scholarly journals Novel antifungal activity of Q-Griffithsin, a broad-spectrum antiviral lectin

2021 ◽  
Vol 3 (12) ◽  
Author(s):  
Henry Nabeta ◽  
Joseph C Kouokam ◽  
Amanda Lasnik ◽  
Joshua Fuqua ◽  
Kenneth E Palmer

Background There is a rising global trend in candida strains with high resistance to fluconazole and other antifungal drugs, hence the need for novel agents. Here, we investigated the anti-Candida activity of Q-Griffithsin (Q-GRFT), a lectin naturally produced by the red-sea algae, Griffithsia spp. Methods To assess in vitro growth inhibitory activity, C. albicans was incubated with Q-GRFT on agar plates and in broth media. We investigated GFP-bound Q-GRFT’s ability to adhere to C. albicans using fluorescence microscopy and fluorescence intensity assessments. To demonstrate in vivogrowth inhibitory activity, CBA/J mice were treated per vaginam with Q-GRFT followed by challenge with C. albicans, and fungal burden determined following vaginal lavage. Results Wild type fluorescently labeled Q-GRFT displayed higher fluorescence than the lectin-binding site deficient variant following incubation with C. albicans. Q-GRFT localized around the fungal cells and bound to α-mannan in the cell wall. Q-GRFT significantly inhibited C. albicans growth in broth and on agar plates, disrupted the integrity of the cell wall, and induced ROS formation. The lectin significantly inhibited the growth of C. glabrata, C. parapsilosis and C. krusei, with modest activity against C. auris CDC388 and C. auris CDC389 strains in vitro. Topical treatment resulted in a lower fungal burden compared to the vehicle control group in vaginal candidiasis. Conclusion Q-GRFT binds to and inhibits C. albicans growth both in vitro and in vivo. Further studies are needed to establish the mechanism of growth inhibition.

Pharmaceutics ◽  
2018 ◽  
Vol 10 (4) ◽  
pp. 227 ◽  
Author(s):  
Bayan Darwesh ◽  
Hibah Aldawsari ◽  
Shaimaa Badr-Eldin

(1) Background: Fluconazole, used orally for vaginal candidiasis, has reported gastrointestinal side effects. Therefore, researchers directed towards the drug vaginal delivery. However, vaginal delivery is limited by poor retention and leakage. Thus, this work aimed at exploring chitosan/anion polyelectrolyte complex (PEC) for the formulation of fluconazole vaginal inserts with controlled release and appreciable mucoadhesion. (2) Methods: PECs were prepared and assessed for interactions. Fluconazole PEC based vaginal inserts were prepared by lyophilization using mannitol. 3151 factorial design was applied to investigate the effect of the anion type and Chitosan/anion ratio on the inserts mucoadhesion and release properties. The optimized insert [based on 5:5 chitosan: anionic polymer (sodium alginate)] release was modulated by the release retardant; Compritol® 888. The selected formulation was subjected to microbiological and histological evaluation. (3) Results: Fluconazole inserts showed satisfactory drug content, acceptable friability percentages and highest swelling indices at six hours. Statistical analysis showed significant effect of the studied factors on detachment force and release properties. Microbiological assays revealed significantly higher antifungal activity of inserts compared to fluconazole solution. Reduced inflammatory cells were confirmed by histological evaluation. (4) Conclusion: CH/Alg based vaginal insert could be a promising platform for vaginal delivery of antifungal drugs used for vaginal candidiasis treatment.


2019 ◽  
Vol 64 (2) ◽  
Author(s):  
Ren-Yi Lu ◽  
Ting-Jun-Hong Ni ◽  
Jing Wu ◽  
Lan Yan ◽  
Quan-Zhen Lv ◽  
...  

