In vitro antidermatophytic activity of bioactive compounds from selected medicinal plants

Fungal infections are among the most difficult diseases to manage in humans. Eukaryotic fungal pathogens share many similarities with their host cells, which impairs the development of antifungal compounds. Therefore, it is desirable to harness the pharmaceutical potential of medicinal plants for antifungal drug discovery. In this study, the antifungal activity of sixteen plant extracts was investigated against selected dermatophytic fungi. Of the sixteen plants, the cladode (leaf) of Asparagus racemosus, and seed extract of Cassia occidentalis showed antifungal activity against Microsporum gypseum, Microsporum nanum, Trichophyton mentagrophytes and Trichophyton terrestre. The plant antifungal compounds were located by direct bioassay against Cladosporium herbarum. IR and NMR spectrometry analyses of these compounds identified the presence of saponin (in A. racemosus) and hydroxy anthraquinone (in C. occidentalis) in these antifungal compounds. The antidermatophytic activity of plant anthraquinone and saponins with reports of little or no hemolytic activity, makes these compounds ideal for alternative antifungal therapy and warrants further in-depth investigation in vivo.

GC-MS Characterization, in vitro Antioxidant, Anti-inflammatory and Potential Antidermatophytic Activity of Citrullus lanatus Seed Oil

Background: Dermatophytes are well-known fungus having the capability to invade keratinized tissues of nails, skin, and hair, of humans and other animals, causing dermatophytosis. Citrullus lanatus (watermelon) seed is a rich source of vitamin E, essential fatty acids, and minerals, bearing various health benefits. Despite the presence of many useful components, the oil is not much explored. Accordingly, the study was planned to investigate the fatty acid profiling, in vitro antioxidant, anti-inflammatory, and potential antidermatophytic activity of Citrullus lanatus seed oil against dermatophytic strains. Methods: The C.lanatus oil was extracted from seeds, and fatty acid profiling was characterized by GC-MS. Further, the oil was subjected to DPPH scavenging activity, and the anti-inflammatory activity was evaluated from Bovine serum albumin assay. The antidermatophytic screening against Microsporum canis, Trichophyton rubrum, and Trichophyton mentagrophytes was carried out by agar well diffusion, broth microdilution assay, and growth kinetics assay. Results: The C. lanatus seed oil exhibited good antioxidant activity close to ascorbic acid, i.e., IC50- 52.22 µg/ml, 35.72 µg/ml, respectively, and the oil exhibited moderate anti-inflammatory activity (315.2 µg/ml) as that of the standard drug diclofenac sodium (174.3µg/ml). The fatty acid profiling indicates the presence of eight main compounds, out of which ç-tocopherol, butylated hydroxytoluene, and hexadecanoic acid are predominantly present. The C.lanatus seed oil showed promising activity against T. rubrum with a lower minimum inhibitory concentration value with respect to positive controls, Fluconazole and Ketoconazole. The oil also had a strong effect on time-dependent kinetic inhibition against T. rubrum. This was the first report of C.lanatus seed oil against any dermatophyte. Conclusion: In conclusion, the study supports the exploitation of C.lanatus seed oil and its main compounds as a source of natural antioxidants, anti-inflammatory, and as a novel agent against dermatophytes for curing superficial fungal infections in the near future.

Antioxidant, antiradical power of Syzygium aromaticum essential oil, and its antidermatophytic activity against Epidermophyton floccosum and Trichophyton soudanense

In order to provide an effective alternative for efficient management of dermatophytosis, we evaluate in vitro the antioxidant and antiradical potentials of the essential oil of the dry flower buds of Syzygium aromaticum and its antidermatophytic activity against Epidermophyton floccosum and Trichophyton soudanense, For this purpose, the essential oil was obtained by hydrodistillation through a Clevenger apparatus and the antioxidant and antiradical potentials were evaluated by the ferric reducing antioxidant power (FRAP) and the trapping of the ABTS•+ radical methods, respectively. The evaluation of the antidermatophytic activity was made by the agar incorporation method. The results showed that the essential oil reduced ferric iron (Fe3+) to ferrous iron (Fe2+) in a more significant manner than BHT (reference antioxidant). Moreover, the antiradical power of the essential oil was twice greater than that of BHT. Furthermore, the essential oil inhibited the mycelial growth of the two dermatophytes, with 500 ppm and 1000 ppm of minimal inhibitory concentrations against Epidermophyton floccosum and Trichophyton soudanense, respectively. This activity was greater than that of griseofulvin whose minimal inhibitory concentration was greater than 4000 ppm against both studied germs. These findings show that, withon the framework of safeguarding human lives and protecting the environment, the essential oil from the dry flower buds of Syzygium aromaticum appeared as reliable alternative for the treatment of dermatophytosis caused by Epidermophyton floccosum and Trichophyton soudanense. Our results lay scientific foundation toward the promotion and development of Cameroonian biodiversity in treatments of dermatophytosis.

