title: Role of hydrogen peroxide in cytotoxicity induction by ascorbates and other redox compounds.
abstract: Role of hydrogen peroxide (H2O2) in the induction of cytotoxicity by ascorbic acid derivatives was investigated. Ascorbic acid derivatives which produced radicals (sodium 5,6-benzylidene-L-ascorbate (SBA), sodium-L-ascorbate, D-isoascorbic acid) dose-dependently reduced the viable cell number of human squamous carcinoma (HSC-2, HSC-4, NA), human salivary gland tumor (HSG) and human promyelocytic leukemia (HL-60) cell lines. Conversely, L-ascorbic acid-2-phosphate magnesium which did not produce radicals, was inactive. This suggests the possible role of the ascorbate radical in apoptosis induction. The cytotoxic activity of SBA was partially reduced by catalase, and the extent of inhibition by catalase was considerably different, depending upon which target cells were used. On the other hand, the cytotoxic activity of sodium ascorbate, isoascorbic acid, hydrogen peroxide and gallic acid was more effectively inhibited by catalase. These data suggest that mechanisms other than H2O2 might be involved in the induction of cytotoxicity by SBA.
authors.affiliation: Department of Dental Pharmacology, Meikai University School of Dentistry, Saitama, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Iwasaka
authors.forename: N
authors.initials: N
authors.lastname: Koyama
authors.forename: A
authors.initials: A
authors.lastname: Nogaki
authors.forename: S
authors.initials: S
authors.lastname: Maruyama
authors.forename: A
authors.initials: A
authors.lastname: Tamura
authors.forename: H
authors.initials: H
authors.lastname: Takano
authors.forename: M
authors.initials: M
authors.lastname: Takahama
authors.forename: M
authors.initials: M
authors.lastname: Kochi
authors.forename: K
authors.initials: K
authors.lastname: Satoh
authors.forename: H
authors.initials: H
authors.lastname: Sakagami
mesh_terms: D000970:Antineoplastic Agents / Q000633:toxicity*; D000975:Antioxidants / Q000633:toxicity*; D001205:Ascorbic Acid / Q000031:analogs & derivatives* / Q000737:chemistry / Q000633:toxicity*; D001597:Benzylidene Compounds / Q000633:toxicity*; D002294:Carcinoma, Squamous Cell; D002374:Catalase / Q000378:metabolism / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D004273:DNA, Neoplasm / Q000187:drug effects / Q000378:metabolism; D018922:HL-60 Cells; D006801:Humans; D006861:Hydrogen Peroxide / Q000633:toxicity*; D012468:Salivary Gland Neoplasms; D013329:Structure-Activity Relationship; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D000975:Antioxidants; D001597:Benzylidene Compounds; D004273:DNA, Neoplasm; C011669:ascorbate-2-phosphate; C005056:isoascorbic acid; D006861:Hydrogen Peroxide; D002374:Catalase; D001205:Ascorbic Acid; C070680:zilascorb