Methacycline hydrochloride is a tetracycline antibiotic and can inhibits bacterial protein synthesis. Methacycline hydrochloride is a potent epithelial-mesenchymal transition (EMT) inhibitor. Methacycline hydrochloride blocks EMT in vitro and fibrogenesis in vivo without directly affecting TGF-β1 Smad signaling. Methacycline hydrochloride is an antimicrobial and has the potential for pulmonary fibrosis Methacycline hydrochloride is a tetracycline antibiotic and can inhibits bacterial protein synthesis. Methacycline hydrochloride is a potent epithelial-mesenchymal transition (EMT) inhibitor. Methacycline hydrochloride blocks EMT in vitro and fibrogenesis in vivo without directly affecting TGF-β1 Smad signaling. Methacycline hydrochloride is an antimicrobial and has the potential for pulmonary fibrosis