title: Unraveling the response of plant cells to cytotoxic saponins: role of metallothionein and nitric oxide.
abstract: A wide range of pharmacological properties are ascribed to natural saponins, in addition to their biological activities against herbivores, plant soil-borne pathogens and pests. As for animal cells, the cytotoxicity and the chemopreventive role of saponins are mediated by a complex network of signal transduction pathways which include reactive oxygen species (ROS) and nitric oxide (NO). The involvement of other relevant components of the saponin-related signaling routes, such as the Tumor Necrosis Factor(TNF)-α, the interleukin(IL)-6 and the Nuclear Transcription Factor-kB (NF-κB), has been highlighted in animal cells. By contrast, information concerning the response of plant cells to saponins and the related signal transduction pathways is almost missing. To date, there are only a few common features which link plant and animal cells in their response to saponins, such as the early burst in ROS and NO production and the induction of metallothioneins (MTs), small cysteine-rich, metal-binding proteins. This aspect is discussed in the present paper in view of the recent hypothesis that MTs and NO are part of a novel signal transduction pathway participating in the cell response to oxidative stress.
authors.affiliation: University of Pavia, Genetics and Microbiology, Pavia, Italy.
authors.forename: Alma
authors.initials: A
authors.lastname: Balestrazz
authors.forename: Anca
authors.initials: A
authors.lastname: Macovei
authors.forename: Aldo
authors.initials: A
authors.lastname: Tava
authors.forename: Pinarosa
authors.initials: P
authors.lastname: Avato
authors.forename: Elena
authors.initials: E
authors.lastname: Raimondi
authors.forename: Daniela
authors.initials: D
authors.lastname: Carbonera
mesh_terms: D015850:Interleukin-6 / Q000378:metabolism; D008668:Metallothionein / Q000378:metabolism*; D008954:Models, Biological; D016328:NF-kappa B / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D010944:Plants / Q000187:drug effects / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D012503:Saponins / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D015850:Interleukin-6; D016328:NF-kappa B; D017382:Reactive Oxygen Species; D012503:Saponins; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide; D008668:Metallothionein