Co-Doped CeO2/Activated C Nanocomposite Functionalized with Ionic Liquid for Colorimetric Biosensing of H2O2 via Peroxidase Mimicking.

Hydrogen peroxide acts as a byproduct of oxidative metabolism, and oxidative stress caused by its excess amount, causes different types of cancer. Thus, fast and cost-friendly analytical methods need to be developed for H2O2. Ionic liquid (IL)-coated cobalt (Co)-doped cerium oxide (CeO2)/activated carbon (C) nanocomposite has been used to assess the peroxidase-like activity for the colorimetric detection of H2O2. Both activated C and IL have a synergistic effect on the electrical conductivity of the nanocomposites to catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB). The Co-doped CeO2/activated C nanocomposite has been synthesized by the co-precipitation method and characterized by UV-Vis spectrophotometry, FTIR, SEM, EDX, Raman spectroscopy, and XRD. The prepared nanocomposite was functionalized with IL to avoid agglomeration. H2O2 concentration, incubation time, pH, TMB concentration, and quantity of the capped nanocomposite were tuned. The proposed sensing probe gave a limit of detection of 1.3 × 10-8 M, a limit of quantification of 1.4 × 10-8 M, and an R2 of 0.999. The sensor gave a colorimetric response within 2 min at pH 6 at room temperature. The co-existing species did not show any interference during the sensing probe. The proposed sensor showed high sensitivity and selectivity and was used to detect H2O2 in cancer patients' urine samples.

Phyto-Extract-Mediated Synthesis of Silver Nanoparticles (AgNPs) and Their Biological Activities.

Background: Nanotechnology finds broad applications in the field of nanomedicine, an emerging new field used for diagnosis, treatment, prevention of diseases, and improvement of health. Objectives: To synthesize silver nanoparticles (AgNPs) from Withania somnifera and Fagonia indica and to carry out their antimicrobial, insecticidal, and phytotoxic activities, a step toward the new range of nanomedicines. Methods: Silver nanoparticles were synthesized from Withania somnifera and Fagonia indica by chemical reduction method, and further biological activities of these nanoparticles were compared with crude methanolic extract, prepared through cold maceration process, at the concentration of 50 mg/ml. Results: Among all tested bacterial pathogens, crude extract of W. somnifera showed a statistically high significant inhibition zone in millimeter against Pseudomonas aeruginosa (21; p < 0.01). AgNPs showed highly significant result against Streptococcus pneumonia (14; p < 0.01). In comparison with crude extracts, AgNPs showed statistically significant (p < 0.01) results against S. pneumonia (AgNPs, 14; crude, 8.33 mm). Crude extract showed significant inhibition zone against two bacterial strains, P. aeruginosa (crude, 21; AgNPs, 11.67 mm) and Klebsiella pneumoniae (crude, 11.33; AgNPs, 8 mm). Crude extracts of F. indica showed the significant activity against Vibrio cholera (p < 0.01; 11.33 mm). Silver nanoparticles of F. indica exhibited the highest significant activity against Aspergillus flavus and Fusarium oxysporum while AgNPs of W. somnifera were active only against A. flavus. Extracts of W. somnifera and F. indica showed increasing phytotoxic activity with increasing concentrations. The highest significant inhibition was obtained for crude extract (46.7) and AgNPs (45.7) of F. indica at 1000 µg/ml. Insecticidal activity of crude and AgNPs of both plants showed significant inhibition against all tested insects with increasing time intervals, and the highest significant result was obtained at 72 hours with a value of p < 0.01 except T. castaneum. Conclusions: Both crude and AgNPs showed potent activity; however, in comparison, silver nanoparticles showed slightly enhanced activity. Crude and AgNPs of both plants showed good phytotoxic and insecticidal inhibition. Antimicrobial studies of AgNPs on diseases causing pathogens open a door for new antimicrobial agents and could be the answer to antibiotic resistance after further analysis.

