scholarly journals Inhibitory Activity of β-lactamases by Hydro-Ethanolic Extracts of Harungana madagascariensis, a Plant of the Ivorian Pharmacopoeia

2020 ◽  
pp. 157-162
Author(s):  
Toty Abalé Anatole ◽  
Aka Ayébé Edwige ◽  
Guédé Kipré Bertin ◽  
Konan K. Fernique ◽  
Adrien Jehaes ◽  
...  
Keyword(s):  
Inhibitory Activity ◽  
Inhibitory Effect ◽  
Health Concern ◽  
Resistant Bacteria ◽  
Water Mixture ◽  
Phytochemical Screening ◽  
Public Health Concern ◽  
Ethanolic Extracts ◽  
New Antibiotics ◽  
Inhibitory Potential

Infection due to multi-resistant bacteria is a public health concern. Unfortunately, the prospect of developing new antibiotics seem not to be on the horizon. Faced with this impasse, medicinal plants could be an alternative for the development of new molecules. The aim of this study was to determine the inhibitory effect of H. madagascariensis extracts on β-lactamases. Extraction of bioactive compounds from trunk barks and leaves of the plant was done in an ethanol-water mixture (70:30). Anti-β-lactamase activity was evaluated by spectrophotometry after the removal of tannins and a phytochemical screening was used to identify the groups of compounds. Concentrations inhibiting 50% of enzyme activity were 0.005±0.001 mg/mL (CTX-M-15), 0.01±0.001 mg/mL (P99) and 0.027±0.009 mg/mL (NDM-1) for bark extracts and 0.704 mg/mL for leaves extracts. Phytochemical screening revealed the presence of flavonoids in bark extracts. The ethanolic extracts of the trunk bark exert a good inhibitory activity on CTX-M-15, P99 and NDM-1 β-lactamases and this activity could be attributed to the presence of the flavonoids. Further studies by bio-guided fractionation of the ethanolic extracts of the bark could yield fractions with high inhibitory potential of β-lactamases.

scholarly journals Acetylcholinesterase Inhibitory Activity of Alkaloids Isolated from Stephania venosa

2016 ◽  
Vol 11 (12) ◽  
pp. 1934578X1601101 ◽  
Author(s):  
Sumet Kongkiatpaiboon ◽  
Nongnaphat Duangdee ◽  
Saisuree Prateeptongkum ◽  
Wanna Chaijaroenkul
Keyword(s):  
Inhibitory Activity ◽  
Ache Activity ◽  
Hplc Analysis ◽  
Inhibitory Effect ◽  
Inhibition Assay ◽  
Phytochemical Screening ◽  
Ache Inhibition ◽  
Ache Inhibitory Activity ◽  
Inhibitory Potential ◽  
Protoberberine Alkaloid

Stephania venosa (Blume) Spreng or “Sa-Bu-Leud” is a Thai medicinal plant used for treatment of cancer and diabetes, and as a blood-tonic and aphrodisiac. This plant contains alkaloids as its major components and has been of interest for its acetylcholinesterase (AChE) inhibitory activity. Phytochemical screening of S. venosa was made using HPLC analysis and showed the chemical variation between the same species from different provenances. Fractionation of S. venosa extract yielded three alkaloids, namely, dicentrine, crebanine, and tetrahydropalmatine. AChE inhibitory potential of the isolated alkaloids was evaluated using Ellman's AChE inhibition assay. Dicentrine, crebanine, and tetrahydropalmatine inhibited AChE activity with IC50 values of 93.5, 86.6, and 168.6 μg/mL, respectively. The AChE inhibitory activity of the tertiary protoberberine alkaloid, tetrahydropalmatine, was lower than that of the aporphine alkaloids, dicentrine and crebanine, whereas the quaternary protoberberine alkaloid, berberine, showed a higher AChE inhibitory effect than the others.

scholarly journals The Synergistic Effect of Biosynthesized Silver Nanoparticles and Phage ZCSE2 as a Novel Approach to Combat Multidrug-Resistant Salmonella enterica

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 678
Author(s):  
Abdallah S. Abdelsattar ◽  
Rana Nofal ◽  
Salsabil Makky ◽  
Anan Safwat ◽  
Amera Taha ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Color Change ◽  
Antibacterial Properties ◽  
Multidrug Resistant ◽  
Inhibitory Effect ◽  
Health Concern ◽  
Resistant Bacteria ◽  
Mortality And Morbidity ◽  
Novel Approach ◽  
Transmission Electron

