Cerium is a member of the
lanthanide series or rare earth elements which exert diverse
biological effects mainly by their resemblance to
calcium. This similarity, which is particularly characteristic for the lighter members of the
lanthanide series, enables these elements to replace
calcium in biomolecules without necessarily substituting for it functionally. While the inhibitory effects on
calcium-dependent physiological processes (such as those involved in the blood clotting cascade as well as in neuronal and muscular functions) are well-known, their relevance for the pharmacological properties of
cerium are less clear. Historically,
cerium oxalate was used as an
antiemetic, especially in
vomiting of pregnancy and kinetoses, although its mechanism of action has never been clarified. At present,
cerium nitrate is available as an adjunct to
silver sulfadiazine cream for the topical treatment of extensive
burns not amenable to early
wound excision. Apart from direct
antiseptic effects,
cerium helps to prevent postburn
sepsis and systemic inflammatory response by fixing
burn toxins. The
antineoplastic potential of
cerium compounds, which had fallen into oblivion, is currently being re-explored in experimental settings, though the mechanistic basis remains to be elucidated.