Investigating the Antibacterial and Anti-inflammatory Potential of Polyol-Synthesized Silver Nanoparticles.

Silver nanoparticles (Ag-NPs) were synthesized by using the polyol method. The structural and morphological characteristics of Ag-NPs were studied by using X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM). The XRD analysis revealed the formation of single-phase polycrystalline Ag-NPs with an average crystallite size and lattice constant of ∼23 nm and 4.07 Å, respectively, while the FE-SEM shows the formation of a uniform and spherical morphology. Energy-dispersive X-ray spectroscopy confirmed the formation of single-phase Ag-NPs, and no extra elements were detected. A strong absorption peak at ∼427 nm was observed in the UV-vis spectrum, which reflects the surface plasmon resonance (SPR) behavior characteristic of Ag-NPs with a spherical morphology. Fourier-transform infrared (FTIR) spectra also supported the XRD and EDX results with regard to the purity of the prepared Ag-NPs. Anti-inflammatory activity was tested using HRBCs membrane stabilization and heat-induced hemolysis assays. The antibacterial activity of Ag-NPs was evaluated against four different types of pathogenic bacteria by using the disc diffusion method (DDM). The Gram-negative bacterial strains used in this study are Escherichia coli (E. coli), Klebsiella, Shigella, and Salmonella. The analysis suggested that the antibacterial activities of Ag-NPs have an influential role in inhibiting the growth of the tested Gram-negative bacteria, and thus Ag-NPs can find a potential application in the pharmaceutical industry.

Occurrence of selected antibiotics in urban rivers in northwest Pakistan and assessment of ecotoxicological and antimicrobial resistance risks.

Antibiotics in aquatic systems of developing countries are a growing concern, particularly with the potential ecological risks and emergence of antimicrobial resistance. In Pakistan, antibiotics are widely consumed and released untreated into rivers, however, there is little information on their occurrence and potential risks. In this study, the concentrations and risk assessment of three commonly consumed antibiotics, ciprofloxacin (CIP), amoxicillin (AMX), and cefixime (CFM) belonging to different classes of fluoroquinolone, penicillin, and cephalosporin respectively were investigated in the Kabul River and its two tributaries, Bara River and Shah Alam River in the northwest region of the country. Composite samples were collected in different sampling campaigns and analyzed using the LC-ESI-MS/MS technique. All three antibiotics were found in higher concentrations ranging from 410 to 1810 ng/L, 180-850 ng/L, and 120-600 ng/L for CIP, AMX, and CFM respectively. The Friedman and Wilcoxon signed-ranked tests revealed insignificant differences in average concentrations of each antibiotic in the three rivers and the Pearson Correlation showed a significant positive correlation of CIP with both AMX and CFM indicating their similar pollution sources. Ecotoxicological risk assessment showed a higher risk to algae and bacteria (P. putida) in the rivers with CIP posing a greater risk. The potential risk of antimicrobial resistance development (ARD) was higher in all the three rivers, particularly in Kabul River where maximum risk quotients (RQARD) of 28.3, 9.4 and 3.4 were noted for CIP, CFM and AMX respectively. The human health (HH) risk was insignificant, though the RQHH was higher for the lower age groups (0-3 months). In addition, the combined flux of the antibiotics in the Kabul River was estimated as 59 tons/year with CIP having a significant flux relative to the other antibiotics.

Thiophene-Derived Schiff Base Complexes: Synthesis, Characterization, Antimicrobial Properties, and Molecular Docking.

Novel thiophene-derived Schiff base ligand DE, where DE is (E)-N1,N1-diethyl-N2-(thiophen-2-ylmethylene)ethane-1,2-diamine, and the corresponding M(II) complexes, [M(DE)X2] (M = Cu or Zn, X = Cl; M = Cd, X = Br), were prepared and structurally characterized. X-ray diffraction studies revealed that the geometry around the center of the M(II) complexes, [Zn(DE)Cl2] and [Cd(DE)Br2], could be best described as a distorted tetrahedral. In vitro antimicrobial screening of DE and its corresponding M(II) complexes, [M(DE)X2], was performed. The complexes were more potent and showed higher activities against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa, fungi Candida albicans, and protozoa Leishmania major compared to the ligand. Among the studied complexes, [Cd(DE)Br2] exhibited the most promising antimicrobial activity against all the tested microbes compared to its analogs. These results were further supported by molecular docking studies. We believe that these complexes may significantly contribute to the efficient designing of metal-derived agents to treat microbial infections.

