Glycyrrhetinic acid alleviates radiation-induced lung injury in mice.

Abstract

Radiation-induced lung injury (RILI) is a common complication of thoracic radiotherapy, but efficacious therapy for RILI is lacking. This study ascertained whether glycyrrhetinic acid (GA; a functional hydrolyzed product of glycyrrhizic acid, which is extracted from herb licorice) can protect against RILI and investigated its relationship to the transforming growth factor (TGF)-β1/Smads signaling pathway. C57BL/6 mice were divided into four groups: a control group, a GA group and two irradiation (IR) groups. IR groups were exposed to a single fraction of X-rays (12 Gy) to the thorax and administered normal saline (IR + NS group) or GA (IR + GA group). Two days and 17 days after irradiation, histologic analyses were performed to assess the degree of lung injury, and the expression of TGF-β1, Smad2, Smad3 and Smad7 was recorded. GA administration mitigated the histologic changes of lung injury 2 days and 17 days after irradiation. Protein and mRNA expression of TGF-β1, Smad2 and Smad3, and the mRNA level of Smad7, in lung tissue were significantly elevated after irradiation. GA decreased expression of TGF-β1, Smad2 and Smad3 in lung tissue, but did not increase Smad7 expression. GA can protect against early-stage RILI. This protective effect may be associated with inhibition of the TGF-β1/Smads signaling pathway.

• Authors: Jinmei Chen, Weijian Zhang, Lurong Zhang, Jiemin Zhang, Xiuying Chen, Meichun Yang, Ting Chen, Jinsheng Hong
• Journal: Journal of radiation research (J Radiat Res) Vol. 58 Issue 1 Pg. 41-47 (Jan 2017) ISSN: 1349-9157 [Electronic] England
• PMID: 27672101 (Publication Type: Journal Article)
• Copyright: © The Author 2016. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

Chemical References

• Smad Proteins
• Transforming Growth Factor beta1
• Glycyrrhetinic Acid

Topics

• Animals
• Enzyme-Linked Immunosorbent Assay
• Female
• Gene Expression Regulation (drug effects)
• Glycyrrhetinic Acid (pharmacology, therapeutic use)
• Immunohistochemistry
• Lung (drug effects, metabolism, pathology)
• Lung Injury (drug therapy, genetics, pathology)
• Mice, Inbred C57BL
• Radiation Injuries (drug therapy, genetics, pathology)
• Smad Proteins (genetics, metabolism)
• Transforming Growth Factor beta1 (genetics, metabolism)