scholarly journals Novel Bi-Factorial Strategy against Candida albicans Viability Using Carnosic Acid and Propolis: Synergistic Antifungal Action

2020 ◽  
Vol 8 (5) ◽  
pp. 749
Author(s):  
Alejandra Argüelles ◽  
Ruth Sánchez-Fresneda ◽  
José P. Guirao-Abad ◽  
Cristóbal Belda ◽  
José Antonio Lozano ◽  
...  

The potential fungicidal action of the natural extracts, carnosic acid (obtained from rosemary) and propolis (from honeybees’ panels) against the highly prevalent yeast Candida albicans, used herein as an archetype of pathogenic fungi, was tested. The separate addition of carnosic acid and propolis on exponential cultures of the standard SC5314 C. albicans strain caused a moderate degree of cell death at relatively high concentrations. However, the combination of both extracts, especially in a 1:4 ratio, induced a potent synergistic pattern, leading to a drastic reduction in cell survival even at much lower concentrations. The result of a mathematical analysis by isobologram was consistent with synergistic action of the combined extracts rather than a merely additive effect. In turn, the capacity of SC5314 cells to form in vitro biofilms was also impaired by the simultaneous presence of both agents, supporting the potential application of carnosic acid and propolis mixtures in the prevention and treatment of clinical infections as an alternative to antibiotics and other antifungal agents endowed with reduced toxic side effects.

Antibiotics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1395
Author(s):  
Alejandra Argüelles ◽  
Ruth Sánchez-Fresneda ◽  
Elisa Martínez-Mármol ◽  
José Antonio Lozano ◽  
Francisco Solano ◽  
...  

Current antifungal chemotherapy against the prevalent basidiomycete Cryptococcus neoformans displays some drawbacks. This pathogenic fungus is refractory to echinocandins, whereas conventional treatment with amphotericin B plus 5-fluorocytosine has a limited efficacy. In this study, we explored the potential cryptococcal activity of some natural agents. After conducting a screening test with a set of propolis from different geographical areas, we selected an extract from China, which displayed a certain cytotoxic activity against C. neoformans, due to this extract being cheap and easily available in large amounts. The combination of this kind of propolis with carnosic acid in a 1:4 ratio induced a stronger fungicidal effect, which occurred following a synergistic pattern, without visible alterations in external cell morphology. Furthermore, several carnosic acid–propolis formulations applied onto preformed biofilms decreased the metabolic activity of the sessile cells forming biofilms. These data support the potential application of mixtures containing these two natural extracts in the design of new antifungal strategies in order to combat opportunistic infections caused by prevalent pathogenic fungi.


2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Tamirat Bekele Beressa ◽  
Serawit Deyno ◽  
Paul E. Alele

Background. Echinops kebericho is an endemic medicinal plant in Ethiopia widely used in the treatment of infectious and noninfectious diseases. Essential oils are known for their antibacterial, antifungal, antiviral, insecticidal, and antioxidant properties. This study evaluated the antifungal activity of essential oil from E. kebericho against four common pathogenic fungi and two standard strains. Methods. The essential oil was obtained by hydrodistillation. The antifungal screening was done by agar well diffusion method. Minimal inhibitory concentrations (MICs) were determined by broth microdilution. Minimal fungicidal concentrations (MFCs) were determined by subculturing fungal strains with no visible growth onto a Sabouraud dextrose agar (SDA) plate. Results. Candida albicans and Cryptococcus neoformans were highly sensitive while Aspergillus flavus did not show sensitivity up to 1 mg/ml of essential oil; MICs ranged from 0.083 mg/ml to 0.208 mg/ml. Concentration and fungal species showed significant dose-dependent associations ( p < 0.0001 ) with antifungal activity. The MICs of essential oil were comparable to those of the standard drug (fluconazole) against C. glabrata and C. krusei. The lowest MFC of the essential oil was observed against Candida parapsilosis (0.145 mg/ml) while the highest MFC was against Candida krusei (0.667 mg/ml). Conclusion. Echinops kebericho essential oil showed noteworthy antifungal activity against Cryptococcus neoformans, Candida albicans, and Candida glabrata and could be a potential candidate for further antifungal drug development.


2006 ◽  
Vol 19 (1) ◽  
pp. 205873920601900 ◽  
Author(s):  
F. Marcucci ◽  
L. Sensi ◽  
G. DI Cara ◽  
G. Gidaro ◽  
C. Incorvaia ◽  
...  

