In vitro antifungal activity of luliconazole against nondermatophytic moulds.

In vitro antifungal activity of luliconazole against nondermatophytic moulds causing superficial infections was compared with that of five classes of 12 topical and systemic drugs. The minimum inhibitory concentration (MIC) of the drugs against the genera of Neoscytalidium, Fusarium, Aspergillus, Scedosporium, and Alternaria was measured via modified microdilution method. In results, the nondermatophytic moulds were found to be less susceptible to drugs to which Neoscytalidium spp. and Fusarium spp. were typically drug resistant. However, luliconazole was effective against all the genera tested, including afore-mentioned two species, and had the lowest MICs among the drugs tested.

Guinea pig seborrheic dermatitis model of Malassezia restricta and the utility of luliconazole.

Seborrheic dermatitis (SD) is a multifactorial disease in which Malassezia restricta has been proposed as the predominant pathogenic factor. However, experimental evidence supporting this hypothesis is limited. A guinea pig SD model using a clinical isolate of M. restricta was used to elucidate the pathogenicity of M. restricta. Also, the efficacy of 1% luliconazole (LLCZ) cream, a topical imidazole derivative, against M. restricta was compared with that of a 2% ketoconazole (KCZ) cream in the same guinea pig model. Dorsal skin hairs of guinea pig were clipped and treated with M. restricta by single or repeated inoculations without occlusion. Skin manifestations were examined macroscopically and histologically. A quantitative polymerase chain reaction (PCR) assay was also performed for mycological evaluation. An inflammatory response mimicking SD occurred after repeated as well as single inoculation but not in abraded skin. The inflammation score attained its maximum on day 11 and persisted until day 52. The yeast form of the fungal elements was distributed on the surface of stratum corneum and around the follicular orifices, and an epidermal and dermal histological reaction was observed. Application of 1% LLCZ or 2% KCZ cream significantly improved the skin manifestations and decreased the quantity of M. restricta rDNA in the skin lesions. The efficacy of topical antifungal drugs suggested that M. restricta is a pathogenic factor contributing to SD.

[In vitro Antifungal Activity of Luliconazole against Trichophyton spp].

The minimum inhibitory concentration (MIC) and the minimum fungicidal concentration (MFC) of luliconazole against Trichophyton rubrum (14 strains) and Trichophyton mentagrophytes (14 strains), which are the most common cause of tinea, were compared with those of 6 topical antifungal drugs of lanoconazole, bifonazole, efinaconazole, liranaftate, naftifine and terbinafine.　Luliconazole showed the most potent antifungal activity (MIC90 =0.00098 µg/ml and MFC90 =0.0078 µg/ml) among the compounds tested against the two species. Efinaconazole and bifonazole, the drug of azole-class, showed a large MFC/MIC ratio. On the other hand, these ratios of luliconazole and lanoconazole were as small as those of liranaftate, naftifine and terbinafine which are thought to possess fungicidal mechanism. These results suggest that luliconazole possesses fungicidal activity against both species of Trichophyton.　In this study, we found that luliconazole had the most potent antifungal activity among the major topical antimycotics used in Japan and the US. Luliconazole would be the best-in-class drug for dermatophytosis in clinics.

Luliconazole Retention in Stratum Corneum and Prevention of Fungal Infection in a Guinea Pig Tinea Pedis Model.

OBJECTIVE: To compare drug concentrations in the stratum corneum following daily application of luliconazole and terbinafine cream in a guinea pig tinea pedis model. METHODS: Luliconazole 1% cream or terbinafine 1% cream were topically applied once daily to hind limbs of guinea pigs for 14 days. Drug concentration in stratum corneum of plantar skin was measured by HPLC-UV on days 1, 3, 7, 10, and 14. Separately, creams were applied daily for 5 days to the hind limbs of guinea pigs and skin drug release determined. In addition, drug retention in the stratum corneum was assessed by infecting guinea pigs with Trichophyton mentagrophytes, 14 and 21 days after a single application of luliconazole or terbinafine creams. RESULTS: Luliconazole stratum corneum concentrations were higher than those of terbinafine throughout the study. Concentrations of luliconazole and terbinafine were 71.6µg/g and 36.6µg/g, respectively, after a single application (P<.05), reaching steady state after 10 days. Cumulative release of luliconazole from the stratum corneum was 4.5 times greater than with terbinafine. Unlike terbinafine, no fungal invasion of the stratum corneum was seen 14 days post-treatment with luliconazole. CONCLUSIONS: Drug concentrations of luliconazole in the stratum corneum and subsequent release are greater than those achieved with terbinafine and may contribute to clinical efficacy. Luliconazole may also provide greater protection against disease recurrence.

Disulphide-reduced psoriasin is a human apoptosis-inducing broad-spectrum fungicide.

