Natural Compound 2-Chloro-1,3-dimethoxy-5-methylbenzene, Isolated from Hericium Erinaceus, Inhibits Fungal Growth by Disrupting Membranes and Triggering Apoptosis

Efficient extraction of Licochalcone a with deep eutectic solvent: A promising drug for the treatment of dermatophytosis

Uncontrolled breeding and improper management of pet cats and dogs have led to the spread of zoonotic Microsporum canis (M. canis) infection, which poses challenges to clinical medication. Therefore, there is an urgent need to explore and discover potential fungicides against M. canis. In this study, licochalcone A (LicoA) was prepared by a green and efficient deep eutectic solvent method based on ultrasonic assisted extraction (DES-UAE). The DES-UAE process with choline chloride and propionic acid as solvent was optimized by response surface method with the extraction amount of LicoA as the objective. Following separation and purification, the purity of LicoA reached 99.79 %. Additionally, LicoA demonstrated significant antifungal activity against M. canis with MIC of 4 μg/mL. LicoA inhibited the synthesis of ergosterol in the fungal membrane, destroy the integrity of the cell membrane, lead to the increase of membrane permeability, the release of intracellular electrolytes, the leakage of nucleic acids and proteins, and affect the normal growth of hyphae. ATPase activity was reduced, and mitochondrial membrane potential (MMP) was reduced, resulting in increased levels of ROS, which eventually induced apoptosis in M. canis. Further transcriptome analysis revealed that LicoA treatment affected "cell integrity", "energy metabolism", and "oxidative stress" metabolic pathways in M. canis, including cell wall synthesis, ergosterol synthesis, tricarboxylic acid cycle, electron transport chain, and ribosome metabolism, leading to fungal cell apoptosis. These studies establish an efficient method for LicoA extraction and provide a basis for its use as a novel antifungal agent for the treatment of dermatophytosis.

The Antifungal Effects of Berberine and Its Proposed Mechanism of Action Through CYP51 Inhibition, as Predicted by Molecular Docking and Binding Analysis

Fungal infections present a significant health risk, particularly in immunocompromised individuals. Berberine, a natural isoquinoline alkaloid, has demonstrated broad-spectrum antimicrobial activity, though its antifungal potential and underlying mechanisms against both yeast-like and filamentous fungi are not fully understood. This study investigates the antifungal efficacy of berberine against Candida albicans, Cryptococcus neoformans, Trichophyton rubrum, and Trichophyton mentagrophytes in vitro, as well as its therapeutic potential in a murine model of cryptococcal infection. Berberine showed strong antifungal activity, with MIC values ranging from 64 to 128 µg/mL. SEM and TEM analyses revealed that berberine induced notable disruptions to the cell wall and membrane in C. neoformans. No signs of cell necrosis or apoptosis were observed in fungal cells treated with 2 × MIC berberine, and it did not increase intracellular ROS levels or affect mitochondrial membrane potential. Molecular docking and binding affinity assays demonstrated a strong interaction between berberine and the fungal enzyme CYP51, with a dissociation constant (KD) of less than 1 × 10-12 M, suggesting potent inhibition of ergosterol biosynthesis. In vivo studies further showed that berberine promoted healing in guinea pigs infected with T. mentagrophytes, and in a murine cryptococcal infection model, it prolonged survival and reduced lung inflammation, showing comparable efficacy to fluconazole. These findings indicate that berberine exerts broad-spectrum antifungal effects through membrane disruption and CYP51 inhibition, highlighting its potential as a promising therapeutic option for fungal infections.

Influence of flavonoids from Sedum aizoon L. on mitochondrial function of Rhizopus nigricans in strawberry

Rhizopus nigricans (R. nigricans), one of the fungi that grows the fastest, is frequently discovered in postharvest fruits, it's the main pathogen of strawberry root rot. Flavonoids in Sedum aizoon L. (FSAL) is a kind of green and safe natural substance extracted from Sedum aizoon L. which has antifungal activity. In this study, the minimum inhibitory concentration (MIC) of FSAL on R. nigricans and cell apoptosis tests were studied to explore the inhibitory effect of FSAL on R. nigricans. The effects of FSAL on mitochondria of R. nigricans were investigated through the changes of mitochondrial permeability transition pore(mPTP), mitochondrial membrane potential(MMP), Ca2+ content, H2O2 content, cytochrome c (Cyt c) content, the related enzyme activity and related genes of mitochondria. The results showed that the MIC of FSAL on R. nigricans was 1.800 mg/mL, with the addition of FSAL (1.800 mg/mL), the mPTP openness of R. nigricans increased and the MMP reduced. Resulting in an increase in Ca2+ content, accumulation of H2O2 content and decrease of Cyt c content, the activity of related enzymes was inhibited and related genes were up-regulated (VDAC1, ANT) or down-regulated (SDHA, NOX2). This suggests that FSAL may achieve the inhibitory effect of fungi by damaging mitochondria, thereby realizing the postharvest freshness preservation of strawberries. This lays the foundation for the development of a new plant-derived antimicrobial agent.