Inhibitory Concentration
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Author(s):  
Ana Maria Mesa-Vanegas ◽  
◽  
Esther Julia Naranjo-Gomez ◽  
Felipe Cardona ◽  
Lucia Atehortua-Garces ◽  
...  

Solanum nudum Dunal (Solanaceae) is most commonly known and used by the population of the colombian Pacific coast as an antimalarial treatment. This article study into optimization and quantitative analysis of compounds steroidal over time of development of this species when grown in vitro and wild. A new steroidal compound named SN6 was elucidated by NMR and a new method of quantification of seven steroidal compounds (Diosgenone DONA and six steroids SNs) using HPLC-DAD-MS in extracts of cultures in vitro and wild was investigated. Biology activity of extracts was found to a range of antiplasmodial activity in FCB2 and NF-54 with inhibitory concentration (IC50) between (17.04 -100 μg/mL) and cytotoxicity in U-937 of CC50 (7.18 -104.7 μg/mL). This method creates the basis for the detection of seven sterols antiplasmodial present in extracts from S. nudum plant as a quality parameter in the control and expression of phytochemicals.


Author(s):  
Franciana Aparecida Volpato Bellaver ◽  
◽  
Anildo Cunha Junior ◽  
Thais Carla Dal Bello ◽  
Ana Julia Longo Neis ◽  
...  

Escherichia coli is a pathogen associated with infections in piglets in the post-weaning phase, its pathogenicity is related to the animal's susceptibility to bacterial enterotoxins. The objective of the present study was to determine the EOs activity against E. coli strain, in the form planktonic and sessile. Although the Disc-Diffusion tests to determine the Minimum Inhibitory Concentration, do not fully corroborate with the other analyzes of this study, it was noticed bacteria inhibition. The EOs were prepared at 0.4%, 0.8% and 1.0% for tests. The tested EOs were effective against E. coli planktonic cells (p<0.05). As for the sessile cells, the most significant result was inhibition and 100% sessile cells at the concentration of 1.0% of Cymbopogon citratus EO. Although there was resistance in some treatments, the tested EOs demonstrated inhibition capacity, constituting promising alternatives for the control of E. coli, especially of planktonic cells.


2022 ◽  
Vol 4 (1) ◽  
Author(s):  
Paul Prasse ◽  
Pascal Iversen ◽  
Matthias Lienhard ◽  
Kristina Thedinga ◽  
Chris Bauer ◽  
...  

ABSTRACT Computational drug sensitivity models have the potential to improve therapeutic outcomes by identifying targeted drug components that are likely to achieve the highest efficacy for a cancer cell line at hand at a therapeutic dose. State of the art drug sensitivity models use regression techniques to predict the inhibitory concentration of a drug for a tumor cell line. This regression objective is not directly aligned with either of these principal goals of drug sensitivity models: We argue that drug sensitivity modeling should be seen as a ranking problem with an optimization criterion that quantifies a drug’s inhibitory capacity for the cancer cell line at hand relative to its toxicity for healthy cells. We derive an extension to the well-established drug sensitivity regression model PaccMann that employs a ranking loss and focuses on the ratio of inhibitory concentration and therapeutic dosage range. We find that the ranking extension significantly enhances the model’s capability to identify the most effective anticancer drugs for unseen tumor cell profiles based in on in-vitro data.


Biomolecules ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 131
Author(s):  
Thibaut Barbier ◽  
Alexia Barbry ◽  
Jérémy Magand ◽  
Cédric Badiou ◽  
Floriane Davy ◽  
...  

The benzo[b]thiophene nucleus and the acylhydrazone functional group were combined to prepare three new series of compounds for screening against Staphylococcus aureus. The reaction of substituted benzo[b]thiophene-2-carboxylic hydrazide and various aromatic or heteroaromatic aldehydes led to a collection of 26 final products with extensive structural diversification on the aromatic ring and on position 6 of the benzo[b]thiophene nucleus. The screening lead to the identification of eight hits, including (E)-6-chloro-N’-(pyridin-2-ylmethylene)benzo[b]thiophene-2-carbohydrazide (II.b), a non-cytotoxic derivative showing a minimal inhibitory concentration of 4 µg/mL on three S. aureus strains, among which were a reference classical strain and two clinically isolated strains resistant to methicillin and daptomycin, respectively.


