved the survival rates of mice exposed to bleomycin. The marked morphological changes and increased hydroxyproline levels resulted from the instillation of bleomycin (on Day 17) in the lungs were significantly inhibited by NKM. These results revealed that NKM can attenuate bleomycin-induced lung fibrosis, suggesting that NKM could be used to prevent bleomycin-induced lung damage or other interstitial pulmonary fibrosis.

A further investigation concerning correlation between anti-fibrotic effect of liposomal quercetin and inflammatory cytokines in pulmonary fibrosis

It is widely accepted that inflammatory cells and cytokines play vital roles in the process of pulmonary fibrosis. The aim of this study was to evaluate the preventative effects of liposomal quercetin against bleomycin-induced pulmonary fibrosis in vivo. The underlying molecular mechanisms were also investigated. Bleomycin was injected intratracheally at a single dose of 5 U/kg for pulmonary fibrosis induction. Liposomal quercetin was intravenously injected 1 day prior to bleomycin administration and continued to the end of the study (for 4 weeks). Our results showed that liposomal quercetin diminished the increase of total cell counts and macrophage counts in bronchoalveolar lavage fluid. The neutrophil and lymphocyte counts were also significantly decreased both on day 7 and 14 after liposomal quercetin injection (P<0.05). The levels of TNF-alpha, IL-1beta, and IL-6 in bronchoalveolar lavage fluid at day 7 were strikingly reduced in liposomal quercetin treated group compared with bleomycin-induced group (TNF-alpha: 56.21+/-3.16 pg/ml vs.79.85+/-6.91 pg/ml; IL-1beta: 37.64+/-2.10 pg/ml vs. 73.29+/-5.78 pg/ml; IL-6: 88.52+/-5.96 pg/ml vs. 128.56+/-8.72 pg/ml; P<0.05). Moreover, the treatment with liposomal quercetin exerted approximately 35.8% reduction of the hydroxyproline content in contrast to the bleomycin-induced group (P<0.05). Histopathological assessment revealed that treatment with liposomal quercetin apparently lessened the lung fibrosis areas and collagen deposition accompanied with decreased expression of TGF-beta1. Thus, our results suggested that liposomal quercetin could attenuate the bleomycin-induced pulmonary fibrosis in vivo by the suppression of inflammatory cytokines.

Phosphodiesterase-5 inhibition by sildenafil citrate in a rat model of bleomycin-induced lung fibrosis

Sildenafil, a selective and potent inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase (PDE)5, has a relaxant effect on the smooth muscle cells of the arterioles supplying the human corpus cavernosum acting via nitric oxide (NO)-dependent mechanism. This study aimed to investigate the possible protective effect of sildenafil citrate on the extent of tissue integrity, oxidant-antioxidant status and neutrophil infiltration to the inflamed organ in a rat model of bleomycin-induced lung fibrosis. Lung fibrosis was induced by intratracheal administration of 0.1 ml of bleomycin hydrochloride (5 mg/kg in 0.9% NaCl) under anesthesia to Sprague-Dawley rats (200-250 g; n = 7-8 per group). Control rats received an equal volume of saline intratracheally. In the treatment groups, the rats were treated with either sildenafil citrate (10 mg/kg per day; subcutaneously) or saline for 14 days. Another group of rats were administered subcutaneously with N(G)-nitro-l-arginine methyl ester (l-NAME; 20 mg/kg in 0.9% NaCl) 5 min after sildenafil injections. After decapitation, the lungs were excised and taken for microscopic evaluation or stored for the measurement of malondialdehyde (MDA) and glutathione (GSH) levels, and myeloperoxidase (MPO) activity, and for the assessment of apoptosis. Trunk blood was collected for the assessment of serum tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta levels. In the group with lung fibrosis, the lung tissue was characterized by microscopic lesions, increased lipid peroxidation with a concomitant reduction in GSH content, increased MPO activity and apoptosis. Serum TNF-alpha and IL-1beta levels were higher in the lung fibrosis group compared to control values. Sildenafil reversed tissue MDA levels, MPO activity and serum pro-inflammatory cytokine levels, and preserved GSH content although its effect on the extent of tissue lesion and apoptosis was not statistically significant. Treatment with l-NAME reversed the effect of sildenafil on GSH content. In conclusion, sildenafil citrate administration to rats with bleomycin-induced lung fibrosis seems to be beneficial via prevention of lipid peroxidation, cytokine production and/or release and neutrophil accumulation.

