Abstract
In the past several decades, marine organisms have generously
gifted to the pharmaceutical industries numerous naturally
bioactive compounds with antiviral, antibacterial,
antimalarial, anti-inflammatory, antioxidant, and anticancer
potentials. But till date only few anticancer drugs (cytarabine,
vidarabine) have been commercially developed from marine
compounds while several others are currently in different
clinical trials. Majority of these compounds were tested in the
tumor xenograft models, however, lack of anticancer potential
data in the chemical- and/or oncogene-induced pre-initiation
animal carcinogenesis models might have cost some of the marine
anticancer compounds an early exit from the clinical trials. This
review critically discusses importance of preclinical
evaluation, failure of human clinical trials with certain
potential anticancer agents, the screening tests used, and choice
of biomarkers.