Comparison of the preventive effect of vitamin C and E on hexavalent chromium induced pulmonary fibrosis in rat.

Many studies have shown that hexavalent chromium (Cr(6+)) compounds cause variety of toxicity, such as carcinogenic effects and pulmonary fibrosis. The aim of this study was to investigate the effect of vitamins C and E on hexavalent chromium-induced lung fibrosis in animal model. Rats weighing 180-210 g were used during the study. The negative control group received a single dose of 0.2 ml intratracheal normal saline. Other groups were given single intratracheal instillation of 50 mg/kg sodium dichromate in saline vehicle and then treated with either vitamin C or E orally. Vit C group treated with 75 mg/kg/day vit C. Vit E group treated with 20 mg/kg/day vit E. Vit C+E group treated with 75 mg/kg/day vit C + 20 mg/kg/day vit E. Three weeks after such treatments animals were killed, lungs were removed for histology and biochemical investigation. Collagen and hydroxyproline content of lung tissue were determined using spectrophotometric methods. Hexavalent chromium caused marked alveolar thickening associated with fibroblasts and myofibroblasts proliferation and collagen production in interstitial tissue leading to pulmonary fibrosis. Administration of vitamins C and E reduced the fibrotic damage in lung tissue. The combination of vit E and C had more pronounced effect. From this study it can be concluded that co-administration of vit C & E may significantly diminish the toxic effects of hexavalent chromium on lung.