Blad-containing oligomer: a novel fungicide used in crop protection as an alternative treatment for tinea pedis and tinea versicolor.

PURPOSE: The lack of novel antifungal drugs and the increasing incidence and severity of fungal infections are major concerns worldwide. Herein, we tested the activity of the Blad-containing oligomer (BCO), a new antifungal molecule already in use for agriculture, on Malassezia spp. and dermatophytes, the causal agents of human tinea versicolor and tinea pedis. Given the lack of a standard method for Malassezia susceptibility testing and the plethora of published methods, we also developed an improved method for this genus. METHODOLOGY: The efficacy of BCO was assessed in vitro and compared to that of the drugs currently utilized in the treatment of tinea versicolor (fluconazole and itraconazole) and tinea pedis (itraconazole and terbinafine). For dermatophytes, the standard microdilution broth-based method was used, with small adjustments, and several broth formulations and inocula sizes were tested to develop an improved susceptibility method for Malassezia spp. RESULTS: We successfully developed a microdilution broth-based method with considerable advantages over other available methods, and used it for all in vitro susceptibility tests of Malassezia spp. isolates. We report that, on a molar basis, BCO was more effective than fluconazole or itraconazole on most strains of Malassezia spp. isolated from clinical samples (n=29). By contrast, BCO was less effective than itraconazole or terbinafine on the common dermatophytes Trichophyton rubrum and Trichophyton interdigitale. CONCLUSION: These data place BCO as a promising drug for the treatment of Malassezia-associated skin diseases. Further in vivo studies are now required to ascertain its applicability in the clinical setting.

Discovery of antifungal constituents from the Miao medicinal plant Isodon flavidus.

ETHNOPHARMACOLOGICAL RELEVANCE: Leigong Mountain is an area in the Southwest of China where there is a high incidence rate of athlete's foot, but the Miao people, a Chinese minority who reside in this mountainous area have suffered less from this disease due to their use of the herbal medicine Isodon flavidus (Hand.-Mazz.) H. Hara. AIM OF THE STUDY: The present study is to identify the active chemical constituents responsible for antifungal effects of the folk medicine plant. MATERIALS AND METHODS: The natural compounds were separated from the methanol extract of the twigs and leaves of I. flavidus by phytochemical study using chromatographic methods, and their chemical structures were determined by analysis of the spectroscopic data including 1D and 2D NMR spectra. The absolute configuration of fladin A (1) was further confirmed by X-ray crystallographic analysis. The compounds were evaluated for their antifungal activity against the athlete's foot fungus Trichophyton rubrum. They were further evaluated for their antimicrobial and anti-biofilm activity against the dental pathogens Streptococcus mutans, Porphyromonas gingivalis and Candida albicans. RESULTS: Phytochemical and biological studies of I. flavidus led to the discovery of two antifungal compounds, fladin A (1) and lophanic acid (2). Fladin A (1) is a novel diterpene with an unprecedented cyclic ether group formed between C-4 and C-9. Lophanic acid (2) displayed inhibition activity against the athlete's foot fungus Trichophyton rubrum with an MIC value of 7.8µg/mL, and fladin A (1) also showed inhibition activity against the fungus with a MIC value of 62.5µg/mL. CONCLUSIONS: Our identification of two antifungal compounds provided strong evidence for the Miao people to use I. flavidus as a medicinal plant for treatment of athlete's foot disease. The very different chemical structures of the active compounds from those in the market presents them as potential antifungal lead compounds for follow-up study.

Anti-dermatophytic activity of bakuchiol: in vitro mechanistic studies and in vivo tinea pedis-inhibiting activity in a guinea pig model.

