Improvement Of Antifungal Activity Research Articles

Development and Evaluation of Antifungal Efficacy of Ketoconazole Pharmacosome

Pharmacosomes are neutral colloidal, lipid vesicular drug delivery system having both negative & positive charge that enhance the bioavailability of drugs by enhacing their solubility both in aqueous as well as non-aqueous phase, additionally reduce gastrointestinal toxicity of drug. Ketoconazole is an imidazole derivative agent which is used both in the treatment of topical or systematic fungal infections with fungi static activity against dermatophytes, yeasts and other pathogenic fungi. Ketoconazole is Biopharmaceutical classification system (BCS) class II drugs that display pH dependent dissolution and absorption. In this present research work Pharmacosome of Ketoconazole was prepared in different ratios of Ketoconazole-PC complex (1:1, 1:1.5 and1:2) using conventional solvent evaporation method. FT-IR spectra showed no significant untoward interaction, Vesicles shape and morphology was carried out with Phase contrast microscopy (PCM) and Scanning electron microscopy (SEM), In-vitro permeation study and anti-fungal activity were duly examined. Drug content in the formulations (1:1) (1:1.5) and (1:2) were found 92.5%, 94.3% and 89.7% respectively. FT-IR conformed proper formation of drug- Pharmaosome complex. Particle size distribution were found to be regular and of spherical shape. In-vitro permeation study showed 78.03%, 89.05% and 55.27% drug release as per respectively formulations (KTP1, KTP2 and KTP3). Pharmacosomes of ketoconazole show improvement in antifungal activity than ketoconazole (Pure).

A New Amphotericin B-loaded Trimethyl Chitosan Nanoparticles as a Drug Delivery System and Antifungal Activity on Candida albicans Biofilm.

Amphotericin B (AmB) is an effective antifungal agent; however, the application of AmB is associated with a number of drawbacks. Application of nanoparticles (NPs) is known to improve the efficiency of drug delivery to the target tissues, compared to the traditional methods. In this study, a novel method of NPs preparation was developed. The trimethyl chitosan (TMC) was synthesized using low molecular weight chitosan and was used for the preparation of TMC-NPs through ionic gelation method. Afterward, AmB-loaded TMC-NPs (TMC-NPs/AmB) were prepared and their drug delivery potential was testes. The TMC-NPs and TMC-NPs/AmB were characterized for their structure, particle size, Zeta potential, polydispersity index, morphology, loading efficiency, loading capacity, in vitro release profile, release kinetic, and entrapped AmB potency. The cytotoxicity and antifungal activity of TMC-NPs/AmB against Candida albicans biofilm were evaluated. The quaternization of TMC was estimated to be 36.4%. The mean particle size of TMC-NPs and TMC NPs/AmB were 210±15 and 365±10 nm, respectively, with a PDI of 0.30 and 0.4, ZP of +34±0.5 and +28±0.5 mV, respectively. Electron microscopy analysis indicated uniform spherical shapes with smooth surfaces. The TMC-NPs/AmB indicated LE of 76% and LC of 74.04 % with a potency of 110%. The release profile of TMC-NPs/AmB was best explained by the Higuchi model. The initial release after 10 h was obtained at 38%, and the rates of release after 36 and 84 h were determined at 67% and 76% respectively, which was significantly different (P<0.05) from previous time points. The minimum inhibitory concentration (MIC) (50%) of NPs/AmB and AmB were 0.65 and 1.75 μg/mL, and the MIC 80% were determined at 1.95 and 7.75 μg/mL, respectively, demonstrating a significant improvement in antifungal activity. The half-maximal inhibitory concentration for TMC-NPs/AmB and AmB were estimated at 86 and 105 μg/mL, respectively, indicating a significant reduction in cytotoxicity and the adverse effect. This study could successfully introduce a practical method to synthesize TMC-NPs. The encapsulation process was efficient and significantly improved the antifungal activity of AmB. The developed method can be applied to improve the feasibility of oral delivery while reducing the adverse effects associated with traditional methods.