Biosynthesis and Anti-inflammatory Activity of Zinc Oxide Nanoparticles Using Leaf Extract of Senecio chrysanthemoides.

Nanotechnology has recently appeared as an important study subject in modern material sciences. Greener synthesis of nanoparticles has gained the attention of many scientists because of its integral characteristics such as effectiveness, eco-friendly, and low cost. In the present study by following the green synthesis approach, zinc oxide nanoparticles (ZnO NPs) were formed for the very first time by using Senecio chrysanthemoides leaf extract as a reducing agent. The UV-Vis spectrophotometer was used to study the synthesized ZnO NPs, and the specific peak was found to be at 349 nm. The characteristic Fourier transform infrared (FTIR) peak was found to be at 449 cm-1 which displays the peak of ZnO molecules. The surface morphology of the ZnO NPs was determined via scanning electron microscopy (SEM). The energy-dispersive X-ray spectroscopy (EDX) study showed that the synthesized ZnO NPs are present at the weight percentage of 66.38%. The X-ray diffraction (XRD) spectrum confirmed the hexagonal phase wurtzite structure, with the average particle size of 31 nm, and demonstrated the crystalline structure of ZnO NPs. Additionally, to all these experiments, we compared the anti-inflammatory properties of biogenic ZnO NPs to a standard drug. Biosynthesized ZnO NPs have revealed an effective anti-inflammatory activity at a higher concentration (100 mL-1) and showed 73% inhibition in comparison with diclofenac sodium drug. Zinc oxide was shown to be compatible with diclofenac sodium, according to the results. The ZnO NPs produced using the greener synthesis process have the potential to be used in a broad range of fields and also used as a good anti-inflammatory agent.

Implication and evaluations of indoor soot particles from domestic fuel energy sources using characterization techniques in northern Pakistan.

Soot particles emitted from the burning of solid fuel sources in the households carry important environmental and public health implications. In this study, the indoor soot particles released from firewood, cow dung, and bagasse burning at households of selected rural areas of Khyber Pakhtunkhwa province of Pakistan were investigated by characterization analyses to study its morphological and elemental compositions. Results demonstrated diverse compositions of soot particles from each fuel source. The surface areas of soot particles emitted by the firewood, cow dung, and bagasse were about 0.3, 0.4, and 8.64 m2  g-1 , respectively. For the soot particles emitted by the firewood burning, the major functional groups for aromatic compounds were C═C at the 1,431-1,599 at 1,000-2,000 cm-1 . The absorbance rate of alkanes was about 1,599-1,431 at 1,000-2,000 cm-1 . However, silicon band vibration was more prominent in bagasse soot particles as compared to other samples. The emission of soot particles with high surface area in the atmosphere could provide an elevated adsorption sites for atmospheric pollution and trap more energy resulting in increased atmospheric temperature. Findings from the present study suggest that current households' fuel combustion practices significantly contribute to increase the particulate matter in the atmosphere and possible enhance climate change phenomenon and related disasters in northern Pakistan.

Reactive oxygen species generating photosynthesized ferromagnetic iron oxide nanorods as promising antileishmanial agent.

Aim: To investigate the photodynamic therapeutic potential of ferromagnetic iron oxide nanorods (FIONs), using Trigonella foenum-graecum as a reducing agent, against Leishmania tropica. Materials & methods: FIONs were characterized using ultraviolet visible spectroscopy, x-ray diffraction and scanning electron microscopy. Results: FIONs showed excellent activity against L. tropica promastigotes and amastigotes (IC50 0.036 ± 0.003 and 0.072 ± 0.001 µg/ml, respectively) upon 15 min pre-incubation light-emitting diode light (84 lm/W) exposure, resulting in reactive oxygen species generation and induction of cell death via apoptosis. FIONs were found to be highly biocompatible with human erythrocytes (LD50 779 ± 21 µg/ml) and significantly selective (selectivity index >1000) against murine peritoneal macrophages (CC50 102.7 ± 2.9 µg/ml). Conclusion: Due to their noteworthy in vitro antileishmanial properties, FIONs should be further investigated in an in vivo model of the disease.

Photo-inactivation of bacteria in hospital effluent via thiolated iron-doped nanoceria.

