Ascorbic acid potentiates the cytotoxicity of the naphthoquinone 5-methoxy-3,4-dehydroxanthomegnin.
The interaction of ascorbic acid with 5-methoxy-3,4-dehydroxanthomegnin, an 1,4-naphthoquinone, was investigated using the cytotoxic index for McCoy cells by neutral red assay. The synergistic effect was observed when such compounds were added simultaneously, most probably due to hydrogen peroxide being generated by ascorbate-driven 5-methoxy-3,4-dehydroxanthomegnin redox cycling. Incubation of cells in the presence of 5-methoxy-3,4-dehydroxanthomegnin/ascorbic acid/catalase, an enzyme that destroys H2O2, resulted in an increase of cell survival, reinforcing the involvement of hydrogen peroxide generated as an important oxidizing agent that kills McCoy cells.
Kitagawa
Rodrigo R
RR
Universidade Estadual Paulista-UNESP, Instituto de Química, Rua Prof. Francisco Degni, s/n, CEP 14801-970, Araraquara, SP, Brazil.
da Fonseca
Luiz M
LM
Ximenes
Valdecir F
VF
Khalil
Najeh M
NM
Vilegas
Wagner
W
Raddi
Maria Stella G
MS
D000818:Animals; D001205:Ascorbic Acid / Q000737:chemistry*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D051379:Mice; D015394:Molecular Structure; D009285:Naphthoquinones / Q000737:chemistry* / Q000633:toxicity*
C531413:5-methoxy-3,4-dehydroxanthomegnin; D009285:Naphthoquinones; D001205:Ascorbic Acid