OBJECTIVETo explore the mechanism of paraquat (PQ) poisoning and to observe the changes in inflammatory cytokines in PQ-exposed rats treated in different ways.

METHODSFifty 8-week-old clean male Wistar rats were randomly divided into high-dose curcumin plus conventional treatment group, low-dose curcumin plus conventional treatment group, high-dose curcumin group, PQ poisoning group, and blank control group. On days 1, 3, 5, 7, 14, and 21 after PQ exposure, serum levels of transforming growth factor-β₁(TGF-β₁) , tumor necrosis factor-α (TNF-α) , and interleukin-6 (IL-6) were measured. The pathological changes in lung tissue were evaluated by HE staining.

RESULTSCompared with the blank control group, the high-dose curcumin plus conventional treatment group, low-dose curcumin plus conventional treatment group, high-dose curcumin group, and PQ poisoning group had significantly increased serum levels of TGF-β₁, TNF-α, and IL-6 (P<0.05) , and the three cytokines in each group reached peak levels on day 14 after exposure. Compared with the PQ poisoning group, the high-dose curcumin group had significantly reduced serum levels of TGF-β₁, TNF-α, and IL-6 (P<0.05). On day 21 after exposure, there were no significant differences in serum levels of TGF-β₁, TNF-α, and IL-6 between the high-dose curcumin plus conventional treatment group and the low-dose curcumin plus conventional treatment group (P>0.05). The HE staining revealed alveolar inflammatory changes on days 1~7 and massive pulmonary fibrosis on days 14~21 in the high-dose curcumin plus conventional treatment group, low-dose curcumin plus conventional treatment group, high-dose curcumin group, and PQ poisoning group, but the above changes were milder in the high-dose curcumin group than in the PQ poisoning group.

CONCLUSIONFor rats with PQ poisoning, curcumin can significantly reduce inflammatory response and pathological changes in lung tissue and inhibit and delay the development and progression of body injury.