Objective  To investigate effects of Chinese herbal kombucha, a dust clearance sorbent biologics, on lung inflammatory injury induced by particulate matter ≤ 2.5 μm in aerodynamic diameter (PM_2.5) in rats.

  Methods   PM_2.5 samples were collected in Zhengzhou High-tech Zone in the winter of 2016. Twenty male Sprague-Dawley (SD) rats were randomly divided into 4 groups (5 in each group). All the rats were exposed to PM_2.5 suspension by intratracheal instillation once a day continuously for 3 days, while the rats of control group were exposed to normal saline. Then, two groups of rats were treated with Chinese herbal kombucha with intratracheal instillation and aerosol inhalation once a day continuously for 3 days. All the rats were sacrificed and bronchoalveolar lavage fluid (BALF) and lung tissues of the rats were collected. Total protiens (TP), lactate dehydrogenase (LDH), sialic acid (SA), interleukin-8 (IL-8), and interleukin-1 beta (IL-1β) in BALF samples were detected. Pathological sections of lung tissues were prepared for the examination of pulmonary inflamation.

  Results  PM_2.5 exposure significantly increased IL-8, IL-1β, TP, LDH and SA in BALF. Obviously damaged alveolar walls, significantly thickened pulmonary interstitium, and inflammatory cell infiltration of alveolar spaces were observed in the PM_2.5 exposed rats. The rats with intratracheal instillation of Chinese herbal kombucha had significantly decreased IL-8, TP, and LDH (P < 0.05 for all); while the rats with aerosol inhalation of Chinese herbal kombucha had significantly decreased TP concentration and LDH activity related to PM_2.5 exposure (both P < 0.05). Obviously alleviated neutrephil infiltration and congestion in pulmonary interstitium were observed in the rats with intratracheal instillation and aerosol inhalation of Chinese herbal kombucha.

  Conclusion  Intratracheal instillation and aerosol inhalation of Chinese herbal kombucha could alleviate pulmonary injury induced by PM_2.5.