The effect of ketoconazole and a combination of rifampicin/amphotericin B on cutaneous leishmaniasis in laboratory mice

Efficacy of rifampicin and isoniazid in cutaneous leishmaniasis

Thirty-nine patients with cutaneous leishmaniasis caused by Leishmania major were treated with rifampicin alone or in combination with isoniazid. No significant difference was found between these two therapeutic regimens, and about half of the patients were cured 2 months from the beginning of treatment. A review of rifampicin in cutaneous leishmaniasis is attached.

Sterols of ketoconazole-inhibited Leishmania mexicana mexicana promastigotes

Leishmania mexicana mexicana promastigotes grown with cholesterol, supplied in natural products as the free sterol and as cholesteryl esters, were exposed to [2-14C]mevalonate and to the antimycotic drug ketoconazole. Growth was inhibited and cholesterol and 14 alpha-methyl sterols accumulated in free and esterified forms (cholesterol much greater than 4 alpha,14 alpha-dimethylcholesta-8,24-dien-3 beta-ol much greater than 14 alpha-methylcholesta-8,24-dien-3 beta-ol congruent to 14 alpha-methylergosta-8,24(28)-dien-3 beta-ol much greater than 4 alpha,14 alpha-dimethylergosta-8,24(28)-dien-3 beta-ol; identified by capillary gas chromatography/mass spectrometry, and by 1H and 13C nuclear magnetic resonance spectrometry). The 14 alpha-methyl sterols were preferentially labelled with 14C. The cholesterol was unlabelled and substituted for a substantial fraction of the major product of sterol biosynthesis, ergosta-5,7, 24(28)-trien-3 beta-ol (5-dehydroepisterol), but did not replace it and did not offer remarkable protection against either growth inhibition or alteration of sterol biosynthesis. Promastigotes grown with [6-2H]cholesterol or [4-14C]cholesterol did not contain labelled forms of Leishmania sterols, or other sterols. The chromatographic and spectrometric sterol analyses and the isotopic tracer findings suggested that ketoconazole impaired the cytochrome P-450 dependent 14 alpha-demethylation of lanosterol, that cholesterol was neither biosynthesized nor metabolized, and that the physiological functions of 5-dehydroepisterol had sterol structural requirements not entirely met by cholesterol. In all these studies, L. mexicana mexicana demonstrated a sterol biochemistry remarkably similar to that of fungi. This recommends an increase in interest in antimycotic drugs as chemotherapeutic agents for leishmanial infections.