Enhancement of adriamycin toxicity by carboxymethylcellulose in mice

Prenatal prednisone exposure impacts liver development and function in fetal mice and its characteristics

Prednisone, a widely used glucocorticoid drug in human and veterinary medicine, has been reported to cause developmental toxicity. However, systematic studies about the effect of prednisone on fetal liver development are still unclear. We investigated the potential effects of maternal exposure to clinically equivalent doses of prednisone during different gestational stages on cell proliferation and apoptosis, cell differentiation, glucose and lipid metabolism, and hematopoiesis in the liver of fetal mice, and explored the potential mechanisms. Results showed that prenatal prednisone exposure (PPE) could suppress cell proliferation, inhibit hepatocyte differentiation, and promote cholangiocyte differentiation in the fetal liver. Meanwhile, PPE could result in the enhancement of glyconeogenesis and bile acid synthesis and the inhibition of fatty acid β-oxidation and hematopoiesis in the fetal liver. Further analysis found that PPE-induced alterations in liver development had obvious stage and sex differences. Overall, the alteration in fetal liver development and function induced by PPE was most pronounced during the whole pregnancy (GD0-18), and the males were relatively more affected than the females. Additionally, fetal hepatic insulin-like growth factor 1 (IGF1) signaling pathway was inhibited by PPE. In conclusion, PPE could impact fetal liver development and multiple functions, and these alterations might be partially related to the inhibition of IGF1 signaling pathway.

1: Final Report on the Safety Assessment of Hydroxyethylcellulose, Hydroxypropylcellulose, Methylcellulose, Hydroxypropyl Methylcellulose, and Cellulose Gum

Hydroxyethylcellulose, Hydroxypropylcellulose, Methylcellulose, Hydroxypropyl Methylcellulose, and Cellulose Gum are modified cellulose polymers that are used in cosmetic products at concentrations up to 10%. The cellulose derivatives pass essentially unchanged through the gastrointestinal tract following oral administration. They are practically nontoxic when administered by inhalation or by oral, intraperitoneal, subcutaneous, or dermal routes. Subchronic and chronic oral studies indicate that the cellulose derivatives are nontoxic when administered to laboratory animals. No significant teratogenic or reproductive effects have been demonstrated. Ocular and dermal irritation studies show that the cellulose derivatives are, at most, minimally irritating to rabbit eyes and nonirritating to slightly irritating to rabbit skin when tested at concentrations up to 100%. No mutagenic activity of theseingredients was demonstrated. The cellulose derivatives at concentrations up to 100% were nonirritating to mildly irritating, nonsensitizing, and nonphotosensitizing when evaluated in clinical studies. It is concluded that theingredients reviewed are safe as cosmeticingredients in the present practices of use and concentration.

Pharmacological preconditioning with doxorubicin. Implications of heme oxygenase-1 induction in doxorubicin-induced hepatic injury in rats

Heme oxygenase (HO) is the rate-limiting enzyme in the degradation of heme into biliverdin, carbon monoxide, and iron. HO-1, an inducible form, is thought to contribute to resistance to various types of oxidative stress. Doxorubicin (DOX) produces clinically useful responses in a variety of human cancers. We reported previously that prior administration of DOX ameliorated subsequent hepatic ischemia and reperfusion injury. The aim of this study was to examine whether this pharmacological preconditioning was useful for another type of hepatic injury induced by a non-surgical method. When a high dose of DOX (10 mg/kg body weight) was administered directly to rat liver via the portal vein, serum aspartate transaminase (AST) and alanine transaminase (ALT) levels increased markedly 24 hr after the injection. Under this condition, zinc-protoporphyrin IX, a specific inhibitor of HO-1, caused both serum AST and ALT levels to be elevated further. When a low dose of DOX (5 mg/kg body weight) was administered to rats via the tail vein as pharmacological preconditioning 3 days before the injection of a high dose of DOX via the portal vein, the levels of serum AST and ALT in rats clearly were improved as compared with rats without the preconditioning. Expression of HO-1 in the liver was confirmed 3 days after the administration of a low dose of DOX. In addition, prior administration of zinc-protoporphyrin IX abolished the effect of DOX preconditioning. Immunohistochemical analysis showed that the positive staining of HO-1 protein induced by a low dose of DOX was localized to histiocytes infiltrating periportal areas. These results strongly suggest that pharmacological preconditioning with DOX may generally help to attenuate subsequent oxidant-induced hepatic injury.

Effects of methylcellulose on hepatic glutathione levels and plasma ALAT following single oral administration to male Bom:NMRI mice

1. A single p.o. dose of 1% w/v methylcellulose 0.013 ml/kg was given to male Bom:NMRI mice using untreated animals as controls. 2. A circadian fluctuation was seen in the hepatic glutathione levels (GSH) of both the methylcellulose and untreated animal group. 3. The methylcellulose administration did not affect the hepatic GSH or plasma ALAT level compared to untreated animals. 4. Histological examination did not reveal any abnormalities of the stomach wall, liver or kidney during the 12 hr trial period. 5. Male Bom:NMRI mice treated with 1% w/v methylcellulose can be considered representative of untreated controls in short-term experiments studying liver GSH and plasma ALAT levels.

Influence of dietary manganese and vitamin E on adriamycin toxicity in mice

Adriamycin (ADR) administration can result in cardiac toxicity. One suggested mechanism of damage is through increased lipid peroxidation. We have evaluated the biochemical response of mice to ADR treatment when fed Mn-sufficient, vitamin E-sufficient (+Mn, +E); Mn-sufficient, low vitamin-E (+Mn, -E); Mn-deficient, vitamin E-sufficient (-Mn, +E); or Mn-deficient, low vitamin-E (-Mn, -E) diets. Mice were injected i.p. with ADR (10 mg/kg bw) or saline (0.9% w/v). ADR injection resulted in a reduction of food intake by 2 days postinjection; by 5 days postinjection ADR-treated mice lost an average of 6.0 g. Heart Mn superoxide dismutase (SOD) activity of -Mn mice was 50% that of +Mn mice; ADR did not affect MnSOD activity. Lipid peroxidation was highest in the -Mn, -E mice, being 2-fold higher than that observed in +Mn, +E mice. ADR injection did not affect lipid peroxidation. An interaction between Fe and ADR treatment was apparent; ADR injected -Mn, -E mice had liver Fe concentrations which were twice that of the saline injected mice fed -Mn, -E diets. These data show that the antioxidant status of an animal may influence ADR toxicity.