8 research outputs found
Antimicrobial and toxicological activities of five medicinal plant species from Cameroon Traditional Medicine
<p>Abstract</p> <p>Background</p> <p>Infectious diseases caused by multiresistant microbial strains are on the increase. Fighting these diseases with natural products may be more efficacious. The aim of this study was to investigate the <it>in vitro </it>antimicrobial activity of methanolic, ethylacetate (EtOAc) and hexanic fractions of five Cameroonian medicinal plants (<it>Piptadeniastum africana</it>, <it>Cissus aralioides, Hileria latifolia, Phyllanthus muellerianus </it>and <it>Gladiolus gregasius) </it>against 10 pathogenic microorganisms of the urogenital and gastrointestinal tracts.</p> <p>Methods</p> <p>The fractions were screened for their chemical composition and <it>in vivo </it>acute toxicity was carried out on the most active extracts in order to assess their inhibitory selectivity.</p> <p>The agar well-diffusion and the micro dilution methods were used for the determination of the inhibition diameters (ID) and Minimum inhibitory concentrations (MIC) respectively on 8 bacterial species including two Gram positive species (<it>Staphylococcus aureus, Enterococcus faecalis)</it>, and six Gram negative <it>(Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis, Shigella flexneri, Salmonella typhi) </it>and two fungal isolates (<it>Candida albicans, Candida krusei)</it>. The chemical composition was done according to Harbone (1976), the acute toxicity evaluation according to WHO protocol and the hepatic as well as serum parameters measured to assess liver and kidney functions.</p> <p>Results</p> <p>The chemical components of each plant's extract varied according to the solvent used, and they were found to contain alkaloids, flavonoids, polyphenols, triterpens, sterols, tannins, coumarins, glycosides, cardiac glycosides and reducing sugars. The methanolic and ethylacetate extracts of <it>Phyllanthus muellerianus </it>and <it>Piptadeniastum africana </it>presented the highest antimicrobial activities against all tested microorganisms with ID varying from 8 to 26 mm and MIC from 2.5 to 0.31 mg/ml. The <it>in vivo </it>acute toxicity study carried out on the methanolic extracts of <it>Phyllanthus muellerianus </it>and <it>Piptadeniastrum africana </it>indicated that these two plants were not toxic. At the dose of 4 g/kg body weight, kidney and liver function tests indicated that these two medicinal plants induced no adverse effect on these organs.</p> <p>Conclusion</p> <p>These results showed that, all these plant's extracts can be used as antimicrobial phytomedicines which can be therapeutically used against infections caused by multiresistant agents.</p> <p>Phyllanthus muellerianus, Piptadeniastum africana, antimicrobial, acute toxicity, kidney and liver function tests, Cameroon Traditional Medicine</p
Distal leg epidermal nerve fiber density as a surrogate marker of HIV-associated sensory neuropathy risk: risk factors and change following initial antiretroviral therapy
Poly(<i>N</i>‑isopropylacrylamide)-Stabilized Gold Nanoparticles in Combination with Tricationic Branched Phenylene-Ethynylene Fluorophore for Protein Identification
Gold
nanoparticles stabilized by thermoresponsive polymer, polyÂ(<i>N</i>-isopropylacrylamide) (PNIPAM-AuNPs) were prepared by surface
grafting of thiol-terminated PNIPAM onto citrate-stabilized AuNPs.
The color change of the PNIPAM-AuNPs solution from red to blue-purple
without precipitation when the solution was heated to 40 °C,
above the lower critical solution temperature (LCST) of PNIPAM, indicated
the thermoresponsive property of the synthesized AuNPs. PNIPAM-AuNPs
were used to detect proteins by chemical nose approach based on fluorescence
quenching of fluorophore by AuNPs. An array-based sensing platform
for detection of six proteins, namely bovine serum albumin, lysozyme,
fibrinogen, concanavalin A, hemoglobin, holo-transferrin human can
be successfully developed from the PNIPAM-AuNPs having different molecular
weights (4 and 8 kDa) and conformation (varied heat treatment from
25 to 40 °C) in combination with a tricationic branched phenylene-ethynylene
fluorophore. From principal component analysis (PCA) followed by linear
discriminant analysis (LDA), 100% accuracy of protein classification
using a leave-one-out (LOO) approach can be achieved by using only
two types of PNIPAM-AuNPs
Patterned Poly(acrylic acid) Brushes Containing Gold Nanoparticles for Peptide Detection by Surface-Assisted Laser Desorption/Ionization Mass Spectrometry
Patterned polyÂ(acrylic acid) (PAA)
brushes was successfully generated
via photolithography and surface-initiated reversible addition–fragmentation
chain transfer (RAFT) polymerization of acrylic acid as verified by
water contact angle measurements and FT-IR analysis. The carboxyl
groups of PAA brushes can act as reducing moieties for in situ synthesis
of gold nanoparticles (AuNPs), without the use of additional reducing
agent. The formation of AuNPs was confirmed by transmission electron
microscopy and X-ray photoelectron spectroscopy. The glass surface-modified
by PAA brushes and immobilized with AuNPs (AuNPs-PAA) can be used
as a substrate for SALDI-MS analysis, which is capable of detecting
both small peptides having <i>m</i>/<i>z</i> ≤
600 (glutathione) and large peptides having <i>m</i>/<i>z</i> ≥ 1000 (bradykinin, ICNKÂQDCPÂILE) without
the interference from matrix signal suggesting that AuNPs were stably
trapped within the PAA brushes and the carboxyl groups of PAA can
serve as internal proton source. By employing AuNPs as the capture
probe, the AuNPs-PAA substrate can selectively identify thiol-containing
peptides from the peptide mixtures with LOD as low as 0.1 and 0.05
nM for glutathione and ICNKÂQDCPÂILE, respectively. An ability
to selectively detect ICNKÂQDCPÂILE in a diluted human serum
is also demonstrated. The patterned format together with its high
sensitivity and selectivity render this newly developed substrate
a potential platform for high-throughput analysis of other biomarkers,
especially those with low molecular weight in complex biological samples