Erdosteine modulates radiocontrast-induced hepatotoxicity in rat

It has been suggested that reactive oxygen species (ROS) plays an important role in radio contrast media (RCM)-induced ischemia reperfusion tissue injury although antioxidants may have protective effects on the injury. We investigated the effects of erdosteine as an antioxidant agent on RCM-induced liver toxicity in rats by evaluation of lipid peroxidation (as TBARS), catalase (CAT), superoxide dismutase (SOD), reduced glutathione (GSH) and glutathione peroxidase (GSH-Px) values and histological evaluation. Twenty-one rats were equally divided into three groups as follows: control, RCM, and RCM plus erdosteine. RCM was intraperitoneally administered for 1 day. Erdosteine was administered orally for 2 days after RCM administration. Liver samples were taken from the rats and they homogenized in a motor-driven tissue homogenizer. TBARS levels were significantly (p < 0.005) higher in RCM group than in control although SOD activities significantly (p < 0.05) decreased in RCM group. TBARS levels were lower in RCM plus erdosteine group than in control although SOD activity and GSH level increased (p < 0.05) in liver as compared to RCM alone. Erdosteine showed also histopathological protection (p < 0.0001) against RCM induced hepatotoxicity. GSH-Px and CAT activities were not statistically changed by the erdosteine. According to our results, it can be concluded that radiocontrast media can induce oxidative stress in liver as suggested by previous studies. Erdosteine seems to be protective agent on the radiocontrast media-induced liver toxicity by inhibiting the production of ROS via the enzymatic antioxidant system.

The protective effect of erdosteine on short-term global brain ischemia/reperfusion injury in rats

Experimental studies have demonstrated that free radicals play a major role on neuronal injury during ischemia/reperfusion (I/R) in rats. Erdosteine is a thioderivative endowed with mucokinetic, mucolytic and free-radical-scavenging properties. The aim of the present study was to investigate the effect of erdosteine treatment against short-term global brain ischemia/reperfusion injury in rats. The study was carried out on Wistar rats divided into four groups. (i) Control group, (ii) ischemia/reperfusion group, (iii) ischemia/reperfusion+erdosteine group, and (iv) erdosteine group. Superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities as well as thiobarbituric acid reactive substances (TBARSs) and nitric oxide (NO) levels were analysed in erythrocyte and plasma of rats. Plasma NO levels were significantly higher in the ischemia/reperfusion group than the other groups. The activities of SOD and GSH-Px were decreased, while TBARS levels increased in the ischemia/reperfusion group compared to other groups in both plasma and erythrocyte. The erythrocyte CAT activity was higher in erdosteine group and there was a statistically significant increase, when compared with the erdosteine plus ischemia/reperfusion group. By treating the rats with erdosteine, the depletion of endogenous antioxidant enzymes (SOD, CAT, GSH-Px) and increase of TBARS and NO levels were prevented. This study, therefore, suggests that erdosteine reduces parameters of oxidative stress is well supported by the data.

