Effects of curcumin on pulmonary inflammation and p38 expression in an infant murine model of pneumococcal pneumonia / 国际中医中药杂志

ABSTRACT

Objective To investigate the effects of curcumin on pneumococcal pneumonia-induced pneumonia, apoptosis and p38 MAPK expression in infant mice. Methods A total of 60 male infant C57BL/6 mice at three weeks of age were randomly divided into 6 groups control group, model group, high-dose curcumin treatment group, middle-dose curcumin treatment group, low-dose curcumin treatment group and SB203580 treatment group. The Curcumin and SB203580 were intraperitoneally applied at doses of 200, 60, and 20 mg/kg (for curcumin) and 100 mg/kg (for SB203580) from two days before bacterial infection to three days post-infection. The control group and model group were intraperitoneally injected with an equal volume of saline. The model group, curcumin treatment groups and SB203580 treatment group were transnasally inoculated with approximately 106 CFU/ml of pneumococcal pneumonia in 50 μl of PBS applied to the tip of the nose to establish the experimental pneumococcal pneumonia. Subsequently, all the mice were killed and lung tissues were harvested for hematoxylin-eosin staining, calculation of lung score indexes, measurement of IL-1β and TNF-α contents by ELISA, and measurement of Bax, Bcl-2and p38 MAPK expression by Western blot. Results Compared to the model group, the edema score (0.50 ± 0.10, 1.51 ± 0.16, 1.38±0.11, vs. 2.50 ± 0.20), hemorrhage score (0.32 ± 0.09, 1.01 ± 0.11, 0.85±0.09 vs. 1.80 ± 0.20), inflammatory cell infiltrate score (0.35 ± 0.09, 1.61 ± 0.16, 1.52±0.10 vs. 3.21 ± 0.22), small airway damage score (0.12 ± 0.03, 0.53 ± 0.14, 0.50±0.04 vs. 1.12 ± 0.19) in the medium-, high-dose group and SB203580 treatment group significantly decreased (P<0.01). Compared to the model group, the contents of IL-1β (20.38 ± 1.69 pg/ml, 25.73 ± 2.08 pg/ml vs. 40.22 ± 5.70 pg/ml) and TNF-α (160.39 ± 15.81 pg/ml, 198.67 ± 18.97 pg/ml vs. 282.22 ± 25.30 pg/ml), Bax/Bcl-2 (0.31 ± 0.05, 0.53 ± 0.06 vs. 1.79 ± 0.17) and expression of phosphorylated p38 MAPK (0.69 ± 0.05, 0.81 ± 0.07 vs. 1.71 ± 0.14) in the high-dose group and SB203580 treeatment group significantly decreased (P<0.01). Conclusions Curcumin can inhibit the inflammatory response and cellular apoptosis in the lungs of mice with pneumococcal pneumonia, and the mechanisms maybe related to its inhibition of p38 MAPK expression.