The unexpected resistance of psoriasis lesions to fungal infections suggests local production of an antifungal factor. We purified Trichophyton rubrum-inhibiting activity from lesional psoriasis scale extracts and identified the Cys-reduced form of S100A7/psoriasin (redS100A7) as a principal antifungal factor. redS100A7 inhibits various filamentous fungi, including the mold Aspergillus fumigatus, but not Candida albicans. Antifungal activity was inhibited by Zn(2+), suggesting that redS100A7 interferes with fungal zinc homeostasis. Because S100A7-mutants lacking a single cysteine are no longer antifungals, we hypothesized that redS100A7 is acting as a Zn(2+)-chelator. Immunogold electron microscopy studies revealed that it penetrates fungal cells, implicating possible intracellular actions. In support with our hypothesis, the cell-penetrating Zn(2+)-chelator TPEN was found to function as a broad-spectrum antifungal. Ultrastructural analyses of redS100A7-treated T. rubrum revealed marked signs of apoptosis, suggesting that its mode of action is induction of programmed cell death. TUNEL, SYTOX-green analyses, and caspase-inhibition studies supported this for both T. rubrum and A. fumigatus. Whereas redS100A7 can be generated from oxidized S100A7 by action of thioredoxin or glutathione, elevated redS100A7 levels in fungal skin infection indicate induction of both S100A7 and its reducing agent in vivo. To investigate whether redS100A7 and TPEN are antifungals in vivo, we used a guinea pig tinea pedes model for fungal skin infections and a lethal mouse Aspergillus infection model for lung infection and found antifungal activity in both in vivo animal systems. Thus, selective fungal cell-penetrating Zn(2+)-chelators could be useful as an urgently needed novel antifungal therapeutic, which induces programmed cell death in numerous fungi.

Short-term therapy with luliconazole, a novel topical antifungal imidazole, in guinea pig models of tinea corporis and tinea pedis.

Luliconazole is a novel topical antifungal imidazole with broad-spectrum and potent antifungal activity. The drug is under clinical development in the United States for management of dermatophytosis with a short-term treatment regimen. The present study was undertaken to investigate the clinical benefit of short-term therapy with luliconazole cream in guinea pig models of tinea corporis and tinea pedis induced with Trichophyton mentagrophytes. The dose-dependent therapeutic efficacy of topical luliconazole cream (0.02 to 1%), measured by macroscopic improvement of skin lesions and by fungal eradication as determined by a culture assay, was demonstrated using a tinea corporis model. The improvement in skin lesions seen with luliconazole cream was observed even at a concentration of 0.02%, and its efficacy at 0.1% was equal to that of 1% bifonazole cream. The efficacy of short-term therapy with 1% luliconazole cream, which is used for clinical management, was investigated using the tinea corporis model (4- and 8-day treatment regimens) and the tinea pedis model (7- and 14-day treatment regimens). The 1% luliconazole cream completely eradicated the fungus in half or less of the treatment time required for 1% terbinafine cream and 1% bifonazole cream, as determined by a culture assay for both models. These results clearly indicate that 1% luliconazole cream is sufficiently potent for short-term treatment for dermatophytosis compared to existing drugs. Luliconazole is expected to be useful in the clinical management of dermatophytosis.

In vitro antifungal activities of luliconazole, a new topical imidazole.

Luliconazole is a topical antifungal drug newly developed in Japan. The present study compares the in vitro antifungal activity of luliconazole against clinically important dermatomycotic fungi with that of other representative antifungal drugs. The reference drugs chosen were five classes of nine topical agents, i.e., allylamine (terbinafine), thiocarbamate (liranaftate), benzylamine (butenafine), morpholine (amorolfine), and azole (ketoconazole, clotrimazole, neticonazole, miconazole and bifonazole). The minimum inhibitory concentrations (MIC) of luliconazole and the reference drugs against Trichophyton spp. (T. rubrum, T. mentagrophytes and T. tonsurans) and Candida albicans were measured by the standardized broth microdilution method. Luliconazole demonstrated greater potency against Trichophyton spp. (MIC range:

[In vitro activities of antifungal drugs against clinical isolates of Trichophyton tonsurans].

To determine drug susceptibility of Trichophyton tonsurans endemic in Japan, in vitro MICs of antifungal drugs against a total of 10 clinical isolates of T. tonsurans collected from dermatophytosis patients were measured by the agar dilution method and the broth microdilution method. The agar dilution method was not appropriate as the growth of T. tonsurans on the agar medium was too slow to determine drug activity, while the broth microdilution method was thought to be an appropriate method for this study. The MIC90 values determined by the broth microdilution method for terbinafine, itraconazole, miconazole and ketoconazole were 0.013, 0.1, 0.8 and 0.4 microg/ml, respectively. Meanwhile, the MIC90 values of lanoconazole and luliconazole, known to be antifungal drugs potent against dermatomycosis, were 0.00078 and 0.00039 microg/ ml, respectively. The drug susceptibility of these T. tonsurans isolates to the aforementioned antifungal drugs was found to be on a similar level with that of T. mentagrophytes and T. rubrum, major causative agents of dermatomycosis. The results also demonstrated the strong antifungal activity of lanoconazole and luliconazole against T. tonsurans.