Bakuchiol was an active antifungal compound isolated from Psoraleae Fructus by means of bioassay-guided fractionation in our previous study. The present work aimed to investigate the underlying mechanisms and the therapeutic effect of bakuchiol in Trichophyton mentagrophytes-induced tinea pedis. After exposure to bakuchiol at 0.25-fold, 0.5-fold and 1-fold of minimum inhibitory concentration (MIC) (3.91 µg/ml) for 24h, the fungal conidia of T. mentagrophytes demonstrated a significant dose-dependent increase in membrane permeability. Moreover, bakuchiol at 1-fold MIC elicited a 187% elevation in reactive oxygen species (ROS) level in fungal cells after a 3-h incubation. However, bakuchiol did not induce DNA fragmentation. In a guinea pig model of tinea pedis, bakuchiol at 1%, 5% or 10% (w/w) concentration in aqueous cream could significantly reduce the fungal burden of infected feet (p<0.01-0.05). In conclusion, this is the first report to demonstrate that bakuchiol is effective in relieving tinea pedis and in inhibiting the growth of the dermatophyte T. mentagrophytes by increasing fungal membrane permeability and ROS generation, but not via induction of DNA fragmentation.

Topical treatment of tinea pedis using 6% coriander oil in unguentum leniens: a randomized, controlled, comparative pilot study.

BACKGROUND: The antifungal activity of coriander oil has already been demonstrated in vitro. OBJECTIVE: Evaluation of the efficacy and tolerability of 6% coriander oil in unguentum leniens in the treatment of interdigital tinea pedis. METHODS: Half-side comparative pilot study on subjects with symmetric, bilateral interdigital tinea pedis. Active drug and placebo control were applied twice daily on the affected areas, and follow-up visits were performed on days 14 and 28. RESULTS: 40 participants (mean age 52.5 years, 60% male) were included in the study. For 6% coriander oil in unguentum leniens, a highly significant improvement of the clinical signs (p < 0.0001) was observed during the entire observation period; the number of positive fungal cultures also tended to decrease (p = 0.0654). The tolerability of the tested substances was good. CONCLUSION: Coriander oil is effective and well tolerated in the treatment of interdigital tinea pedis.

Therapeutic effectiveness of Ageratina pichinchensis on the treatment of chronic interdigital tinea pedis: a randomized, double-blind clinical trial.

OBJECTIVES: Interdigital tinea pedis is the most frequent presentation, as well as the most severe clinical form of tinea pedis, constituting a therapeutic challenge. The aim of the study was to evaluate the effectiveness and tolerability of two concentrations of Ageratina pichinchensis extract (encecalin content, 0.76 and 1.52%, respectively) on patients with clinical and mycological diagnosis of chronic interdigital tinea pedis. DESIGN: By means of a randomized, double-blind clinical trial, three groups of patients were treated topically for 4 weeks with a cream containing the following: Group I-the lower concentration of A. pichinchensis extract, group II-the higher concentration, group III-2% ketoconazole. SUBJECTS: One hundred and sixty (160) ambulatory patients of either sex between the ages of 18 and 65 years were enrolled. OUTCOME MEASURES: The primary outcome variables were: clinical effectiveness, mycological effectiveness, therapeutic cure, tolerability, and treatment compliance. The secondary outcome variable was therapeutic success. RESULTS: At the end of treatment, therapeutic cure was achieved by 34.1, 41.8, and 39.53% of Groups I, II, and III, respectively. No statistical difference between the groups was observed. CONCLUSIONS: Both treatments were effective for the treatment of interdigital-type tinea pedis, while better results were observed on patients that received the higher concentration of the extract.

In vitro antifungal susceptibility of dermatophyte strains causing tinea pedis and onychomycosis in patients with non-insulin-dependent diabetes mellitus: a case-control study.

BACKGROUND: The efficacy of antifungal treatment may be reduced and/or delayed in diabetic patients. To date, no study has investigated the in vitro antifungal susceptibility of dermatophytes in this patient group. OBJECTIVE: We aimed to determine the dermatophyte species causing tinea pedis and onychomycosis, and in vitro susceptibility of these dermatophytes to terbinafine, itraconazole, and fluconazole in patients with non-insulin-dependent diabetes mellitus. We compared the findings in diabetic patients with those in non-diabetic individuals. MATERIALS AND METHODS: One hundred patients with non-insulin-dependent diabetes mellitus and 100 otherwise healthy controls clinically suspected with tinea pedis and/or onychomycosis were included. Skin scrapings and/or nail clippings were taken and cultured on Sabouraud dextrose agar, mycobiotic agar, and dermatophyte test medium. In vitro antifungal susceptibility tests were carried out according to the Clinical and Laboratory Standards Institute (CLSI) M-38P protocol with some modifications. RESULTS: Fifty-seven samples of 54 diabetics and 50 samples of 50 controls grew dermatophytes. In both groups, Trichophyton rubrum was the most common isolate. Mean MIC values of terbinafine, itraconazole, and fluconazole for all of the isolated dermatophyte strains were similar in two groups (P>0.05). The difference in mean MIC values of three antifungals for T. rubrum and T. mentagrophytes between two groups was not statistically significant (P>0.05). CONCLUSIONS: Dermatophyte types causing tinea pedis and onychomycosis, their frequency patterns, and in vitro activity of three antifungals against dermatophytes in diabetics are similar to the non-diabetics. Terbinafine is the most active agent in vitro in both groups.

