Intervention effect of sulfotanshinoneⅡA sodium on lung inflammation induced by ambient fine particulate matters in rats

Background Inhaling ambient fine particulate matters (PM_2.5) can cause inflammatory damage to the lungs, so it is necessary to find a medicine for effective intervention.

Objective This experiment investigates the intervention effect of sulfotanshinoneⅡA sodium (TanⅡA) on lung inflammation induced by ambient PM_2.5 in rats.

Methods Healthy male SD rats were randomly divided into four groups, with six rats in each group: control group, model group, TanⅡA group, and dexamethasone positive control group. A rat lung inflammation model was established by tracheal instillation of PM_2.5. Each group except the control group was exposed to PM_2.5 (5.4 mg·kg^-1) once every three days for a total of 10 times. The rats of the TanⅡA group (15 mg·kg-1 TanⅡA) and the dexamethasone positive control group (0.5 mg·kg^-1 dexamethasone), from the first day of exposure, were treated by intraperitoneal injection once a day for 28 days. All rats were neutralized within two days after the last exposure. The body weight, morphological changes of lung tissues, the counts of leukocytes, the proportions of neutrophils and eosinophils, the concentration of total protein, and the activities of alkaline phosphatase and lactate dehydrogenase in bronchoalveolar lavage fluid were detected.

Results Compared with the control group, after designed treatment, the body weight of the model group decreased (P < 0.01); the pathological results of lung tissues showed black fine particles deposited in alveolar septum, along with focal inflammatory cell infiltration, pulmonary septal broadening, alveolar atresia, and other injuries; the number of leukocytes(2.46±0.74)×10⁶ mL^-1 vs (0.91±0.51)×10⁶ mL^-1 (P < 0.01), the proportions of neutrophils and eosinophils(45.2±10.3)% vs (24.7±7.5)%, (5.7±2.7)% vs (2.0±1.4)% (both P < 0.01), the concentration of total protein, and the activities of alkaline phosphatase and lactate dehydrogenase(0.4±0.1) g·L^-1 vs (0.2±0.1) g·L^-1, (65.4±6.5) U·L^-1 vs (43.1±10.5) U·L^-1, and (151.4±29.0) U·L^-1 vs (82.5±18.5) U·L^-1 (all P < 0.01) increased. Compared with the model group, the body weight of the TanIIA group increased (P < 0.05); under light microscope, few inflammatory cells were observed, and the degree of injury such as disordered alveolus and thickened alveolar septum was alleviated; and the number of leukocytes(1.14±0.48)×10⁶ mL^-1 vs (2.46±0.74)×10⁶ mL^-1 (P < 0.01), the proportions of neutrophils and eosinophils(32.3±6.1)% vs (45.2±10.3)%, (2.8±1.8)% vs (5.7±2.7)% (both P < 0.05), and the concentration of total protein, and the activities of alkaline phosphatase and lactate dehydrogenase(0.2±0.1) g·L^-1 vs (0.4±0.1) g·L^-1, (50.9±3.0) U·L^-1 vs (65.4±6.5) U·L^-1, and (97.4±12.8) U·L^-1 vs (151.4±29.0) U·L^-1 (P < 0.05, P < 0.01) decreased. There were no significant differences in the above-mentioned indexes between the TanⅡA group and the control group or the dexamethasone positive control group (all P > 0.05).

Conclusion TanⅡA may reduce the lung inflammation induced by PM_2.5 in rats.