Effects of erdosteine on bleomycin-induced lung fibrosis in rats

This study was designed to examine the effects of erdosteine on bleomycin (BLM)-induced lung fibrosis in rats. Thirty-three Sprague-Dawley rats were divided randomly into three groups, bleomycin alone (BLM), bleomycin + erdosteine (BLM + ERD), and saline alone (control). The BLM and BLM + ERD groups, were given 2.5 mg/kg BLM intratracheally. The first dose of oral erdosteine (10 mg/kg/day) in the BLM + ERD group was started 2 days before BLM administration and continued until animals were sacrificed. Animals were sacrificed 14 days after intratracheal instillation of BLM. The effect of erdosteine on pulmonary fibrosis was studied by analysis of bronchoalveolar lavage (BAL) fluid, histopathology, and biochemical measurements of lung tissue superoxide dismutase (SOD) and glutathione (GSH) as antioxidants, malondialdehyde (MDA) as an index for lipid peroxidation, and nitrite/nitrate levels. Bleomycin-induced lung fibrosis as determined by lung histology was prevented with erdosteine (grades of fibrosis were 4.9, 2.3, and 0.2 in BLM, BLM + ERD, and control groups, respectively). Erdosteine also prevented bleomycin-induced increase in MDA (MDA levels were 0.50 +/- 0.15, 0.11 +/- 0.02, and 0.087+/- 0.03 nmol/mg protein in BLM, BLM + ERD, and control groups, respectively) and nitrite/nitrate (nitrite/nitrate levels were 0.92 +/- 0.06, 0.60 +/- 0.09, and 0.56+/- 0.1 micromol/mg protein in BLM, BLM + ERD, and control groups respectively) levels. Bleomycin-induced decrease in GSH and SOD levels in the lung tissue also prevented by erdosteine [(GSH levels were 213.5 +/- 12.4, 253.2+/- 25.2, and 287.9+/- 34.4 nmol/mg protein) (SOD levels were 1.42+/- 0.12, 1.75+/- 0.17, and 1.89+/- 0.09 U/mg protein) in BLM, BLM + ERD, and control groups respectively]. Erdosteine prevented bleomycin-induced increases in total cell number and neutrophil content of the BAL fluid. In conclusion, oral erdosteine is effective in prevention of BLM-induced lung fibrosis in rats possibly via the repression of neutrophil accumulation, inhibition of lipid peroxidation, and maintenance of antioxidant and free radical scavenger properties.

Epigallocatechin-3-gallate augments antioxidant activities and inhibits inflammation during bleomycin-induced experimental pulmonary fibrosis through Nrf2-Keap1 signaling

The mechanism involved in the enhancement of antioxidant activities and resolved inflammation after epigallocatechin-3-gallate (EGCG) treatment during bleomycin-induced pulmonary fibrosis is investigated in this study. The levels of reactive-oxygen species (ROS), lipid peroxidation (LPO), hydroxyproline and the activity of myeloperoxidase (MPO) were increased due to bleomycin challenge and were brought back to near normal status on EGCG supplementation. The decreased antioxidant status due to bleomycin challenge was also restored upon EGCG treatment. Bleomycin-induced rats showed increased cell counts as compared to control and EGCG-treated rats. Histopathological analysis showed increased inflammation and alveolar damage, while picrosirius red staining showed an increased collagen deposition in bleomycin-challenged rats that were decreased upon EGCG treatment. Immunohistochemical, immunofluorescent and immunoblot studies revealed that EGCG supplementation decreased the levels of nuclear factor-kappaB (NF-kappaB), tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta), which were increased upon bleomycin induction. The declined activities of Phase II enzymes such as glutathione-S-transferase (GST) and NAD(P)H:quinone oxidoreductase 1 (NQO1) in bleomycin-injured rats were restored upon EGCG treatment. Confocal microscopy, immunoblot and RT-PCR studies confirm that EGCG is a potent inducer of NF-E2-related factor 2 (Nrf2). Expression of Kelch like ECH-associated protein (Keap)-1, a vital factor in Nrf2 signaling cascade was analyzed by immunoblotting. However, there was no significant change in the expression of Keap1 in control and experimental groups. This study demonstrates the involvement of Nrf2-Keap1 signaling through which EGCG enhances antioxidant activities and Phase II enzymes with subsequent restraint inflammation during bleomycin-induced pulmonary fibrosis.

Effects of Erdosteine on Acetaminophen-induced Hepatotoxicity in Rats

We investigated the effects of erdosteine on acetaminophen (APAP)-induced hepatotoxicity in rats. Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), AST (aspartate aminotransferase), and ALT (alanine transaminase) activities, and malonyldialdehyde (MDA) and nitric oxide levels as oxidant/antioxidant biochemical parameters were investigated with light microscopic evaluation in adult female Wistar Albino rats. APAP administration produced a decrease in hepatic SOD, CAT, and GSH-Px activities, and coadministration of erdosteine (150 and 300 mg/kg) resulted in increases in the activities. MDA and NO levels increased in the APAP group, and erdosteine treatments prevented these increases. Significant elevations in serum AST and ALT levels were observed in the APAP group, and when erdosteine and APAP were coadministered, their serum levels were close to those in the control group. Light microscopic evaluation of livers showed that there were remarkable centrilobular (zone III) hepatic necrosis and mild to moderate sinusoidal congestion in the APAP group, whereas in the erdosteine group, cellular necrosis was minimal and the hepatocytes maintained a better morphology when compared to the APAP group. Erdosteine prevented APAP-induced liver injury and toxic side effects probably through the antioxidant and radical scavenging effects of erdosteine.