ABSTRACT In the past decades, the incidence of cryptococcosis has increased dramatically, which poses a new threat to human health. However, only a few drugs are available for the treatment of cryptococcosis. Here, we described a leading compound, NT-a9, an analogue of isavuconazole, that showed strong antifungal activities in vitro and in vivo. NT-a9 showed a wide range of activities against several pathogenic fungi in vitro, including Cryptococcus neoformans, Cryptococcus gattii, Candida albicans, Candida krusei, Candida tropicalis, Candida glabrata, and Candida parapsilosis, with MICs ranging from 0.002 to 1 μg/ml. In particular, NT-a9 exhibited excellent efficacy against C. neoformans, with a MIC as low as 0.002 μg/ml. NT-a9 treatment resulted in changes in the sterol contents in C. neoformans, similarly to fluconazole. In addition, NT-a9 possessed relatively low cytotoxicity and a high selectivity index. The in vivo efficacy of NT-a9 was assessed using a murine disseminated-cryptococcosis model. Mice were infected intravenously with 1.8 × 106 CFU of C. neoformans strain H99. In the survival study, NT-a9 significantly prolonged the survival times of mice compared with the survival times of the control group or the isavuconazole-, fluconazole-, or amphotericin B-treated groups. Of note, 4 and 8 mg/kg of body weight of NT-a9 rescued all the mice, with a survival rate of 100%. In the fungal-burden study, NT-a9 also significantly reduced the fungal burdens in brains and lungs, while fluconazole and amphotericin B only reduced the fungal burden in lungs. Taken together, these data suggested that NT-a9 is a promising antifungal candidate for the treatment of cryptococcosis infection.


2009 ◽  
Vol 53 (9) ◽  
pp. 3963-3971 ◽  
Author(s):  
Akihiro Kitamura ◽  
Saito Higuchi ◽  
Masato Hata ◽  
Katsuhiro Kawakami ◽  
Kumi Yoshida ◽  
...  

ABSTRACT β-1,6-Glucan is a fungus-specific cell wall component that is essential for the retention of many cell wall proteins. We recently reported the discovery of a small molecule inhibitor of β-1,6-glucan biosynthesis in yeasts. In the course of our study of its derivatives, we found a unique feature in their antifungal profile. D21-6076, one of these compounds, exhibited potent in vitro and in vivo antifungal activities against Candida glabrata. Interestingly, although it only weakly reduced the growth of Candida albicans in conventional media, it significantly prolonged the survival of mice infected by the pathogen. Biochemical evaluation of D21-6076 indicated that it inhibited β-1,6-glucan synthesis of C. albicans, leading the cell wall proteins, which play a critical role in its virulence, to be released from the cell. Correspondingly, adhesion of C. albicans cells to mammalian cells and their hyphal elongation were strongly reduced by the drug treatment. The results of the experiment using an in vitro model of vaginal candidiasis showed that D21-6076 strongly inhibited the invasion process of C. albicans without a significant reduction in its growth in the medium. These evidences suggested that D21-6076 probably exhibited in vivo efficacy against C. albicans by inhibiting its invasion process.


2020 ◽  
Vol 6 (3) ◽  
pp. 183
Author(s):  
Julián E. Muñoz ◽  
Diego C. P. Rossi ◽  
Daniela L. Jabes ◽  
David Aciole Barbosa ◽  
Fernanda F. M. Cunha ◽  
...  

Commensal yeast from the genus Candida is part of the healthy human microbiota. In some cases, Candida spp. dysbiosis can result in candidiasis, the symptoms of which may vary from mild localized rashes to severe disseminated infections. The most prevalent treatments against candidiasis involve fluconazole, itraconazole, miconazole, and caspofungin. Moreover, amphotericin B associated with prolonged azole administration is utilized to control severe cases. Currently, numerous guidelines recommend echinocandins to treat invasive candidiasis. However, resistance to these antifungal drugs has increased dramatically over recent years. Considering this situation, new therapeutic alternatives should be studied to control candidiasis, which has become a major medical concern. Limonene belongs to the group of terpene molecules, known for their pharmacological properties. In this study, we evaluated in vitro the limonene concentration capable of inhibiting the growth of yeast from the genus Candida susceptible or resistant to antifungal drugs and its capacity to induce fungal damage. In addition, intravaginal fungal infection assays using a murine model infected by Candida albicans were carried out and the fungal burden, histopathology, and scanning electron microscopy were evaluated. All of our results suggest that limonene may play a protective role against the infection process by yeast from the genus Candida.


