Erythromycin Stress Upregulates Antiangiogenic Metabolites in the Gut Bacterium <i>Aneurinibacillus aneurinilyticus</i>

The interplay among antibiotics, gut microbiota, and disease pathogenesis remains poorly understood, particularly in the context of rare gut bacteria. This study identifies a novel correlation between erythromycin-induced stress and the production of antiangiogenic metabolites in <i>Aneurinibacillus aneurinilyticus</i>, a human gut bacterium. We report the isolation and structural characterization of aneuristatin (<b>1</b>), a metabolite featuring a unique pyrrolo[1,2-<i>a</i>]pyrazine scaffold, along with seven structurally related metabolites (<b>2</b>-<b>8</b>) from <i>A. aneurinilyticus</i> ATCC 12856^T. These metabolites were upregulated via the erythromycin-induced activation of the <i>arnA</i> biosynthetic gene. Aneuristatin (<b>1</b>) enhanced prolyl hydroxylase activity, promoting hypoxia-inducible factor-1α (HIF-1α) degradation and reducing downstream targets, including VEGF and EPO. It also exhibited antioxidant effects by reducing ROS levels under hypoxia. Additionally, it inhibited angiogenesis in HUVECs and zebrafish and effectively reduced inflammation, fibrosis, and angiogenesis in a mouse corneal injury model. Our study establishes a molecular basis for the potential of erythromycin-induced aneuristatin (<b>1</b>) to prevent or treat angiogenesis-related diseases such as cancer.