Molecules ◽  
2022 ◽  
Vol 27 (2) ◽  
pp. 483
Author(s):  
Sofia Zazouli ◽  
Mohammed Chigr ◽  
Patrícia A. B. Ramos ◽  
Daniela Rosa ◽  
Maria M. Castro ◽  
...  

Zizyphus lotus L. is a perennial shrub particularly used in Algerian folk medicine, but little is known concerning the lipophilic compounds in the most frequently used parts, namely, root bark, pulp, leaves and seeds, which are associated with health benefits. In this vein, the lipophilic fractions of these morphological parts of Z. lotus from Morocco were studied by gas chromatography–mass spectrometry (GC–MS), and their antiproliferative and antimicrobial activities were evaluated. GC–MS analysis allowed the identification and quantification of 99 lipophilic compounds, including fatty acids, long-chain aliphatic alcohols, pentacyclic triterpenic compounds, sterols, monoglycerides, aromatic compounds and other minor components. Lipophilic extracts of pulp, leaves and seeds were revealed to be mainly composed of fatty acids, representing 54.3–88.6% of the total compounds detected. The leaves and seeds were particularly rich in unsaturated fatty acids, namely, (9Z,12Z)-octadeca-9,12-dienoic acid (2431 mg kg−1 of dry weight) and (9Z)-octadec-9-enoic acid (6255 mg kg−1 of dry weight). In contrast, root bark contained a high content of pentacyclic triterpenic compounds, particularly betulinic acid, accounting for 9838 mg kg−1 of dry weight. Root bark extract showed promising antiproliferative activity against a triple-negative breast cancer cell line, MDA-MB-231, with a half-maximal inhibitory concentration (IC50) = 4.23 ± 0.18 µg mL−1 of extract. Leaf extract displayed interesting antimicrobial activity against Escherichia coli, methicillin-sensitive Staphylococcus aureus and Staphylococcus epidermis, presenting minimum inhibitory concentration (MIC) values from 1024 to 2048 µg mL−1 of extract. Our results demonstrate that Zizyphus lotus L. is a source of promising bioactive components, which can be exploited as natural ingredients in pharmaceutical formulations.


2022 ◽  
Author(s):  
Deyun Qiu ◽  
Jinxin V. Pei ◽  
James E. O. Rosling ◽  
Dongdi Li ◽  
Yi Xue ◽  
...  

Small-molecule inhibitors of PfATP4, a Plasmodium falciparum protein that is believed to pump Na+ out of the parasite while importing H+, are on track to become much-needed new antimalarial drugs. The spiroindolone cipargamin is poised to become the first PfATP4 inhibitor to reach the field, having performed strongly in Phase 1 and 2 clinical trials. Previous attempts to generate cipargamin-resistant parasites in the laboratory have yielded parasites with reduced susceptibility to the drug; however, the highest 50% inhibitory concentration reported to date is 24 nM. Here, we show that P. falciparum parasites can acquire a clinically-significant level of resistance to cipargamin that enables them to withstand micromolar concentrations of the drug. Independent experiments to generate high-level cipargamin resistance using different protocols and strains led to the same change each time - a G358S mutation in PfATP4. Parasites with this mutation showed high-level resistance not only to cipargamin, but also to the dihydroisoquinolone (+)-SJ733. However, for certain other (less clinically advanced) PfATP4-associated compounds the G358S mutation in PfATP4 conferred only moderate resistance or no resistance. The G358S mutation in PfATP4 did not affect parasite susceptibility to antimalarials that do not target PfATP4. The G358S mutation in PfATP4, and the equivalent mutation in the Toxoplasma gondii ATP4 homologue (G419S), decreased the sensitivity of the Na+-ATPase activity of ATP4 to inhibition by cipargamin and (+)-SJ733, and decreased the sensitivity of parasites expressing these ATP4 mutations to disruption of parasite Na+ regulation by cipargamin- and (+)-SJ733. The G358S mutation in PfATP4 reduced the affinity of the protein for Na+ and was associated with an increase in the parasite's resting cytosolic Na+ concentration; however, no significant defect in parasite growth rate was observed. Our findings suggest that codon 358 in pfatp4 should be monitored closely in the field as a molecular marker for cipargamin resistance, and that PfATP4 inhibitors in clinical development should be tested for their activity against PfATP4G358S parasites.


