Cerium Oxide Nanorods Synthesized by Dalbergia sissoo Extract for Antioxidant, Cytotoxicity, and Photocatalytic Applications.

In this study, cerium oxide nanorods (CeO2-NRs) were synthesized by using the phytochemicals present in the Dalbergia sissoo extract. The physiochemical characteristics of the as-prepared CeO2-NRs were investigated by using ultraviolet-visible spectroscopy (UV-VIS), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction analysis (XRD). The SEM and UV-VIS analyses revealed that the acquired nanomaterials possessed a rod-like morphology while the XRD results further confirmed that the synthesized NRs exhibited a cubic crystal lattice system. The antioxidant capacity of the synthesized CeO2-NRs was investigated by using several in vitro biochemical assays. It was observed that the synthesized NRs exhibited better antioxidant potential in comparison to the industrial antioxidant of the butylated hydroxyanisole (BHA) in 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The biochemical assays, including lipid peroxidation (LPO), total antioxidant capacity (TAC), and catalase activity (CAT), were also performed in the human lymphocytes incubated with the CeO2-NRs to investigate the impact of the NRs on these oxidative biomarkers. Enhanced reductive capabilities were observed in all the assays, revealing that the NRs possess excellent antioxidant properties. Moreover, the cytotoxic potential of the CeO2-NRs was also investigated with the MTT assay. The CeO2-NRs were found to effectively kill off the cancerous cells (MCF-7 human breast cancer cell line), further indicating that the synthesized NRs exhibit anticancer potential as well. One of the major applications studied for the prepared CeO2-NRs was performing the statistical optimization of the photocatalytic degradation reaction of the methyl orange (MO) dye. The reaction was optimized by using the technique of response surface methodology (RSM). This advanced approach facilitates the development of the predictive model on the basis of central composite design (CCD) for this degradation reaction. The maximum degradation of 99.31% was achieved at the experimental optimized conditions, which corresponded rather well with the predicted percentage degradation values of 99.58%. These results indicate that the developed predictive model can effectively explain the performed experimental reaction. To conclude, the CeO2-NRs exhibited excellent results for multiple applications.

Novel Nd-N/TiO2 Nanoparticles for Photocatalytic and Antioxidant Applications Using Hydrothermal Approach.

In this study, photocatalysis was employed to degrade a wastewater pollutant (AB-29 dye) under visible light irradiation. For this purpose, nitrogen (N)- and neodymium (Nd)-doped TiO2 nanoparticles were prepared using the simple hydrothermal method. X-ray diffraction (XRD) revealed an anatase phase structure of the Nd-N/TiO2 photocatalyst, whereas properties including the surface morphology, chemical states/electronics structure and optical structure were determined using transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV-visible (UV-vis.) and photoluminescence (PL) spectroscopies. Photocatalytic testing of the prepared nanomaterials was performed to remove acid blue-29 (AB-29) dye under visible-light exposure. The prepared Nd-N/TiO2 nanoparticles demonstrated a superior photocatalytic activity and the decolorization efficiency was about 92% after visible-light illumination for 1 h and 20 min, while N/TiO2, Nd/TiO2 and TiO2 only showed a 67%, 43% and 31% decolorization efficiency, respectively. The enhanced photocatalytic activity of the Nd-N/TiO2 photocatalyst was due to a decrease in the electron/hole's recombination and the increased absorption of TiO2 in the visible range. The reusability results showed that the average photocatalytic activity decrease for all the samples was only about 16% after five consecutive cycles, indicating a good stability of the prepared nanomaterials. Moreover, the radical scavenging activity of the prepared nanomaterials was evaluated using the DPPH method. The novel Nd-N/TiO2 exhibited a higher antioxidant activity compared to all the other samples.

Extraction of Bioactive Compounds for Antioxidant, Antimicrobial, and Antidiabetic Applications.

