Effect of a urinary preparation on liver injury by short-term carbon tetrachloride treatment in rats

Inhibitory effect of CDA-II, a urinary preparation, on aflatoxin B(1)-induced oxidative stress and DNA damage in primary cultured rat hepatocytes

The effects of CDA-II (cell differentiation agent II; a urinary preparation) on both aflatoxin B(1) (AFB(1))-induced cell injury and DNA damage were investigated using cultured rat hepatocytes. CDA-II was able to suppress both the lipid peroxidation and lactate dehydrogenase leakage induced by AFB(1). Glutathione (GSH) depletion by AFB(1) was replenished by CDA-II treatment. Under these experimental conditions, CDA-II enhanced the activity of GSH peroxidase, but not GSH S-transferase. By evaluation of unscheduled DNA synthesis, CDA-II reduced AFB(1)-induced DNA damage in hepatocyte cultures. These findings suggest that CDA-II can inhibit cytotoxicity of AFB(1) through enhancing the activity of GSH peroxidase and preventing GSH depletion.

Effect of CDA-II on cell viability, lipid peroxidation, glutathione concentration and its related enzyme activities in primary rat hepatocytes

This study investigated the effects of various concentrations and incubation time intervals of CDA-II (cell differentiation agent: a preparation of human urine) on cell viability, lipid peroxidation and glutathione and its related enzyme activities in rat hepatocytes. Based on the results of lactate dehydrogenase leakage and microscopic examination, treatment with CDA-II significantly elevated the viability of hepatocytes. The level of lipid peroxidation of cells treated with 2.5 or 5 mg/ml CDA-II was lower than the control after 4, 8 and 24 hours of incubation. Intracellular glutathione (GSH) content of cells treated with 0.25-5 mg/ml CDA-II was significantly higher than controls after 8 and 24 hours of incubation. These phenomena are beneficial to the antioxidant capabilities of hepatocytes. Furthermore, treatment of hepatocytes with CDA-II has no effect on the activities of GSH peroxidase, GSH reductase and GSH S-transferase. In conclusion, adequate concentration of CDA-II could enhance the viability and antioxidative capability of hepatocytes.

Synergistic effect of cell differential agent-II and arsenic trioxide on induction of cell cycle arrest and apoptosis in hepatoma cells

AIM: To illustrate the possible role of cell differential agent-II (CDA-II) in the apoptosis of hepatoma cells induced by arsenic trioxide (As₂O₃).

METHODS: Hepatoma cell lines BEL-7402 and HepG2 were treated with As₂O₃ together with CDA-II. Cell surviving fraction was determined by MTT assay; morphological changes were observed by immunofluorescence staining of Hoechst 33258; and cell cycle and the apoptosis index were determined by flow cytometry (FCM).

RESULTS: Cytotoxity of CDA-II was low. Nevertheless, CDA-II could strongly potentiate arsenic trioxide-induced apoptosis. At 1.0 g/L CDA-II, IC₅₀ of As₂O₃ in hepatoma cell lines was reduced from 5.0 µmol/L to 1.0 µmol/L (P < 0.01). The potentiation of apoptosis was dependent on the dosage of CDA-II. FCM indicated that in hepatoma, cell growth was inhibited by CDA-II at lower concentrations (< 2.0 g/L) primarily by arresting at S and G₂ phase, and at higher concentrations (> 2.0 g/L) apoptotic cell and cell cycle arresting at G₁ phase increased proportionally. The combination of two drugs led to much higher apoptotic rates, as compared with the either drug used alone.

CONCLUSION: CDA-II can strongly potentiate As₂O₃-induced apoptosis in hepatoma cells, and two drugs can produce a significant synergic effect.

Effect of CDA-II, urinary preparation, on lipofuscin, lipid peroxidation and antioxidant systems in young and middle-aged rat brain

The levels of lipofuscin and lipid peroxidation reflect the degree of free radical-induced oxidative damage in the brain. We examined the effects of CDA-II, a preparation of human urine, on lipofuscin and lipid peroxidation in the brain of young (3.5 months) and middle-aged rats (17 months). The rats were given CDA-II orally at dosages of 0.3 or 1.0 g/kg daily for 8 weeks. CDA-II significantly suppressed the contents of lipofuscin and lipid peroxidation in both young and middle-aged rats. CDA-II also elevated the activity of superoxide dismutase, and the amounts of glutathione and ascorbic acid in the middle-aged rats, but not in the young ones. Our results suggest that the protection against oxidative damage by CDA-II in the young rat brain may be due to its scavenging activity against free radicals. In the middle-aged rats, in addition to the scavenging activity, the levels of endogenous antioxidants were also enhanced by the CDA-II treatment.