Protective effects of S-methylisothiourea sulfate on different aspiration materials-induced lung injury in rats

The effect of methylene blue treatment on aspiration pneumonia

BACKGROUND

The study aimed to examine whether methylene blue (MB) prevents different pulmonary aspiration materials-induced lung injury in rats.

METHODS

The experiments were designed in 60 Sprague-Dawley rats, ranging in weight from 250-300 g, randomly allotted into one of six groups (n = 10): saline control, Biosorb Energy Plus (BIO), hydrochloric acid (HCl), saline + MB treated, BIO + MB treated, and HCl + MB treated. Saline, BIO, and HCl were injected into the lungs in a volume of 2 mL/kg. After surgical procedure, MB was administered intraperitoneally for 7 days at a daily dose of 2 mg/kg per day. Seven days later, rats were killed, and both lungs in all groups were examined biochemically and histopathologically.

RESULTS

Our findings show that MB inhibits the inflammatory response reducing significantly (P < 0.05) peribronchial inflammatory cell infiltration, alveolar septal infiltration, alveolar edema, alveolar exudate, alveolar histiocytes, interstitial fibrosis, granuloma, and necrosis formation in different pulmonary aspiration models. Pulmonary aspiration significantly increased the tissue hydroxyproline content, malondialdehyde levels, and decreased (P < 0.05) the antioxidant enzyme (superoxide dismutase and glutathione peroxidase) activities. MB treatment significantly (P < 0.05) decreased the elevated tissue hydroxyproline content and malondialdehyde levels and prevented the inhibition of superoxide dismutase and glutathione peroxidase (P < 0.05) enzymes in the tissues. Furthermore, there is a significant reduction in the activity of inducible nitric oxide synthase (iNOS), terminal deoxynucleotidyl transferase dUTP nick end labeling, and arise in the expression of surfactant protein D in lung tissue of different pulmonary aspiration models with MB therapy.

CONCLUSIONS

MB treatment might be beneficial in lung injury and therefore shows potential for clinical use.

The protective effect of melatonin and S-methylisothiourea treatments in nitrogen mustard induced lung toxicity in rats

OBJECTIVES

Mustard is highly toxic to the lung. Its toxic effects are associated with inflammatory cell accumulation and increased pro-inflammatory cytokines as well as reactive oxygen and nitrogen species. In this study, we aimed to investigate the efficiency of melatonin (MEL) and S-methylisothiourea (SMT) on mechlorethamine (MEC) induced lung toxicity.

METHODS

Thirty-six male rats were randomly divided into four groups: control, MEC, MEC+MEL, and MEC+SMT. Control group was given saline only via transdermal route. Other groups were exposured to a single dose of MEC (3.5 mg/kg) via transdermal route. MEL (100 mg/kg) was administered intraperitoneally 30 min after the application of MEC, and after the same dose of MEL was given every 12 h for a total of six doses. SMT (50 mg/kg) was also given intraperitoneally 30 min after the application of MEC.

RESULTS

MEC injection resulted in alveolar epithelial injury, hemorrhage, inflammation, edema and interalveolar septal thickening in the lung tissues. The tissue TNF-α, IL-1β, and nitrate/nitrite (NOx) levels were found significantly different for all groups (p<0.001). TNF-α and IL-1β levels increased significantly with MEC exposure, and MEL and SMT ameliorated these increases in lung tissues. MEC also elevated NOx levels in lung tissue. Melatonin showed meaningful protection against lung injury. But protection of SMT was weaker.

CONCLUSION

Inflammation plays an important role in the MEC induced lung toxicity as well as oxidative and nitrosative stress. Melatonin has also anti-inflammatory properties similar to SMT, as well as anti-oxidant properties. But melatonin treatment was found more efficient than SMT treatment.

Desferrioxamine reduces oxidative stress in the lung contusion

Our hypothesis in this study is that desferrioxamine (DFX) has therapeutic effects on experimental lung contusions in rats. The rats were divided into four groups (n = 8): control, control+DFX, contusion, and contusion+DFX. In the control+DFX and contusion+DFX groups, 100 mg/kg DFX was given intraperitoneally once a day just after the contusion and the day after the contusion. Contusions led to a meaningful rise in the malondialdehyde (MDA) level in lung tissue. MDA levels in the contusion+DFX group experienced a significant decline. Glutathione levels were significantly lower in the contusion group than in the control group and significantly higher in the contusion+DFX group. Glutathione peroxidase (GPx) and superoxide dismutase (SOD) levels in the contusion group were significantly lower than those in the control group. In the contusion+DFX group, SOD and GPx levels were significantly higher than those in the contusion group. In light microscopic evaluation, the contusion and contusion+DFX groups showed edema, hemorrhage, alveolar destruction, and leukocyte infiltration. However, histological scoring of the contusion+DFX group was significantly more positive than that of the contusion group. The iNOS staining in the contusion group was significantly more intensive than that in all other groups. DFX reduced iNOS staining significantly in comparison to the contusion group. This study showed that DFX reduced oxidative stress in lung contusions in rats and histopathologically ensured the recovery of the lung tissue.