Oral Allergy Syndrome (OAS) in patients with pollen-induced rhinoconjunctivitis is caused by specific IgE recognizing cross-reacting epitopes of fruits and plants, which were clearly shown in vitro, but failed to be demonstrated in vivo by cross-challenges in the target organs. Considering the hypothesis of degradation of such epitopes in natural extracts, challenges with recombinant pollen allergens were done to evaluate the reactivity of the oral mucosa in OAS patients. Seventeen patients with OAS and rhinitis from birch (10) and grass pollen (7) and 10 non-atopic controls were studied by skin prick tests (SPT), allergen specific nasal challenges (ASNC) and allergen specific sublingual challenges (ASSC) with birch and timothy extracts and with rBet v1 and rPhl p1 at increasing concentrations from 1 to 1000 mcg/ml. None of the healthy subjects in the control group had any positive test for birch and timothy extracts or for recombinant allergens. In the OAS group the following results were observed: SPTs with recombinant allergens were positive in all patients, mostly at 10 mcg/ml concentration; ASNC with rBet v1 were positive in all patients, mostly at 100 mcg/ml; ASSC with natural pollen extracts were positive in only 2 of 17 patients, but in 15 of 17 with rBet v1 and rPhl p1, mostly at 500 mcg/ml and 1000 mcg/ml. ASSC with rBet v1 and rPhl p1 were positive with a mean concentration of 677 and 533 mcg/ml, respectively. The results of sublingual challenges with rBet v1 and rPhl p1 showed the in vivo cross-reactivity between pollens and foods in patients with OAS, but high concentrations of the recombinant allergens were needed to reproduce oral symptoms, thus explaining the failure of challenges performed with natural extracts, which have concentrations of major allergens lower than 50 mcg/ml. This indicates that sublingual mucosa is much less reactive to allergens than other surfaces, such as skin and nasal mucosa, probably because of its anatomic and immunologic peculiarity.


2012 ◽  
Vol 79 (5) ◽  
pp. 1639-1645 ◽  
Author(s):  
Josie E. Parker ◽  
Andrew G. S. Warrilow ◽  
Hans J. Cools ◽  
Bart A. Fraaije ◽  
John A. Lucas ◽  
...  

ABSTRACTProthioconazole is a new triazolinthione fungicide used in agriculture. We have usedCandida albicansCYP51 (CaCYP51) to investigate thein vitroactivity of prothioconazole and to consider the use of such compounds in the medical arena. Treatment ofC. albicanscells with prothioconazole, prothioconazole-desthio, and voriconazole resulted in CYP51 inhibition, as evidenced by the accumulation of 14α-methylated sterol substrates (lanosterol and eburicol) and the depletion of ergosterol. We then compared the inhibitor binding properties of prothioconazole, prothioconazole-desthio, and voriconazole with CaCYP51. We observed that prothioconazole-desthio and voriconazole bind noncompetitively to CaCYP51 in the expected manner of azole antifungals (with type II inhibitors binding to heme as the sixth ligand), while prothioconazole binds competitively and does not exhibit classic inhibitor binding spectra. Inhibition of CaCYP51 activity in a cell-free assay demonstrated that prothioconazole-desthio is active, whereas prothioconazole does not inhibit CYP51 activity. Extracts fromC. albicansgrown in the presence of prothioconazole were found to contain prothioconazole-desthio. We conclude that the antifungal action of prothioconazole can be attributed to prothioconazole-desthio.


F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 559
Author(s):  
Tatiana de los Ángeles Mosquera Tayupanta ◽  
Sandra Elizabeth Ayala Valarezo ◽  
Tatiana Alexandra Vasquez Villareal ◽  
María Belén Montaluisa Álvarez

Background: Currently, there is a trend towards using natural and ethnopharmacological species with therapeutic potential. This investigation evaluated the antifungal activity of two species in the Ecuadorian Andes, which are used in treating dermatomycosis: Ambrosia arborescens Mill. (Marco) and Aristeguietia glutinosa Lam. (Matico). Methods: We worked with seven concentrations (100 to 700ppm) of Ambrosia arborescens Mill. extract and ten concentrations (0.5 to 5%) of essential oil (EO) of Aristeguietia glutinosa Lam. on Trichophyton mentagrophytes ATCC 9533, Trichophyton rubrum ATCC 28188, Microsporum canis ATCC 36299 and Candida albicans ATCC 10231. The methodology used was a modified version of the Kirby-Bauer method, using diffusion in agar wells. Results: The Tukey test, after the one-way Anova, determined effective concentrations of EO: 5% for Trichophyton mentagrophytes, 4.5% for Trichophyton rubrum, 5% for Microsporum canis and 2% for Candida albicans. In the extracts, the concentration of 700ppm was used for Trichophyton mentagrophytes, Trichophyton rubrum, and 600ppm for Microsporum canis and Candida albicans. Conclusions: The evaluation of the antifungal activity of the Ambrosia arborescens extract showed inhibition in the studied dermatophytes in each one of the planted concentrations (100 to 700ppm). The evaluation of the antifungal activity of Aristeguietia glutinosa EO showed inhibition in the studied dermatophytes in each of the planted concentrations (0.5 to 5%).