Hospital wastewater is a major contributor of disease-causing microbes and the emergence of antibiotic resistant bacteria. In this study, thiolated iron-doped nanoceria was synthesised and tested for killing of microbes from hospital effluent. These particles were designed to inhibit the efflux pumps of the bacteria found in hospital effluent with further ability to activate in visible light via iron doping thus generating tunable amount of reactive oxygen species (ROS). The quantum yield of the ROS generated by the nanoceria was 0.67 while the ROS types produced were singlet oxygen (36%), hydroxyl radical (31%) and hydroxyl ions (32%), respectively. The particles were initially synthesised through green route using Foeniculum vulgare seeds extract and were annealed at 200°C and further coated with thiolated chitosan to enhance the solubility and efflux pump inhibition. X-ray diffraction confirmed the polycrystalline nature of nanoparticles and uniform spherical shape with 30 nm size, confirmed by scanning electron microscope. The nanoparticles exhibited 100% bactericidal activity at 100 µg/mL against all the isolated bacteria. The enhanced bactericidal effect of iron-doped nanoceria could be attributed to efflux inhibition via thiolated chitosan as well as the production of ROS upon illumination in visible light, causing oxidative stress against microbes found in hospital effluent.

Antioxidant Potential, Phytochemicals Composition, and Metal Contents of Datura alba.

This study investigated the phytochemical characteristics and antioxidant activity in leaves, roots, stem, flower, and seed parts of Datura alba (D. alba). The study also assessed the heavy metal (Cr, Mn, Zn, and Cu) accumulation in each part of the plant. Among the phytochemicals, alkaloids were found only in leaves while tannins, flavonoids, and phenols were present in all parts of the plant. For antioxidant activity, free radical scavenging assay for 2,2-diphenyl-1-picrylhydrazyl (DPPH) was performed using ascorbic acid as the standard. Higher activity was shown by stem extract in methanol and leaf extract in n-hexane, ethyl acetate, and chloroform. Furthermore, all the target heavy metals were detected in all plant sections with the highest concentration of Zn in leaves and Cu in stem, root, flower, and seed. Due to stronger antioxidant potential and phytochemical composition, D. alba could prove as valuable prospect in pharmaceutical formulations by taking part in the antioxidant defense system against generation of free radicals.

Photo-inactivation and efflux pump inhibition of methicillin resistant Staphylococcus aureus using thiolated cobalt doped ZnO nanoparticles.

Multidrug resistance (MDR) in bacteria is a major concern these days. One of the reasons is the mutation in efflux pump that prevents the retention of antibiotics and drugs in the bacterial cell. The current work is a step to overcome MDR in bacteria via inhibition of efflux pump and further photoinhibition by thiolated chitosan coated cobalt doped zinc oxide nanoparticles (Co-ZnO) in visible light. Co-ZnO were synthesized in a size range of 40-60 nm. Antibacterial activity of the Co-ZnO against methicillin resistant Staphylococcus aureus (MRSA) was found 100% at a concentration of 10 µg/ml upon activation in sunlight for 15 min. Interestingly, it was found that cobalt as a dopant was able to increase the photodynamic and photothermal activity of Co-ZnO, as in dark conditions, there was only 3-5% of inhibition at 10 µg/ml of nanoparticle concentration. Upon excitation in light, these nanoparticles were able to generate reactive oxygen species (ROS) with a quantum yield of 0.23 ±â€¯0.034. The nanoparticles were also generating heat, Because of the magnetic nature, thus helping in more killing. Thiolated chitosan further helped in blocking the efflux pump of MRSA. The current nanoparticles were also found biocompatible on human red blood cells (LD50 = 214 µg/ml). These data suggest that the MRSA killing ability was facilitated through efflux inhibition and oxidative stress upon excitation in visible light hence, were in accordance with previous findings.

Characteristics of pipe corrosion scales in untreated water distribution system and effect on water quality in Peshawar, Pakistan.

