title: Photodynamic activity of 5,10,15,20-tetrakis(4-methoxyphenyl)porphyrin on the Hep-2 human carcinoma cell line: effect of light dose and wavelength range.
abstract: The photodynamic activity of 5,10,15,20-tetrakis(4-methoxyphenyl)porphyrin (TMP) has been investigated in two systems: reverse micelles of n-heptane/sodium bis(2-ethylhexyl)sulfosuccinate (AOT)/water-bearing photooxidizable substrates and on a Hep-2 human carcinoma cell line. The effect of variation in the light dose and wavelength range (360-800, 455-800, and 590-800 nm) was compared in both media. The aerobic singlet oxygen-mediated photooxidation of L-tryptophan (Trp) was used as a model of biological substrate in a micellar system. A considerable increase of the observed rate constants of Trp (k(Trp)(obs)) was noted, increasing the irradiated area of the TMP spectrum. In vitro, the survival curves of Hep-2 cells, treated with TMP, were markedly dependent on the light wavelength ranges used for irradiation. A linear behavior between k(Trp)(obs) and the photoinactivation rate of Hep-2 cells was found, indicating that the singlet oxygen (1O2 ) is the main species responsible for cell inactivation. These results contributed to an understanding of the photodynamic process yielded by this porphyrin in vitro and the sensitivity of Hep-2 cells to photodamage.
authors: Departamento de Química y Física, Universidad Nacional de Río Cuarto, Argentina.
authors: M
authors: M
authors: La Penna
authors: M G
authors: MG
authors: Alvarez
authors: E I
authors: EI
authors: Yslas
authors: V
authors: V
authors: Rivarola
authors: E N
authors: EN
authors: Durantini
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D006801:Humans; D007700:Kinetics; D008027:Light; D008114:Liver Neoplasms, Experimental / Q000188:drug therapy* / Q000473:pathology; D008823:Micelles; D010084:Oxidation-Reduction; D010777:Photochemistry; D010778:Photochemotherapy; D011166:Porphyrins / Q000627:therapeutic use*; D014364:Tryptophan / Q000737:chemistry / Q000528:radiation effects; D014407:Tumor Cells, Cultured
chemical_list: C445706:5,10,15,20-tetrakis(4-methoxyphenyl)porphyrin; D000970:Antineoplastic Agents; D008823:Micelles; D011166:Porphyrins; D014364:Tryptophan