Phytochemical Constituents of Tulbaghia violacea Harv Extract and its Antifungal Potential Against Cryptococcus neoformans and Cryptococcus gattii

2019 ◽  
Vol 9 (4) ◽  
pp. 330-340
Author(s):  
Mitradev Pattoo ◽  
Vuyokazi Belewa ◽  
Benesh Munilal Somai

Background:In both the developed and developing world, the mortality rates of people afflicted with cryptococcosis are unacceptably high despite the availability of antifungal therapy. The disease is caused by Cryptococcus neoformans (predominantly in immunocompromised individuals) and by Cryptococcus gattii. Globally the disease is estimated to cause around 600,000 deaths annually. Antifungal therapy is available, but in the developing world, may be unaffordable to many people, there is an increasing threat of resistance to the available drugs and our repertoire of antifungal drugs is very limited. Consequently, more research has been focusing on the use of medicinal plants as therapeutic agents. The originality of the current study is that although Tulbaghia violacea is a well-documented medicinal plant, the chemical composition of aqueous extracts and their antifungal potential against pathogenic yeasts are unknown. This is the first study that evaluates the chemical constituents of aqueous T. violacea root, leaf, rhizome and tuber extracts and their corresponding antifungal activities against C. neoformans and C. gattii.Objectives:The study aimed to investigate the phytochemical composition and antifungal potential of Tulbaghia violacea root, leaf, rhizome and tuber extracts against Cryptococcus neoformans and Cryptococcus gattii.Methods:Roots, leaves, rhizomes and tubers were extracted with water only for 48 h at room temperature with continuous shaking. Extracts were filter sterilized, freeze-dried and, chemically analyzed for saponin, flavonol, phenolic and tannin content. Chemical constituents of each extract were also identified by GC-MS analysis. The Minimum Inhibitory Concentration (MIC) of suitably diluted extracts of each plant part were also performed against C. neoformans and C. gattii, yeast pathogens commonly associated with HIV/AIDS sufferers.Results:Phytochemical analysis showed different concentrations of saponins (between 1023 and 2896.73 µg/ml), phenolics (between 16.48 and 51.58 µg/ml) and tannins (between 122.30 and 543.07 µg/ml) present in the different extracts. No flavonols were detected. GC-MS analysis identified a complex mixture of phytochemicals composed predominantly of sulphide, pyran, furan and ketone containing compounds to be present in the different plant parts. All extracts were dominated by the presence of 4 H-pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl, a pyran known to have antifungal properties. Although the root, leaf, rhizome and tuber extracts exhibited antifungal activities against both fungi, the rhizome and tuber extract were found to possess the lowest MIC’s of 1.25 mg/ml and 2.5 mg/ml against Cryptococcus neoformans and Cryptococcus gattii respectively.Conclusion:T. violacea extracts have a complex constituent of phytochemicals and each plant part exhibited a strong antifungal activity against C. neoformans and C. gattii. The rhizome and tuber extracts showed the highest antifungal activity against C. neoformans and C. gattii respectively. Thus, T. violacea aqueous extracts are strong candidates for further development into an antifungal chemotherapeutic agent.

mSphere ◽  
2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Eric H. Jung ◽  
David J. Meyers ◽  
Jürgen Bosch ◽  
Arturo Casadevall

