title: Antitumor activity of Mn(III) complexes in combination with phototherapy and antioxidant therapy.
abstract: Manganese (Mn) is an essential trace element and trivalent Mn complexes have been used as oxidation catalysts and enzyme mimetics. We studied the cytotoxicity of Mn(III) derivatives of citrate, pyrophosphate and salicylene diamine (respectively, MnCit, MnPPi and EUK8) toward HeLa cells stressed by ultraviolet irradiation and the effect of the co-administration of ascorbate and para-amino salicylate (PAS) on cell viability. Metal complexes enhanced the lethality of irradiated cells, and this effect was even more pronounced when ascorbate was co-administered with Mn(III) species. The active role of Mn(III) compounds in the antitumor activity was demonstrated by the treatment of the cells with the chelator PAS, which restored the viability of both non-irradiated and UV-irradiated cells. The association of the Mn(III) metallodrugs with radiation and an antioxidant proved to be a very effective approach to chemotherapy.
authors.affiliation: Instituto de Química, Universidade de São Paulo, Av. Lineu Prestes 748, São Paulo 05508-000, Brazil.
authors.forename: Tatiana Araujo
authors.initials: TA
authors.lastname: Pereira
authors.forename: Gisele Espinha Teixeira
authors.initials: GE
authors.lastname: da Silva
authors.forename: Raúl Bonne
authors.initials: RB
authors.lastname: Hernández
authors.forename: Fabio Luis
authors.initials: FL
authors.lastname: Forti
authors.forename: Breno Pannia
authors.initials: BP
authors.lastname: Espósito
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology*; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004354:Drug Screening Assays, Antitumor; D006367:HeLa Cells; D006801:Humans; D008345:Manganese / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry / Q000494:pharmacology*; D010789:Phototherapy; D013329:Structure-Activity Relationship
chemical_list: D000970:Antineoplastic Agents; D000975:Antioxidants; D009942:Organometallic Compounds; D008345:Manganese