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

Abstract

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.

Antifungal activity of Carica papaya fruit extract against Microsporum canis: in vitro and in vivo study

“…Additionally, dark, electron-dense areas were observed. Notably, four other studies reported similar findings regarding fungi hyphae and spores using SEM and TEM, although they used different types of plant extracts and fungi ( Ghannoum et al, 2012 ; Aala et al, 2014 ; Mihalache et al, 2018 ; Abdallah et al, 2023 ). The last part of the project’s experiments is an in vivo result which agree with the findings of the in vitro results.…”

Biosynthesis, characterization, and antifungal activity of plant-mediated silver nanoparticles using Cnidium monnieri fruit extract

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Hinokitiol inhibits Aspergillus fumigatus by interfering with the cell membrane and cell wall

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