Antioxidants as potential therapeutics for lung fibrosis

Interstitial lung disease encompasses a large group of chronic lung disorders associated with excessive tissue remodeling, scarring, and fibrosis. The evidence of a redox imbalance in lung fibrosis is substantial, and the rationale for testing antioxidants as potential new therapeutics for lung fibrosis is appealing. Current animal models of lung fibrosis have clear involvement of ROS in their pathogenesis. New classes of antioxidant agents divided into catalytic antioxidant mimetics and antioxidant scavengers are being developed. The catalytic antioxidant class is based on endogenous antioxidant enzymes and includes the manganese-containing macrocyclics, porphyrins, salens, and the non-metal-containing nitroxides. The antioxidant scavenging class is based on endogenous antioxidant molecules and includes the vitamin E analogues, thiols, lazaroids, and polyphenolic agents. Numerous studies have shown oxidative stress to be associated with many interstitial lung diseases and that these agents are effective in attenuating fibroproliferative responses in the lung of animals and humans.

Oxidative stress, plasminogen activator inhibitor 1, and lung fibrosis

Fibrosis is characterized by excessive accumulation of extracellular matrix (ECM) in basement membranes and interstitial tissues, resulting from increased synthesis or decreased degradation of ECM or both. The plasminogen activator/plasmin system plays an important role in ECM degradation, whereas the plasminogen activator inhibitor 1 (PAI-1) is a physiologic inhibitor of plasminogen activators. PAI-1 expression is increased in the lung fibrotic diseases and in experimental fibrosis models. The deletion of the PAI-1 gene reduces, whereas the overexpression of PAI-1 enhances, the susceptibility of animals to lung fibrosis induced by different stimuli, indicating an important role of PAI-1 in the development of lung fibrosis. Many growth factors, including transforming growth factor beta (TGF-beta) and tumor necrosis factor alpha (TNF-alpha), as well as other chemicals/agents, induce PAI-1 expression in cultured cells and in vivo. Reactive oxygen and nitrogen species (ROS/RNS) have been shown to mediate the induction of PAI-1 by many of these stimuli. This review summarizes some recent findings that help us to understand the role of PAI-1 in the development of lung fibrosis and ROS/RNS in the regulation of PAI-1 expression during fibrogenesis.

Enhancement of antioxidant defense system by epigallocatechin-3-gallate during bleomycin induced experimental pulmonary fibrosis

Oxidative stress resulting from an imbalance between radical-generating and radical scavenging systems plays an important role in the pathogenesis of pulmonary fibrosis. Epigallocatechin-3-gallate (EGCG), a polyphenol and a major component of green tea, possess a potent antioxidant property. This study was designed to evaluate the potential antioxidative activity of EGCG in the plasma and lungs during bleomycin induced experimental pulmonary fibrosis. Intratracheal administration of bleomycin (6.5 U/kg body weight) to rats resulted in significant reduction of body weight, enzymic antioxidants (superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase) and non-enzymic antioxidants (reduced glutathione, vitamin C, vitamin E and vitamin A). Elevations in lung W/D (wet weight/dry weight) ratio, hydroxyproline content was observed with a synchronized increase in lipid peroxidation markers (thiobarbituric acid reactive substances and hydroperoxides). Intraperitoneal administration of EGCG at a dose of 20 mg/kg body weight significantly improved the body weight, enzymic and non enzymic antioxidants and considerably decreased the W/D ratio, hydroxyproline and lipid peroxidation marker levels. Histological observations also correlated with the biochemical parameters. Thus, this study confirms the beneficial use of EGCG in alleviating the oxidative stress induced during pulmonary fibrosis.

Protective effect of Houttuynia cordata extract on bleomycin-induced pulmonary fibrosis in rats

The present study aimed to examine the antioxidant properties of Houttuynia cordata (HC) and its protective effect on bleomycin-induced pulmonary fibrosis in rats. Results showed that aqueous extract of HC exhibited a different magnitude of antioxidant activities in all model systems tested. Although HC showed weaker free radical scavenging and xanthine oxidase inhibitory activity than vitamin E, its anti-lipid peroxidation activity in rat liver homogenate was close to that of vitamin E. In animal studies, HC significantly decreased the levels of superoxide dismutase, malondialdehyde, hydroxyproline, interferon-gamma, and tumor necrosis factor-alpha. However, an increase in the concentration of catalase was noted in the bronchoalveolar lavage fluid. HC also remarkably improved the morphological appearance of the lung of bleomycin-treated rats. These results suggest that HC possesses a protective effect against bleomycin-induced pulmonary fibrosis. Interestingly, this protective effect was more pronounced than that of vitamin E. In conclusion, the protective effect of HC on pulmonary fibrosis could be partly associated with the reduction of oxidative damage caused by bleomycin.

