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The Potential of Medicinal Plants as Treatments for Infections Caused by Aspergillus spp.
Published in Namrita Lall, Medicinal Plants for Cosmetics, Health and Diseases, 2022
Tefo K. Pule, Marco N. De Canha, Namrita Lall, Quenton Kritzinger
Amphotericin B (AmB) is a polyene drug that binds to ergosterol in fungal membranes. The binding action forms pores in the membrane, which eventually leads to death due to cell lysis (Jenks and Hoenigl, 2018). It has been a preferred antifungal agent for most patients, having a recommended dose of less than 2 mg/kg per day (Jenks and Hoenigl, 2018). Triazoles such as voriconazole, itraconazole and posaconazole have been introduced as part of aspergillosis treatments. These are heterocyclic compounds that bind to lanosterol-14-α-demethylase, which prevents the conversion of lanosterol to ergosterol. This in turn inhibits the synthesis of ergosterol (Sherif and Segal, 2010). The triazole compound, voriconazole, is more effective than AmB; however, this drug shows significant inter-individual variability (Alastruey-Izquierdo et al., 2018). In some cases, the voriconazole dosage may need to be increased over time. Finally, echinocandins are lipopeptides that act as fungistatic by inhibiting fungal wall synthesis. This occurs by echinocandins binding to the enzyme β-(1,3)-D-glucan synthases, thereby preventing hyphal tip growth (Maghrabi and Denning, 2017).
Macronutrients
Published in Chuong Pham-Huy, Bruno Pham Huy, Food and Lifestyle in Health and Disease, 2022
Chuong Pham-Huy, Bruno Pham Huy
Like cholesterol and phytosterols, mycosterols are sterols present in fungi (mushrooms) (132–133). Ergosterol (24R-methyl-cholesta-5,7,22(E)-trienol) is the main mycosterol found in cell membranes of fungi, yeasts, and protozoa. Ergosterol is a sterol which was first discovered in 1889, in the plant pathogenic ergot fungus Claviceps purpurea (132–133). It is an analog of cholesterol present in mammalian cell membranes. Ergosterol is the major sterol among several sterols present in fungi. Like cholesterol, ergosterol and other mycosterols play similar roles in the permeability and fluidity of fungal cell membranes. They are also needed for fungal growth, a fact that has been exploited in the development of antifungal pesticides widely used in agriculture and antimycotics used to control fungal diseases of humans and animals (132). Ergosterol is converted into vitamin D2 when it is irradiated by sunlight or UV-B. Therefore, cultivated white mushrooms are often exposed to sunlight or UV-B light before marketing to obtain high vitamin D2 levels. Ergosterol also has antioxidant properties (133).
Spices as Eco-friendly Microbicides: From Kitchen to Clinic
Published in Mahendra Rai, Chistiane M. Feitosa, Eco-Friendly Biobased Products Used in Microbial Diseases, 2022
The fungal cell wall is a dynamic structure that protects fungal protoplasts from external osmotic shocks and defines fungal morphogenesis. Thus, changes in the organization or functional disruption of the cell wall induced by antifungal agents are involved in fungal death. The fungal cell membrane is a dynamic structure composed of a lipid bilayer where enzymes and transport proteins are embedded. Ergosterol is a unique sterol found only in the cell membrane of fungi, important for their proper growth and functioning and also acts as an important regulator of membrane fluidity. Thymol have been shown to decrease ergosterol in cell membranes of Candida and Cryptococcus, thereby causing disruption of membrane integrity, membrane-associated enzyme disturbances, extensive damage and, finally cell death (Kowalczyk et al. 2020). Similarly eugenol exerts its antifungal activity on the cell wall and cell membrane of Trichophyton rubrum by disrupting ergosterol biosynthesis and such a result may serve as a guide for future in vivo studies of clinical use of eugenol in treating dermatophyte infections (de Oliveira Pereira et al. 2013).