2003 ◽  
Vol 4 (2) ◽  
Author(s):  
Nayanna Coutinho De FARIAS ◽  
Marilene Magalhães BUFFON ◽  
Rafael CINI

O estudo tem como objetivo avaliar comparativamente as propriedades antifúngicas da nistatina 100.000 UI em relação à solução de digluconato de clorhexidina a 0.2%. A suspensão de C. albicans foi semeada em meio de cultura de BHI com ágar, com cerca de 6mm de espessura distribuídos em placas de petri com escavações de 7mm de diâmetro. Após 10 repetições, obteve-se os resultados de acordo com o halo de inibição formado pela solução. Para o digluconato de clorhexidina o halo de inibição foi de 27mm e para nistatina foi 17mm. Assim, pode-se considerar a clorhexidina 0,2% no estudo in vitro como superior no combate antifúngico das cepas de leveduras em relação à nistatina. IN VITRO EVALUATION OF ANTIFUNGAL ACTION OF CHLORHEXIDINA DIGLUCONATE AND NYSTATIN ON THE GROWING CONTROL OF Candida albicans Abstract The study aim to compare the antifungal properties between 100.000 IU nystatin and 0.2% chlorhexidine digluconate solution. The C. albicans suspension was seeded in a BHI agar culture, with 6mm of thickness distributed in Petri plates with 7mm diameters holes. After 10 repetitions, the results were measured according to the inhibitions halos created by the solution. The chlorhexidine solution inhibition halo was 27mm and the nystatin was 17mm. Therefore, the 0.2% chlorhexidine solution may be considered more effective them nystatin in the antifungal action against yeast strains.


1998 ◽  
Vol 42 (5) ◽  
pp. 1057-1061 ◽  
Author(s):  
Neil S. Ryder ◽  
Sonja Wagner ◽  
Ingrid Leitner

ABSTRACT Terbinafine is active in vitro against a wide range of pathogenic fungi, including dermatophytes, molds, dimorphic fungi, and some yeasts, but earlier studies indicated that the drug had little activity against Candida albicans. In contrast, clinical studies have shown topical and oral terbinafine to be active in cutaneous candidiasis and Candida nail infections. In order to define the anti-Candida activity of terbinafine, we tested the drug against 350 fresh clinical isolates and additional strains by using a broth dilution assay standardized according to the guidelines of the National Committee for Clinical Laboratory Standards (NCCLS) M27-A assay. Terbinafine was found to have an MIC of 1 μg/ml for reference C. albicans strains. For 259 clinical isolates, the MIC at which 50% of the isolates are inhibited (MIC50) of terbinafine was 1 μg/ml (fluconazole, 0.5 μg/ml), and the MIC90 was 4 μg/ml (fluconazole, 1 μg/ml). Terbinafine was highly active against Candida parapsilosis(MIC90, 0.125 μg/ml) and showed potentially interesting activity against isolates of Candida dubliniensis,Candida guilliermondii, Candida humicola, andCandida lusitaniae. It was not active against theCandida glabrata, Candida krusei, andCandida tropicalis isolates in this assay.Cryptococcus laurentii and Cryptococcus neoformans were highly susceptible to terbinafine, with MICs of 0.06 to 0.25 μg/ml. The NCCLS macrodilution assay provides reproducible in vitro data for terbinafine against Candidaand other yeasts. The MICs for C. albicans and C. parapsilosis are compatible with the known clinical efficacy of terbinafine in cutaneous infections, while the clinical relevance of its activities against the other species has yet to be determined.


1996 ◽  
Vol 183 (4) ◽  
pp. 1829-1840 ◽  
Author(s):  
H L Pahl ◽  
B Krauss ◽  
K Schulze-Osthoff ◽  
T Decker ◽  
E B Traenckner ◽  
...  

Opportunistic infections, such as aspergillosis, are among the most serious complications suffered by immunocompromised patients. Aspergillus fumigatus and other pathogenic fungi synthesize a toxic epipolythiodioxopiperazine metabolite called gliotoxin. Gliotoxin exhibits profound immunosuppressive activity in vivo. It induces apoptosis in thymocytes, splenocytes, and mesenteric lymph node cells and can selectively deplete bone marrow of mature lymphocytes. The molecular mechanism by which gliotoxin exerts these effects remains unknown. Here, we report that nanomolar concentrations of gliotoxin inhibited the activation of transcription factor NF-kappaB in response to a variety of stimuli in T and B cells. The effect of gliotoxin was specific because, at the same concentrations, the toxin did not affect activation of the transcription factor NF-AT or of interferon-responsive signal transducers and activators of transcription. Likewise, the activity of the constitutively DNA-binding transcription factors Oct-1 and cyclic AMP response element binding protein (CREB), as well as the activation of protein tyrosine kinases p56lck and p59fyn, was not altered by gliotoxin. Very high concentrations of gliotoxin prevented NF-kappaB DNA binding in vitro. However, in intact cells, inhibition of NF-kappaB did not occur at the level of DNA binding; rather, the toxin appeared to prevent degradation of IkappaB-alpha, NF-kappaB's inhibitory subunit. Our data raise the possibility that the immunosuppression observed during aspergillosis results in part from gliotoxin-mediated NF-kappaB inhibition.


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