Antifungal Efficacy of Luliconazole in an Experimental Rabbit Model of Fungal Keratitis Caused by Fusarium solani.

Fungal keratitis is a corneal fungal infection that potentially leads to blindness and is mainly caused by filamentous fungi, such as Fusarium, with limited drug options available, such as natamycin and voriconazole. Therefore, this study aimed to evaluate the therapeutic effects of the imidazole antifungal drug-luliconazole-using a rabbit experimental model of fungal keratitis caused by Fusarium solani, which is the dominant causative agent of fungal keratitis. F. solani was inoculated into rabbit corneas. luliconazole 1% suspension or natamycin 5% eye drops were administered four times a day (N = 6 for each group) 3 days after inoculation. Signs were scored up to 14 days after inoculation to evaluate the efficacy of the drugs. Compared with the peak mean sign scores of the placebo control group, there was a significant decrease in the mean sign scores of both the treatment groups (P < 0.05). Sign score trends were similar between the two treatment groups. In conclusion, luliconazole demonstrated therapeutic efficacy comparable to that of natamycin in treating experimental fungal keratitis. This suggests that luliconazole can be a novel therapeutic agent for human fungal keratitis.

A comparative study between two antifungal agents, Luliconazole and Efinaconazole, of their preventive effects in a Trichophyton-infected guinea pig onychomycosis model.

An efficacious period of two topical antifungal drugs was compared in a Trichophyton mentagrophytes-infected onychomycosis model in guinea pigs treated with antifungal drugs prior to infection. Luliconazole 5% (LLCZ) and efinaconazole 10% (EFCZ) test solutions were applied to the animals' nails once daily for 2 weeks followed by a nontreatment period of 2, 4, and 8 weeks. After each nontreatment period, the nails were artificially infected by the fungus. Drug efficacy was quantitatively evaluated by qPCR and histopathological examination of the nails collected following a 4-week post-infection period. The fungal infection was confirmed in the untreated group. Both LLCZ and EFCZ prevented fungal infection in the treated groups with the nontreatment period of 2 weeks. After the nontreatment period of 4 weeks, no infection was observed in the LLCZ-treated group; however, infection into the nail surface and fungal invasion into the nail bed were observed in the EFCZ-treated group. After the nontreatment period of 8 weeks, fungi were found in the nail surface and nail bed in some nails treated with EFCZ; however, no infection was observed in the nail bed of the LLCZ-treated group. The results suggest that LLCZ possesses longer-lasting antifungal effect in nails of the guinea pigs than EFCZ, and that this animal model could be useful for translational research between preclinical and clinical studies to evaluate the pharmacological efficacy of antifungal drugs to treat onychomycosis. This experimentally shown longer-lasting preventive effects of LLCZ could also decrease the likelihoods of onychomycosis recurrence clinically.

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.

Efficacy of Luliconazole Against Broad-Range Filamentous Fungi Including Fusarium solani Species Complex Causing Fungal Keratitis.

PURPOSE: Fungal keratitis can be difficult to medically treat. Topical antifungals are usually applied empirically as the initial option in treating fungal keratitis. Natamycin (NAT) and/or voriconazole (VRCZ) have been widely used in the treatment of fungal keratitis. However, Fusarium solani species complex (FSSC), which are the dominant species of fungal keratitis, are resistant to VRCZ. This study investigated in vitro efficacy of luliconazole (LLCZ), a new imidazole antifungal, against FSSC and other filamentous fungi. METHODS: A total of 18 Fusarium isolates and 7 others were grown on potato dextrose agar at 30 and 37°C. For Fusarium, species identification and phylogenetic tree analysis were performed based on elongation factor-1α (EF-1α) DNA sequencing. The broth microdilution method was used for antifungal susceptibility testing of 11 antifungal drugs including LLCZ. RESULTS: The 18 identified Fusarium isolates belonged to FSSC (n = 13), Fusarium oxysporum species complex (FOSC; n = 2), Fusarium chlamydosporum species complex (FCSC; n = 1), Fusarium incarnatum-equiseti species complex (FIESC; n = 1), and Fusarium fujikuroi species complex (FFSC; n = 1). We further divided 13 FSSC isolates into 3 clades, FSSC5 (n = 8), FSSC3 + 4 (n = 4), and FSSC9-a (n = 1), with 8 FSSC strains growing at 37°C. LLCZ showed lowest minimum inhibitory concentrations (MICs) against all tested filamentous fungi, with a MIC90 against the Fusarium species of 0.06 µg/mL, whereas MIC90 for NAT and VRCZ were 4 and 8 µg/mL, respectively. CONCLUSIONS: LLCZ has the strongest in vitro antifungal activity among all drugs used against broad-range filamentous fungi including FSSC. LLCZ may potentially be a new medical treatment option for fungal keratitis.