Analysis of the protective biochemical and pathologic effects of aminoguanidine on an experimental aspiration pneumonitis model induced by bile acids

BACKGROUND

Gastroesophageal reflux (GER) is a common clinical pathology detected in childhood. Bile acids (BAs) are present in reflux and cause various pathologies in the esophagus, the larynx, and the lungs.

OBJECTIVE

We aimed to show if aminoguanidine (AG) contributes to the biochemical and histopathologic treatment of experimental aspiration pneumonitis induced by BAs.

METHODS

Twenty-eight female Sprague Dawley rats were used. There were 4 groups in the study: (1) group aspirated with 0.9% saline (n = 7), (2) group aspirated with 0.9% saline and treated with AG (n = 7), (3) group aspirated with a solution of 10 mg/kg taurocholic acid and 5 mg/kg taurochenodeoxycholate (n = 7), and (4) group aspirated with BA and treated with AG (n = 7). The saline and BA solutions were administered as 1 mL/kg intratracheally. The AG was administered intraperitoneally twice a day at a 150 mg/kg dose for 7 days. The different histopathologic and biochemical parameters were analyzed.

RESULTS

Clara cell protein 16 and malondialdehyde levels were found to be significantly higher in the BA group than in the group where saline was administered; however, they were significantly lower in the BA + AG group than in the BA group. The total superoxide dismutase activity decreased significantly in the BA group compared with the group where saline was administered. A significant increase in superoxide dismutase activity was observed in the BA + AG group when compared with the group where only BA was administered. When the group where BA was administered solely was compared with the group where saline was administered, peribronchial inflammatory cell infiltration, alveolar septal infiltration, alveolar histiocytes, interstitial fibrosis, and granuloma were significantly higher in the BA group than in the saline group. When the BA + AG group was compared with the BA group, peribronchial inflammatory cell infiltration, alveolar septal infiltration, alveolar histiocytes, interstitial fibrosis, and granuloma were found to be significantly lower.

CONCLUSIONS

Oxidant stress increases and antioxidant capacity decreases in pneumonitis induced by BAs. AG administration as an antioxidant helps in recovery, both biochemically and histopathologically. Consequently, AG seems to be an alternative that should be considered in a conservative approach to treating aspiration pneumonitis.

Anti-inflammatory and antioxidant effects of infliximab on acute lung injury in a rat model of intestinal ischemia/reperfusion

The purpose of this study was to investigate the role of infliximab on acute lung injury induced by intestinal ischemia/reperfusion (I/R). A total of 30 male Wistar albino rats were divided into three groups: sham, I/R and I/R+ infliximab; each group contain 10 animals. Sham group animals underwent laparotomy without I/R injury. After I/R groups animals underwent laparotomy, 1 h of superior mesenteric artery ligation were followed by 1 h of reperfusion. In the infliximab group, 3 days before I/R, infliximab (3 mg/kg) was administered by intravenously. All animals were sacrificed at the end of reperfusion and lung tissues samples were obtained for biochemical and histopathological investigation in all groups. To date, no more biochemical and histopathological changes on intestinal I/R injury in rats by infliximab treatment have been reported. Infliximab treatment significantly decreased the elevated tissue malondialdehyde levels and increased of reduced superoxide dismutase, and glutathione peroxidase enzyme activities in lung tissues samples. Intestinal I/R caused severe histopathological injury including edema, hemorrhage, increased thickness of the alveolar wall and a great number of inflammatory cells that infiltrated the interstitium and alveoli. Infliximab treatment significantly attenuated the severity of intestinal I/R injury. Furthermore, there is a significant reduction in the activity of inducible nitric oxide synthase and arise in the expression of surfactant protein D in lung tissue of acute lung injury induced by intestinal I/R with infliximab therapy. It was concluded that infliximab treatment might be beneficial in acute lung injury, therefore, shows potential for clinical use. Because of its anti-inflammatory and antioxidant effects, infliximab pretreatment may have protective effects in acute lung injury induced by intestinal I/R.