Inflammatory related changes in lung tissue mechanics after bleomycin-induced lung injury

The impact of lung remodelling in respiratory mechanics has been widely studied in bleomycin-induced lung injury. However, little is known regarding the relationship between the amount of lung inflammation and pulmonary tissue mechanics. For this purpose, rats were intratracheally instilled with bleomycin (n=29) or saline (n=8) and sacrificed at 3, 7, or 15 days. Forced oscillatory mechanics as well as indices of remodelling (elastic fibre content and hydroxyproline) and inflammation (myeloperoxidase content, total cell count, alveolar wall thickness, and lung water content) were studied in lung tissue strips. Tissue resistance increased significantly at day 15, while hysteresivity was significantly higher in bleomycin group compared to control at all time points. Elastic fibres, hydroxyproline and myeloperoxidase contents augmented after bleomycin at days 7 and 15. Tissue resistance and hysteresivity were significantly correlated with myeloperoxidase, elastic fibre and lung water content. In conclusion, inflammatory structural changes and elastogenesis are the main determinants for hysteretic changes in this 2-week bleomycin-induced lung injury model.

Examination of lung toxicity, oxidant/antioxidant status and effect of erdosteine in rats kept in coal mine ambience

Occupational exposure to coal dust causes pneumoconiosis and other diseases. Reactive oxygen species (ROS) have been implicated in the pathogenesis of coal dust-induced lung toxicity. In this experimental study, we investigated the oxidant/antioxidant status, nitric oxide (NO) and hydroxyproline (HP) levels in lungs and blood of rats exposed to coal dust in mine ambience. In addition, we also investigated the attenuating effects of erdosteine. At the end of the experiment processes, tissue levels of HP, malondialdehyde (MDA) and NO, as well as the activities of superoxide dismutase, glutathione peroxidase, catalase, xanthine oxidase (XO), myeloperoxidase (MPO) and proinflammatory cytokines (IL-6 and TNF-α) were evaluated in the lung tissues, plasma samples or erythrocytes of rats. Exposure to coal dust resulted in a significant increase in the oxidant parameters (MDA, NO levels, and XO activity) and HP levels, as compared to the controls. A decrease in activities of antioxidant enzymes, and an increase in MPO activity were found in the study group, compared to the controls. Increased NO levels of lung were found in the study groups, that were significantly reduced by erdosteine. Our studies provide evidence that supports the hypothesis for ROS mediated coal workers' pneumoconiosis. Erdosteine may be beneficial in the coal dust-induced lung toxicity via antioxidant and free radical scavenger properties.

The bleomycin animal model: a useful tool to investigate treatment options for idiopathic pulmonary fibrosis?

Different animal models of pulmonary fibrosis have been developed to investigate potential therapies for idiopathic pulmonary fibrosis (IPF). The most common is the bleomycin model in rodents (mouse, rat and hamster). Over the years, numerous agents have been shown to inhibit fibrosis in this model. However, to date none of these compounds are used in the clinical management of IPF and none has shown a comparable antifibrotic effect in humans. We performed a systematic review of publications on drug efficacy studies in the bleomycin model to evaluate the value of this model regarding transferability to clinical use. Between 1980 and 2006 we identified 240 experimental studies describing beneficial antifibrotic compounds in the bleomycin model. 222 of those used a preventive regimen (drug given < or =7 days after last bleomycin application), only 13 were therapeutic trials (>7 days after last bleomycin application). In 5 studies we did not find enough details about the timing of drug application to allow inter-study comparison. It is critical to distinguish between drugs interfering with the inflammatory and early fibrogenic response from those preventing progression of fibrosis, the latter likely much more meaningful for clinical application. All potential antifibrotic compounds should be evaluated in the phase of established fibrosis rather than in the early period of bleomycin-induced inflammation for assessment of its antifibrotic properties. Further care should be taken in extrapolation of drugs successfully tested in the bleomycin model due to partial reversibility of bleomycin-induced fibrosis over time. The use of alternative and more robust animal models, which better reflect human IPF, is warranted.