ABSTRACTSimilarities in fungal and animal cells make antifungal discovery efforts more difficult than those for other classes of antimicrobial drugs. Currently, there are only three major classes of antifungal drugs used for the treatment of systemic fungal diseases: polyenes, azoles, and echinocandins. Even in situations where the offending fungal organism is susceptible to the available drugs, treatment courses can be lengthy and unsatisfactory, since eradication of infection is often very difficult, especially in individuals with impaired immunity. Consequently, there is a need for new and more effective antifungal drugs. We have identified compounds with significant antifungal activity in the Malaria Box (Medicines for Malaria Ventures, Geneva, Switzerland) that have higher efficacy than some of the currently used antifungal drugs. Our best candidate, MMV665943 (IUPAC name 4-[6-[[2-(4-aminophenyl)-3H-benzimidazol-5-yl]methyl]-1H-benzimidazol-2-yl]aniline), here referred to as DM262, showed 16- to 32-fold-higher activity than fluconazole againstCryptococcus neoformans. There was also significant antifungal activity in other fungal species with known antifungal resistance, such asLomentospora prolificansandCryptococcus gattii. Antifungal activity was also observed against a common fungus,Candida albicans. These results are important because they offer a potentially new class of antifungal drugs and the repurposing of currently available therapeutics.IMPORTANCEMuch like the recent increase in drug-resistant bacteria, there is a rise in antifungal-resistant strains of pathogenic fungi. There is a need for novel and more potent antifungal therapeutics. Consequently, we investigated a mixed library of drug-like and probe-like compounds with activity inPlasmodiumspp. for activity against two common fungal pathogens,Cryptococcus neoformansandCandida albicans, along with two less common pathogenic species,Lomentospora prolificansandCryptococcus gattii. We uncover a previously uncharacterized drug with higher broad-spectrum antifungal activity than some current treatments. Our findings may eventually lead to a compound added to the arsenal of antifungal therapeutics.


Author(s):  
Mfouapon Mbetyoumoun Heroine ◽  
Hzounda Fokou Jean Baptiste ◽  
Yimgang Victorine Lorette ◽  
Toghueo Kouipou Rufin Marie ◽  
Fogue Soubgwi Pythagore ◽  
...  

The discovery of novel antifungal agents with low toxicity and high therapeutic efficacy is needed to overcome the limitation of the actually existing antifungal therapies. Endophytic fungi acknowledge for their outstanding ability to produce bioactive metabolites can be exploited for this purpose. Therefore, this study was designed to investigate the antifungal potential of endophytic fungi leaving in tissues of Cola acuminata. Endophytic fungi associated with Cola acuminata were isolated from healthy and matured plant tissues and characterized based on their morphological and microscopic characters. Each isolated fungus was cultured on potato dextrose broth for ten days and crude extract prepared from the resulting medium after filtration. The resulting extracts were tested for their antifungal potential using broth microdilution method. One hundred and six fungal isolates were obtained from leaves, fruit, stem, stem bark, root, and root bark of C. acuminate. They belong to six genera including Aspergillus, Alternaria, Curvularia, Cunnighamella, Fusarium, Trichoderma. Non-sporulating isolates were designated as Mycelia. Out of the 106 extracts screened for their antifungal activities, 21, 13 and 43 showed antifungal activities against C.albicans NR-29450, C.parapsilosis ATCC 22019 and C.krusei ATCC 6258 respectively. Five of these isolates including Cal14, Casb122, Cab259, Cab31 and Cab244 were the most potent, inhibiting the growth of the three tested Candida species more than 85% against. Isolate Casb122 appears to be one of the most potent antifungal against Candida species (MIC 500-1000µg/mL). The results suggest that endophytic fungi from C. acuminata can produce metabolites with antifungal activity


2018 ◽  
Vol 73 (11-12) ◽  
pp. 449-455 ◽  
Author(s):  
Djalma M. de Oliveira ◽  
Cristiane B. Pereira ◽  
Graziele Mendes ◽  
Jochen Junker ◽  
Markus Kolloff ◽  
...  

Abstract The endophytic fungus Mycosphaerella sp. (UFMGCB2032) was isolated from the healthy leaves of Eugenia bimarginata, a plant from the Brazilian savanna. Two novel usnic acid derivatives, mycousfuranine (1) and mycousnicdiol (2), were isolated from the ethyl acetate extract, and their structure was elucidated by NMR and MS analyses. Compounds 1 and 2 exhibited moderate antifungal activities against Cryptococcus neoformans and Cryptococcus gattii, each with minimum inhibitory concentration values of 50.0 μg/mL and 250.0 μg/mL, respectively.


2020 ◽  
Vol 58 (7) ◽  
pp. 906-912
Author(s):  
Raimunda Sâmia Nogueira Brilhante ◽  
Wilker Jose Perez Gotay ◽  
Vandbergue Santos Pereira ◽  
Jonathas Sales de Oliveira ◽  
Waldemiro Aquino Pereira-Neto ◽  
...  