This study was designed to check the potential of secondary metabolites of the selected plants; Citrullus colocynthis, Solanum nigrum, Solanum surattense, Calotropis procera, Agave americana, and Anagallis arvensis for antioxidant, antibacterial, antifungal, and antidiabetic agents. Plant material was soaked in ethanol/methanol to get the crude extract, which was further partitioned via solvent extraction technique. GCMS and FTIR analytical techniques were applied to check the compounds responsible for causing antioxidant, antimicrobial, and antidiabetic activities. It was concluded that about 80% of studied extracts/fractions were active against α-amylase, ranging from 43 to 96%. The highest activity (96.63%) was exhibited by butanol fractions of A. arvensis while the least response (43.65%) was shown by the aqueous fraction of C. colocynthis and the methanol fraction of fruit of S. surattense. The highest antioxidant activity was shown by the ethyl acetate fraction of Anagallis arvensis (78.1%), while aqueous as well as n-hexane fractions are the least active throughout the assay. Results showed that all tested plants can be an excellent source of natural products with potential antimicrobial, antioxidant, and antidiabetic potential. The biological response of these species is depicted as a good therapeutic agent, and, in the future, it can be encapsulated for drug discovery.

Novel Copper-Zinc-Manganese Ternary Metal Oxide Nanocomposite as Heterogeneous Catalyst for Glucose Sensor and Antibacterial Activity.

A novel copper-zinc-manganese trimetal oxide nanocomposite was synthesized by the simple co-precipitation method for sensing glucose and methylene blue degradation. The absorption maximum was found by ultraviolet-visible spectroscopy (UV-Vis) analysis, and the bandgap was 4.32 eV. The formation of a bond between metal and oxygen was confirmed by Fourier Transform Infrared Spectroscopy (FT-IR) analysis. The average crystallite size was calculated as 17.31 nm by X-ray powder diffraction (XRD) analysis. The morphology was observed as spherical by scanning electron microscope (SEM) and high-resolution transmission electron microscopy (HR-TEM) analysis. The elemental composition was determined by Energy Dispersive X-ray Analysis (EDAX) analysis. The oxidation state of the metals present in the nanocomposites was confirmed by the X-ray photoelectron spectroscopy (XPS) analysis. The hydrodynamic diameter and zeta potential of the nanocomposite were 218 nm and -46.8 eV, respectively. The thermal stability of the nanocomposite was analyzed by thermogravimetry-differential scanning calorimetry (TG-DSC) analysis. The synthesized nanocomposite was evaluated for the electrochemical glucose sensor. The nanocomposite shows 87.47% of degradation ability against methylene blue dye at a 50 µM concentration. The trimetal oxide nanocomposite shows potent activity against Escherichia coli. In addition to that, the prepared nanocomposite shows strong antioxidant application where scavenging activity was observed to be 76.58 ± 0.30, 76.89 ± 0.44, 81.41 ± 30, 82.58 ± 0.32, and 84.36 ± 0.09 % at 31, 62, 125, 250, and 500 µg/mL, respectively. The results confirm the antioxidant potency of nanoparticles (NPs) was concentration dependent.

Electrochemical Methodologies for Investigating the Antioxidant Potential of Plant and Fruit Extracts: A Review.

In recent years, the growing research interests in the applications of plant and fruit extracts (synthetic/stabilization materials for the nanomaterials, medicinal applications, functional foods, and nutraceuticals) have led to the development of new analytical techniques to be utilized for identifying numerous properties of these extracts. One of the main properties essential for the applicability of these plant extracts is the antioxidant capacity (AOC) that is conventionally determined by spectrophotometric techniques. Nowadays, electrochemical methodologies are emerging as alternative tools for quantifying this particular property of the extract. These methodologies address numerous drawbacks of the conventional spectroscopic approach, such as the utilization of expensive and hazardous solvents, extensive sample pre-treatment requirements, long reaction times, low sensitivity, etc. The electrochemical methodologies discussed in this review include cyclic voltammetry (CV), square wave voltammetry (SWV), differential pulse voltammetry (DPV), and chronoamperometry (CAP). This review presents a critical comparison between both the conventional and electrochemical approaches for the quantification of the parameter of AOC and discusses the numerous applications of the obtained bioextracts based on the AOC parameter.