2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Fang Yang ◽  
Yi Sun ◽  
Qiaoyun Lu

Abstract Background This study was aimed to determine the potency of Minocycline (MIN) and azoles, including itraconazole (ITR), voriconazole (VOR) and posaconazole (POS) against Scedosporium and Lomentospora species. Results This study revealed that MIN exhibited no significant antifungal activity against any of the tested strains, whereas in vitro combination of MIN with ITR, VOR or POS showed satisfactory synergistic effects against 8 (80%), 1 (10%), and 9 (90%) strains, respectively. Moreover, combined use of MIN with azoles decreased the minimum inhibitory concentration (MIC) range from 5.33–16 μg/ml to 1–16 μg/ml for ITR, from 0.42–16 μg/ml to 0.21–16 μg/ml for VOR, and from 1.33–16 μg/ml to 0.33–16 μg/ml for POS. Meanwhile, no antagonistic interactions were observed between the above combinations. The G. mellonella infection model demonstrated the in vivo synergistic antifungal effect of MIN and azoles. Conclusions The present study demonstrated that combinations between MIN and azoles lead to synergistic antimicrobial effects on Scedosporium and Lomentospora species, while showing a potential for overcoming and preventing azole resistance.


2022 ◽  
Vol 9 ◽  
Author(s):  
Jun Tang ◽  
Xueshuang Huang ◽  
Ming-Hang Cao ◽  
Zhiyan Wang ◽  
Zhiyin Yu ◽  
...  

During a screening for antifungal secondary metabolites, six new mono-/bis-alkenoic acid derivatives (2–7) and one known alkenoic acid derivative (1) were isolated from an endophytic fungi Scopulariopsis candelabrum. Their chemical structures were identified by 1H-NMR, 13C-NMR, 2D NMR, and high-resolution mass spectrometry, as well as comparisons with previously reported literatures. Among them, fusariumesters C‒F (2–5) are bis-alkenoic acid derivatives dimerized by an ester bond, while acetylfusaridioic acid A (6) and fusaridioic acid D (7) are alkenoic acid monomers. All the isolates were submitted to an antifungal assay against Candida albicans and the corn pathogen Exserohilum turcicum using the filter paper agar diffusion method. As a result, only compound 1 decorating with β-lactone ring turned out to be active against these two tested fungi. The broth microdilution assay against Candida albicans showed the minimum inhibitory concentration (MIC) value of 1 to be 20 μg/ml, while the minimum inhibitory concentration value of the positive control (naystatin) was 10 μg/ml. And the half maximal inhibitory concentration (IC50) value (21.23 μg/ml) of 1 against Exserohilum turcicum was determined by analyzing its inhibition effect on the mycelial growth, using cycloheximide (IC50 = 46.70 μg/ml) as the positive control.


