In vitro release of granulocyte/macrophage colony-stimulating factor by peripheral blood mononuclear cells of dermatophytosis patients in response to stimulation with trichophytin

Potential Treatment of Dermatophyte Trichophyton rubrum in Rat Model Using Topical Green Biosynthesized Silver Nanoparticles with Achillea santolina Extract

Trichophyton rubrum is the most common dermatophyte, and can cause cutaneous infections in humans and animals (dermatophytosis). In this study, we investigated the anti-dermatophytic potential of green synthesized silver nanoparticles using Achillea santolina extract (AS-AgNPs) in an in vitro and in vivo rat model of dermal T. rubrum dermatophytosis (TRD). The green synthesis of AS-AgNPs was performed using A. santolina extract and characterized by UV-VIS spectroscopy, zeta potential, imaging (transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Energy dispersive X-ray analysis (EDX). The antifungal activity of AS-AgNPs was determined by the broth microdilution method, conidial germination, and hyphal growth inhibition. TEM and SEM were used to study the mode of the antifungal action of AS-AgNPs. AS-AgNPs inhibited the growth of T. rubrum with an MIC of 128 μg/mL, and suppressed the conidial germination and hyphal growth by 55.3% 84.6%, respectively. AS-AgNPs caused modified mycelial structures, increased cell membrane permeability, and cell wall damage. AS-AgNPs significantly increase the permeability of the fungal membrane, as revealed by reducing ergosterol biosynthesis. An increase in the intracellular ROS and the induction of apoptosis were also observed during AS-AgNP treatment. In addition, AS-AgNPs reduced the cell wall integrity, as shown by the reduction in the β-(1,3)-d-glucan synthase and chitin synthase activities. AS-AgNPs showed very low toxicity on primary human dermal fibroblasts (HDF) at the MIC. The topical treatment of the infected skin in the TRD rat model with AS-AgNPs showed a significant reduction in the fugal burden after 7 days and a complete clearance of fungal conidia, with a high recovery of epidermal and dermal structures after 14 days, compared to control rats. Interestingly, AS-AgNPs significantly attenuated the infiltrated inflammatory cells, in association with reducing the tissue proinflammatory cytokines including TNF-α, IL-1, IL-6, MOP and IL-17. In conclusion, our data prove AS-AgNPs to be a novel green topical therapy for dermatophytosis caused by T. rubrum.

Effect of lactoferrin feeding on the host antifungal response in guinea-pigs infected or immunised with Trichophyton mentagrophytes

Earlier studies revealed that oral administration of lactoferrin (LF), a multi-functional milk protein, facilitated curing of dermatophytosis in guinea-pigs and man by an unknown mechanism. The present study aimed to assess the effect of feeding bovine LF on the host antifungal defence systems in guinea-pigs infected or immunised with Trichophyton mentagrophytes, a dermatophytosis-causing fungus. The unbound iron-binding capacity (UIBC) of the plasma of individual animals varied, and plasma with higher UIBC inhibited growth of T. mentagrophytes in vitro. However, LF administration did not enhance plasma UIBC or the anti-T. mentagrophytes activity of plasma in infected or uninfected animals. Phagocytic activity and reactive oxygen (RO) production of blood neutrophil polymorphonuclear leucocytes (PMNLs) were estimated by flow cytometry. LF administration caused no significant effects on phagocytic activity or RO production of neutrophil PMNLs in infected or uninfected animals. The functions of mononuclear cells (MNC) from the spleen were investigated in guinea-pigs immunised with heat-killed T. mentagrophytes conidia. The MNC were cultured with concanavalin A or inactivated T. mentagrophytes. In the bromo-deoxyuridine incorporation assay, the stimulation index was higher for MNC derived from LF-treated animals than for those from control animals. The culture supernates of MNC enhanced the ability of macrophages to kill T. mentagrophytes conidia. Furthermore, stronger augmentation was observed with the culture supernate from LF-treated animals than with that from control animals. In conclusion, LF feeding may potentiate the host antifungal defence systems by modulating MNC function rather than plasma antifungal activity or peripheral blood neutrophil PMNL activity.