Active compounds against tinea pedis dermatophytes from Ageratina pichinchensis var. bustamenta.

Secondary metabolites 5-acetyl-3beta-angeloyloxy-2beta-(1-hydroxyisopropyl)-2,3-dihydrobenzofurane (1), 5-acetyl-3beta-angeloyloxy-2beta-(1-hydroxyisopropyl)-6-methoxy-2,3-dihydrobenzofurane (2), espeletone (3), encecalinol (4), O-methylencecalinol (5), encecalin (6), sonorol (7), taraxerol (8), (+)-beta-eudesmol (9), and a mixture of beta-sitosterol and stigmasterol, were isolated from the aerial parts of Ageratina pichinchensis var. bustamenta. The antimicrobial activity of compounds 6, 8 and 9, together with derivatives 9a and 9b against the most important dermatophytes responsible for tinea pedis infection, Trichophyton rubrum and T. mentagrophytes, and against Candida albicans and Aspergillus niger were determined, showing that the three natural products were active against both Trichophyton species. Ageratina pichinchensis var. bustamenta is used in folk medicine to treat skin infections and wounds, and this study confirms that the n-hexane extract contains metabolites which are responsible for these utilities.

Effectiveness and tolerability of a standardized extract from Ageratina pichinchensis on patients with tinea pedis: an explorative pilot study controlled with ketoconazole.

Ageratina pichinchensis has been used for many years in Mexican traditional medicine for the treatment of superficial mycosis. Previous studies have demonstrated the antifungal effectiveness of a hexane extract from aerial parts of this plant on in vitro cultures of Candida albicans, Aspergillium niger, Trichophyton mentagrophytes, and Trichophyton rubrum. To compare the effectiveness and tolerability of A. pichinchensis with ketoconazole in patients with the clinical and mycological diagnosis of tinea pedis, we carried out a double-blind pilot study. The experimental group was treated topically with a cream containing A. pichinchensis standardized extract (10 %), while the control group was administered a similarly colored cream containing 2 % ketoconazole. All patients were clinically followed weekly for 4 weeks. By means of a mycological examination (direct microscopic detection), the mycological diagnosis of tinea pedis was performed. This technique was also used for evaluating the mycological effectiveness at the end of treatment. A total of 120 patients were included, 60 in each treatment group. Of these, 97 patients were included in the statistical analysis, 51 from the experimental group and 46 controls. The remainder of the patients withdrew from the study due to non-medical causes. Clinical effectiveness was reached in 80.3 and 76 %, while therapeutic success was achieved in 80.3 and 71.7 % of the experimental and control groups, respectively. There were no statistical differences between groups (P = 0.31). Our results suggest the effectiveness and tolerability of a standardized extract from A. pichinchensis in treatment of patients with tinea pedis.

Evaluation of the anti-Trichophyton activity of a prodigiosin analogue produced by gamma-proteobacterium, using stratum corneum epidermis of the Yucatan micropig.