Correction: pH responsive N-succinyl chitosan/Poly (acrylamide-co-acrylic acid) hydrogels and in vitro release of 5-fluorouracil.

[This corrects the article DOI: 10.1371/journal.pone.0179250.].

pH responsive N-succinyl chitosan/Poly (acrylamide-co-acrylic acid) hydrogels and in vitro release of 5-fluorouracil.

There has been significant progress in the last few decades in addressing the biomedical applications of polymer hydrogels. Particularly, stimuli responsive hydrogels have been inspected as elegant drug delivery systems capable to deliver at the appropriate site of action within the specific time. The present work describes the synthesis of pH responsive semi-interpenetrating network (semi-IPN) hydrogels of N-succinyl-chitosan (NSC) via Schiff base mechanism using glutaraldehyde as a crosslinking agent and Poly (acrylamide-co-acrylic acid)(Poly (AAm-co-AA)) was embedded within the N-succinyl chitosan network. The physico-chemical interactions were characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and field emission scanning electron microscope (FESEM). The synthesized hydrogels constitute porous structure. The swelling ability was analyzed in physiological mediums of pH 7.4 and pH 1.2 at 37°C. Swelling properties of formulations with various amounts of NSC/ Poly (AAm-co-AA) and crosslinking agent at pH 7.4 and pH 1.2 were investigated. Hydrogels showed higher swelling ratios at pH 7.4 while lower at pH 1.2. Swelling kinetics and diffusion parameters were also determined. Drug loading, encapsulation efficiency, and in vitro release of 5-fluorouracil (5-FU) from the synthesized hydrogels were observed. In vitro release profile revealed the significant influence of pH, amount of NSC, Poly (AAm-co-AA), and crosslinking agent on the release of 5-FU. Accordingly, rapid and large release of drug was observed at pH 7.4 than at pH 1.2. The maximum encapsulation efficiency and release of 5-FU from SP2 were found to be 72.45% and 85.99%, respectively. Kinetics of drug release suggested controlled release mechanism of 5-FU is according to trend of non-Fickian. From the above results, it can be concluded that the synthesized hydrogels have capability to adapt their potential exploitation as targeted oral drug delivery carriers.

DFT for exploring the antioxidant potential of homogentisic and orsellinic acids.

In recent years, much attention has been focused on the antioxidant potential of different phenolic acids. But still no theoretical investigation is reported on the antioxidant potential of Homogentisic and Orsellinic acids. In this study, computational investigation based on the density functional theory (DFT) has been carried out to understand the antioxidant potential of Homogentisic and Orsellinic acids. The bond dissociation enthalpy (BDE) of O-H, spin densities and electronic properties such as dipole moment, ionization potential, electron affinity, HOMO and LUMO energies, electronegativity, electrophilic index, energy gap, softness and hardness have been calculated. These properties show that both phenolic acids are good antioxidants. Comparison of BDE of Homogentisic and Orsellinic acids with many other phenolic acids also indicate the good antioxidant potential of these compounds. Homogentisic acid has very high antioxidant potential due to the presence of semiquinone structure. This study will be helpful for the better utilization of these compounds in pharmaceutical and food industry.

Optimization of extraction conditions for the extraction of phenolic compounds from Moringa oleifera leaves.

The aim of this study was to optimize the extraction conditions for the extraction of phenolic compounds from Moringa oleifera leaves using response surface methodology (RSM). A user-defined design was applied to determine the effects of extraction time (min), extraction temperature ((o)C) and ethanol concentration (%), on total phenolic content (TPC) from Moringa oleifera leaves dried by three methods (oven, sunlight and ambient air). The RSM was used to optimize the extraction conditions for the extraction of TPC of Moringa oleifera leaves. The optimum conditions that maximize the extraction of TPC were extraction time, 60 min; extraction temperature, 90(o)C and % of methanol, 50 % (v/v). TPC extracted under these conditions were 12.28, 12.65 and 13.14 mg GAE/g DW for samples dried by different methods. Significant difference between drying methods was found (p<0.001). Pair wise significant difference was found only between oven and ambient air drying methods (p<0.001).