Protective effects of erdosteine on doxorubicin-induced hepatotoxicity in rats

BACKGROUND

Oxidative stress has an important role in the pathogenesis of doxorubicin-induced hepatotoxicity. The aim of this study was to investigate the hepatoprotective effects of erdosteine, an antioxidant agent, on doxorubicin-induced hepatotoxicity.

METHODS

Rats were divided into control, doxorubicin alone (20 mg/kg, i.p.) and doxorubicin plus erdosteine (50 mg/kg/day, oral) groups. At the end of the 10(th) day, liver tissues were removed for light microscopy and analysis. The levels of tissue protein carbonyl content, malondialdehyde and nitric oxide, as well as the activities of superoxide dismutase, catalase, were determined.

RESULTS

The tissue of the doxorubicin group showed some histopathological changes such as necrosis, hepatocyte degeneration, sinusoidal dilatation, hemorrhage and vascular congestion and dilatation. In the doxorubicin plus erdosteine group, histopathological evidence of hepatic damage was markedly reduced. Biochemical parameters were consistent with histological parameters.

CONCLUSIONS

Doxorubicin caused hepatotoxicity, and erdosteine treatment prevented lipid peroxidation and protein oxidant in liver tissue.

Erdosteine treatment attenuates oxidative stress and fibrosis in experimental biliary obstruction

Oxidative stress, in particular lipid peroxidation, induces collagen synthesis and causes fibrosis. The aim of this study was to assess the antioxidant and antifibrotic effects of erdosteine on liver fibrosis induced by biliary obstruction in rats. Liver fibrosis was induced in Wistar albino rats by bile duct ligation (BDL). Erdosteine (10 mg/kg, orally) or saline was administered for 28 days. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) levels were determined to assess liver functions and tissue damage, respectively. Pro-inflammatory cytokines, TNF-alpha, IL-1beta and IL-6 and antioxidant capacity (AOC) were assayed in plasma samples. Liver tissues were taken for determination of malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity and collagen content. Production of reactive oxidants was monitored by chemiluminescence assay. Serum AST, ALT, LDH, and plasma cytokines were elevated in the BDL group as compared to controls and were significantly decreased by erdosteine treatment. Hepatic GSH level and plasma AOC, depressed by BDL, were elevated back to control level with erdosteine treatment. Furthermore, hepatic luminol and lucigenin chemiluminescence (CL), MDA level, MPO activity and collagen content in BDL group increased dramatically compared to control and reduced by erdosteine treatment. Since erdosteine administration alleviated the BDL-induced oxidative injury of the liver and improved the hepatic functions, it seems likely that erdosteine with its antioxidant and antifibrotic properties, may be of potential therapeutic value in protecting the liver fibrosis and oxidative injury due to biliary obstruction.

Protective effect of α-tocopherol on oxidative stress in experimental pulmonary fibrosis in rats

The study was undertaken to investigate the influence of alpha-tocopherol (vitamin E) on malondialdehyde (MDA) and glutathione (GSH) levels and catalase (CAT) activity in lung of rats with bleomycin-induced pulmonary fibrosis (PF). Fourteen Wistar-albino rats were randomly divided into two groups of seven animals each. The first group was treated intra-tracheally with bleomycin hydrochloride (BM group); the second group was also instilled with BM but received injections of alpha-tocopherol twice a week (BM + E group). The third group was treated in the same manner with saline solution only, acting as controls (C). There were decreases in GSH level and CAT activity while an increase in MDA level in BM group was found compared to the control group (p < 0.05). Vitamin E had a regulator effect on these parameters. After administration of alpha-tocopherol, the increase in GSH level and CAT activity and the decrease in MDA level were seen in BM + E group compared to BM group (p < 0.05). Distinct histopathological changes were found in the BM group compared to the untreated rats. Less severe fibrotic lesions were also observed in the BM + E group. The results show that vitamin E is effective on the prevention of BM-induced PF, as indicated by differences in the lung levels of oxidants and antioxidants.