Abstract Cryptococcus neoformans/Cryptococcus gattii are fungal pathogens that affect the central nervous system, mainly in immunocompromised individuals. Due to the limited pharmacological arsenal available for the treatment of cryptococcosis associated with cases of antifungal resistance of Cryptococcus spp. reported in some studies, the search for new compounds with antifungal potential becomes relevant. Thus, the objective of this study was to evaluate the inhibitory effect of phenothiazines (promethazine and chlorpromazine) on C. neoformans/C. gattii planktonic cells and biofilms. In vitro planktonic susceptibility testing was performed using the broth microdilution assay. The effect of phenothiazines was evaluated against biofilm formation and mature Cryptococcus biofilms. Biofilm morphology and ultrastructure were also evaluated by scanning electron microscopy. Promethazine and chlorpromazine showed antifungal activity against planktonic cells, with minimum inhibitory concentrations of 8–32 μg/ml and 4–16 μg/ml, respectively. As for biofilm formation, phenothiazines reduced biomass by 60% and metabolic activity by 90% at 64 μg/ml; while in mature biofilms, reductions of 85% and 90% in biomass and metabolic activity, respectively, were observed at 1024 μg/ml. Promethazine and chlorpromazine were also able to disrupt and fragment biofilms. In conclusion, promethazine and chlorpromazine have antifungal activity against planktonic cells and biofilms of Cryptococcus spp. These data show the potential of promethazine and chlorpromazine as antibiofilm drugs.


2008 ◽  
Vol 53 (1) ◽  
pp. 309-311 ◽  
Author(s):  
George R. Thompson ◽  
Nathan P. Wiederhold ◽  
Annette W. Fothergill ◽  
Ana C. Vallor ◽  
Brian L. Wickes ◽  
...  

ABSTRACT We measured antifungal activity against 128 cryptococcal isolates (86 of C. neoformans and 42 of C. gattii) to determine if differences in serotype susceptibility exist. Contrary to previous results, we found no serotype susceptibility differences. Isavuconazole, posaconazole, and voriconazole demonstrated excellent potency against each isolate and serotype, including isolates with reduced fluconazole susceptibilities.


2015 ◽  
Vol 10 (9) ◽  
pp. 1934578X1501000
Author(s):  
Adriana Campos ◽  
Greice Maria Rodrigues Souza ◽  
Franco Delle Monache ◽  
Estefanía Butassi ◽  
Susana Zacchino ◽  
...  

Previous studies with the bulbs of Cipura paludosa (Iridaceae) showed the presence of pyranonaphthoquinones, including eleutherine, isoeleutherine and eleutherol. The aim of this study was to evaluate the antifungal properties of these compounds. The activity was tested against the clinically relevant yeasts Candida albicans, C. tropicalis, Saccharomyces cerevisiae and Cryptococcus neoformans with the microbroth dilution method, following the guidelines of CLSI. Eleutherine, isoeleutherine and eleutherol all presented significant antifungal activity, especially the first two, the major components, with MIC values between 7.8 and 250 μg/mL. In conclusion, these results demonstrate that C. paludosa bulbs produce active principles with relevant antifungal potential, contributing, at least in part, to the antimicrobial effect evidenced for this plant and justifying its popular use against infections.


2020 ◽  
Vol 17 (5) ◽  
pp. 526-532
Author(s):  
Si Liu ◽  
Li-Zhi Niu ◽  
Yan-Hua Shi ◽  
Fu-Xian Wan ◽  
Lin Jiang

Background: Oxime compounds, including oxime ethers and oxime esters, possess various biological activities. Many oxime ethers have been widely used in the fields of pesticides and medicines. However, oxime ethers are rarely used in the field of pesticides. Methods: We chose the excellent fungicide pyrifenox as the lead compound, integrated pyridinyl, adamantyl and benzoyl moieties into one molecule, while also designed and synthesized ten 1- (adamantan-1-yl)ethanone oxime esters containing pyridinyl moiety. Moreover, we also evaluated their preliminary antifungal activities against S. sclerotiorum and B. cinerea. Results: The target compounds were characterized by NMR, IR and HRMS. The preliminary bioactivity test showed that they exhibited some antifungal activity to S. sclerotiorum and B. cinerea, and EC50 values were in the range of 14.16-32.97 and 27.60-52.82 μg/mL, respectively. Conclusion: Some target compounds such as 3d, 3e, 3h and 3i, exhibited moderate activities against S. sclerotiorum, with EC50 values of 14.16-18.18 μg/mL.


