# Anti-Inflammatory Effect of Pestalotic Acid A Derived from Pestalotiopsis vismiae, an Endophytic Fungus of Ilex prenatal, in Lipopolysaccharide-Stimulated RAW264.7 Cells

## TL;DR

Pestalotic acid A, a compound from a plant fungus, reduces inflammation in lab-grown mouse cells by blocking a key inflammatory pathway.

## Contribution

This study is the first to demonstrate the anti-inflammatory effects of pestalotic acid A in macrophages and identify its mechanism of action.

## Key findings

- Pestalotic acid A increased macrophage viability and reduced nitric oxide production in LPS-stimulated cells.
- The compound suppressed the release of pro-inflammatory cytokines IL-6, IL-1β, and TNF.
- Pestalotic acid A inhibited NF-κB p65 phosphorylation, a key step in inflammation.

## Abstract

Background/Objectives: Pestalotic acid A (PAA), a polyketide derived from Pestalotiopsis vismiae, an endophyte of the Japanese holly (Ilex crenata), is known to exhibit known antimicrobial activity, but its anti-inflammatory properties remain uncharacterized. This study aimed to investigate the anti-inflammatory effects of PAA in lipopolysaccharide (LPS)-stimulated murine macrophages, RAW264.7 cells. Methods: PAA was isolated from P. vismiae endophytes of Ilex crenata, and its structure was confirmed. RAW264.7 macrophages were treated with 0–50 μM of PAA in the presence of 100 ng/mL LPS. Cell viability was assessed by MTS assay; nitric oxide (NO) production was measured via Griess reagent; interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF) were quantified by enzyme-linked immunosorbent assay. Protein expression of inducible NO synthase (iNOS), nuclear factor (NF)-κB p65 phosphorylation, and related signaling proteins was evaluated by Western blot analysis and immunofluorescence staining. Results: PAA significantly increased macrophage viability and dose-dependently inhibited the release of NO by alleviating the protein expression of iNOS in LPS-treated RAW264.7 cells. Furthermore, PAA suppressed the release of IL-6, IL-1β, and TNF induced by LPS. Western blot and immunofluorescence results also indicated that PAA blocked the p65 subunit phosphorylation of NF-κB, which is one of the underlying mechanisms of the anti-inflammatory action of pestalotic acid A. Conclusions: PAA exerts potent anti-inflammatory effects in LPS-stimulated macrophages via inhibition of the NF-κB pathway, highlighting its potential as a natural therapeutic agent for inflammatory diseases.