Hypobaric-hypoxia-induced pulmonary damage in rats ameliorated by antioxidant erdosteine

Free radical-mediated injury to lung and pulmonary vasculature is an important mechanism in hypoxia-induced lung damage. In this study, we aimed to investigate the potential protective effects of erdosteine as an antioxidant agent on hypobaric hypoxia-induced pulmonary hypertension. Adult male rats were assigned randomly to three groups. The first group of rats was exposed to hypobaric-hypoxia and the second group was treated with erdosteine (20mg/kg, daily) for 2 weeks, during which time they were in a hypoxic chamber. These groups were compared with normoxic controls. All rats were sacrificed after 2 weeks. The hypoxia-induced increase in right ventricle to left ventricle plus septum weight ratio (from 0.20+/-0.01 to 0.26+/-0.01) was reduced significantly in the erdosteine-treated group (0.23+/-0.01). Malondialdehyde levels were elevated (from 0.33+/-0.11 to 0.59+/-0.02) and total antioxidant status was not changed significantly (from 1.77+/-0.42 to 2.61+/-0.23) by hypoxia. In contrast to the hypoxia-exposed group, malondialdehyde levels were significantly decreased in the erdosteine-treated group (0.37+/-0.02). Total antioxidant status (4.03+/-0.22) was significantly higher in erdosteine-treated rats when compared to non-treated rats. Histopathological examination demonstrated that erdosteine prevented inflammation and protected lung parenchyma and pulmonary endothelium of hypoxia-exposed rats.

Preventive effect of melatonin on bleomycin-induced lung fibrosis in rats

Oxidative stress has an important role in the pathogenesis of idiopathic pulmonary fibrosis. Melatonin has direct and indirect free radical-detoxifying activity. The present study investigated whether melatonin treatment attenuates bleomycin-induced lung fibrosis in rats. A group of rats was given one dose of bleomycin while the control animals were given saline. The first dose of melatonin (4 mg/kg/day) was given 2 days before the bleomycin injection. At day 14, fibrotic changes were evaluated using Aschoft's criteria and lung hydroxyproline content. Bleomycin produced a 2.7-fold rise in the fibrosis score that was decreased 65% by melatonin (P < 0.05) and a 1.4-fold increase in hydroxyproline content which was completely prevented by melatonin. Protein carbonyl and thiobarbituric acid reactive substances levels, which were significantly elevated in the bleomycin treated rats, were significantly attenuated by melatonin. Bleomycin administration significantly reduced the activities of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in lung tissue. The reduction in CAT activity was prevented by melatonin but SOD and GSH-Px were not influenced. These results revealed that melatonin may prevent the development of bleomycin-induced lung fibrosis via the repression of protein and lipid peroxidation.

Protective agent, erdosteine, against cisplatin-induced hepatic oxidant injury in rats

Cisplatin, one of the most active cytotoxic agents against cancer, has several toxicities. Hepatotoxicity is one of them occurred during high doses treatment. The aim of this study was to determine the effects of erdosteine against cisplatin-induced liver injury through tissue oxidant/antioxidant parameters and light microscopic evaluation. The rats were randomly divided into three groups: control (n=5), cisplatin (10 mg/kg, n=6) and cisplatin+erdosteine (50 mg/kg/day oral erdosteine, n=8) groups. The rats were sacrificed at the 5th day of cisplatin treatment. The liver tissues were examined with light microscopy and oxidant/antioxidant biochemical parameters. The malondialdehyde (MDA) and nitric oxide (NO) levels were increased in the cisplatin group in comparison with the control and cisplatin+erdosteine groups (p<0.05). There was no significant difference in MDA and NO levels between control and cisplatin+erdosteine groups. The activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) were higher in cisplatin+erdosteine group than cisplatin group (p<0.05). However, the CAT and GSH-Px activities were significantly lower in cisplatin group than in control group (p<0.05). The light microscopic examination revealed that cytoplasmic changes especially around cells of central vein were observed in cisplatin group. Hepatocellular vacuolization was seen in these cells. In the cisplatin plus erdosteine group, a decrease in cytoplasmic changes with the hepatocytes and sinusoidal dilatations around cells of central vein were noticed in as compared to cisplatin group. In the light of microscopic and biochemical results, it was concluded that cisplatin-induced liver damage in high dose and erdosteine prevented this toxic side effect by the way of its antioxidant and radical scavenging effects.

