Protective effects of ethyl gallate and pentagalloylglucose, the active components of Qingwen Baidu Decoction, against lipopolysaccharide-induced acute lung injury in rats

Abstract

Background

The aim of this study was to investigate the bioactive constituents of Qingwen Baidu Decoction (QBD) in a rat model of acute lung injury (ALI) induced by lipopolysaccharide (LPS). Our previous studies showed that ethyl gallate (EG) and pentagalloylglucose (PGG) were the active components of QBD for the treatment of ALI.

Materials and methods

We isolated two compounds and identified the structures of them by nuclear magnetic resonance and mass spectrometer. Lung injury was induced by intratracheal instillation with LPS (5 mg/kg). Rats were randomly divided into six groups: Control group; LPS group; 5 mL/kg DEX + LPS group; 6.6 g/kg QBD extract + LPS group; 17.16 mg/kg PGG + LPS group; 7.26 mg/kg EG + LPS group. The effects of compounds on LPS-induced the number of total cells, neutrophils influx, protein leakage, W/D weight ratio and pulmonary histological changes were examined.

Results

The results demonstrated that pretreatment with EG and PGG could notably inhibit lung edema and attenuate the pulmonary histological changes (P<0.05). The pretreatment also decreased the number of total cells and polymorphonuclear leukocytes in bronchoalveolar lavage fluid (BALF) (P<0.05).

Conclusion

Ethyl gallate and pentagalloylglucose of QBD played a protective role in preventing LPS-induced ALI. The results supported further study of EG and PGG as potential candidates for preventing ALI.

Keywords:

• ethyl gallate
• pentagalloylglucose
• acute lung injury
• Qingwen Baidu Decoction

Acknowledgments

This work was supported in part by grants from the National Science Foundation of China (grant no 81173562) and Fujian Province health and family planning research talent training project (grant no 2018-1-73).

Disclosure

The authors report no conflicts of interest in this work.