Hirudo medicinalis, also known as medicinal leeches, secretes several biologically active substances including fibrinase protease inhibitors, hyaluronidase and hirudin, an anticoagulant reducing venous congestion and preventing tissue necrosis.藥用水蛭,也稱為藥用水蛭,會分泌幾種生物活性物質,包括纖維蛋白酶抑制劑、透明質酸酶和水蛭素,一種抗凝劑,可減輕靜脈鬱血並預防組織壞死。