This study investigated the characteristics of iron corrosion scales in pipes at tube well, overhead tank, and consumers' end in older untreated water distribution system in Peshawar city, Pakistan. Effect of water quality conditions on corrosion scales and that of scales on drinking water quality in such systems was also assessed by undertaking a comparison with new piped distribution systems. The scales were analyzed for chemical composition and morphology using X-ray diffraction (XRD), inductively coupled plasma (ICP), and a scanning electron microscope (SEM), while water quality was examined for physicochemical and biological characteristics. The main crystalline phases of corrosion scales were goethite, magnetite, siderite, and quartz. From tube well to consumers' end, goethite increased from 36 up to 48%, quartz declined from 22 to 15%, while magnetite fluctuated and siderite disappeared. Elemental composition of scales showed the deposition of Zn, Al, Mn, Cr, Pb, Cu, As, and Cd with Zn (13.9 g/kg) and Al (3.6 g/kg) in highest proportion. The SEM analysis illustrated the presence of microbial communities indicating the formation of biofilms in the corrosion scales. The significant difference (P < 0.05) in levels of dissolved oxygen (DO), Cl-, SiO44-, electrical conductivity (EC), SO42-, NO3-, alkalinity, hardness, and trace metals between old (DS-O) and new piped systems indicated their role in corrosion scale formation/destabilization and the effect of scale dissolution on water quality. In DS-O, EC, Cu, and Mn were significantly higher (P < 0.05), whereas turbidity, EC, DO, and SiO44- significantly increased from source to consumers' end implying a higher dissolution of scales and lowered corrosion rates in DS-O to utilize SiO44- and DO for iron oxidation.

Prevalence of selected pharmaceuticals in surface water receiving untreated sewage in northwest Pakistan.

This study investigated the occurrence of four non-steroidal anti-inflammatory drugs (NSAIDs) and four benzodiazepines/anti-depressants (ADs) in municipal wastewater in Mardan city, Pakistan, and in River Kabul and River Indus receiving untreated sewage. Liquid chromatography with a triple quadrupole tandem mass spectrometry (LC-MS/MS) was used for the analysis of paracetamol, diclofenac, ibuprofen, and codeine (NSAIDs) and diazepam, bromazepam, lorazepam, and temazepam (ADs). Except codeine and lorazepam, all the target compounds were observed in sewage and surface water in various concentrations. In sewage, paracetamol was found at the higher end (32.4 µg/L) of the reported ranges in literature for other countries. Results of river samples showed that the target compounds were usually lower in concentration than the respective EC50 values for aquatic organisms. However, the levels for paracetamol and ibuprofen were critical depicting the consequence of untreated disposal. Environmental risk assessment by estimating the risk quotient (RQ) as the ratio of measured environmental concentration and predicted no-effect concentration showed medium to high (RQ > 1 and 0.1 < RQ < 1) risk from paracetamol and ibuprofen to aquatic organisms in River Kabul and Kalpani stream, Pakistan.

Assessment of tap water quality and corrosion scales from the selected distribution systems in northern Pakistan.

Corrosion deposits formed within drinking water distribution systems deteriorate drinking water quality and resultantly cause public health consequences. In the present study, an attempt was made to investigate the concurrent conditions of corrosion scales and the drinking water quality in selected water supply schemes (WSS) in districts Chitral, Peshawar, and Abbottabad, northern Pakistan. Characterization analyses of the corrosion by-products revealed the presence of α-FeOOH, γ-FeOOH, Fe3O4, and SiO2 as major constituents with different proportions. The constituents of all the representative XRD peaks of Peshawar WSS were found insignificant as compared to other WSS, and the reason could be the variation of source water quality. Well-crystallized particles in SEM images indicated the formation of dense oxide layer on corrosion by-products. A wider asymmetric vibration peak of SiO2 appeared only in Chitral and Abbottabad WSS, which demonstrated higher siltation in the water source. One-way ANOVA analysis showed significant variations in pH, turbidity, TDS, K, Mg, PO4, Cl, and SO4 values, which revealed that these parameters differently contributed to the source water quality. Findings from this study suggested the implementation of proper corrosion prevention measures and the establishment of international collaboration for best corrosion practices, expertise, and developing standards.

Post-denitrification using alginate beads containing organic carbon and activated sludge microorganisms.

