Effects of puerarin combined with edaravone on inhalation lung injury induced by black gunpowder smog in rats

Objective To explore the protective effects of puerarin combined with edaravone on inhalation lung injury induced by black gunpowder smog in rats. Methods Forty healthy male Wistar rats were randomly divided into normal control group(group N), inhalation group(group X), puerarin group(group P), edaravone group(group E) and edaravone combined with puerarin group(group L), with 8 rats in each group. Rat model of inhalation lung injury was reproduced by a self-made smoke generator. Rats in group E were given intraperitoneal injections of edaravone(9 mg/kg) at 30 minutes and 1 day after modeling(twice totally). Rats in group P were given intraperitoneal injections of puerarin(100 mg/kg) at 30 minutes and 1, 2, 3, 4, 5 days after modeling(6 times totally). Rats in group L were treated the way of both group E and P. The rats in group N and group X were given intraperitoneal injections of normal saline(12 ml/kg) at the time-points above. The animals were sacrificed 6 days after modeling, and the blood samples were collected from abdominal aorta to assess arterial blood gas values, meanwhile the serum levels of tumor necrosis factor-α(TNF-α), interleukin-6(IL-6), interleukin-10(IL-10) were determined by ELISA. Lung tissue homogenates were prepared to determine the protein content and myeloperoxidase(MPO) activity. The pathological changes in the lung tissue with HEstaining were observed under light microscope. Results Arterial blood gas analysis revealed that the Pa O2 levels in groups P, E and L were higher than that in group X(P0.05), and the Pa O2 levels in groups E and L were higher than that in group P(P0.05), while the Pa CO2 level in group L was lower than that in groups X and E(P0.05). The TNF-α, IL-6 and IL-10 levels in serum, the protein content and MPO activity in lung tissue homogenate in groups P, E and L were lower than those of group X(P0.05). The TNF-α and IL-6 levels in serum and protein content and MPO activity in lung tissue homogenate in groups E and L were lower than those of group P(P0.05), while IL-10 level in serum was higher than that of group P(P0.05). The TNF-α and IL-6 levels in serum and protein content in lung tissue homogenate in group L were lower than those of group E(P0.05). HE staining revealed that lung edema was alleviated and inflammatory exudate and infiltration in groups P, E and L were less marked when compared with group X, while they were more significant in group L. Conclusions Edaravone combined with puerarin can alleviate the inflammatory reaction of inhalation lung injury induced by black gunpowder smog via reducing the production and release of pro-inflammatory mediators, thus playing a protective role against lung injury. The effect of a combination of the drugs is better than that of either drug alone.