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Ethnopharmacology and Therapeutic Potential of Carica papaya
Published in Megh R. Goyal, Preeti Birwal, Durgesh Nandini Chauhan, Herbs, Spices, and Medicinal Plants for Human Gastrointestinal Disorders, 2023
Gurpreet Singh, Pooja Chawla, Abdul Faruk, Viney Chawla
The papaya leaves and seeds of ripe and unripe fruits were evaluated against phytopathogenic fungi (i.e., R. stolonifer, Fusarium spp. and C. gloeosporioides), which exhibited good antifungal activity. The antifungal activity was observed to increase in a concentration-dependent manner.19 The latex of papaya also inhibits the growth of Candida albicans. The latex shows antifungal activity due to partial degradation of the outermost layers of fungal cell wall, which lacks polysaccharides.26 The synergistic effect of latex of papaya with fluconazole in C. albicans was also reported.25
Fungi and Water
Published in Chuong Pham-Huy, Bruno Pham Huy, Food and Lifestyle in Health and Disease, 2022
Chuong Pham-Huy, Bruno Pham Huy
Fungi have cell walls similar to plants and are different from animals. The fungal cell wall is composed of chitin that gives shape, form, and rigidity to fungi. It protects against mechanical injury, prevents osmotic lysis, and provides passive protection against the ingress of potentially harmful macromolecules (2–3). Chitin is a polymer of N-acetyl-D-glucosamine. The major polysaccharides of the cell wall matrix consist of non-cellulosic glucans such as glycogen-like compounds, mannans (polymers of mannose), chitosan (polymers of glucosamine), and galactans (polymers of galactose). Small amounts of fucose, rhamnose, xylose, and uronic acids may be present (2). Glucan refers to a large group of D-glucose polymers having glycosidic bonds. Insoluble β-glucans are apparently amorphous in the cell wall. Yeast cell wall is composed of three layers and is about 200- to 600-nm thick. Its inner surface is chitinous, and its outer layer contains α-glucan (2). In addition to chitin, glucan, and mannan, cell walls may contain lipid, protein, chitosan, acid phosphatase, α-amylase, protease, melanin, and inorganic ions such as phosphorus, calcium, and magnesium (2). The fungal wall also protects cells against mechanical injury and blocks the ingress of toxic macromolecules. The fungal cell wall is also essential to prevent osmotic lysis. Even a small lesion in the cell wall can result in extrusion of cytoplasm due to the internal (turgor) pressure of the protoplast. The cell membrane of a fungus has a unique sterol and ergosterol (3).
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).
High iron-mediated increased oral fungal burden, oral-to-gut transmission, and changes to pathogenicity of Candida albicans in oropharyngeal candidiasis
Published in Journal of Oral Microbiology, 2022
Aparna Tripathi, Anubhav Nahar, Rishabh Sharma, Trevor Kanaskie, Nezar Al-Hebshi, Sumant Puri
The fungal cell wall plays a crucial role in the virulence of systemic and mucosal infections, including OPC. The dynamic structure of the C. albicans cell wall is crucial for cell shape, viability, pathogenesis, interaction with other microbial species, and evasion of host immune cells [7]. The outer layer of the cell wall is made of mannans, while the inner layer consists of β-1,3-glucan complexed with chitin, along with small amounts of β-1,6-glucan [8]. Mannans mask β-1,3-glucans and a decrease in mannan levels induces β-1,3-glucan exposure on the cell surface. Also, an increase in chitin levels can be associated with enhanced exposure of β-1,3-glucan [9,10]. As the primary fungal pathogen-associated molecular pattern (PAMP), β-1,3-glucan binds to Dectin-1, a C-type lectin pattern recognition receptor (PRR) of the host’s immune cells [11]; and promotes phagocytosis and inflammatory responses [12].
Subtle relationships between Pseudomonas aeruginosa and fungi in patients with cystic fibrosis
Published in Acta Clinica Belgica, 2022
Kaicheng Yan, Hong Yin, Jin Wang, Yun Cai
In PA and other Pseudomonas species, Rhls are usually produced in the form of a mixture of homologous di- and mono-Rhls in terms of the length of the lipid chain [46]. During nutritional restriction (e.g. iron starvation), PA can over-generate Rhls in vitro [47]. The inhibition of AF growth and the increase of AF cell wall thickness are attributed to the secretion of diRhls, which inhibit fungal β-1,3-glucanase (GS) [48]. When growing in the presence of PA, AF shows a thick cell wall. The results suggest that bacterial co-culture induces the modification of fungal cell wall structure. In the presence of diRhls, the decreased growth of AF and its morphology change are attributed to the inhibition of β-1,3-GS by diRhls. The specific inhibition of diRhls against fungal GS activity results in the modified nature of fungal extracellular matrix surrounding the AF hyphae, inhibits the growth of AF and induces the formation of short multibranched hyphae.
Azole resistance in Aspergillus species: promising therapeutic options
Published in Expert Opinion on Pharmacotherapy, 2021
Shirisha Pasula, Pranatharthi H. Chandrasekar
This is an oral Hos2 fungal histone deacetylase (HDAC) inhibitor that also affects non-histone proteins such as Hsp90. MGCD290 appears to exhibit some level of intrinsic antifungal activity, but most research has pursued its value in synergizing with other antifungal agents. The inhibition of these fungal proteins could impair the cellular stress response, possibly potentiating the fungicidal effect of agents that target fungal cell wall or membrane. Several in vitro studies have found that the addition of low concentrations of MGCD290 enhanced both azole and echinocandin activity against Aspergillus species, reducing MICs and driving categorical shifts from resistant to intermediate or susceptible in many samples. Despite promising in vitro results, MGCD290 has thus far failed to show efficacy in vivo [54].