Prodigiosins (PGs) are known to be a family of natural red pigments, characterized by a common pyrrolydipyrrolylmethane skeleton structure with a C-4 methoxy group, and some of these pigments have been isolated from some microorganisms. Members of the PG family have been reported to show several biological activities, such as immunosuppressive and cytotoxic activities. Recently, we discovered a bacterial strain (MS-02-063), from our microbial library, that produces large amounts of a PG analogue (PG-L-1). In this study, we examined the anti-Trichophyton activity of PG-L-1 (produced by strain MS-02-063) against clinically isolated Trichophyton spp., by a method using stratum corneum epidermis (SCE) of the Yucatan micropig, which is suitable for estimating the antifungal activity of drugs in vitro. In the National Committee for Clinical Laboratory Standards (NCCLS) method, PG-L-1 showed potent antifungal activity against nine clinically isolated strains of Trichophyton spp., although the minimum inhibitory concentration (MIC) values were slightly higher than those of bifonazole. In spite of the lower efficiency of PG-L-1 transfer into SCE from medium than that of bifonazole, PG-L-1 transferred into SCE showed more potent antifungal activity than bifonazole, at lower concentrations.

A novel mycological analysis valuable for evaluating therapeutic efficacy of antimycotics against experimental dermatophytosis in guinea pigs.

Although antimycotic effects are mainly evaluated with regard to whether or not the fungi grow from a specimen obtained from the drug-treated skin, the potential for discrepancies in skin specimens in which the fungi are grown has not been evaluated, in the experimental tinea model. In this study, to evaluate the therapeutic effectiveness of antimycotic agents against fungal skin infection, a novel form of mycological assessment, which focuses on the size of colonies grown from skin specimens was examined and developed. When microconidia of Trichophyton mentagrophytes were inoculated onto a Sabouraud dextrose agar (SDA) plate and incubated at 27 degrees C for 5 days, a linear relationship was observed between the growth area of mycelia and the logarithm of the quantity of microconidia. This relationship between the growth area and the logarithm of the number of T. mentagrophytes microconidia did not change with the addition of skin homogenate and/or keratin powder. Next, the number of fungi in skin blocks attendant upon experimental, cutaneous infection in guinea pigs was evaluated and analyzed via a calibration curve, determined based on a microconidium suspension of T. mentagrophytes. Estimates of severity of dermatophytic infection in experimental animals were parallel to, but more reliable than, results obtained via the conventional mycological method (fungus-positive skin ratio of treated skin) in culture studies of infected dermal tissues. This new analytical method may also be applicable to the in vivo assessment of the therapeutic effect against dermatophytosis experimentally produced in guinea pigs.

Low-voltage direct current as a fungicidal agent for treating onychomycosis.

Onychomycosis, most commonly caused by two species of dermatophyte fungi--Trichophyton rubrum and Trichophyton mentagrophytes--is primarily treated with regimens of topical and systemic antifungal medications. This study was undertaken to evaluate in vitro the efficacy of low-voltage direct current as an antifungal agent for treating onychomycosis. Agar plate cultures of T rubrum and T mentagrophytes were subjected to low-voltage direct current electrostimulation, and antifungal effects were observed as zones in the agar around the electrodes lacking fungal growth. Zones devoid of fungal growth were observed for T rubrum and T mentagrophytes around anodes and cathodes in a dose-dependent manner in the current range of 500 microA to 3 mA. Low-voltage direct current electrostimulation has great clinical potential for the treatment of onychomycosis and perhaps other superficial maladies of fungal etiology.

Efficacy of flutrimazole 1% powder in the treatment of tinea pedis.

The aim of the study was to compare the efficacy and tolerability of flutrimazole 1% powder vs. bifonazole 1% powder in treating tinea pedis. A multicentre, double blind, randomized, parallel and comparative study was conducted. Two hundred and twenty-two patients with clinically and mycologically confirmed tinea pedis were randomized to flutrimazole (n = 136) or bifonazole (n = 138) 1% powder applied twice daily for 4 weeks. The corresponding clinical cure rates were assessed at 2 and 4 weeks of treatment, and the global (clinical and mycological) cure rates were determined at the fourth week. Clinical cure rates were 83.5 and 82.4% for flutrimazole and bifonazole, respectively (95% CI: -0.0806 to 0.1009). Global cure rates were observed in 65.3 and 70.1% of patients treated with flutrimazole and bifonazole, respectively (95% CI: -0.0828 to 0.1779). Three non serious adverse events at the application site--itching (one patient per group) and dishydrotic eczema (one patient treated with flutrimazole)--were recorded during the study. These results support that flutrimazol 1% powder applied twice daily for a duration of 4 weeks is highly effective in the treatment of tinea pedis, showing a similar therapeutic profile with that of bifonazole 1% powder.