Phytochemical Screening, Antibacterial Activity and Heavy Metal Analysis of Ethnomedicinal Recipes and Their Sources Used Against Infectious Diseases.

Plants are a rich source of secondary metabolites that have been found to have medicinal properties. The present study was conducted to evaluate the phytochemical screening, antibacterial activities and heavy metal analysis of seven medicinal plants i.e., Nigella sativa (seeds), Trigonella foenum-graecum (seeds), Brassica campestris (seeds), Pistacia integerrima (galls), Linum usitatissimum (seeds), Hyssopus officinalis (flowers), Ephedra vulgaris (dry branches) and its two recipes which are used by hakims (Practitioners of local herbal medicines), against different diseases particularly respiratory tract infections. The obtained results revealed that alkaloids (30%) and flavonoids (41%) were in maximum quantity in P. integerrima (galls) while saponins (10.9%) were in maximum quantity in Recipe 1. The antibacterial activity was determined by the agar well disc diffusion method using methanol, ethanol, chloroform and deionized water extracts. Each plant extract was tested against one Gram-positive (Streptococcus pneumonia) and two Gram-negative (Pseudomonas aeruginosa and Klebsiella pneumonia) bacteria. Maximum zones of inhibition in methanol, ethanol, chloroform and aqueous extract were seen in T. foenum-graecum against S. pneumonia (20.06 ± 0.16 mm), B. campestris against S. pneumonia (22.40 ± 0.24 mm), Recipe 2 against K. pneumonia (20.06 ± 0.16 mm) and N. sativa against S. pneumonia (20.23 ± 0.16 mm), respectively. The concentrations of heavy metals were determined by atomic absorption spectrophotometer and showed the existence of high concentration of Iron (Fe), Lead (Pb) and Chromium (Cr). Thus, it has been found that medicinal plants individually as well as their recipes are potentially active against various diseases particularly respiratory tract infections.

Antibacterial Activities, Phytochemical Screening and Metal Analysis of Medicinal Plants: Traditional Recipes Used against Diarrhea.

The aim of this study was to explore the phytochemical composition, heavy metals analysis and the antibacterial activity of six medicinal plants i.e., Terminalia chebula Retz (fruits), Aegle marmelos L., (fruits), Curcuma longa L., (rhizomes), Syzygium aromaticum L., (flower buds), Piper nigrum L., (seeds), Cinnamomum cassia L., (barks) and its two remedial recipes (recipe 1 and 2) used against diarrhea obtained from the local herbal practitioners (Hakeems). A preliminary phytochemical screening of the above-mentioned plants extract in methanol, chloroform, n-hexane and distilled water revealed the presence of various constituents such as alkaloids, flavonoids, tannins and saponins by using standard procedures. The quantitative phytochemical studies shows that alkaloids, flavonoid and saponins were in maximum amount in Terminalia chebula. The concentration of Cd, Ni, Pb, Fe, Cr, Cu and Zn were investigated by using an atomic absorption spectrometer. The obtained analysis shows that Cr, Fe and Pb were present in the highest concentration in medicinal plants and their recipes. The antibacterial activities of the crude extract found in the recipes of methanol, chloroform, n-hexane and distilled water were analyzed by using agar well disc diffusion assay and minimum inhibitory concentration (MIC) by broth dilution method against four bacterial strains, namely, E. coli, Salmonella, Shigella and Methicillin-resistant Staphylococcus aureus (MRSA), respectively. The maximum zones of inhibition in methanol, water, chloroform and n-hexane extracts were seen in recipe 2 against Shigella (22.16 ± 0.47 mm), recipe 2 against Shigella (20.33 ± 0.24 mm), recipe 1 against Shigella (20.30 ± 0.29 mm) and recipe 2 against E. coli (30.23 ± 0.12 mm), respectively. Furthermore, the recipe extracts are more active against the tested bacterial strains than the extracts from individual plants. Therefore, it is concluded that the use of herbal plants and their recipes are the major source of drugs in a traditional medicinal system to cure different diseases.