Marine Actinomycetes Derived Pyrrolo Compounds Mediated Green Synthesis of AgO and Ag2O3 Nanoparticles and its Antidermatophytic Activity

Background: Antimicrobial potential of silver nanoparticles synthesised by using various biological sources was already been reported by many researchers. The green synthesis of silver nanoparticles using microbial sources has been proved to be more effective. Methods: In this study, anti-dermatophytic silver nanoparticles were synthesised by using pyrrolo metabolites producing actinomycetes as a green catalyst. Different characterization methods such as UV-Visible, XRD, and AFM were used to identify the physiochemical characteristics of synthesised nanoparticles. Results: The synthesised nanoparticles showed λ-max at 427 nm and 402 nm, respectively. The XRD analysis based on the JCPDS database identified the two synthesized nanoparticles as silver oxide nanoparticles (AgO NPs) and silver peroxide nanoparticles (Ag2O3 NPs). The size of these nanoparticles was found to be in the range of 40-44 nm (AgO NPs) and 23-25 nm (Ag2O3 NPs), respectively. The synthesized nanoparticles demonstrated significant anti-fungal activity against dermatophytic fungi Trichophyton mentagrophyes with the zone of inhibition of 38 mm by AgO NP and 17 mm by Ag2O3 NPs. Conclusion: Screening of marine actinomycetes LG003 and LG005 revealed the presence of pyrrolo derivatives as the major metabolites, suggesting that these pyrrolo derivatives could be responsible for synthesis and stabilization of AgO and Ag2O3NPs. Among the synthesized NPs, the AgO NPs showed great potential as an anti-dermatophytic agent. This study provides further research opportunities for AgONPs as anti-fungal agents.

Antidermatophytic activity of some newly synthesized arylhydrazonothiazoles conjugated with monoclonal antibody

A new series of 5-arylhydrazonothiazole derivatives 5a–d has been synthesized, elucidated, and evaluated for their antidermatophytic activity. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of the newly synthesized products were investigated against 18 dermatophyte fungal isolates related to Epidermophyton floccosum, Microsporum canis, and Trichophyton rubrum. The morphological alterations induced by the synthesized derivatives singly or conjugated with the monoclonal antibody were examined on spores of T. rubrum using a scanning electron microscope. The efficacy of synthesized derivative 5a applied at its respective MFC alone or conjugated with anti-dermatophyte monoclonal antibody 0014 in skin infection treatment of guinea pigs due to inoculation with one of the examined dermatophytes, in comparison with fluconazole as standard reference drug was evaluated. In an in vivo experiment, the efficiency of 5a derivative conjugated with the antibody induced 100% healing after 45 days in the case of T. rubrum and M. canis-infected guinea pigs.

Ringworm in calves: risk factors, improved molecular diagnosis, and therapeutic efficacy of an Aloe vera gel extract

Background Dermatophytosis in calves is a major public and veterinary health concern worldwide because of its zoonotic potential and associated economic losses in cattle farms. However, this condition has lacked adequate attention; thus, to develop effective control measures, we determined ringworm prevalence, risk factors, and the direct-sample nested PCR diagnostic indices compared with the conventional methods of dermatophytes identification. Moreover, the phenolic composition of an Aloe vera gel extract (AGE) and its in vitro and in vivo antidermatophytic activity were evaluated and compared with those of antifungal drugs. Results Of the 760 calves examined, 55.79% (424/760) showed ringworm lesions; 84.91% (360/424) were positive for fungal elements in direct-microscopy, and 79.72% (338/424) were positive in culture. Trichophyton verrucosum was the most frequently identified dermatophyte (90.24%). The risk of dermatophytosis was higher in 4–6-month-old vs. 1-month-old calves (60% vs. 41%), and in summer and winter compared with spring and autumn seasons (66 and 54% vs. 48%). Poor hygienic conditions, intensive breeding systems, animal raising for meat production, parasitic infestation, crossbreeding, and newly purchased animals were statistically significant risk factors for dermatophytosis. One-step PCR targeting the conserved regions of the 18S and 28S genes achieved unequivocal identification of T. verrucosum and T. mentagrophytes in hair samples. Nested-PCR exhibited an excellent performance in all tested diagnostic indices and increased the species-specific detection of dermatophytes by 20% compared with culture. Terbinafine and miconazole were the most active antifungal agents for dermatophytes. Gallic acid, caffeic acid, chlorogenic acid, cinnamic acid, aloe-Emodin, quercetin, and rutin were the major phenolic compounds of AGE, as assessed using high-performance liquid chromatography (HPLC). These compounds increased and synergized the antidermatophytic activity of AGE. The treated groups showed significantly lower clinical scores vs. the control group (P < 0.05). The calves were successfully treated with topical AGE (500 ppm), resulting in clinical and mycological cure within 14–28 days of the experiment; however, the recovery was achieved earlier in the topical miconazole 2% and AGE plus oral terbinafine groups. Conclusions The nested PCR assay provided a rapid diagnostic tool for dermatophytosis and complemented the conventional methods for initiating targeted treatments for ringworm in calves. The recognized antidermatophytic potential of AGE is an advantageous addition to the therapeutic outcomes of commercial drugs.