The emergence and evolution of antibiotic-resistant bacteria is considered a public health concern. Salmonella is one of the most common pathogens that cause high mortality and morbidity rates in humans, animals, and poultry annually. In this work, we developed a combination of silver nanoparticles (AgNPs) with bacteriophage (phage) as an antimicrobial agent to control microbial growth. The synthesized AgNPs with propolis were characterized by testing their color change from transparent to deep brown by transmission electron microscopy (TEM) and Fourier-Transform Infrared Spectroscopy (FTIR). The phage ZCSE2 was found to be stable when combined with AgNPs. Both minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were evaluated for AgNPs, phage, and their combination. The results indicated that MIC and MBC values were equal to 23 µg/mL against Salmonella bacteria at a concentration of 107 CFU/mL. The combination of 0.4× MIC from AgNPs and phage with Multiplicity of Infection (MOI) 0.1 showed an inhibitory effect. This combination of AgNPs and phage offers a prospect of nanoparticles with significantly enhanced antibacterial properties and therapeutic performance.

scholarly journals Modes of Inhibition ofα-Amylase andα-Glucosidase by Aqueous Extract ofMorinda lucidaBenth Leaf

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
M. I. Kazeem ◽  
J. O. Adamson ◽  
I. A. Ogunwande
Keyword(s):  
Diabetes Mellitus ◽  
Aqueous Extract ◽  
Inhibitory Activity ◽  
Inhibitory Effect ◽  
Leaf Extracts ◽  
Glucosidase Inhibitors ◽  
Ethanolic Extracts ◽  
Insulin Secretagogues ◽  
Percentage Yield ◽  
Oral Hypoglycemic Drugs

Diabetes mellitus is a metabolic disorder of glucose metabolism. The management of blood glucose level is the hallmark in the treatment of this disease. This may be achieved through the use of oral hypoglycemic drugs such as biguanides, insulin secretagogues, andα-glucosidase inhibitors. The purpose of the present study was to investigate the inhibitory effect ofMorinda lucidaleaf extracts on the activities ofα-amylase andα-glucosidase. This was performed usingα-amylase fromAspergillus oryzaeandα-glucosidase fromSaccharomyces cerevisiae.Aqueous extract ofMorinda lucidagave the highest percentage yield (9.99%) of the plant out of the three extracts (compared to acetone and ethanolic extracts) and possesses the highest inhibitory activity againstα-amylase (IC50value of 2.30 mg/mL) andα-glucosidase (IC50value of 2.00 mg/mL). Kinetic analysis revealed that the aqueous extract of this plant leaf inhibited theα-amylase competitively but displayed mixed noncompetitive mode of inhibition towardsα-glucosidase. It can be concluded that aqueous extract ofMorinda lucidaexhibited the best inhibitory activity on the two enzymes studied and the presence of phytochemicals like flavonoids, saponins, and tannins may have contributed greatly to the inhibitory activity of the plant extract.

scholarly journals 1,4,7-Triazacyclononane Restores the Activity of β-Lactam Antibiotics against Metallo-β-Lactamase-Producing Enterobacteriaceae: Exploration of Potential Metallo-β-Lactamase Inhibitors

2018 ◽  
Vol 85 (3) ◽  
Author(s):  
Anou M. Somboro ◽  
Daniel G. Amoako ◽  
John Osei Sekyere ◽  
Hezekiel M. Kumalo ◽  
René Khan ◽  
...  
Keyword(s):  
Inhibitory Activity ◽  
Bacterial Infections ◽  
World Health ◽  
Health Concern ◽  
Computational Studies ◽  
Synergistic Activity ◽  
Carbapenem Resistant ◽  
Catalytic Active Site ◽  
Significant Public Health ◽  
New Antibiotics

