An ethanolic extract of the leaves of Vernonia amygdalina ameliorates TPA-induced acute skin inflammation in mice

J. Y. Wu, Y. J. Chen, X. Q. Fu, R. J. Wang, Y. Y. Deng, Z. L. Yu*

*Corresponding author for this work

Research output: Contribution to conferenceConference abstractpeer-review


Uncontrolled inflammation causes health problems1. Extracellular signal-regulated kinase (ERK) phosphorylates signal transducer and activator of transcription 3 (STAT3) at Ser727, resulting in inflammation2. The leaf of Vernonia amygdalina (VA) is a medicinal herb for managing inflammation-associated diseases3. Oral administration or topical application of VA leaf extract exerts anti-inflammatory effects in rat models4-5. However, the anti-inflammatory mechanisms of the herb are not fully understood. The present study aimed to investigate the involvement of ERK/STAT3 (Ser727) signaling in the anti-inflammatory effects of an ethanolic extract of VA leaves.

Extracts of VA leaves were prepared with different concentrations of ethanol. A
LPS-stimulated RAW 264.7 cell model was used for in vitro assays, and a TPA (12-O-tetradecanoylphorbol-13-acetate)-induced ear edema mouse model was employed for in vivo assays. The 95% ethanol extract of VA leaves (VAE) exerted the strongest inhibitory effect on nitric oxide (NO) production in LPS-stimulated macrophages; thus, it was selected for use in this study. We found that topical application of VAE ameliorated mouse ear edema induced by TPA. VAE suppressed the phosphorylation of ERK (Thr202/Tyr204) and STAT3 (Ser727); and decreased protein levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin (IL)-6, IL-1³ and tumor necrosis factor-α (TNF-α) in mouse ear tissues and in LPS-stimulated RAW 264.7 cells. VAE also inhibited NO production, and lowered mRNA levels of IL-6, IL-1³ and TNF-α in macrophages.

In summary, VAE ameliorates TPA-induced mouse ear edema, and suppression of
ERK/STAT3 (Ser727) signaling is involved in VAE’s anti-inflammatory effects. These novel data provide further pharmacological justifications for the medicinal use of VA in treating inflammation-associated diseases, and lay the groundwork for developing VAE into a new anti-inflammatory agent.


Symposium第七届可食和药用植物资源及功能成分国际学术研讨会 = 7th International Symposium on Edible & Medical Plant Resources and the Bioactive Ingredients, ISEPR 2022
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User-Defined Keywords

  • Acute inflammation
  • TPA
  • ERK
  • STAT3
  • Vernonia amygdalina


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