Biomaterial Database

Cytotoxicity of chloroquine in isolated rat hepatocytes. 2007

Akram Jamshidzadeh, and Hossein Niknahad, and Hamed Kashafi

Department of Pharmacology and Toxicology, Pharmaceutical Research Center, Shiraz University of Medical Sciences, Shiraz, Iran. sjamshid@sums.ac.ir

Chloroquine is a synthetic quinoline being used as an antimalaria and antirheumatoid agent. Several cases of hepatotoxicity have been reported with the use of chloroquine. However, the mechanism(s) of its hepatotoxic effect is unknown. The purpose of this study was to investigate the cytotoxic mechanism of chloroquine. Cytotoxicity was studied using freshly isolated rat hepatocytes incubated in Krebs-Henseleit buffer under a flow of 95% O(2) and 5% CO(2). Chloroquine was toxic towards hepatocytes and caused cell death with an ED(50) of about 100 mm in 2 h. The events before cell death were rapid GSH depletion and lipid peroxidation. Cytochrome P-450 inhibitors, troleandromycine, cimetidine and quinidine increased the cytotoxicity of chloroquine. Antioxidants significantly prevented the cytotoxicity of chloroquine. Depleting the hepatocyte GSH beforehand increased the chloroquine cytotoxicity. Preventing chloroquine metabolism by specific P-450 inhibitors increased its toxicity, suggesting that a major part of its toxicity is mediated by chloroquine and not by its metabolites. A depletion of the antioxidant defense system is involved in the mechanism of cytotoxicity.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D002478	Cells, Cultured	Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.	Cultured Cells,Cell, Cultured,Cultured Cell
D002738	Chloroquine	The prototypical antimalarial agent with a mechanism that is not well understood. It has also been used to treat rheumatoid arthritis, systemic lupus erythematosus, and in the systemic therapy of amebic liver abscesses.	Aralen,Arechine,Arequin,Chingamin,Chlorochin,Chloroquine Sulfate,Chloroquine Sulphate,Khingamin,Nivaquine,Sulfate, Chloroquine,Sulphate, Chloroquine
D003577	Cytochrome P-450 Enzyme System	A superfamily of hundreds of closely related HEMEPROTEINS found throughout the phylogenetic spectrum, from animals, plants, fungi, to bacteria. They include numerous complex monooxygenases (MIXED FUNCTION OXYGENASES). In animals, these P-450 enzymes serve two major functions: (1) biosynthesis of steroids, fatty acids, and bile acids; (2) metabolism of endogenous and a wide variety of exogenous substrates, such as toxins and drugs (BIOTRANSFORMATION). They are classified, according to their sequence similarities rather than functions, into CYP gene families (>40% homology) and subfamilies (>59% homology). For example, enzymes from the CYP1, CYP2, and CYP3 gene families are responsible for most drug metabolism.	Cytochrome P-450,Cytochrome P-450 Enzyme,Cytochrome P-450-Dependent Monooxygenase,P-450 Enzyme,P450 Enzyme,CYP450 Family,CYP450 Superfamily,Cytochrome P-450 Enzymes,Cytochrome P-450 Families,Cytochrome P-450 Monooxygenase,Cytochrome P-450 Oxygenase,Cytochrome P-450 Superfamily,Cytochrome P450,Cytochrome P450 Superfamily,Cytochrome p450 Families,P-450 Enzymes,P450 Enzymes,Cytochrome P 450,Cytochrome P 450 Dependent Monooxygenase,Cytochrome P 450 Enzyme,Cytochrome P 450 Enzyme System,Cytochrome P 450 Enzymes,Cytochrome P 450 Families,Cytochrome P 450 Monooxygenase,Cytochrome P 450 Oxygenase,Cytochrome P 450 Superfamily,Enzyme, Cytochrome P-450,Enzyme, P-450,Enzyme, P450,Enzymes, Cytochrome P-450,Enzymes, P-450,Enzymes, P450,Monooxygenase, Cytochrome P-450,Monooxygenase, Cytochrome P-450-Dependent,P 450 Enzyme,P 450 Enzymes,P-450 Enzyme, Cytochrome,P-450 Enzymes, Cytochrome,Superfamily, CYP450,Superfamily, Cytochrome P-450,Superfamily, Cytochrome P450
D003603	Cytotoxins	Substances that are toxic to cells; they may be involved in immunity or may be contained in venoms. These are distinguished from CYTOSTATIC AGENTS in degree of effect. Some of them are used as CYTOTOXIC ANTIBIOTICS. The mechanism of action of many of these are as ALKYLATING AGENTS or MITOSIS MODULATORS.	Cytolysins,Cytotoxic Agent,Cytotoxic Agents,Cytotoxin,Agent, Cytotoxic
D004098	Dihydroxyacetone	A ketotriose compound. Its addition to blood preservation solutions results in better maintenance of 2,3-diphosphoglycerate levels during storage. It is readily phosphorylated to dihydroxyacetone phosphate by triokinase in erythrocytes. In combination with naphthoquinones it acts as a sunscreening agent.	1,3-Dihydroxy-2-Propanone,Chromelin,Vitadye,1,3 Dihydroxy 2 Propanone
D004305	Dose-Response Relationship, Drug	The relationship between the dose of an administered drug and the response of the organism to the drug.	Dose Response Relationship, Drug,Dose-Response Relationships, Drug,Drug Dose-Response Relationship,Drug Dose-Response Relationships,Relationship, Drug Dose-Response,Relationships, Drug Dose-Response
D005632	Fructose	A monosaccharide in sweet fruits and honey that is soluble in water, alcohol, or ether. It is used as a preservative and an intravenous infusion in parenteral feeding.	Levulose,Apir Levulosa,Fleboplast Levulosa,Levulosa,Levulosa Baxter,Levulosa Braun,Levulosa Grifols,Levulosa Ibys,Levulosa Ife,Levulosa Mein,Levulosado Bieffe Medit,Levulosado Braun,Levulosado Vitulia,Plast Apyr Levulosa Mein,Levulosa, Apir,Levulosa, Fleboplast
D005978	Glutathione	A tripeptide with many roles in cells. It conjugates to drugs to make them more soluble for excretion, is a cofactor for some enzymes, is involved in protein disulfide bond rearrangement and reduces peroxides.	Reduced Glutathione,gamma-L-Glu-L-Cys-Gly,gamma-L-Glutamyl-L-Cysteinylglycine,Glutathione, Reduced,gamma L Glu L Cys Gly,gamma L Glutamyl L Cysteinylglycine
D006536	Heptanes	Seven-carbon alkanes with the formula C7H16.	Heptane,Isoheptane,Isoheptanes