Ibrexafungerp: An orally active β-1,3-glucan synthesis inhibitor

We previously reported medicinal chemistry efforts that identified MK-5204, an orally efficacious β-1,3-glucan synthesis inhibitor derived from the natural product enfumafungin. Further extensive optimization of the C2 triazole substituent identified 4-pyridyl as the preferred replacement for the carboxamide of MK-5204, leading to improvements in antifungal activity in the presence of serum, and increased oral exposure. Reoptimizing the aminoether at C3 in the presence of this newly discovered C2 substituent, confirmed that the (R) t-butyl, methyl aminoether of MK-5204 provided the best balance of these two key parameters, culminating in the discovery of ibrexafungerp, which is currently in phase III clinical trials. Ibrexafungerp displayed significantly improved oral efficacy in murine infection models, making it a superior candidate for clinical development as an oral treatment for Candida and Aspergillus infections.

A chitosan hydrogel-thickened nanoemulsion containing Pelargonium graveolens essential oil for treatment of vaginal candidiasis

The use of nanosystems can be an appropriate approach to develop essential oils formulations by improving their active compounds delivery. This work reports an evaluation of antifungal activity of essential oils of Pelargonium graveolens from different countries and the development of a mucoadhesive hydrogel-thickened nanoemulsion containing the essential oil to treat vaginal candidiasis. The antifungal activities of six essential oils were evaluated against five species of Candida. Then, a hydrogel-thickened nanoemulsion with the most active essential oil was produced, characterized and had its MIC determined. Formulations were also monitored for irritancy properties by HET-CAM test and had their mucoadhesive properties assessed. The hydrogel containing the essential oil of P. graveolens showed higher antifungal activity reaching MIC values 64 times lower when compared to essential oil dilution and to nanoemulsion. Also, the final formulation showed droplets lower than 300 nm with positive zeta potential, reduced irritant potential and better mucoadhesive properties when compared to the nanoemulsion. Thus, it can be considered a promising alternative to treat vaginal candidiasis, once it showed an improvement in antifungal activity against Candida spp., besides having biodegradable materials and mucoadhesive properties, increasing the time residence on vaginal mucosa, leading to an improvement of treatment efficacy.

Combinatorial effect of mutagenesis and medium component optimization on Bacillus amyloliquefaciens antifungal activity and efficacy in eradicating Botrytis cinerea

This work is directed towards Bacillus amyloliquefaciens strain BLB371 metabolite production for biocontrol of fungal phytopathogens. In order to maximise antifungal metabolite production by this strain, two approaches were combined: random mutagenesis and medium component optimization. After three rounds of mutagenesis, a hyper active mutant, named M3-7, was obtained. It produces 7 fold more antifungal metabolites (1800AU/mL) than the wild strain in MC medium. A hybrid design was applied to optimise a new medium to enhance antifungal metabolite production by M3-7. The new optimized medium (35g/L of peptone, 32.5g/L of sucrose, 10.5g/L of yeast extract, 2.4g/L of KH2PO4, 1.3g/L of MgSO4 and 23mg/L of MnSO4) achieved 1.62 fold enhancement in antifungal compound production (3000AU/mL) by this mutant, compared to that achieved in MC medium. Therefore, combinatory effect of these two approaches (mutagenesis and medium component optimization) allowed 12 fold improvement in antifungal activity (from 250UA/mL to 3000UA/mL). This improvement was confirmed against several phytopathogenic fungi with an increase of MIC and MFC over than 50%. More interestingly, a total eradication of gray mold was obtained on tomato fruits infected by Botrytis cinerea and treated by M3-7, compared to those treated by BLB371. From the practical point of view, combining random mutagenesis and medium optimization could be considered as an excellent tool for obtaining promising biological products useful against phytopathogenic fungi.

Effect of alanine, leucine, and arginine substitution on antimicrobial activity against candida albicans and action mechanism of a cationic octadecapeptide derived from α-amylase of rice.

