ABSTRACT
Non-physiological inducers of terminal differentiation have been used as novel therapies for the prevention and therapy of cancer. We have used cultured HL-60 promyelocytic cells to monitor differentiation, proliferation and cell death events as induced by a large set of extracts derived from plants. Screening of more than 1400 extracts led to the discovery of 34 with potent activity (ED50 <8 mg/ml). Bioassay-guided fractionation led to the isolation of zapotin and 2',5,6-trimethoxyflavone as active principles from Casimiroa edulis, dibenzyltrisulfide and 2-[(phenylmethyl)dithio]ethanol as active principles from Petiveria alliacea, and desmethylrocaglamide from Aglaia ponapensis. Zapotin demonstrated the most favorable biological profile in that induction of differentiation correlated with proliferation arrest, and a lack of cytotoxicity. We conclude that the HL-60 cell model is a useful system for the discovery of novel pharmacophores with potential to suppress the process of carcinogenesis, and that flavonoids may be especially useful in this capacity.
Subject(s)
Antineoplastic Agents/pharmacology , Neoplasms/drug therapy , Plant Extracts/pharmacology , 9,10-Dimethyl-1,2-benzanthracene , Animals , Biological Assay , Carcinogens , Cell Death , Cell Differentiation , Cell Division , Esterases/metabolism , HL-60 Cells , Humans , Indicators and Reagents/pharmacology , Mammary Neoplasms, Animal/drug therapy , Mice , Models, Chemical , Nitroblue Tetrazolium/pharmacology , Organ Culture TechniquesABSTRACT
Six constituents (1-6) were isolated from EtOAc-soluble partitions of two separate collections of the whole plants of Cotinus coggygria, namely, disulfuretin ¿2,2'-[1,2-bis(3,4-dihydroxyphenyl)-1, 2-ethanedylidene]bis[6-hydroxy-3(2H)-benzofuranone] (1)¿, sulfuretin (2), sulfurein (3), gallic acid (4), methyl gallate (5), and pentagalloyl glucose (6). The structure of the novel biaurone 1 was determined by spectral and chemical methods. Compounds 1-6 were found to be potent antioxidants in a 1,1-diphenyl-2-picrylhydrazyl free-radical scavenging assay.