2022 ◽  
Vol 12 ◽  
Author(s):  
Abimbola O. Aro ◽  
Ibukun M. Famuyide ◽  
Ademola A. Oyagbemi ◽  
Prudence N. Kabongo-Kayoka ◽  
Lyndy J. McGaw

Tuberculosis (TB) is a disease of global importance that affects millions of people. Approximately a quarter of the world’s population is currently infected with M. tuberculosis, and about 10% of those infected will develop into active disease, particularly immune compromised individuals. Helminthiasis is of global health importance, affecting over 2 billion people mostly in resource-poor countries. Co-infection with tuberculosis (TB) and helminths (worms) is an emerging global public health concern with both affecting about one-third of the global population. Chronic infection with helminths can result in impaired immune responses to TB as well as enhancing failure to TB therapy and BCG vaccination. Antimycobacterial and anthelmintic activities of the acetone extract and fractions of Psychotria capensis were evaluated, including their in vitro safety. In addition, the anti-inflammatory and immunomodulatory effect of the fractions and crude extract of P. capensis were assessed. Antimycobacterial activity of the extract and fractions was tested against four non-tuberculous mycobacteria (Mycobacterium smegmatis, M. fortuitum, M. aurum, M. bovis BCG) and pathogenic M. tuberculosis H37Rv while the Egg Hatch Assay (EHA) was used for the anthelmintic test on eggs of Haemonchus contortus. Cytotoxicity was determined against Vero kidney cells while in vitro immune modulation via cytokine production was determined on activated macrophages. The minimum inhibitory concentration (MIC) values of the Psychotria capensis acetone extract and fractions ranged from 39 to 1,250 μg/ml with the crude extract and hexane fraction having the best MIC values (both 39 μg/ml). In the EHA, the inhibitory concentration (IC50) ranged from 160 to 630 μg/ml with the hexane fraction having the best activity. The hexane and chloroform fractions were relatively non-toxic with LC50 values of 290 and 248 μg/ml respectively, while the acetone crude extract (64 μg/ml) and n-butanol fraction (71 μg/ml) were moderately toxic. The SI values (LC50/MIC) ranged from 0.1 to 7.4 with the hexane fraction having the highest value against M. smegmatis (7.4). The hexane fraction had the best dual anthelmintic and antimycobacterial activity. This fraction had the best NO inhibitory activity and was the least cytotoxic, indicating that its activity was not due to general metabolic toxicity, with 96.54% cell viability. Pro-inflammatory cytokines such as IL-12p70 were upregulated while IL-10 expression was inhibited by the extracts. Compounds were detected using GC-MS analysis, and in both the crude acetone extract and the hexane fraction was the diterpene neophytadiene, which has anti-inflammatory and antimicrobial activity. Finding alternative or complementary approaches to dealing with TB infections by, amongst other things, reducing the incidence of helminth infestations may lessen the burden of TB, contributing to slowing the spread of multi-drug resistance.


Antibiotics ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 77
Author(s):  
Friederike Hahne ◽  
Simon Jensch ◽  
Gerd Hamscher ◽  
Jessica Meißner ◽  
Manfred Kietzmann ◽  
...  

Prudent use of antibiotics in livestock is widely considered to be important to prevent antibiotic resistance. This study aimed to evaluate the interactions between biofilms and veterinary antibiotics in therapeutic concentrations administrated via drinking water through a standardized experimental setup. In this context, two biofilms formed by pseudomonads (Pseudomonas (P.) aeruginosa or P. fluorescens) and a susceptible Escherichia (E.) coli strain were developed in a nutrient-poor medium on the inner surface of polyvinyl chloride pipe pieces. Subsequently, developing biofilms were exposed to sulfadiazine/trimethoprim (SDZ/TMP) or tylosin A (TYL A) in dosages recommended for application in drinking water for 5 or 7 days, respectively. Various interactions were detected between biofilms and antibiotics. Microbiological examinations revealed that only TYL A reduced the number of bacteria on the surface of the pipes. Additionally, susceptible E. coli survived both antibiotic treatments without observable changes in the minimum inhibitory concentration to 13 relevant antibiotics. Furthermore, as demonstrated by HPLC-UV, the dynamics of SDZ/TMP and TYL A in liquid media differed between the biofilms of both pseudomonads over the exposure period. We conclude that this approach represents an innovative step toward the effective evaluation of safe veterinary antibiotic use.


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