pulegone and Chemical-and-Drug-Induced-Liver-Injury

Acetaminophen and pulegone are just two examples for many agents that can form reactive metabolites that can cause acute liver injury. Two other classic organic compounds that have been extensively studied are carbon tetrachloride (for a recent review see Ref. 159, and for other discussions see Refs. 8 and 9) and bromobenzene (for review see Ref. 160). Different kinds of protein adducts of reactive metabolites of bromobenzene have been partially characterized [161], and specific antibodies to these adducts are now being used to isolate and identify the proteins that are modified (162). In contrast, carbon tetrachloride and other agents, such as the herbicide diquat, may form radicals that bind to and/or oxidize lipids and proteins in causing liver injury (163, 164). Therefore, the recent development [165] of antibodies to detect oxidative damage to proteins will be important in the identification and characterization of macromolecules that do not form adducts with reactive metabolites but are damaged oxidatively. Thus, some major challenges in the coming years are to identify hepatocellular macromolecules that are modified by reactive metabolites, and then approach the more difficult task of integrating this information into a time course and sequence of events leading to lethal hepatocellular injury.

Topics: Acetaminophen; Animals; Chemical and Drug Induced Liver Injury; Cyclohexane Monoterpenes; Humans; Menthol; Monoterpenes; Pharmaceutical Preparations; Terpenes

Topics: Acetaminophen; Aged; Biological Variation, Individual; Biomarkers; Chemical and Drug Induced Liver Injury; Cyclohexane Monoterpenes; Female; Humans; Liver; Male; MicroRNAs; Middle Aged; Monoterpenes

Effect of C-phycocyanin (from Spirulina platensis) pretreatment on carbontetrachloride and R-(+)-pulegone-induced hepatotoxicity in rats was studied. Intraperitoneal (i.p.) administration (200 mg/kg) of a single dose of phycocyanin to rats, one or three hours prior to R-(+)-pulegone (250 mg/kg) or carbontetrachloride (0.6 ml/kg) challenge, significantly reduced the hepatotoxicity caused by these chemicals. For instance, serum glutamate pyruvate transaminase (SGPT) activity was almost equal to control values. The losses of microsomal cytochrome P450, glucose-6-phosphatase and aminopyrine-N-demethylase were significantly reduced, suggesting that phycocyanin provides protection to liver enzymes. It was noticed that the level of menthofuran, the proximate toxin of R-(+)-pulegone was nearly 70% more in the urine samples collected from rats treated with R-(+)-pulegone alone than rats treated with the combination of phycocyanin and R-(+)-pulegone. The possible mechanism involved in the hepatoprotection is discussed.

Topics: Alanine Transaminase; Aminopyrine N-Demethylase; Animals; Carbon Tetrachloride; Chemical and Drug Induced Liver Injury; Cyclohexane Monoterpenes; Cytochrome P-450 Enzyme System; Glucose-6-Phosphatase; Liver; Liver Diseases; Male; Menthol; Microsomes, Liver; Monoterpenes; Phycocyanin; Rats; Terpenes

Oral administration of pulegone (400 mg/kg) to rats once daily for five days caused significant decreases in the levels of liver microsomal cytochrome P-450 and heme. Cytochrome b5 and NAD(P)H-cytochrome c-reductase activities were not affected. Massive hepatotoxicity accompanied by an increase in serum glutamate pyruvate transaminase (SGPT) and a decrease in glucose-6-phosphatase were observed upon treatment with pulegone. A significant decrease in aminopyrine N-demethylase was also noticed after pulegone administration. Menthone or carvone (600 mg/kg), compounds related to pulegone, when administered orally did not cause any decrease in cytochrome P-450 levels. The hepatotoxic effects of pulegone were both dose and time dependent. Pretreatment of rats with phenobarbital (PB) or diethylmaleate (DEM) potentiated the hepatotoxicity caused by pulegone, whereas, pretreatment with 3-methylcholanthrene (3-MC) or piperonyl butoxide protected from it. It appears that a PB induced cytochrome P-450 catalysed reactive metabolite(s) may be responsible for the hepatotoxicity caused by pulegone.

Topics: Alanine Transaminase; Animals; Chemical and Drug Induced Liver Injury; Cyclohexane Monoterpenes; Cytochrome P-450 Enzyme Inhibitors; Dose-Response Relationship, Drug; Drug Interactions; Glucose-6-Phosphatase; Heme; Liver Diseases; Male; Menthol; Microsomes, Liver; Monoterpenes; Rats; Time Factors

1. R-(+)-Pulegone was administered orally to rats and the urinary metabolites were investigated. Six metabolites were isolated and purified using column and thin layer chromatographic techniques. Metabolites were identified by i.r., n.m.r. and mass spectral analyses. 2. The neutral metabolites isolated from urine of rats treated with pulegone (I) were: pulegone (II), 2-hydroxy-2(1'-hydroxy-1'-methylethyl)-5-methylcyclohexanone (III), 3,6-dimethyl-7a-hydroxy-5,6,7,7a-tetrahydro-2(4H)-benzofuranone (V) and menthofuran (VII). Metabolites II and III were also excreted in conjugated form. 3. Acidic metabolites isolated from urine of rats treated with pulegone (I) were: 5-methyl-2(1'-methyl-1'-carboxyethylidene)cyclohexanone (IV) and 5-methyl-5-hydroxy-2(1'hydroxy-1'-carboxyethyl)cyclohexanone (VI).

Topics: Administration, Oral; Animals; Benzofurans; Chemical and Drug Induced Liver Injury; Chromatography, Thin Layer; Cyclohexane Monoterpenes; Cyclohexanones; Magnetic Resonance Spectroscopy; Male; Mass Spectrometry; Menthol; Monoterpenes; Rats

Intraperitoneal injection of R-(+)-pulegone (pulegone), the main constituent of pennyroyal oil, to ddY mice caused extensive liver injury as characterized by an increase in serum glutamic pyruvic transaminase (GPT) activity and centrilobular necrosis of hepatocytes. Treatments of mice with the cytochrome P-450 enzyme inhibitors, SKF-525A, metyrapone, piperonyl butoxide, and carbon disulfide (CS2), prevented or markedly alleviated the hepatotoxicity of pulegone. These results are compatible with the view that some metabolite of pulegone is responsible for the liver injury in mice.

Topics: Animals; Biotransformation; Carbon Disulfide; Chemical and Drug Induced Liver Injury; Cyclohexane Monoterpenes; Liver; Male; Menthol; Metyrapone; Mice; Mice, Inbred Strains; Monoterpenes; Oxidation-Reduction; Phenobarbital; Piperonyl Butoxide; Pyridines

Pulegone and menthol, components of peppermint oil, were investigated in rats. The substances were administered by gavage for 28 days at 0, 20, 80, 160 mg pulegone and 0, 200, 400, 800 mg menthol/kg body wt./day, respectively. At the two highest doses, pulegone induced atonia, decreased blood creatinine content, lowered terminal body weight and caused histopathological changes in the liver and in the white matter of cerebellum. For menthol at all dose levels a significant increase in absolute and relative liver weights and vacuolisation of hepatocytes was found. No sign of encephalopathy was observed in rats given menthol. The no effect level for pulegone was 20 mg/kg body wt./day and for menthol less than 200 mg/kg body wt./day.

Topics: Animals; Body Weight; Cerebellum; Chemical and Drug Induced Liver Injury; Creatinine; Cyclohexane Monoterpenes; Female; Liver Diseases; Male; Menthol; Monoterpenes; Organ Size; Rats