bromochloroacetic-acid and liarozole

Liarozole, a novel imidazole derivative, inhibits the cytochrome P450-dependent 4-hydroxylation of retinoic acid, resulting in increased tissue levels of retinoic acid. Twelve male patients with ichthyosis were given oral liarozole, 150 mg twice daily, in an open study for 12 weeks. Immunohistochemical parameters of inflammation, epidermal proliferation and differentiation were assessed before and after treatment. Extent and severity of the skin lesions was markedly reduced in all patients. Clinical side-effects were reminiscent of those with synthetic retinoids. No relevant changes were found in the haematological, urinary and biochemical parameters. Immunohistochemical assessment showed a statistically significant induction of keratin 4 after liarozole treatment in 10 of 12 patients. In two of these patients keratin 13 was induced. This open study showed that oral liarozole treatment was efficacious and well tolerated in the treatment of different types of ichthyosis. The immunohistochemical results suggest a retinoid mechanism as the mode of action.

Topics: Adolescent; Adult; Aged; Androgen Antagonists; Cytochrome P-450 Enzyme Inhibitors; Follow-Up Studies; Humans; Ichthyosis; Imidazoles; Keratins; Male; Middle Aged; Prospective Studies; Severity of Illness Index

Liarozole showed antitumoral activity in the Dunning AT-6sq, an androgen-independent rat prostate carcinoma. To investigate its potential mechanism of action, the effects of the drug doses (ranging from 3.75 to 80 mg/kg b.i.d.) on endogenous plasma and tissue all-trans-retinoic acid levels and on the differentiation status of the tumor cells were evaluated. To follow modulation of differentiation, cytokeratins were localized in the (un)treated tumors by immunocytochemistry and quantitatively determined by immunoblotting. Results showed that liarozole statistically significantly reduced tumor weight from 30 mg/kg upwards and induced accumulation of all-trans-retinoic acid both in plasma and tumors. In the tumors, a statistically significant accumulation was already noted from 7.5 mg liarozole/kg upwards. Concomitantly, the differentiation status shifted from a keratinizing towards a non-keratinizing squamous carcinoma, which was further confirmed by the cytokeratin profile of the carcinoma (presence of CK 8, 10, 13, 14, 18, 19). Immunoblotting revealed an overall decrease in cytokeratin content, except for CK 8. These findings suggest that the antitumoral properties of liarozole might be related to an increase in the degree of tumor differentiation through accumulation of all-trans-retinoic acid.

Topics: Animals; Antibodies, Monoclonal; Antineoplastic Agents; Carcinoma, Squamous Cell; Dose-Response Relationship, Drug; Gene Expression Regulation, Neoplastic; Imidazoles; Immunoblotting; Immunohistochemistry; Keratins; Male; Neoplasm Transplantation; Organ Size; Prostate; Prostatic Neoplasms; Random Allocation; Rats; Rats, Inbred F344; Tretinoin; Tumor Cells, Cultured; Vimentin

Liarozole is an imidazole-containing compound that inhibits the cytochrome P-450-dependent metabolism of all-trans-retinoic acid (RA). In vitro, liarozole (IC50, 2.2 microM) suppressed the P-450-mediated conversion of RA to more polar metabolites by hamster liver microsomes. In vivo, it enhanced the plasma level of RA from mostly undetectable values (less than 0.5 ng/ml) in control rats to 1.4 +/- 0.1 and 2.9 +/- 0.1 ng/ml in animals treated p.o. with 5 and 20 mg/kg of liarozole, respectively. Moreover, liarozole possessed antikeratinizing activity: when dosed subchronically (5-20 mg/kg, once daily for 3 days) to ovariectomized rats, the compound reversed the vaginal keratinization induced in these animals by estrogenic stimulation. Dose response experiments indicated that the antikeratinizating effect of liarozole was as potent as that of RA. One-dimensional electrophoresis and immunoblotting of extracted vaginal epithelia showed that liarozole shared with RA the ability to inhibit the synthesis of high molecular weight (57-60 kDa) keratin proteins, and to enhance the expression of the 45 to 47 kDa keratin polypeptides. Furthermore, we found that antikeratinizing doses of liarozole doubled the RA concentration in the vagina of ovariectomized rats: the mean amount of RA extracted from 200 mg of vaginal tissue was increased from 1.1 +/- 0.1 ng in vehicle-treated animals to 2.2 +/- 0.2 and 2.6 +/- 0.2 ng after treatment with 5 and 20 mg/kg of liarozole, respectively. These findings indicate that liarozole, an inhibitor of RA metabolism and RA produce similar morphologic and biochemical effects on the differentiation process of rat vaginal epithelium.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Antineoplastic Agents; Chromatography, High Pressure Liquid; Cricetinae; Female; Imidazoles; Injections, Subcutaneous; Keratins; Mesocricetus; Microsomes, Liver; Ovariectomy; Rats; Rats, Inbred Strains; Tretinoin; Vagina