Thymoquinone ameliorates the PM2.5-induced lung injury in rats

Abstract

Background

This study aims to explore the effect of thymoquinone (TQ) on particulate matter 2.5 (PM2.5)-induced lung injury.

Methods

The PM2.5 sample was provided by Shenyang Environment Monitor Central Station. Lung injury was established by intratracheal instillation PM2.5 (7.5 mg/kg) followed by TQ treatment (20 and 40 mg/kg) for 14 d in rats. Hematoxylin and eosin (HE) and Evans blue dye (EBD) staining were detected on lung tissues. ELISA, real-time PCR, western blotting and TUNEL assays were also performed.

Results

The data showed that TQ diminished lung injury and EBD accumulation. The number of macrophages, neutrophils, eosinophils, and lymphocytes was ameliorated after TQ treatment. In addition, TQ suppressed the inflammation reaction parameters (interleukin-1β and −6, IL-1β and IL-6; tumor necrosis factor-α, TNF-α) and oxidative stress in PM2.5-induced lung injury. The levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase (HO-1) were increased due to the treatment of TQ. The number of TUNEL-positive cells was prominently reduced in TQ-treated rats compared with that in PM2.5 group. Intratracheal instillation PM2.5 activated autophagy, whilst TQ blocked it in lung.

Conclusions

Taken together, this study provides the first in vivo evidence that TQ suppresses inflammation, oxidative stress, apoptosis, and autophagy in PM2.5-induced lung injury.

Keywords:

• Thymoquinone
• PM2.5
• lung injury
• inflammation
• oxidative stress
• apoptosis
• autophagy

Author contributions

Mingqing Mao and Jing Li performed the experiments and wrote this manuscript. Aiping Bi, Hui Jia, Qiong Li, Yang Liu, Xiaochuan Jiang, and Desheng Huang performed the experiments. Shuyue Xia designed this study and polished the manuscript.

Conflict of interest

All authors declare that they have no any conflict of interests.

Additional information

Funding

This study was supported by grants from the Key Special Project for Social Development of Shenyang Science and Technology Bureau (No. F16-156-9-00) and the Key Special Project for Technology Innovation of Shenyang Science and Technology Bureau (No. 17-230-9-05).