[Affinity of Luliconazole for Human Nail Derived Keratin].

Affinity of Luliconazole (LLCZ), an antifungal drug used for topical treatment of onychomycosis in Japan, to nail keratin was demonstrated. Efinaconazole (EFCZ) was used as a reference drug. Drugs at fixed concentrations were added to 4 ml of buffer solution containing 40 mg of nail keratin powder prepared from healthy volunteers or from tinea unguium patients. The mixtures were shaken at 37℃, and adsorption and desorption rates of the drug in nail keratin were measured. Theoretical analysis using the Freundlich adsorption isotherm was applied to eliminate effects of testing conditions on the results. Results showed that compared with EFCZ, LLCZ exhibited high adsorption rates and low desorption rates in nail keratins. These results were verified by Freundlich analysis, in which adsorption coefficient (KadsF) and desorption coefficient (KadsF) of LLCZ were 5-7 times and about 2 times higher than EFCZ, respectively. In addition, antifungal activity against Trichophyton rubrum of the desorbed LLCZ samples was determined using disk diffusion assay. In conclusion, LLCZ is considered to possess high affinity to nail keratin. LLCZ, therefore, can be retained in the nail as a reservoir and continuously desorbed at the infection site to exhibit antifungal activity against pathogenic fungi. The pharmacokinetics of LLCZ in the nail is believed to differ from that of EFCZ. As adsorption and desorption rates of the two drugs in nail keratin tended to be different between healthy volunteers and patients, further detailed study is needed.

Development of a novel acaricide, pyflubumide.

Pyflubumide is a novel carboxanilide acaricide discovered and developed by Nihon Nohyaku Co., Ltd., that exhibits excellent acaricidal activity against Tetranychus and Panonychus species, including strains that have developed resistance to conventional acaricides. Its safety profile against non-target arthropods is suitable for integrated pest management (IPM) programs. Pyflubumide was registered and launched in Japan in 2015 and Korea in 2017. This paper describes pyflubumide's invention history, synthesis, exploratory synthesis, biological activity, toxicological profile, and mode of action.

Spontaneous intraocular hemorrhage in rats during postnatal ocular development.

To study spontaneous intraocular hemorrhage in rats during postnatal ocular development and to elucidate the underlying mechanism, postnatal ocular development in the albino Wistar Hannover (WH) and Sprague-Dawley (SpD) and pigmented Long-Evans (LE) strains was analyzed. Pups (n = 2 to 5) from each strain were euthanized daily on postnatal days (PND) 0 through 21 and their eyes examined macroscopically and histologically; similar analyses were performed in 26 to 39 additional WH pups daily from PND 7 to 14. At necropsy, ring-shaped red regions and red spots were present in the eyes of WH and SpD rats. These lesions were attributed histologically to hemorrhage of the tunica vasculosa lentis or of the retina, choroid, and hyaloid artery, respectively. Similar intraocular hemorrhages occurred in LE rats, although the macroscopic alterations found in WH and SpD rats were not present in this strain. Among the 3 strains evaluated, the incidence of the intraocular hemorrhage was highest in WH rats. We here showed that intraocular hemorrhage occurs spontaneously during normal ocular development in rats regardless of the strain; however, the region, degree, and incidence of intraocular hemorrhage differ among strains. Hemorrhage in the tunica vasculosa lentis and hyaloid artery may result from the leakage of erythrocytes from the temporary vasculature of these tissues during regression. The mechanisms underlying hemorrhage in the retina and choroid remain unclear. To our knowledge, this report is the first to describe the spontaneous intraocular hemorrhage that occurs during postnatal ocular development in rats.