Collagenase inhibitory activity in human breast milk

Numerous investigations have been made on the biochemistry of mammalian colostrum and milk, and previous studies have documented the presence of proteinase inhibitors in human and bovine milk (1–4). Collagenase inhibitors, however, have not yet been described in human breast milk. This preliminary report documents the presence of collagenase inhibitory activity in a fraction of human breast milk (molecular weight of 72,000 or less) collected 7 weeks postpartum.