1990 ◽  
Vol 10 (5) ◽  
pp. 1882-1890
Author(s):  
P S Linsley ◽  
J Kallestad ◽  
V Ochs ◽  
M Neubauer

Oncostatin M is a polypeptide cytokine, produced by normal and malignant hematopoietic cells, that has several in vitro activities, including the ability to inhibit growth of cultured carcinoma cells. Here we present a structural and functional comparison of two oncostatin M-related proteins (Mr 36,000 and 32,000) secreted by COS cells transfected with oncostatin M cDNA. The smaller of these forms lacked a hydrophilic C-terminal domain comprising predominantly basic amino acids. This domain was also absent from native oncostatin M produced by U937 cells. The 32,000-Mr form of oncostatin M was not produced by cells transfected with plasmids (G195 and G196) in which a potential trypsinlike cleavage site within the hydrophilic C-terminal domain was altered by site-directed mutagenesis. A 32,000-Mr fragment was produced by trypsin treatment of the 36,000-Mr form of oncostatin M. These observations suggest that the 32,000-Mr form of oncostatin M was derived from the 227-amino-acid propeptide by proteolytic cleavage at or near the paired basic residues at positions 195 and 196. Pro-oncostatin M was equally active in radioreceptor assays as the processed form but was 5- to 60-fold less active in growth inhibition assays. Likewise, nonprocessed mutant protein encoded by plasmid G196 was equally active in the radioreceptor assays as the processed form but was five- to ninefold less active in growth inhibition assays. Thus, the highly charged C-terminal domain of pro-oncostatin M is not required for receptor binding or growth-inhibitory activity but may alter the functional properties of the molecule. Propeptide processing of oncostatin M may be important for regulating in vivo activities of this cytokine.


2001 ◽  
Vol 45 (1) ◽  
pp. 217-222 ◽  
Author(s):  
Luiz E. Bermudez ◽  
Clark B. Inderlied ◽  
Peter Kolonoski ◽  
Mary Petrofsky ◽  
Priscilla Aralar ◽  
...  

ABSTRACT Moxifloxacin activity against Mycobacterium aviumcomplex (MAC) was evaluated in vitro against 25 strains. The MIC was determined to range from 0.125 to 2.0 μg/ml. In addition, U937 macrophage monolayers infected with MAC strain 101 (serovar 1) were treated with moxifloxacin (0.25 to 8 μg/ml) daily, and the number of intracellular bacteria was quantitated after 4 days. Moxifloxacin showed inhibitory activity at 0.5 μg/ml and higher. To assess the activity of moxifloxacin containing regimens in vivo, we infected C57BLbg +/bg + mice with 3 × 107 MAC strain 101 bacteria intravenously. One week later treatment was begun with the following: (i) moxifloxacin (50 mg/kg/day or 100 mg/kg/day), ethambutol (100 mg/kg/day), or a combination of moxifloxacin and ethambutol; or (ii) moxifloxacin (100 mg/kg/day), azithromycin (200 mg/kg/day), or rifabutin (40 mg/kg/day) as oral monotherapy; or (iii) all permutations of two-drug therapy or all three drugs in combination. All groups contained at least 14 animals, and the control group received the drug vehicle. After 4 weeks, quantitative blood cultures were obtained and the number of bacteria in liver and spleen was quantitated. Moxifloxacin, ethambutol, and azithromycin were active as single agents in liver, spleen, and blood. Rifabutin showed inhibitory activity only in the blood. Two-drug combinations containing azithromycin were no more active than azithromycin alone. Similarly, the three-drug combination was not more active than azithromycin alone in the spleen. Rifabutin did not add to the activity of any other single agent or two-drug combination. Moxifloxacin at both concentrations in combination with ethambutol was significantly more active than each drug alone.