The effects of isoniazid on hippocampal NMDA receptors: Protective role of Erdosteine

Isoniazid (INH) has neurotoxic effects such as seizure, poor concentration, subtle reduction in memory, anxiety, depression and psychosis. INH-induced toxic effects are thought to be through increased oxidative stress, and these effects have been shown to be prevented by antioxidant therapies in various organs. Increased oxidative stress may be playing a role in these neurotoxic effects. N-methyl D-aspartat receptors (NMDA) are a member of the ionotropic group of glutamate receptors. These receptors are involved in a wide variety of processes in the central nervous system including synaptogenesis, synaptic plasticity, memory and learning. Erdosteine is a potent antioxidant and mucolytic agent. We aimed to investigate adverse effects of INH on rat hippocampal NMDAR receptors, and to elucidate whether erdosteine prevents possible adverse effects of INH. In the present study, compared to control group, NMDAR2A (NR2A) receptors were significantly decreased and malondialdehyde (MDA), end product of lipid peroxidation, production was significantly increased in INH-treated group. On the other hand, administration of erdosteine to INH-treated group significantly increased NR2A receptors and decreased MDA production. In conclusion, decreasing NR2A receptors in hippocampus and increasing lipid peroxidation correlates with the degree of oxidative effects of INH and erdosteine protects above effect of INH on NR2A receptors and membrane damage due to lipid peroxidation by its antioxidant properties.

Effects of aminoguanidine and antioxidant erdosteine on bleomycin-induced lung fibrosis in rats

Reactive oxygen and nitrogen species have been implicated in the pathogenesis of bleomycin-induced lung fibrosis. The effects of aminoguanidine and erdosteine on the bleomycin-induced lung fibrosis were evaluated in rats. The animals were placed into five groups: Vehicle + vehicle, vehicle + bleomycin (2.5 U/kg), bleomycin + aminoguanidine (200 mg/kg), bleomycin + erdosteine (10 mg/kg), and bleomycin + erdosteine + aminoguanidine. Bleomycin administration resulted in prominent lung fibrosis as measured by lung hydroxyproline content and lung histology, which is completely prevented by erdosteine and aminoguanidine. A strong staining for nitro tyrosine antibody in lung tissue and increased levels of lung NO were found in bleomycin group, that were significantly reduced by aminoguanidine and erdosteine. Aminoguanidine and erdosteine significantly prevented depletion of superoxide dismutase and glutathione peroxidase and elevated myeloperoxidase activities, malondialdehyde level in lung tissue produced by bleomycin. Data presented here indicate that aminoguanidine and erdosteine prevented bleomycin-induced lung fibrosis and that nitric oxide mediated tyrosine nitration of proteins plays a significant role in the pathogenesis of bleomycin-induced lung fibrosis. Also our data suggest that antifibrotic affect of antioxidants may be due to their inhibitory effect on nitric oxide generation in this model.

Attenuation of bleomycin-induced lung fibrosis by oral sulfhydryl containing antioxidants in rats: erdosteine and N-acetylcysteine

Antioxidant therapy may be useful in diseases with impaired oxidant antioxidant balance such as lung fibrosis. The effects of sulfhydryl-containing antioxidant agents N-acetylcysteine (NAC) and erdosteine on the bleomycin-induced lung fibrosis were compared in rats. The animals were divided into four groups: Vehicle + vehicle, vehicle + bleomycin (2.5 U/kg), bleomycin + (10 mg/kg), and bleomycin + NAC (3 mmol/kg). Bleomycin administration resulted in prominent lung fibrosis as measured by lung hydroxyproline content and lung histology which is almost completely prevented by erdosteine and NAC. Hydroxyproline content was 18.7 +/- 3.5 and 11.2 +/- 0.6 mg/g dried tissue in bleomycin and saline treated rats, respectively (P < 0.001), and this level was 11.3 +/- 1.2 and 13.8 +/- 1.2 mg/g dried tissue in erdosteine and NAC pretreated, respectively. Erdosteine and NAC significantly reduced depletion of glutathione peroxidase, and prevented increases in myeloperoxidase activities, nitric oxide, and malondialdehyde levels in lung tissue produced by bleomycin. Data presented here indicate that erdosteine and NAC similarly prevented bleomycin-induced lung fibrosis and their antioxidant effects were also similar in this experiment.