Antioxidant function of metallothioneins

Since the discovery of metallothionein in 1957, it has been accepted that the primary roles of this protein are: 1) detoxification of heavy metals, and 2) regulation of the metabolism of essential metals. Recently, studies have suggested an additional role for metallothionein as a free radical scavenger. This article reviews in vitro and in vivo evidence which supports the role for metallothionein in modulation of reactive oxygen species.