The role of iNOS inhibitors on lung injury induced by gastrointestinal decontamination agents aspiration

Aspiration is a devastating complication during decontamination procedure in poisoning patients. We have investigated whether S-methylisothiourea protects different pulmonary aspiration gastrointestinal decontamination agent-induced lung injury in rats. Forty-two male Sprague-Dawley rats were assigned to one of six groups (n = 7): normal saline, activated charcoal, polyethylene glycol, normal saline + S-methylisothiourea treated activated charcoal + S-methylisothiourea treated and polyethylene glycol + S-methylisothiourea treated. Normal saline, activated aharcoal and polyethylene glycol were instilled into the lungs. The rats received S-methylisothiourea i.p twice daily for 7 days. Serum surfactant protein D, oxidative stress products and inducible nitric oxide synthase expression in the lung were investigated. The aspiration of activated charcoal significantly increased all histopathological scores (P < 0.01). Only peribronchial inflammatory cell infiltration, alveolar edema, and alveolar histiocytes were increased in the polyethylene glycol groups as compared to the normal saline group (P < 0.05). Pulmonary aspiration increased serum malondialdehyde (P < 0.001), and surfactant protein D (P < 0.05) levels and decreased serum superoxide dismutase levels (P < 0.05). S-methylisothiourea treatment decreased all histopathological scores in the activated charcoal treated S-methylisothiourea group (P < 0.01) and only decreased alveolar edema and alveolar histiocytes in the polyethylene glycol-treated S-methylisothiourea group (P < 0.05). S-methylisothiourea treatment reduced elevated oxidative factors, inducible nitric oxide synthase activity and serum surfactant protein D levels. Our findings showed that S-methylisothiourea may be a protective drug against Activated Charcoal and Polyethylene Glycol-induced lung injury.

Protective effect of curcumin on acute lung injury induced by intestinal ischaemia/reperfusion

The aim of this study is to evaluate the role of curcumin on acute lung injury induced by intestinal ischaemia/reperfusion (I/R). A total of 30 male Wistar albino rats were divided into 3 groups: sham, I/R, and I/R + curcumin; each group contains 10 animals. Sham group animals underwent laparotomy without I/R injury. After I/R groups animals underwent laparotomy, 1 h of superior mesenteric artery ligation were followed by 1 h of reperfusion. In the curcumin group, 3 days before I/R, curcumin (100 mg/kg) was administered by gastric gavage. All animals were killed at the end of reperfusion and lung tissue samples were obtained for biochemical and histopathological investigation in all groups. To date, no more biochemical and histopathological changes on intestinal I/R injury in rats by curcumin treatment have been reported. Curcumin treatment significantly decreased the elevated tissue malondialdehyde levels and increased reduced superoxide dismutase, and glutathione peroxidase enzyme activities in lung tissue samples. Intestinal I/R caused severe histopathological injury including oedema, haemorrhage, increased thickness of the alveolar wall, and infiltration of inflammatory cells into alveolar spaces. Curcumin treatment significantly attenuated the severity of intestinal I/R injury. Furthermore, there is a significant reduction in the activity of inducible nitric oxide synthase and increase in the expression of surfactant protein D in lung tissue of acute lung injury induced by intestinal I/R with curcumin therapy. It was concluded that curcumin treatment may have beneficial effects in acute lung injury, and therefore has potential for clinical use.

The effect of hyperbaric oxygen treatment on aspiration pneumonia

We have studied whether hyperbaric oxygen (HBO) prevents different pulmonary aspiration materials-induced lung injury in rats. The experiments were designed in 60 Sprague-Dawley rats, ranging in weight from 250 to 300 g, randomly allotted into one of six groups (n = 10): saline control, Biosorb Energy Plus (BIO), hydrochloric acid (HCl), saline + HBO treated, BIO + HBO treated, and HCl + HBO treated. Saline, BIO, HCl were injected into the lungs in a volume of 2 ml/kg. A total of seven HBO sessions were performed at 2,4 atm 100% oxygen for 90 min at 6-h intervals. Seven days later, rats were sacrificed, and both lungs in all groups were examined biochemically and histopathologically. Our findings show that HBO inhibits the inflammatory response reducing significantly (P < 0.05) peribronchial inflammatory cell infiltration, alveolar septal infiltration, alveolar edema, alveolar exudate, alveolar histiocytes, interstitial fibrosis, granuloma, and necrosis formation in different pulmonary aspiration models. Pulmonar aspiration significantly increased the tissue HP content, malondialdehyde (MDA) levels and decreased (P < 0.05) the antioxidant enzyme (SOD, GSH-Px) activities. HBO treatment significantly (P < 0.05) decreased the elevated tissue HP content, and MDA levels and prevented inhibition of SOD, and GSH-Px (P < 0.05) enzymes in the tissues. Furthermore, there is a significant reduction in the activity of inducible nitric oxide synthase, TUNEL and arise in the expression of surfactant protein D in lung tissue of different pulmonary aspiration models with HBO therapy. It was concluded that HBO treatment might be beneficial in lung injury, therefore, shows potential for clinical use.

