OBJECTIVETo investigate the change of oxidative stress and nuclear factor-kappaB (NF-kappaB) activity in acute paraquat (PQ) poisoned rats and the effect of PDTC.

METHODS144 SD rats were randomly divided into four experimental groups: control group (6 rats), PDTC group (36 rats), PQ group (56 rats) and PQ + PDTC group (46 rats). On the 1st, the 3rd, the 7th, the 14th, the 28th and the 56th day after treatment, the level of malondialdehyde (MDA), the activity of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT) and myeloperoxidase (MPO) in serum were detected; the content of hydroxyproline (Hyp) and the activity of NF-kappaB in lung tissues were detected; the lung pathological changes of rats were observed.

RESULTSThe level of MDA and MPO in serum increased and the activity of GSH-Px, SOD, CAT in serum decreased significantly in PQ group compared with control and PDTC group (P<0.05 or P<0.01) in the corresponding sacrifice dates. There were a significant decrease of MDA and increase of GPx, SOD, CAT in PQ + PDTC group compared with PQ group (P<0.05 or P<0.01) in the corresponding sacrifice dates. The activity of NF-kappaB in lung tissue of PQ group significantly increased on the 1st, the 3rd, the 7th and 14th day compared with control and PDTC group (P<0.01). There was a significant decrease in NF-kappaB activity on the 1st, the 3 rd, the 7th day in PQ + PDTC group compared with PQ group (P<0.05 or P<0.01). The MPO activity on the 14th day was (119.56 +/- 21.23) U/L, was lower than that of PQ group (P<0.05). Meanwhile, the content of Hyp in PQ group was significantly higher than control and PDTC group on the 14th, the 28th and the 56th day (P<0.01), and its content was lower in PQ + PDTC group on the 28th and the 56th day (0.89 +/- 0.05), (0.93 +/- 0.13) microg/mg compared with PQ group (P<0.01). The histological changes such as alveolitis and fibrosis in PQ + PDTC group were slighter than those in PQ group.

CONCLUSIONOxidative stress and NF-kappaB could play an important role in lung injury of poisoned rats. PDTC may improve redox imbalance and inhibit the expression of NF-kappaB and therefore might have therapeutic effect on acute paraquat poisoning.