o-Phenanthroline (1,10-Phenanthroline) monohydrate, a metal chelator, prevents the induction of chromosomal aberrations in streptozotocin-treated cells. o-Phenanthroline monohydrate forms a red chelate with Fe2+ that absorbs maximally at 510 nm. o-Phenanthroline (1,10-Phenanthroline) monohydrate is also a MMP inhibitor[2].In Vitro: o-Phenanthroline (1,10-Phenanthroline, 1mM) inhibits autolysis of sea cucumber body wall[2].