title: Cyclophosphamide and ascorbic acid-mediated ultrastructural and biochemical changes in Dalton's lymphoma cells in vivo.
abstract: Cyclophosphamide, an antineoplastic drug effective against a wide variety of cancers is cytotoxic to normal cells also. Ascorbic acid (vitamin C) at higher concentrations possesses cytotoxic effects and it can also enhance the cytotoxicity of 5-fluorouracil in a dose-dependent manner in mouse lymphoma. In the present study, effect of cyclophosphamide treatment alone and in combination with ascorbic acid in vivo on the ultrastructure and some biochemical changes in Dalton's lymphoma tumor cells were investigated. Cyclophosphamide treatment causes disappearance of cell membrane processes, thickening and reduction in the number of mitochondrial cristae as well as the manifestation of rounded shape of mitochondria. The combination treatment with ascorbic acid plus cyclophosphamide caused further changes in tumor cells showing disintegration in the cell surface membrane, disruption in the nuclear membrane and roundish mitochondria with reduction and disruption in the mitochondrial cristae. The observed ascorbic acid plus cyclophosphamide-mediated decrease in reduced glutathione (GSH) in tumor cells may play an important role in the antitumor activity of cyclophosphamide by weakening cellular antioxidant-mediated defense mechanism, thereby increasing tumor cell's susceptibility to cell death. The cyclophosphamide-mediated decrease in lactate dehydrogenase activity in tumor cells and simultaneous increase in ascites supernatant may possibly indicate alteration in the membrane permeability of tumor cells for lactate dehydrogenase as well as tumor cell injury. Further investigation should determine detailed mechanism(s) involved in cyclophosphamide-induced ultrastructural and biochemical changes in tumor cells.
authors.affiliation: Cell and Tumor Biology Laboratory, Department of Zoology, North-Eastern Hill University, Shillong-793022, India. sbpnehu@hotmail.com
authors.forename: Surya Bali
authors.initials: SB
authors.lastname: Prasad
authors.forename: Gabriel
authors.initials: G
authors.lastname: Rosangkima
authors.forename: Bonnie M
authors.initials: BM
authors.lastname: Nicol
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology* / Q000627:therapeutic use; D001201:Ascites / Q000378:metabolism; D001205:Ascorbic Acid / Q000008:administration & dosage; D003520:Cyclophosphamide / Q000008:administration & dosage; D005260:Female; D005978:Glutathione / Q000378:metabolism; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D016399:Lymphoma, T-Cell / Q000378:metabolism* / Q000473:pathology / Q000648:ultrastructure*; D008297:Male; D051379:Mice; D046529:Microscopy, Electron, Transmission; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure*; D009368:Neoplasm Transplantation; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D003520:Cyclophosphamide; D007770:L-Lactate Dehydrogenase; D005978:Glutathione; D001205:Ascorbic Acid