Clinical comparison of the efficacy and tolerability of once daily Canesten with twice daily Nizoral (clotrimazole 1% cream vs. ketoconazole 2% cream) during a 28-day topical treatment of interdigital tinea pedis.

The effects of two topical cream formulations containing clotrimazole 1% and ketoconazole 2%, respectively, were clinically compared in a double-blind, randomized manner for a 28-day therapy of interdigital tinea pedis in 106 treated patients. Ketoconazole was to be used twice daily whereas clotrimazole was administered only once daily. The primary response criterion defined as the number of patients with cure or improvement after 28 treatment days was comparable with 62.0% vs. 64.0% (clotrimazole vs. ketoconazole) for the full analysis set of 100 (50 vs. 50) patients. The mycological response revealed a negative culture and microscopy in 53.1% vs. 52.1% of the patients after 14, in 76.0% vs. 79.2% after 28, and in 83.7% vs. 76.9% after 56 days of observation, indicating a possibly better long-term efficacy of clotrimazole. The development of the overall score of tinea-related signs and symptoms did not show relevant differences between the two drugs and continuously decreased from 11+/-5 in both groups at baseline to 2+/-2 vs. 2+/-1 at day 56. As to the remission and improvement rates of single symptoms, better results were obtained under clotrimazole than under ketoconazole particularly for pruritus (97.8 vs. 89.6%) and burning/stinging (97.5 vs. 89.4%) which both are perceived as most bothersome by the patients. Furthermore, both substances appeared as comparably safe and well tolerable (8 vs. 7 adverse events with only 1 vs. 3 drug related). In conclusion, a successful therapy of tinea pedis can be achieved with both clotrimazole and ketoconazole within 28 days of treatment and once-daily clotrimazole is equally effective as twice-daily ketoconazole with favourable influences on the most irritating symptoms of the disease. Mycological and reliable clinical cure cannot be observed during two weeks after start of treatment.

Development of a new medium useful for the recovery of dermatophytes from clinical specimens by minimizing the carryover effect of antifungal agents.

Two surface-active compounds, egg lecithin and polysorbate 80, usually used as the deactivators of various preservatives were tested whether they also counteract either or all of the three major topical antifungal drugs, bifonazole (BFZ), lanoconazole (LCZ) and terbinafine (TBF). Both egg lecithin and polysorbate 80, when added to culture media up to final concentrations of 1.0 and 0.7%, respectively, antagonized the anti-dermatophytic activity of the three drugs in a concentration-dependent manner. A greater extent of antagonistic action was exerted when the two deactivators combined at their maximal levels tested were added; MIC's of BFZ were increased more than 30-fold and those of LCZ and TBF more than 200-fold compared with the values obtained in the absence of the deactivators. Using the agar medium supplemented with the combined deactivators, culture studies were carried out with skin tissues specimens taken from guinea pigs whose feet were infected with dermatophytes and subsequently treated with 1% topical preparations of the three antifungal drugs. The experimental data from this animal study demonstrated that the combined deactivators-supplemented medium yielded increased numbers of fungi compared with the basal medium. It looks, therefore, likely that the fungal recovery on the former medium more correctly reflects to actual fungal burden in the infected lesions than the latter. All these results suggest that the combined deactivators-supplemented medium is more useful for mycological evaluation of therapeutic efficacy of imidazole and allylamine drugs against dermatophytoses in both preclinical and clinical studies.

Efficacy of ozonized sunflower oil in the treatment of tinea pedis.

Ozonized sunflower oil, Oleozon, has a remarkable gerrmicidal action. In the present study, the efficacy of Oleozon in the treatment of tinea pedis was demonstrated in a controlled randomized phase III assay, comparing topical Oleozon with ketoconazole cream 2% (Nizoral) in 200 patients (100 in each group). The treatment administered was twice per day for a period of 6 weeks. The efficacy was evaluated clinically (disappearance of all lesions, with or without negative mycological results) and mycologically (negative culture results). A complete clinical and mycological cure was obtained in 75 and 81% for Oleozon and ketoconazole, respectively, with no significant differences between both groups. No side-effects or bacterial super-infections were observed. Patients were evaluated 6 months after the end of the treatment and no recurrence was observed in the Oleozon group. Oleozon can be an effective alternative low-cost antimycotic drug.