2020 ◽  
Vol 18 ◽  
Author(s):  
Niranjan Kaushik ◽  
Nitin Kumar ◽  
Anoop Kumar ◽  
Vikas Sharma

Background: Fungal infections are opportunistic infections that become a serious problem to human health. Objective: Considering the antifungal potential of triazole nucleus, the study was carried out with the objective to synthesize some novel triazole derivatives with antifungal potential. Method: 1,2,4-triazole derivatives were synthesized via a two step reaction (reported earlier). The first step involves reaction of substituted benzoic acid with thiocarbohydrazide to form 4-amino-3-(substituted phenyl)-5-mercapto-1, 2, 4-triazole derivatives (1a-1k) while in second step, synthesized compounds (1a-1k) were then subsequently treated with substituted acetophenone to yield substituted (4-methoxyphenyl-7H-[1, 2, 4] triazolo [3, 4-b][1,3,4] thiadiazine derivatives (2a-2k). All synthesized compounds were characterized by IR, 1H NMR, and Mass spectral data analysis and were screened for their antifungal properties against different fungal strains i.e. Candida tropicalis (ATCC-13803, ATCC-20913), Candida albicans (ATCC-60193), Candida inconspicua (ATCC-16783) and Candida glabrata (ATCC-90030, ATCC-2001). Results: Compound 2d displayed better percentage inhibition (26.29%, 24.81%) than fluconazole (24.44%, 22.96%) against ATCC-16783, ATCC-2001 fungal strains respectively at 100µg/ml. Compound 2f also displayed better percentage inhibition (28.51%) against ATCC-90030 as compared to fluconazone (27.4%) at 200 µg/ml. Similarly, compounds 2e and 2j also exhibited better antifungal properties than fluconazole at 200µg/ml. Compound 2e was found most potent against ATCC13803 (30.37%) and ATCC-90030 (30.37%) fungal strains as compared to fluconazole (28.14%, 27.4%) at 200 µg/ml respectively whereas compound 2j exhibited better antifungal activity (28.51%) against ATCC-60193 than fluconazole (27.7%) at 200 µg/ml. Conclusion: The results were in accordance with our assertions for triazole derivatives, as all compounds displayed moderate to good antifungal activity.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Benjamin N. Nelson ◽  
Savannah G. Beakley ◽  
Sierra Posey ◽  
Brittney Conn ◽  
Emma Maritz ◽  
...  

AbstractCryptococcal meningitis is a life-threatening disease among immune compromised individuals that is caused by the opportunistic fungal pathogen Cryptococcus neoformans. Previous studies have shown that the fungus is phagocytosed by dendritic cells (DCs) and trafficked to the lysosome where it is killed by both oxidative and non-oxidative mechanisms. While certain molecules from the lysosome are known to kill or inhibit the growth of C. neoformans, the lysosome is an organelle containing many different proteins and enzymes that are designed to degrade phagocytosed material. We hypothesized that multiple lysosomal components, including cysteine proteases and antimicrobial peptides, could inhibit the growth of C. neoformans. Our study identified the contents of the DC lysosome and examined the anti-cryptococcal properties of different proteins found within the lysosome. Results showed several DC lysosomal proteins affected the growth of C. neoformans in vitro. The proteins that killed or inhibited the fungus did so in a dose-dependent manner. Furthermore, the concentration of protein needed for cryptococcal inhibition was found to be non-cytotoxic to mammalian cells. These data show that many DC lysosomal proteins have antifungal activity and have potential as immune-based therapeutics.


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