Effects of plant extracts on gene expression profiling: from macroarrays to microarray technology

Abstract DNA hybridization arrays (macro- and microarrays) are very useful tools for the analysis of gene expression profiles in human pathologies. In addition, macro- and microarrays can be used in pharmacogenomic and toxicogenomic experiments, aimed at extensive analyses of the effects of therapeutic drugs on overall gene expression of target cells. Despite the fact that extracts from medicinal plants have been described to retain interesting biological activity, including anti-inflammatory, antitumor and antimicrobial effects, few data are present in the literature on gene expression profile studies. Here, we review results on the effects of plant extracts from Moringa oleifera on the gene expression profile of a human tumor cell line, the K562 cell line, originally isolated from a patient with chronic myelogenous leukemia (CML) in blast crisis, very useful for the identification of antitumor compounds. The data obtained using macroarrays were compared with those obtained using reverse-transcription polymerase-chain reaction (RT-PCR). Effects of M. oleifera extracts were compared to those of Emblica officinalis . The results obtained suggest that a general strategy for the development of specific therapeutic approaches could be proposed starting from gene expression studies employing macro- or microarrays. Treatment of target cells with plant extracts will allow to identify genes, which are down- or up-regulated. For these genes, the molecular analysis of the promoter regions and coding sequences could allow to design decoy oligonucleiodes (ODN), antisense DNA or RNA, peptides and monoclonal antibodies expected to mimic the biological effects of the employed plant extracts.