A review on the elemental contents of Pakistani medicinal plants: Implications for folk medicines.

ETHNOPHARMACOLOGICAL RELEVANCE: Substantially, plants produce chemicals such as primary and secondary metabolites, which have significant applications in modern therapy. Indigenous people mostly rely on traditional medicines derived from medicinal plants. These plants have the capacity to absorb a variety of toxic elements. The ingestion of such plants for medicinal purpose can have imperative side effects. Hence, with regard to the toxicological consideration of medicinal plants, an effort has been made to review the elemental contents of ethno medicinally important plants of Pakistan and to highlight the existing gaps in knowledge of the safety and efficacy of traditional herbal medications. MATERIALS AND METHODS: Literature related to the elemental contents of ethno medicinal plants was acquired by utilizing electronic databases. We reviewed only macro-elemental and trace elemental contents of 69 medicinal plant taxa, which are traditionally used in Pakistan for the treatment of sundry ailments, including anemia, jaundice, cancer, piles, diarrhea, dysentery, headache, diabetes, asthma, blood purification, sedative and ulcer. RESULTS: A majority of plants showed elemental contents above the permissible levels as recommended by the World health organization (WHO). As an example, the concentrations of Cadmium (Cd) and Lead (Pb) were reportedly found higher than the WHO permissible levels in 43 and 42 medicinal plants, respectively. More specifically, the concentrations of Pb (54ppm: Silybum marianum) and Cd (5.25ppm: Artemisia herba-alba) were found highest in the Asteraceae family. CONCLUSIONS: The reported medicinal plants contain a higher amount of trace and toxic elements. Intake of these plants as traditional medicines may trigger the accumulation of trace and toxic elements in human bodies, which can cause different types of diseases. Thus, a clear understanding about the nature of toxic substances and factors affecting their concentrations in traditional medicines are essential prerequisites for efficacious herbal therapeutics with lesser or no side effects.

The Contrasting Character of Early and Late Transition Metal Fluorides as Hydrogen Bond Acceptors.

The association constants and enthalpies for the binding of hydrogen bond donors to group 10 transition metal complexes featuring a single fluoride ligand (trans-[Ni(F)(2-C5NF4)(PR3)2], R = Et 1a, Cy 1b, trans-[Pd(F)(4-C5NF4)(PCy3)2] 2, trans-[Pt(F){2-C5NF2H(CF3)}(PCy3)2] 3 and of group 4 difluorides (Cp2MF2, M = Ti 4a, Zr 5a, Hf 6a; Cp*2MF2, M = Ti 4b, Zr 5b, Hf 6b) are reported. These measurements allow placement of these fluoride ligands on the scales of organic H-bond acceptor strength. The H-bond acceptor capability ß (Hunter scale) for the group 10 metal fluorides is far greater (1a 12.1, 1b 9.7, 2 11.6, 3 11.0) than that for group 4 metal fluorides (4a 5.8, 5a 4.7, 6a 4.7, 4b 6.9, 5b 5.6, 6b 5.4), demonstrating that the group 10 fluorides are comparable to the strongest organic H-bond acceptors, such as Me3NO, whereas group 4 fluorides fall in the same range as N-bases aniline through pyridine. Additionally, the measurement of the binding enthalpy of 4-fluorophenol to 1a in carbon tetrachloride (-23.5 ± 0.3 kJ mol(-1)) interlocks our study with Laurence's scale of H-bond basicity of organic molecules. The much greater polarity of group 10 metal fluorides than that of the group 4 metal fluorides is consistent with the importance of pπ-dπ bonding in the latter. The polarity of the group 10 metal fluorides indicates their potential as building blocks for hydrogen-bonded assemblies. The synthesis of trans-[Ni(F){2-C5NF3(NH2)}(PEt3)2], which exhibits an extended chain structure assembled by hydrogen bonds between the amine and metal-fluoride groups, confirms this hypothesis.