Nitrate concentration in the final effluent is a key issue in pre-denitrification biological treatment systems. This study investigated post-denitrification with alginate beads containing immobilized activated sludge microorganisms and organic carbon source. A batch study was first performed to identify suitable carbon sources among acetate, glucose, calcium tartrate, starch and canola oil on the basis of nitrate removal and bead stability. Canola oil and starch beads exhibited significantly higher denitrification rates, greater bead stability and lower nitrite accumulation (6 mg/L and 10 mg/L, respectively). Glucose and acetate beads showed longer acclimation phases and degraded faster whereas tartrate beads had higher nitrite build-up (39 mg/L) and degraded due to brittleness. Post-denitrification with canola oil and starch beads was investigated in the final clarifier of a coupled upflow bioreactor and aerobic system treating synthetic dairy farm wastewater, and showed a denitrification efficiency of >90%. Beads faded in 12 days due to alginate degradation. Therefore, enhancement in bead strength or use of more stable nontoxic gel would be required to further prolong the treatment. Moreover, this study was conducted at laboratory scale and further research is needed for application in real systems.

Annihilation of Leishmania by daylight responsive ZnO nanoparticles: a temporal relationship of reactive oxygen species-induced lipid and protein oxidation.

Lipid and protein oxidation are well-known manifestations of free radical activity and oxidative stress. The current study investigated extermination of Leishmania tropica promastigotes induced by lipid and protein oxidation with reactive oxygen species produced by PEGylated metal-based nanoparticles. The synthesized photodynamic therapy-based doped and nondoped zinc oxide nanoparticles were activated in daylight that produced reactive oxygen species in the immediate environment. Lipid and protein oxidation did not occur in dark. The major lipid peroxidation derivatives comprised of conjugated dienes, lipid hydroperoxides, and malondialdehyde whereas water, ethane, methanol, and ethanol were found as the end products. Proteins were oxidized to carbonyls, hydroperoxides, and thiol degrading products. Interestingly, lipid hydroperoxides were produced by more than twofold of the protein hydroperoxides, indicating higher degradation of lipids compared to proteins. The in vitro evidence represented a significant contribution of the involvement of both lipid and protein oxidation in the annihilated antipromastigote effect of nanoparticles.

Micelles as Soil and Water Decontamination Agents.

Contaminated soil and water pose a serious threat to human health and ecosystem. For the treatment of industrial effluents or minimizing their detrimental effects, preventive and remedial approaches must be adopted prior to the occurrence of any severe environmental, health, or safety hazard. Conventional treatment methods of wastewater are insufficient, complicated, and expensive. Therefore, a method that could use environmentally friendly surfactants for the simultaneous removal of both organic and inorganic contaminants from wastewater is deemed a smart approach. Surfactants containing potential donor ligands can coordinate with metal ions, and thus such compounds can be used for the removal of toxic metals and organometallic compounds from aqueous systems. Surfactants form host-guest complexes with the hydrophobic contaminants of water and soil by a mechanism involving the encapsulation of hydrophobes into the self-assembled aggregates (micelles) of surfactants. However, because undefined amounts of surfactants may be released into the aqueous systems, attention must be paid to their own environmental risks as well. Moreover, surfactant remediation methods must be carefully analyzed in the laboratory before field implementation. The use of biosurfactants is the best choice for the removal of water toxins as such surfactants are associated with the characteristics of biodegradability, versatility, recovery, and reuse. This Review is focused on the currently employed surfactant-based soil and wastewater treatment technologies owing to their critical role in the implementation of certain solutions for controlling pollution level, which is necessary to protect human health and ensure the quality standard of the aquatic environment.

Visible-light-responsive ZnCuO nanoparticles: benign photodynamic killers of infectious protozoans.

Human beings suffer from several infectious agents such as viruses, bacteria, and protozoans. Recently, there has been a great interest in developing biocompatible nanostructures to deal with infectious agents. This study investigated benign ZnCuO nanostructures that were visible-light-responsive due to the resident copper in the lattice. The nanostructures were synthesized through a size-controlled hot-injection process, which was adaptable to the surface ligation processes. The nanostructures were then characterized through transmission electron microscopy, X-ray diffraction, diffused reflectance spectroscopy, Rutherford backscattering, and photoluminescence analysis to measure crystallite nature, size, luminescence, composition, and band-gap analyses. Antiprotozoal efficiency of the current nanoparticles revealed the photodynamic killing of Leishmania protozoan, thus acting as efficient metal-based photosensitizers. The crystalline nanoparticles showed good biocompatibility when tested for macrophage toxicity and in hemolysis assays. The study opens a wide avenue for using toxic material in resident nontoxic forms as an effective antiprotozoal treatment.