scholarly journals Evaluation of Small Molecule Combinations against Respiratory Syncytial Virus In Vitro

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2607
Author(s):  
Yuzhen Gao ◽  
Jingjing Cao ◽  
Pan Xing ◽  
Ralf Altmeyer ◽  
Youming Zhang

Respiratory syncytial virus (RSV) is a major pathogen that causes severe lower respiratory tract infection in infants, the elderly and the immunocompromised worldwide. At present no approved specific drugs or vaccines are available to treat this pathogen. Recently, several promising candidates targeting RSV entry and multiplication steps are under investigation. However, it is possible to lead to drug resistance under the long-term treatment. Therapeutic combinations constitute an alternative to prevent resistance and reduce antiviral doses. Therefore, we tested in vitro two-drug combinations of fusion inhibitors (GS5806, Ziresovir and BMS433771) and RNA-dependent RNA polymerase complex (RdRp) inhibitors (ALS8176, RSV604, and Cyclopamine). The statistical program MacSynergy II was employed to determine synergism, additivity or antagonism between drugs. From the result, we found that combinations of ALS8176 and Ziresovir or GS5806 exhibit additive effects against RSV in vitro, with interaction volume of 50 µM2% and 31 µM2% at 95% confidence interval, respectively. On the other hand, all combinations between fusion inhibitors showed antagonistic effects against RSV in vitro, with volume of antagonism ranging from −50 µM2 % to −176 µM2 % at 95% confidence interval. Over all, our results suggest the potentially therapeutic combinations in combating RSV in vitro could be considered for further animal and clinical evaluations.

1982 ◽  
Vol 10 (3) ◽  
pp. 179-182
Author(s):  
B Bresky ◽  
K Lincoln

Thirty out-patients with chronic recurrent urinary tract infections, who had failed to respond to 10 days treatment with either pivmecillinam and/or amoxycillin, received a 3-month course of pivmecillinam at a dose of 200 mg, three times daily. Twenty-seven patients had bacteriuria due to Enterobacteriaceae, mainly Escherichia coli, sensitive to mecillinam in vitro. Pivmecillinam eradicated all the initial urinary pathogens. Reinfections occurred during treatment in three patients, who remained asymptomatic. Four subjects complained of gastro-intestinal side-effects, and therapy was withdrawn in three instances. Another three patients described unusual adverse events towards the end of the course of treatment, described as an odd sensation in the body and a desire for salt. The sensation disappeared a few days after the end of treatment. Treatment with pivmecillinam had no adverse effect on haematopoietic, hepatic or renal function.


2004 ◽  
Vol 48 (2) ◽  
pp. 413-422 ◽  
Author(s):  
Christopher Cianci ◽  
Kuo-Long Yu ◽  
Keith Combrink ◽  
Ny Sin ◽  
Bradley Pearce ◽  
...  

ABSTRACT BMS-433771 was found to be a potent inhibitor of respiratory syncytial virus (RSV) replication in vitro. It exhibited excellent potency against multiple laboratory and clinical isolates of both group A and B viruses, with an average 50% effective concentration of 20 nM. Mechanism-of-action studies demonstrated that BMS-433771 inhibits the fusion of lipid membranes during both the early virus entry stage and late-stage syncytium formation. After isolation of resistant viruses, resistance was mapped to a series of single amino acid mutations in the F1 subunit of the fusion protein. Upon oral administration, BMS-433771 was able to reduce viral titers in the lungs of mice infected with RSV. This new class of orally active RSV fusion inhibitors offers potential for clinical development.


2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Elizabeth Cudjoe ◽  
Dickson Donu ◽  
Ruth E. Okonu ◽  
Jones A. Amponsah ◽  
Linda E. Amoah

Background. The asexual and sexual stages (gametocytes) of Plasmodium falciparum parasites are known to respond differently to antimalarial drugs. Herbal products with extended treatment regimens and inadequate dosing information are widely used to treat malaria in Ghana. This study set out to determine the in vitro activity of selected herbal extracts on the development of asexual and sexual stage malaria parasites. Methods. The 72-hour SYBR Green 1-based in vitro drug assay was used to determine the asexual parasite growth inhibitory effects exhibited by aqueous extracts of Alchornea cordifolia, Polyalthia longifolia, Moringa oleifera, and Mangifera indica on the NF54, CamWT_C580Y, and IPC 4912 strains of Plasmodium falciparum. The effects of exposure of asexual and early-stage NF54 gametocytes to varying concentrations of the aqueous herbal extracts were assessed by microscopy after 7 days of continuous culturing in the presence of the herbal extract. Qualitative and quantitative phytochemical screening were also performed on the herbal extracts. Results. In the SYBR Green 1 assay, aqueous extracts of Alchornea cordifolia exhibited moderate (IC50 of 5.8, 17.4, and 15.8 μg/ml) and Mangifera indica exhibited low (IC50 of 65.4, 96.7, and 81.7 μg/ml) activities against the NF54, Cam WT_C580Y, and IPC 4912 parasites, respectively, whilst Polyalthia longifolia and Moringa oleifera were inactive. Long-term treatment of NF54 parasites with 1 mg/ml of Polyalthia longifolia produced the highest densities of gametocytes and the least (56%) inhibition of asexual parasites on Day 7. Long-term treatment of NF54 parasites with 10 μg/ml Alchornea cordifolia resulted in complete parasite (asexual and gametocyte) clearance on Day 7. Conclusions. Alchornea cordifolia exhibited a ‘moderate’ activity against the three parasites tested in the 72-hour SYBR Green 1 assay and also effectively cleared both asexual parasites and gametocytes. Long-term treatment of malaria parasites with herbal extracts mimics a treatment regimen and should be used to determine the antimalarial properties of herbal extracts.


