RESUMO
<p><b>OBJECTIVE</b>To explore the mechanism of paraquat (PQ) poisoning and to observe the changes in inflammatory cytokines in PQ-exposed rats treated in different ways.</p><p><b>METHODS</b>Fifty 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.</p><p><b>RESULTS</b>Compared 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.</p><p><b>CONCLUSION</b>For 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.</p>