Protection by methylene blue alone or with vitamin C on gastric mucosal damage and brain histopathological changes caused by indomethacin in rats

Abstract

The redox dye methylene blue (MethyB) exerts neuro- and gastric protective effects. In this study, the effect of MethyB and its possible modulation by vitamin C (Vit C) on the gastric and brain histopathological changes induced by indomethacin (IND) was examined. Indomethacin was subcutaneously given to rats at a dose of 30 mg/kg and at the same time rats were also treated with MethyB (30 mg/kg) alone or in combination with Vit C (100 or 200 mg/kg) intraperitoneally and euthanized 24 hr later. The number and severity of mucosal lesions were determined. Gastric mucosal and brain histopathology and histochemical staining for mucopolysaccharides in the gastric mucosa were also done. MethyB markedly reduced the number and severity of gastric mucosal lesions in indomethacin-treated rats. Histologically, IND caused extensive disruption of gastric surface epithelium, mucosal erosions and ulcers and reduced thickness of gastric mucosa. Additionally, there was complete depletion of glycoproteins in the disrupted areas in apical epithelial cells and gastric glands as shown by periodic acid Schiff staining. These changes were markedly attenuated by MethyB alone or combination with Vit C with increased mucosal thickness and restoration of gastric mucus. The histopathological changes observed in the cerebral cortex of rats treated with IND, namely spongiform changes, gliosis, dark pyknotic neurons were markedly reduced by MethyB or Vit C/MethyB co-treatment. Collectively, these results suggest a protective effect of MethyB against gastric mucosal and brain damage caused by IND.