ABSTRACT Metallo-β-lactamase (MBL)-producing Enterobacteriaceae are of grave clinical concern, particularly as there are no metallo-β-lactamase inhibitors approved for clinical use. The discovery and development of MBL inhibitors to restore the efficacy of available β-lactams are thus imperative. We investigated a zinc-chelating moiety, 1,4,7-triazacyclononane (TACN), for its inhibitory activity against clinical carbapenem-resistant Enterobacteriaceae. MICs, minimum bactericidal concentrations (MBCs), the serum effect, fractional inhibitory concentration indexes, and time-kill kinetics were determined using broth microdilution techniques according to Clinical and Laboratory Standards Institute (CSLI) guidelines. Enzyme kinetic parameters and the cytotoxic effects of TACN were determined using spectrophotometric assays. The interactions of the enzyme-TACN complex were investigated by computational studies. Meropenem regained its activity against carbapenemase-producing Enterobacteriaceae, with the MIC decreasing from between 8 and 64 mg/liter to 0.03 mg/liter in the presence of TACN. The TACN-meropenem combination showed bactericidal effects with an MBC/MIC ratio of ≤4, and synergistic activity was observed. Human serum effects on the MICs were insignificant, and TACN was found to be noncytotoxic at concentrations above the MIC values. Computational studies predicted that TACN inhibits MBLs by targeting their catalytic active-site pockets. This was supported by its inhibition constant (Ki), which was 0.044 μM, and its inactivation constant (Kinact), which was 0.0406 min−1, demonstrating that TACN inhibits MBLs efficiently and holds promise as a potential inhibitor. IMPORTANCE Carbapenem-resistant Enterobacteriaceae (CRE)-mediated infections remain a significant public health concern and have been reported to be critical in the World Health Organization’s priority pathogens list for the research and development of new antibiotics. CRE produce enzymes, such as metallo-β-lactamases (MBLs), which inactivate β-lactam antibiotics. Combination therapies involving a β-lactam antibiotic and a β-lactamase inhibitor remain a major treatment option for infections caused by β-lactamase-producing organisms. Currently, no MBL inhibitor–β-lactam combination therapy is clinically available for MBL-positive bacterial infections. Hence, developing efficient molecules capable of inhibiting these enzymes could be a promising way to overcome this phenomenon. TACN played a significant role in the inhibitory activity of the tested molecules against CREs by potentiating the activity of carbapenem. This study demonstrates that TACN inhibits MBLs efficiently and holds promises as a potential MBL inhibitor to help curb the global health threat posed by MBL-producing CREs.

scholarly journals Efficacy of Chromolaena odorata leaf extracts for the healing of rat excision wounds

2017 ◽  
Vol 62 (No. 10) ◽  
pp. 565-578 ◽  
Author(s):  
K. Vijayaraghavan ◽  
J. Rajkumar ◽  
MA Seyed
Keyword(s):  
Wound Healing ◽  
Inhibitory Activity ◽  
Soft Tissues ◽  
Healing Process ◽  
Lipid Peroxide ◽  
Wound Healing Process ◽  
Phytochemical Screening ◽  
Chromolaena Odorata ◽  
Excision Wound ◽  
Ethanolic Extracts

Injury to the soft tissues is followed by wound healing, which consists of four stages: haemostasis, inflammation, proliferation and remodelling. Chromolaena odorata is a weed that is traditionally used for the treatment of various ailments in humans and animals. The present study was aimed at exploring the wound healing potential of aqueous and ethanolic extracts of C. odorata in a rat excision wound model. This investigation involved phytochemical screening and in vitro analyses of various parameters such as antioxidant activity, lipid peroxide inhibitory activity and the effects of extracts on contraction and epithelialisation of the rat excision wounds. The phytochemical screening of both ethanolic and aqueous extracts showed that they were rich in secondary metabolites such as alkaloids, flavonoids, tannins, saponins, terpenoids, anthraquinones, cardiac glycosides and carbohydrates. The aqueous extract showed high antioxidant and lipid peroxide inhibitory activity, while the ethanolic extract showed high total phenol content and hydrogen peroxide inhibitory activity at concentrations of 50, 100 and 250 μg/ml. Our results also indicate that the most effective concentration of the C. odorata extract for excision wound healing was 5.0% (w/w). C. odorata-treated groups exhibited a faster reduction in wound area compared to control and Betadine-treated groups. In addition, the topical application of C. odorata extract increased collagen synthesis and its stabilisation at the wound site, as evidenced by the increase in hydroxyproline and hexosamine levels and expression of collagen. The present investigation demonstrates that aqueous and ethanolic extracts of C. odorata of varying concentrations promote an accelerated wound healing process and might represent a novel healing agent. Our findings are of potential clinical relevance and might be highly beneficial for drug discovery and development in the area of both human and veterinary medicine.

scholarly journals Inhibition of PGHS-1 and PGHS-2 by Triterpenoid Acids from Chaenomelis Fructus

2008 ◽  
Vol 3 (12) ◽  
pp. 1934578X0800301
Author(s):  
Eveline Reininger ◽  
Rudolf Bauer
Keyword(s):  
Inhibitory Activity ◽  
Inhibitory Effect ◽  
Hydroxyl Group ◽  
Prostaglandin H Synthase ◽  
Dried Fruits ◽  
Inhibitory Potential ◽  
Prostaglandin H

The dichloromethane extract of the dried fruits of Chaenomeles speciosa (Sweet) Nakai (Rosaceae) showed strong inhibitory activity against both prostaglandin-H-synthase isoenzymes [IC50 (PGHS-1) = 5.1 μg/mL; IC50 (PGHS-2) = 2.3 μg/mL]. The lipophilic portion of the extract was mainly responsible for the inhibitory effect. Several triterpenoid acids were isolated and identified as contributing to this inhibitory activity (oleanolic, pomolic, 3β-O-acetylursolic and 3β-O-acetylpomolic acids). Comparison of their inhibitory potential with their selectivity to PGHS-2 showed that 3β-O-acetylursolic acid had the highest potency in the inhibition of PGHS-1 and PGHS-2 enzymes, whilst pomolic and 3β-O-acetylpomolic acid, with a hydroxyl group at position 19α, showed selectivity for PGHS-2. The inhibitory effect of the extract seems to be the result of the activity of the mixture of these different triterpenoid acids.

