Docosahexaenoic acid (DHA) ameliorates paraquat-induced pulmonary fibrosis in rats possibly through up-regulation of Smad 7 and SnoN

• Published in: Food and chemical toxicology 2013-07, Vol.57, p.330-337
• Main Authors: Chen, Jingjing, Zeng, Tao, Zhao, Xiangzhong, Xiea, Keqin, Bi, Ye, Zhong, Zhixia, Zhao, Xiulan
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Dietary Supplements; Docosahexaenoic acid; Docosahexaenoic Acids - pharmacology; fibrosis; Gene Expression Regulation - drug effects; humans; hydroxyproline; Hydroxyproline - metabolism; Lung - drug effects; Lung - pathology; Male; Medical sciences; messenger RNA; Nerve Tissue Proteins - metabolism; Paraquat; Paraquat - toxicity; Pesticides, fertilizers and other agrochemicals toxicology; Pneumology; poisoning; Pulmonary fibrosis; Pulmonary Fibrosis - chemically induced; Pulmonary Fibrosis - drug therapy; Pulmonary Fibrosis - metabolism; Pulmonary Fibrosis - pathology; Rats; Rats, Wistar; Respiratory system : syndromes and miscellaneous diseases; Smad 7; Smad7 Protein - metabolism; SnoN; Toxicology; Transcription Factors - metabolism; Transforming Growth Factor beta1 - genetics; Up-Regulation
• ISSN: 0278-6915; 1873-6351
• DOI: 10.1016/j.fct.2013.03.045

•DHA ameliorated the fibrotic alterations of lung induced by paraquat.•DHA inhibited paraquat-induced increase of TGF-β1 mRNA levels.•DHA reversed the decreases of Smad 7 and SnoN protein induced by paraquat. Paraquat (PQ) poisoning has caused a large number of human fatalities due to the progressive and irreversible pulmonary fibrosis. Docosahexaenoic acid (DHA) is well-recognized as important modulators of multiple biological pathways that affect health and disease. A line of studies have shown that DHA supplementation is associated with the alleviation of some tissue fibrosis. In the current study, pulmonary fibrosis of rats was produced by a single oral dose of 50mg/kgbw PQ treatment. Daily 500mg/kgbw DHA supplementation was provided 7days before PQ treatment and lasted for consecutive 35days. DHA was found to ameliorate the pulmonary fibrotic alterations induced by PQ, which was evidenced by significant reduction of histological changes, hydroxyproline content and level of the transforming growth factor-β1 (TGF-β1) mRNA. Furthermore, the protein levels of Smad 7 and SnoN in the DHA supplemented rats were significantly increased compared with those in the rats of the PQ group. These results suggested that DHA ameliorated pulmonary fibrosis induced by PQ might be attributed to its enhancement of Smad 7 and SnoN expression.