AmyI-1-18, an antimicrobial peptide, is a cationic α-helical octadecapeptide derived from α-amylase of rice (Oryza sativa L. japonica) that contains four cationic amino acid residues (two arginines and two lysines). To enhance the antifungal activity of AmyI-1-18 against Candida albicans, 11 analogs bearing substitutions with alanine, leucine, and/or arginine, which were designed on the basis of the helical wheel projection of AmyI-1-18, were synthesized, and their antifungal activity was investigated. The antifungal activities of four analogs obtained by replacing arginine or lysine with alanine were significantly reduced. The results suggested that the cationic arginine and lysine residues in AmyI-1-18 are important for its antifungal activity. The antifungal activities of two single leucine-substituted analogs were not improved, but among three single arginine-substituted analogs, AmyI-1-18(D15R) had approximately a twofold higher antifungal activity [50% growth-inhibitory concentration (IC50 ): 31 μM] than AmyI-1-18 (IC50 : 64 μM) and exhibited low hemolytic activity (4% at 100 μM). Flow cytometric analysis using propidium iodide revealed that the antifungal activity of AmyI-1-18(D15R) was dependent on its membrane-disrupting activity in a manner different from that of AmyI-1-18. Further enhancement of the cationicity and hydrophobicity of AmyI-1-18(D15R) resulted in no improvement in antifungal activity and a significant increase in hemolytic activity. In this study, the results demonstrated that the antifungal activity of AmyI-1-18 against C. albicans was enhanced through increasing its membrane-disrupting activity by replacing aspartic acid at position 15 with arginine without a significant increase in hemolytic activity. © 2016 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 219-229, 2016.

Lysosome and HER3 (ErbB3) Selective Anticancer Agent Kahalalide F: Semisynthetic Modifications and Antifungal Lead-Exploration Studies

Kahalalide F (1) shows remarkable antitumor activity against different carcinomas and has recently completed phase I clinical trials and is being evaluated in phase II clinical studies. The antifungal activity of this molecule has not been thoroughly investigated. In this report, we focused on acetylation and oxidation of the secondary alcohol of threonine, as well as reductive alkylation of the primary amine of ornithine, and each product was evaluated for improvements in antifungal activity. 1 and analogues do not exhibit antimalarial, antileishmania, or antibacterial activity; however, the antifungal activity against different strains of fungi was particularly significant. This series of compounds was highly active against Fusarium spp., which represents an opportunistic infection in humans and plants. The in vitro cytotoxicity for the new analogues of 1 was evaluated in the NCI 60 cell panel. Analogue 5 exhibited enhanced potency in several human cancer cell lines relative to 1.

In-vivo therapeutic efficacy in experimental murine mycoses of a new formulation of deoxycholate-amphotericin B obtained by mild heating.

Heat-induced 'superaggregation' of deoxycholate-amphotericin B (AmB-DOC, Fungizone) was shown previously to reduce the in-vitro toxicity of this antifungal agent. We compared AmB-DOC with the formulation obtained by heating the commercial form (Fungizone, Bristol Myers Squibb, Paris, France) for 20 min at 70 degrees C, in the treatment of murine infections. An improvement of antifungal activity was obtained with heated AmB-DOC formulations due to a lower toxicity which allowed the administration of higher drug doses than those achievable with the commercial preparation. Single intravenous injections of heated AmB-DOC solutions were demonstrated to be two-fold less toxic than unheated ones to healthy mice. For mice infected with Candida albicans, the maximum tolerated dose was higher with heated than with unheated AmB-DOC solutions. In the model of murine candidiasis, following a single dose of heated AmB-DOC 0.5 mg/kg, 85% of mice survived for 3 weeks, whereas at this dose the immediate toxicity of the standard formulation in infected mice restricted the therapeutic efficacy to 25% survival. Both formulations were equally effective in increasing the survival time for murine cryptococcal pneumonia and meningoencephalitis. Injection of heated AmB-DOC solutions at a dose two-fold higher than the maximal tolerated dose observed with the unheated preparation (1.2 mg/kg) increased the survival time by a factor of 1.4 in cryptococcal meningoencephalitis. These results indicate that mild heat treatment of AmB-DOC solutions could provide a simple and economical method to improve the therapeutic index of this antifungal agent by reducing its toxicity on mammalian cells.

Relationship between antifungal activity and hydrophobicity of kojic acid derivatives.

Twenty three kojic acid derivatives were tested in the agar diffusion test against twenty five dermatophytic fungi. The inhibitory effects at equal doses (10 mg/L) were correlated with the 1-octanol-water partition coefficients of the compounds. An improvement in antifungal activity can be achieved by increasing the hydrophobicity of the compounds.