1986 ◽  
Vol 9 (5) ◽  
pp. 301-304 ◽  
Author(s):  
S. Stefoni ◽  
A. Nanni Costa ◽  
G. Liviano D'Arcangelo ◽  
M. Biavati ◽  
S. lannelli ◽  
...  

Biocompatibility of charcoal hemoperfusion was studied in a group of 15 uremic patients, evaluating the effects of long-term treatment on some structural and functional parameters of circulating lymphocytes: in vivo distribution of T-cell subsets; surface T3, T4 and T8 antigen expression, in vivo and in vitro DNA synthesis. A comparative analysis was performed with patients on conventional dialysis using cuprophan membranes.


1998 ◽  
Vol 74 (1) ◽  
pp. 35-40 ◽  
Author(s):  
M.F Melzig ◽  
G Papsdorf ◽  
R Loose ◽  
A Winkler ◽  
M Beyermann ◽  
...  

1986 ◽  
Vol 70 (4) ◽  
pp. 365-369 ◽  
Author(s):  
Michael Öhman ◽  
Stefan L. Marklund

1. Disulfiram has long been used in the treatment of chronic alcoholism. It is in vivo partially reduced to diethyldithiocarbamate, which is an efficient inhibitor of Cu, Zn-containing superoxide dismutase both in vitro and in vivo. The recently described extracellular superoxide dismutase is even more sensitive to diethyldithiocarbamate than Cu, Zn-superoxide dismutase. 2. To test for the possibility that long term treatment with disulfiram leads to inhibition of the superoxide dismutases, plasma extracellular superoxide dismutase and erythrocyte Cu, Zn-superoxide dismutase were determined in 12 disulfiram-treated alcoholics, and compared with 11 non-treated alcoholics and 19 healthy controls. 3. Plasma extracellular superoxide dismutase was moderately reduced (about 20%) in the disulfiram-treated alcoholics as compared with the non-treated alcoholics and the healthy controls. No effect of disulfiram treatment on erythrocyte Cu, Zn-superoxide dismutase activity was demonstrated.


2009 ◽  
Vol 296 (3) ◽  
pp. F605-F613 ◽  
Author(s):  
Francisco J. Mendoza ◽  
Ignacio Lopez ◽  
Rocio Canalejo ◽  
Yolanda Almaden ◽  
David Martin ◽  
...  

To investigate whether the effect of the calcimimetic AMG 641 and calcitriol on CaSR and VDR expression could be separated from their ability to reduce parathyroid cell proliferation, five-sixth nephrectomized (5/6 Nx) rats received vehicle, AMG 641, calcitriol, or AMG 641+calcitriol either daily for 13 days (long-term protocol) or in a single dose (short-term protocol). In the long-term protocol, AMG 641, calcitriol, and their combination significantly reduced the percentage of proliferating parathyroid cells. Proliferation was uncontrolled in the short-term protocol. A significant increase in CaSR mRNA (% vs. β-actin) was detected in rats treated with both calcitriol (1.60 ± 0.30) and AMG 641 (1.66 ± 0.25) for 13 days ( P = 0.01 vs. 5/6 Nx+vehicle, 0.89 ± 0.09); and there was a further increase when both drugs were administered simultaneously (2.46 ± 0.33). In the short-term protocol, only rats receiving AMG 641 alone (2.01 ± 0.33, P < 0.001) showed increased expression of CaSR mRNA, whereas the combination (1.81 ± 0.20) produced no additional benefit. AMG 641 also increased CaSR mRNA expression in vitro. Changes in VDR mRNA paralleled those of CaSR mRNA. In the long-term treatment, both AMG 641 (0.87 ± 0.14) and calcitriol (0.99 ± 0.12) increased VDR mRNA ( P < 0.05 vs. 5/6 Nx+vehicle, 0.49 ± 0.10), and the increase was more accentuated when the drugs were combined (1.49 ± 0.45). In the short-term protocol, only treatment with AMG 641, alone (1.52 ± 0.41) or combined with calcitriol (1.86 ± 0.24), increased VDR mRNA. In conclusion, our results demonstrate an acute increase in CaSR mRNA and VDR mRNA in the parathyroid glands of uremic rats treated with AMG 641, in which cell proliferation was uncontrolled, thus supporting a direct effect of calcimimetics on CaSR and VDR expression by hyperplastic parathyroid cells.


2002 ◽  
Vol 181 (1) ◽  
pp. 29-35 ◽  
Author(s):  
René Klysner ◽  
Jesper Bent-Hansen ◽  
Hanne L. Hansen ◽  
Marianne Lunde ◽  
Elisabeth Pleidrup ◽  
...  

BackgroundThe highly recurrent nature of major depression in the young and the elderly warrants long-term antidepressant treatment.AimsTo compare the prophylactic efficacy of citalopram and placebo in elderly patients; to evaluate long-term tolerability of citalopram.MethodOut-patients, ⩾65 years, with unipolar major depression (DSM – IV: 296.2 x or 296.3 x) and Montgomery – Åsberg Depression Rating Scale score ⩾22 were treated with citalopram 20–40 mg for 8 weeks. Responders continued on their final fixed dose of citalopram for 16 weeks before randomisation to double-blind treatment with citalopram or placebo for at least 48 weeks.ResultsNineteen of the 60 patients using citalopram v. 41 of the 61 patients using placebo had recurrence. Time to recurrence was significantly different between citalopram— and placebo-patients, in favour of citalopram (log-rank test, P < 0.0001). Long-term treatment was well tolerated.ConclusionsLong-term treatment with citalopram is effective in preventing recurrence of depression in the elderly and is well tolerated.


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