Evaluation of effects of s-methyl isothiourea and melatonin on intestinal ischemia/reperfusion injury in rats

The present study was designed to evaluate whether the administration of s-methylisothiourea and melatonin has protective potential in intestinal ischemia/reperfusion injury. Forty male Sprague-Dawley rats were divided into five groups. Ileal specimens were obtained to determine the levels of malondialdehyde, protein carbonyl content, levels of antioxidant enzymes and evaluation of histologic changes. Combination of s-methylisothiourea and melatonin, led to a statistically significant increase in activities of antioxidant enzymes with a decrease in malondialdehyde and protein carbonyl content and intestinal mucosal injury scores. It was shown; combination of SMT and melatonin may exert more promised results.

Effects of Nigella sativa seed extract on ameliorating lung tissue damage in rats after experimental pulmonary aspirations

Aspiration of gastric contents can cause serious lung injury, although the mechanisms of pulmonary damage are still not clear and means of amelioration of the pulmonary damage have been little investigated. The black cumin seed, Nigella sativa L. (NS) has been shown to have specific health benefits and the aim of the current study was to investigate the possible beneficial effects of NS on experimental lung injury in male Wistar rats after pulmonary aspiration of different materials. The rats were randomly allotted into one of six experimental groups (n=7 per group): (1) saline control, (2) saline+NS treated, (3) Pulmocare (a specialized nutritional supplement given to pulmonary patients), (4) Pulmocare+NS treated, (5) hydrochloric acid, (6) hydrochloric acid+NS treated. The saline, Pulmocare and hydrochloric acid were injected into the lungs in a volume of 2 ml/kg. The rats received daily oral doses of NS volatile oil (400mg/kg body weight) by means of intragastric intubation for 7 days starting immediately after the pulmonary aspiration of the materials. After 7 days, the rats were sacrificed and tissue samples from both lungs were taken for histopathological investigation. To date, no similar study investigating the potential for NS treatment to protect against lung injury after pulmonary aspiration of materials has been reported. Our study showed that NS treatment inhibits the inflammatory pulmonary responses, reducing significantly (p<0.05) peribronchial inflammatory cell infiltration, alveolar septal infiltration, alveolar edema, alveolar exudate, alveolar macrophages, interstitial fibrosis, granuloma and necrosis formation in different pulmonary aspiration models. Our data indicate a significant reduction in the activity of inducible nitric oxide synthase (iNOS) and a rise in surfactant protein D in lung tissue of different pulmonary aspiration models after NS therapy. Based on our results, we conclude that NS treatment might be beneficial in lung injury and have potential clinical use.

Preventive effects of curcumin on different aspiration material-induced lung injury in rats

PURPOSE

We have studied whether curcumin protects different pulmonary aspiration material-induced lung injury in rats.

MATERIALS AND METHODS

The experiments were designed in 60 Sprague-Dawley rats, randomly allotted into one of six groups (n=10): normal saline (NS, control), enteral formula (Biosorb Energy Plus, BIO), hydrochloric acid (HCl), NS+curcumin-treated, BIO+curcumin-treated, and HCl+curcumin-treated. NS, BIO, HCl were injected in to the lungs. The rats received curcumin twice daily only for 7 days. Seven days later, both lungs in all groups were examined histopathologically, immunohistochemically, and biochemically. Histopathologic examination was performed according to the presence of peribronchial inflammatory cell infiltration, alveolar septal infiltration, alveolar edema, alveolar exudate, alveolar histiocytes, interstitial fibrosis, granuloma, and necrosis formation. Immunohistochemical assessments were examined for the activity of inducible nitric oxide synthase (iNOS) and the expression of surfactant protein D (SP-D). Malondialdehyde (MDA), hydroxyproline (HP), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activity were measured in the lung tissue.

RESULTS

Our findings show that curcumin inhibits the inflammatory response reducing significantly (P<0.05) all histopathological parameters in different pulmonary aspiration models. Pulmonary aspiration significantly increased the tissue HP content, MDA levels and decreased the antioxidant enzyme (SOD, GSH-Px) activities. Curcumin treatment significantly decreased the elevated tissue HP content, and MDA levels and prevented inhibition of SOD, and GSH-Px enzymes in the tissues. Furthermore, our data suggest that there is a significant reduction in the activity of iNOS and a rise in the expression of SP-D in lung tissue of different pulmonary aspiration models with curcumin therapy.

CONCLUSION

Our findings support the use of curcumin as a potential therapeutic agent in acute lung injury.