Protective role of antioxidant vitamin E and catechin on idarubicin-induced cardiotoxicity in rats

Idarubicin is an anthracycline antibiotic extensively used in acute leukemia. In the present study we investigated whether vitamin E and catechin can reduce the toxic effects of idarubicin. Vitamin E (200 IU kg(-1) week(-1)), catechin (200 mg kg(-1) week(-1)), idarubicin (5 mg kg(-1) week(-1)), idarubicin + vitamin E (200 IU kg(-1) week(-1)), and idarubicin + catechin (200 mg kg(-1) week(-1)) combinations were given to male Sprague-Dawley rats weighing 210 to 230 g (N = 6/group). Idarubicin-treated animals exhibited a decrease in body and heart weight, a decrease in myocardial contractility, and changes in ECG parameters (P<0.01). Catechin + idarubicin- and vitamin E + idarubicin-treated groups exhibited similar alterations, but changes were attenuated in comparison to those in cardiac muscle of idarubicin-treated rats (P<0.05). Superoxide dismutase and catalase activity was reduced in the idarubicin-treated group (P<0.05). Glutathione peroxidase levels were decreased in the idarubicin-treated group (P<0.05) and reached maximum concentrations in the catechin- and catechin + idarubicin-treated groups compared to control (P<0.01). Malondialdehyde activity was decreased in the catechin + idarubicin-treated groups compared to control and increased in the other groups, reaching maximum concentrations in the vitamin E-treated group (P<0.01). In electron microscopy studies, swelling of the mitochondria and dilatation of the sarcoplasmic reticulum of myocytes were observed in the idarubicin-treated groups. In groups that were given idarubicin + vitamin E and idarubicin + catechin, the only morphological change was a weak dilatation of the sarcoplasmic reticulum. We conclude that catechin and vitamin E significantly reduce idarubicin-induced cardiotoxicity in rats.

Effects of garlic extract on oxidant/antioxidant status and atherosclerotic plaque formation in rabbit aorta

BACKGROUND AND AIM

The results of a number of studies suggest that garlic (or garlic extracts) may have favourable effects against the development of atherosclerosis. The aim of this study was to investigate the effects of garlic extract supplementation on oxidant/antioxidant status and atherosclerotic plaque formation in rabbit aortic tissue.

METHODS AND RESULTS

Twenty-two male New Zealand White rabbits were fed a cholesterol-supplemented diet (0.5 g/Kg/day) and nine control rabbits a regular diet for four months. At the end of this period, atherosclerotic plaque formation and antioxidant activity were measured in the aortic tissue of the controls and seven of the cholesterol-fed animals. Of the remaining 15 experimental animals, seven were fed normal laboratory diet and eight a normal diet plus garlic extract (1.5 ml/Kg/day) for a further three months before atherosclerotic plaque formation and antioxidant activity were measured in the aortic tissue of both groups. The cholesterol-fed animals showed a significantly impaired antioxidant system associated with increased plaque formation. However, garlic extract supplementation significantly improved antioxidant status and reduced the plaque surface area.

CONCLUSIONS

In this experimental model, garlic extract dietary supplementation activated the antioxidant system and decreased peroxidation in aortic tissue. There was also a reduction in atherosclerotic plaque area. Although further studies are required to elucidate the mechanisms involved, the protective activity of garlic extract may be due to its antioxidant properties.

The effectiveness of systemic antibiotics in preventing postoperative, intraabdominal adhesions in an animal model

OBJECTIVE

Postoperative intraabdominal adhesions can be prevented by antibiotic lavage. We assessed whether systemic antibiotics could prevent adhesion formation in a rat model.

METHODS

Cecal abrasion was performed in the peritoneal cavities of 40 Wistar albino rats. Twenty rats were treated with a 5-day course of cefepim and metronidazole; the remaining animals were given saline injections. The animals were sacrificed 14 days after surgery. Adhesion severity scores and histopathologic findings were compared.

RESULTS

The median adhesion severity score was 2 (0-3) in the antibiotic group and 2.5 (1-4) in the controls (P = 0.03). In tissue specimens from controls, the adhesions were marked by mature collagen bundles. In treated rats, the adhesions were immature, characterized by early inflammatory cells, less collagen formation, and no collagen bundles.

CONCLUSIONS

Postoperative systemic antibiotics slow adhesion formation and reduce the severity of the adhesions.

The effect of tenoxicam on intraperitoneal adhesions and prostaglandin E2 levels in mice

We determined whether tenoxicam administered intraperitoneally in the preoperative period had an effect on the development of postoperative intraabdominal adhesions (IAA). For this purpose, 100 albino mice were divided into four random groups. Mice in Group 1 were given only 1 mL of 0.9% NaCl intraperitoneally, whereas in Group 2, 1 mL of tenoxicam (150 microg = 5 mg/kg) was administered. After the induction of anesthesia, a median laparotomy was performed, and the bowels were traumatized by touching them with powdered gloves before the incision was closed in Groups 3 and 4. Intraperitoneal tenoxicam was administered to mice in Group 4 after skin closure. All mice were killed after 14 days to determine macroscopic and microscopic IAA; prostaglandin E2 levels were also measured. Postoperative evaluation revealed a reduced IAA formation and a parallel decrease in tissue prostaglandin E2 levels in Group 1 and 2 mice. We conclude that intraperitoneal tenoxicam decreased IAA formation with no peritoneal reaction in the postoperative period.