Broad spectrum herbal therapy against superficial fungal infections.

Skin disease associated with keratinized tissues in animal and human beings has been investigated. The essential oil of Eucalyptus pauciflora in vitro showed strong antifungal activity at 1.0 microl/ml against human pathogenic fungi, viz. Epidermophyton floccosum, Microsporum audouinii, M. canis, M. gypseum, M. nanum, Trichophyton mentagrophytes, T. rubrum, T. tonsurans and T. violaceum. The oil has heavy doses of inoculum potential at 1.0 microl/ml. Moreover, it did not exhibit any adverse effects on mammalian skin up to 5% concentrations. Further, we formulated the oil in the form of ointment 'BSHT' (broad spectrum herbal therapy) (1% v/v) and subjected it to topical testing on patients attending the outpatient department of M.L.N. Medical College, Allahabad. Fifty patients were selected on the basis of KOH-positive results and diagnosed as either tinea pedis, tinea corporis or tinea cruris. After the second week of treatment, all patients were KOH-negative. At the end of medication, 60% of patients recovered completely and 40% showed significant improvement from the disease. No KOH-negative cases of relapse were observed when patients were re-examined after 2 months following the end of treatment. Thus, the ointment can be exploited commercially after undergoing successful multicenter clinical trials, which are in progress.

Efficacy of ajoene, an organosulphur derived from garlic, in the short-term therapy of tinea pedis.

The present report shows the efficacy of ajoene, a garlic-derived organic trisulphur, for short-term therapy of tinea pedis. The use of ajoene as a 0.4% (w/w) cream resulted in complete clinical and mycological cure in 27 of 34 patients (79%) after 7 days of treatment. The remaining seven patients (21%) achieved complete cure after seven additional days of treatment. All patients were evaluated for recurrence of mycotic infections 90 days after the end of treatment, yielding negative cultures for fungus. These results show that ajoene is an alternative, efficient and low-cost antimycotic drug for short-term therapy of tinea pedis. The fact that ajoene can be easily prepared from an alcoholic extract of garlic may make it suitable for Third World public health care.

[Effectiveness of oral treatment with terbinafine in a guinea pig model of tinea pedis].

In order to perform a preclinical evaluation of effectiveness of oral terbinafine (TBF) in tinea pedis, an animal model was produced using guinea pigs by experimentally infecting the plantar skin with Trichophyton mentagrophytes. TBF was administered orally to groups of the infected guinea pigs once-a-day for 4 consecutive weeks. The therapeutic efficacy was assessed on the basis of recovery of fungal cultures from the plantar skin. The group of guinea pigs treated with 12.5 mg/kg/day of TBF resulted in complete cure. The animal group treated with 3.13 mg/kg/day of TBF showed significantly better mycological response to the therapy than the group treated with 12.5 mg/kg/day of griseofulvin. These results suggest clinical usefulness of oral TBF for the treatment of tinea pedis.

[A study on effectiveness of treatment and prevention of relapse using topical administration of terbinafine in a guinea pig model for tinea pedis].

The effectiveness of topical terbinafine (TBF) to tinea pedis was evaluated an animal model in which guinea pigs were experimentally infected through their planta pedis with Trichophyton mentagrophytes, then a 1% TBF or butenafine (BTF) cream was administered topically once daily for 4 consecutive weeks. The therapeutic efficacy was assessed on the basis of recovery of fungal cultures from the planta pedis. The cured guinea pigs were reared in a clean environment that protected the animals from reinfection. The dermal tissues were cultured 2, 4, and 8 weeks post-treatment to examine for relapse of tinea. Complete cure was achieved after 4 weeks of administration of TBF or BTF cream. In animals receiving 4 weeks of treatment with TBF, relapse was not observed up to 8 weeks after the termination of treatment. In animals treated with BTF for 4 weeks, while no relapse occurred 4 weeks after cessation of the treatment, relapse was detected in 2 out of 10 feet at 8 weeks after the termination of treatment. These results suggest that topical TBF is effective in curing the infection and in preventing relapse in a guinea pig model of tinea pedis.