Pachymic acid alleviates secondary lymphedema through the modulation of EETs level and the inhibition of lymphatic fibrosis

Int Immunopharmacol. 2025 Jun 27:162:115066. doi: 10.1016/j.intimp.2025.115066. Online ahead of print.

Abstract

Objective: This study evaluated the lymphangiogenesis-promoting and antifibrotic effects of PA, a natural component derived from Poria cocos, and to explore its mechanisms to mitigate lymphedema progression.

Methods: Tubule formation, spheroid sprouting, cell scratch and transwell assays approaches were used to assess the effects of TGF-β1 and PA on LECs tube formation and migratory capacity. A lymphedema tail loop mouse model was constructed, with tail volume measurements, H&E staining, Masson staining, immunofluorescence, and Western blotting to compare fibrosis and lymphatic vessel neogenesis under PA-treated and untreated conditions. RNA sequencing was employed for transcriptomic analysis, while immunofluorescence and Western blotting were used to investigate the role of the AA-EETs-DHETs pathway in PA-mediated lymphatic repair and the associated mitigation of fibrosis.

Results: Functionally, it enhanced LECs tube formation, sprouting, and migration, while reducing collagen III and α-SMA deposition in both TGF-β1-induced fibrosis and mouse models, alleviating the fibrotic microenvironment. Mechanistically, PA exerted its effects by modulating the AA-CYP2C8/CYP2J2-EETs-sEH-DHETs metabolic pathway, thereby increasing EETs level.

Conclusions: PA promotes lymphangiogenesis and alleviates LECs fibrosis by increasing EETs level, highlighting its potential as a novel therapeutic target for lymphedema.

Keywords: CYP2C8; CYP2J2; Fibrosis; Lymphangiogenesis; Lymphoedema; Pachymic acid; sEH.