IMPLICATIONS

Postoperative intraabdominal adhesions can cause intestinal obstruction, pelvic pain, or infertility. In this study, we showed that intraperitoneally administered tenoxicam decreases tissue prostaglandin E2 levels and intraabdominal adhesions in mice.

Comparison of meshes for the repair of experimental abdominal wall defects

The aim of this experimental study was to compare the effects of polytetrafluoroethylene patch, polypropylene mesh, and porcine dermal collagen implant in rats for the repair of abdominal wall defects. We created experimental abdominal wall defects in 45 rats (three groups of fifteen) and repaired them with polytetrafluoroethylene, polypropylene mesh, and porcine dermal collagen implant by onlay technique. We sacrificed 4 rats from each group at 4, 8, 10, and 12 weeks after implantation and observed if hernia, adhesion, effusion, or infection occurred. We measured the tensile strengths of meshes by a digital tensometer. We made histological and electron microscopic evaluations of the meshes. Postoperative infection and effusion occurred in one rat in each group. Hernia was not found throughout the trial. The tensile strength of polytetrafluoroethylene patch and polypropylene mesh increased more than porcine dermal collagen implant until the end of week 12. Adhesion formation was minimal in the porcine dermal collagen group and moderate in the polytetrafluoroethylene patch and polypropylene mesh groups. Polytetrafluoroethylene patch showed minimum absorption and maximum foreign body reaction. Our results show that although none of the material reached the criteria of ideal mesh, polypropylene mesh is the better mesh for the repair of abdominal defects. Polytetrafluoroethylene patch though expensive, can also be used as a reliable mesh. We do not advise porcine dermal collagen implant as a mesh for abdominal defects due to its weak structure.

Prevention of doxorubicin induced cardiotoxicity by catechin

Doxorubicin (dox) is an anthracycline antibiotic which is broadly used in solid tumors. Long-term therapy with this drug is accompanied by potentially lethal, dose-dependent side effects. Several reports suggest that oxygen free radicals produced during the metabolic activation of dox may have toxic effects on heart muscle. We tried to protect dox cardiotoxicity in rats using catechin which is a known antioxidant and iron chelating agent. Different dose levels and combinations of catechin and doxorubicin have been studied in different experimental groups. Electrocardiograms, myocardial contractility, body weight and the electron microscope were used to assess the cardioprotective effect of catechin in dox-treated animals. We found significant prevention of dox-induced cardiotoxicity by catechin in rats.

Reduced enzymatic antioxidant defense mechanism in kidney tissues from gentamicin-treated guinea pigs: effects of vitamins E and C

In this study, the activities of major enzymes participating in free radical metabolism (xanthine oxidase, XO; Cu,Zn and Mn superoxide dismutases, SOD; glutathione peroxidase, GSH-Px; catalase, CAT) were measured in kidney tissues from guinea pigs treated with gentamicin alone (200 mg/kg/day), gentamicin plus vitamin C (600 mg/kg/day), gentamicin plus vitamin E (400 mg/kg/day), and gentamicin plus vitamins C and E together for 10 days, and from animals treated with physiological saline solution alone during this period. We found no significant differences between control and gentamicin groups with respect to XO and Cu,Zn-SOD activities. However, the activities of Mn-SOD, GSH-Px, and CAT were found to be significantly depressed in the gentamicin-treated group relative to controls. In the gentamicin plus vitamin C group, the renal tissue Mn-SOD activity was found to be higher as compared with control and gentamicin groups. In this group, XO, GSH-Px and CAT activities were also higher than in the gentamicin-treated group, but no statistically significant differences existed between the values of this group and controls. Similar results were also observed in the gentamicin plus vitamin E group for Mn-SOD, GSH-Px, CAT, and XO. In this group, the Cu,Zn-SOD activity was found to be decreased as compared with control and gentamicin groups. In the gentamicin plus vitamins C and E group, the Cu,Zn-SOD activity was found to be decreased, the XO activity to be unchanged, and Mn-SOD, GSH-Px, and CAT activities to be increased as compared with the gentamicin and control groups. The results suggest that the enzymatic antioxidant defense system was significantly disturbed because of the suppressed activities of Mn-SOD, GSH-Px, and CAT in the kidney tissues from animals treated with gentamicin. However, vitamins C and E given concurrently with gentamicin completely abrogated this enzymatic suppression.

[Occlusion of the gastric outlet caused by a trichobezoar]

Bezoars are concretions formed in the gastrointestinal tract. The trichobezoars are hairballs in the stomach or intestines composed of hair. They are usually found in young girls as in our case which we operated in April 1989 on Surgical Ward in Kartal State Hospital in Istanbul. The postgastrectomy state predisposes to bezoar formation. Persimmon peels or pits, orange or grapefruit pulp are the usual offenders. Bezoars are associated with vague upper gastrointestinal discomfort, nausea, and vomiting. The patients may complain of abdominal pain. Ulceration, bleeding, obstruction, and perforation are the most common complications. Treatment consist of mechanical fragmentation via the endoscope or operative extraction. Dissolution of the undigested bolus by ingestion of proteolytic enzymes such as papain may be tried. As prophylaxis the postgastrectomy patient must be warned of ingesting citrus fruits.