83 research outputs found
Honokiol and magnolol: insights into their antidermatophytic effects
Dermatophyte infections represent a significant public health concern, with an alarming
negative impact caused by unsuccessful therapeutic regimens. Natural products have been highlighted
as a promising alternative, due to their long-standing traditional use and increasing scientific
recognition. In this study, honokiol and magnolol, the main bioactives from Magnolia spp. bark, were
investigated for their antidermatophytic activity. The antifungal screening was performed using
dermatophyte standard strains and clinical isolates. The minimal inhibitory concentration (MIC)
and the minimal fungicidal concentration (MFC) were determined in accordance with EUCASTAFST
guidelines, with minor modifications. The effects on ergosterol biosynthesis were assessed in
Trichophyton rubrum cells by HPLC-DAD. Putative interactions with terbinafine against T. rubrum
were evaluated by the checkerboard method. Their impact on cellsâ viability and pro-inflammatory
cytokines (IL-1 , IL-8 and TNF- ) was shown using an ex vivo human neutrophils model. Honokiol
and magnolol were highly active against tested dermatophytes, with MIC and MFC values of 8 and
16 mg/L, respectively. The mechanism of action involved the inhibition of ergosterol biosynthesis,
with accumulation of squalene in T. rubrum cells. Synergy was assessed for binary mixtures of
magnolol with terbinafine (FICI = 0.50), while honokiol-terbinafine combinations displayed only
additive effects (FICI = 0.56). In addition, magnolol displayed inhibitory effects towards IL-1 , IL-8
and TNF- released from lipopolysaccharide (LPS)-stimulated human neutrophils, while honokiol
only decreased IL-1 secretion, compared to the untreated control. Overall, honokiol and magnolol
acted as fungicidal agents against dermatophytes, with impairment of ergosterol biosynthesis
Apiaceae essential oils: boosters of terbinafine activity against dermatophytes and potent anti-inflammatory effectors
Dermatophyte infections represent an important public health concern, affecting up to 25%
of the worldâs population. Trichophyton rubrum and T. mentagrophytes are the predominant dermatophytes
in cutaneous infections, with a prevalence accounting for 70% of dermatophytoses. Although
terbinafine represents the preferred treatment, its clinical use is hampered by side effects, drugâ
drug interactions, and the emergence of resistant clinical isolates. Combination therapy, associating
terbinafine and essential oils (EOs), represents a promising strategy in the treatment of dermatophytosis.
In this study, we screened the potential of selected Apiaceae EOs (ajowan, coriander, caraway,
and anise) to improve the antifungal activity of terbinafine against T. rubrum ATCC 28188 and T. mentagrophytes
ATCC 9533. The chemical profile of EOs was analyzed by gas chromatography. The
minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) of EOs/main
compounds were determined according to EUCAST-AFST guidelines, with minor modifications. The
checkerboard microtiter method was used to identify putative synergistic combinations of EOs/main
constituents with terbinafine. The influence of EOs on the viability and pro-inflammatory cytokine
production (IL-1b, IL-8 and TNF-a) was determined using an ex vivo human neutrophils model. The
binary associations of tested EOs with terbinafine were found to be synergistic against T. rubrum,
with FICI values of 0.26â0.31. At the tested concentrations (6.25â25 mg/L), EOs did not exert cytotoxic
effects towards human neutrophils. Anise EO was the most potent inhibitor of IL-1b release
(46.49% inhibition at 25 mg/L), while coriander EO displayed the highest inhibition towards IL-8
and TNF-a production (54.15% and 54.91%, respectively). In conclusion, the synergistic combinations
of terbinafine and investigated Apiaceae EOs could be a starting point in the development of novel
topical therapies against T. rubrum-related dermatophytosis
Effect of tetra- and penta-cyclic triterpenes on lipid bilayer fluidity by DSC, FTIR, Raman and fluorescence anisotropy
International audienc
Optimization of liposomes formulations for improving the depigmenting effect of cysteamine
International audienc
Development of cysteamine loaded liposomes in liquid and dried forms for improvement of cysteamine stability
International audienceDespite the high aqueous solubility of cysteamine, its unpleasant organoleptic properties, hygroscopicity, instability in solutions, and poor pharmacokinetic profile are the main drawbacks that limit its use for medical and cosmetic purposes. In this study, cysteamineloaded liposomes were prepared using the ethanol injection method. Liposomes were characterized for their size, homogeneity, surface charge, and morphology. The incorporation ratios of cholesterol and phospholipids, the encapsulation efficiency and the loading ratio of cysteamine in liposomes were determined. Moreover, the stability of free and encapsulated cysteamine was assessed at different temperatures (4, 25, and 37°C) in the presence and absence of light. Cysteamine-loaded liposomes were freeze-dried and reconstituted liposomes were characterized. Finally, the storage stability of the freeze-dried cysteamine-loaded liposomes was studied. Liposomes were nanometric, oligolamellar, and spherical. The encapsulation efficiency and the loading ratio of cysteamine varied between 12 and 40% in the different formulations. The encapsulation improved the stability of cysteamine in the various storage conditions. The dried form of cysteamine-loaded liposomes conserved the size of the vesicles and retained 33% of cysteamine present in the liposomal suspension before lyophilization. The freeze-dried liposomes formulations were stable after four months of storage at 4°C
Effect of Progesterone, Its Hydroxylated and Methylated Derivatives, and Dydrogesterone on Lipid Bilayer Membranes
International audienc
Improvement of skin whitening agents efficiency through encapsulation: Current state of knowledge
International audienc
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