Author(s):  
Ramesh C ◽  
Prameela Rani A

Objective: The objective the present work was to investigate in vivo and in vitro anti-diabetic potentials of methanol extract of Tephrosia calophylla against alloxan-induced diabetes in albino rats.Methods: For in vivo evaluation, diabetes was induced in albino rats by administering a single dose of alloxan. The study was designed to test the acute effect of methanol extract of Tephrosia calophylla (TCME) to reduce blood glucose in OGTT. The chronic study of 21 d was performed against diabetic rats and blood glucose was determined at 1st, 7th, 14th and 21st day. In chronic in vivo study, serum concentrations of insulin, urea, creatinine, total cholesterol, triglycerides, ALT and AST were also estimated at 21st day. The in vitro α-glucisidase inhibitory activity and α-amylase inhibitory activity were performed and IC50 values of the extract was determined. The glucose uptake by rat hemidiaphragm model was also used test potentials of the extract to increase utilization of the glucose by tissues.Results: In OGTT, standard glibenclamide and TCME at 400 mg/kg treated animals have shown significant reduction in blood glucose at 90 min but at 120 min, blood glucose level (BGL) was significantly reduced in glibenclamide and TCME at 200 mg/kg and 400 mg/kg treated animals compared to diabetic control group. In chronic modelthe methanol extract effectively reduced blood glucose levels (P<0.001) at 14 th and 21st day of study in therapeutic groups and effect was comparable to that of standard. The extract could also significantly (P<0.001) reduce concentrations of SGOT, triglycerides (TGs), Total cholesterol (TC) and urea in serum and significantly (P<0.001) increased the insulin level in blood which proves beneficial effects of the extract in diabetes. The change in concentrations of SGPT and urea were less significant (P>0.01). In vitro studies, against both glucosidae and  amyalase inhibitory activities, extract has shown significant IC50 values and it also enhanced glucose utilization by rat hemidaphragm.Conclusion: The results obtained from the present study suggest that, the methanol extract of Tephrosia calophylla possess significant in vivo anti-diabetic properties against alloxan induced diabetes in rats. The results also suggests that, TCME also possess the significant in vitro anti-dabetic potentials.


1990 ◽  
Vol 10 (5) ◽  
pp. 1882-1890 ◽  
Author(s):  
P S Linsley ◽  
J Kallestad ◽  
V Ochs ◽  
M Neubauer

Oncostatin M is a polypeptide cytokine, produced by normal and malignant hematopoietic cells, that has several in vitro activities, including the ability to inhibit growth of cultured carcinoma cells. Here we present a structural and functional comparison of two oncostatin M-related proteins (Mr 36,000 and 32,000) secreted by COS cells transfected with oncostatin M cDNA. The smaller of these forms lacked a hydrophilic C-terminal domain comprising predominantly basic amino acids. This domain was also absent from native oncostatin M produced by U937 cells. The 32,000-Mr form of oncostatin M was not produced by cells transfected with plasmids (G195 and G196) in which a potential trypsinlike cleavage site within the hydrophilic C-terminal domain was altered by site-directed mutagenesis. A 32,000-Mr fragment was produced by trypsin treatment of the 36,000-Mr form of oncostatin M. These observations suggest that the 32,000-Mr form of oncostatin M was derived from the 227-amino-acid propeptide by proteolytic cleavage at or near the paired basic residues at positions 195 and 196. Pro-oncostatin M was equally active in radioreceptor assays as the processed form but was 5- to 60-fold less active in growth inhibition assays. Likewise, nonprocessed mutant protein encoded by plasmid G196 was equally active in the radioreceptor assays as the processed form but was five- to ninefold less active in growth inhibition assays. Thus, the highly charged C-terminal domain of pro-oncostatin M is not required for receptor binding or growth-inhibitory activity but may alter the functional properties of the molecule. Propeptide processing of oncostatin M may be important for regulating in vivo activities of this cytokine.


Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.


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