The Wrong Cure: Financial Incentives for Unimpressive New Antibiotics

2020 ◽  
Author(s):  
Michael S Sinha ◽  
John H Powers ◽  
Aaron S Kesselheim
Keyword(s):  
Public Health ◽  
Antimicrobial Resistance ◽  
Patient Outcomes ◽  
Clinical Benefit ◽  
Financial Incentives ◽  
Health Concern ◽  
Incentive Structure ◽  
Public Health Concern ◽  
Antibiotic Development ◽  
New Antibiotics

Though antimicrobial resistance is a public health concern, the basis of approval for many new antibiotics does not distinguish them from older products. We suggest a more tailored incentive structure for antibiotic development, focused on clinical benefit and patient outcomes.

scholarly journals A Synthetic Antibiotic Scaffold Effective Against Multidrug-Resistant Bacterial Pathogens

2021 ◽  
Author(s):  
Matthew Mitcheltree ◽  
Amarnath Pisipati ◽  
Egor A. Syroegin ◽  
Katherine J. Silvestre ◽  
Dorota Klepacki ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Ribosomal Subunit ◽  
Multidrug Resistant ◽  
Health Concern ◽  
Structural Basis ◽  
Resistant Bacteria ◽  
Global Public Health ◽  
Antibiotic Resistant ◽  
New Antibiotics ◽  
Orally Bioavailable

The dearth of new medicines effective against antibiotic-resistant bacteria presents a growing global public health concern. For more than five decades, the search for new antibiotics has relied heavily upon the chemical modification of natural products (semi-synthesis), a method ill-equipped to combat rapidly evolving resistance threats. Semi-synthetic modifications are typically of limited scope within polyfunctional antibiotics, usually increase molecular weight, and seldom permit modifications of the underlying scaffold. When properly designed, fully synthetic routes can easily address these shortcomings. Here we report the structure-guided design and component-based synthesis of a rigid oxepanoproline scaffold which, when linked to the aminooctose residue of clindamycin, produces an antibiotic of exceptional potency and spectrum of activity, here named iboxamycin. Iboxamycin is effective in strains expressing Erm and Cfr rRNA methyltransferase enzymes, products of genes that confer resistance to all clinically relevant antibiotics targeting the large ribosomal subunit, namely macrolides, lincosamides, phenicols, oxazolidinones, pleuromutilins, and streptogramins. X-ray crystallographic studies of iboxamycin in complex with the native 70S bacterial ribosome, as well as the Erm-methylated 70S ribosome, uncover the structural basis for this enhanced activity, including an unforeseen and unprecedented displacement of upon antibiotic binding. In mice, iboxamycin is orally bioavailable, safe, and effective in treating bacterial infections, testifying to the capacity for chemical synthesis to provide new antibiotics in an era of rising resistance.

scholarly journals Inhibitory Effect of Bacteriophages Isolated from Sewage Water in the City of Kirkuk on some Types of Human Pathogenic Bacteria

2017 ◽  
Vol 14 (4) ◽  
pp. 727-734 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Pathogenic Bacteria ◽  
Inhibitory Effect ◽  
Sewage Water ◽  
Resistant Bacteria ◽  
Human Pathogens ◽  
Salmonella Spp ◽  
Antibiotic Resistant ◽  
E Coli ◽  
New Antibiotics ◽  
The City

Most approaches to combat antibiotic resistant bacteria concentrate on discovering new antibiotics or modifying existing ones. However, one of the most promising alternatives is the use of bacteriophages. This study was focused on the isolation of bacteriophages that are specific to some of commonly human pathogens namely E. coli, Streptococcus pyogenes, Staphylococcus aureus, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella spp. and Klebsiella pneumoniae. These bacteriophages were isolated from sewages that were collected from four different locations in Kirkuk City. Apart from S. pyogenes, bacteriophages specific to all tested bacteria were successfully isolated and tested for their effectiveness by spot test. The most effective bacteriophages that were isolated from sewages and sewage water of Al-Jumhori Hospital compared to other sites. It is concluded that the sewage water of hospitals represents a perfect environment for these bacteriophages.

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