Tailoring and optimization of a honey-based nanoemulgel loaded with an itraconazole–thyme oil nanoemulsion for oral candidiasis
Published in Drug Delivery, 2023
Amal M. Sindi, Waleed Y. Rizg, Muhammad Khalid Khan, Hala M. Alkhalidi, Waleed S. Alharbi, Fahad Y. Sabei, Eman Alfayez, Hanaa Alkharobi, Mohammed Korayem, Mohammed Majrashi, Majed Alharbi, Mohammed Alissa, Awaji Y. Safhi, Abdulmajeed M. Jali, Khaled M. Hosny
As might be seen from the above graphs, ThO has a great capacity for expanding the growth inhibition zones of C. albicans. Ergosterol is a special sterol that can only exist in the outer membrane of a fungus and is crucial to its healthy development and operation. As a result, substances affecting the level of ergosterol might have antifungal properties (Kowalczyk et al., 2020). Thymol, the major component of ThO, has potential antifungal action that is based on how it affects the metabolism of fatty acids, especially ergosterol, in fungal cells (De Lira Mota et al., 2012). Among other things, it produces oxidative stress and an increase in reactive oxygen species, and this lowers the levels of capsular polysaccharide and the extracellular polymer matrix (EPS) (Al-Shahrani et al., 2017). In cell membranes of Candida and Cryptococcus that had been exposed to thymol, ergosterol levels decreased, as previously stated in the literature. This resulted in disruptions of the membrane integrity and membrane-associated enzymes, significant damage, and, ultimately, cell death (Poonam et al., 2019).
Fenticonazole nitrate loaded trans-novasomes for effective management of tinea corporis: design characterization, in silico study, and exploratory clinical appraisal
Published in Drug Delivery, 2022
Rofida Albash, Maha H. Ragaie, Mahmoud A. El Hassab, Radwan El-Haggar, Wagdy M. Eldehna, Sara T. Al-Rashood, Shaimaa Mosallam
Fungal diseases are becoming more common these days. They have greater toxic side effects encountered with traditional systemic therapy (Kumar et al., 2014). Tinea corporis, also known as ringworm, is a dermatophytosis (superficial fungal infection especially on the skin) (Merad et al., 2021). The therapeutic efficacy of medication applied topically is mainly determined by its capability to enter and penetrate the skin. Thereby, the development of an innovative drug delivery system will produce better outcomes owing to passing the stratum corneum (SC) and targeting the site of infection (Mosallam et al., 2021a). Fenticonazole nitrate (FTN) is an antifungal agent that belongs to imidazoles. It works by blocking ergosterol production and therefore damaging the cell membrane (Campos et al., 2018). FTN has both fungistatic and fungicidal properties against yeasts, fungi, and dermatophytes. It also inhibits the growth of gram-positive bacteria (Jung et al., 1988). Hence, FTN is thought to be a promising topical agent for treating skin fungal infections. Unfortunately, the low aqueous solubility of FTN (<0.10 mg/mL) (Albash et al., 2020) arouses the need for designing a new vesicular system to deliver FTN effectively and compel cure of fungal infections.
Vitamin D: sources, physiological role, biokinetics, deficiency, therapeutic use, toxicity, and overview of analytical methods for detection of vitamin D and its metabolites
Published in Critical Reviews in Clinical Laboratory Sciences, 2022
Jiří Janoušek, Veronika Pilařová, Kateřina Macáková, Anderson Nomura, Jéssica Veiga-Matos, Diana Dias da Silva, Fernando Remião, Luciano Saso, Kateřina Malá-Ládová, Josef Malý, Lucie Nováková, Přemysl Mladěnka
Unfortunately, there are not many rich natural sources of vitamin D. Vitamin D2 is synthesized almost exclusively by fungi, which includes both microscopic species and fungi that form macroscopic fruiting bodies. UV-B radiation is also needed for the synthesis of vitamin D2 from ergosterol (Figure 2), as in the case of conversion of 7-dehydrocholesterol to vitamin D3. Additionally, various levels of vitamin D2 have been reported in algae, and its traces can also be found in plants, probably as a result of fungal contamination. Contrarily, vitamin D3 occurs mainly in animal sources but can also be found in algae and plants. Due to the symbiotic coexistence of fungi and microscopic algae, both types of vitamin D are found in lichens [37–39].