Green synthesis and characterization of zinc oxide nanoparticles using bush tea (Athrixia phylicoides DC) natural extract: assessment of the synthesis process.

Background: Nanoparticles are globally synthesized for their antimicrobial, anti-inflammatory, wound healing, catalytic, magnetic, optical, and electronic properties that have put them at the forefront of a wide variety of studies. Among them, zinc oxide (ZnO) has received much consideration due to its technological and medicinal applications. In this study, we report on the synthesis process of ZnO nanoparticles using Athrixia phylicoides DC natural extract as a reducing agent. Methods: Liquid chromatography–mass spectrometry (LC-MS) was used to identify the compounds responsible for the synthesis of ZnO nanoparticles. Structural, morphological and optical properties of the synthesized nanoparticles have been characterized through X-ray diffraction (XRD), Ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). Results: LC-MS results showed that different flavonoids and polyphenols, as well as Coumarin, an aromatic compound, reacted with the precursor to form ZnO nanoparticles. XRD and UV-Vis analysis confirmed the synthesis of ZnO nanoparticles, with a spherical shape showed in SEM images. The quasi-spherical ZnO crystals had an average crystallite size of 24 nm. EDS and FTIR analysis confirmed that the powders were pure with no other phase or impurity. Conclusions: This study successfully demonstrated that the natural plant extract of A. phylicoides DC. can be used in the bio-reduction of zinc nitrate hexahydrate to prepare pure ZnO nanoparticles, thus, extending the use of this plant to an industrial level.

Photoprotection and Photostability of a New Lignin-Gelatin-Baccharis antioquensis-Based Hybrid Biomaterial

The aim of this study was to develop a new hybrid biomaterial that could photo-stabilize and improve the photoprotective capacity of a Baccharis antioquensis extract. Different combinations of lignin/gelatin/natural extract were applied to prepare hybrid biomaterial nanoparticles (NPs), which were then incorporated into an emulsion. The in vitro photoprotection and photostability were evaluated. The methanolic extract showed high phenolic content (646.4 ± 9.5 mg GAE/g dry extract) and a DPPH radical assay revealed that the antiradical capacity of the extract (0.13 to 0.05 g extract/mmol DPPH) was even better than that of BHT. The particle size of the hybrid biomaterial ranged from 100 to 255 nm; a polydispersity index (PdI) between 0.416 and 0.788 is suitable for topical use in dermocosmetic products. The loading capacity of the extract ranged from 27.0 to 44.5%, and the nanoparticles (NPs) showed electrostatic stability in accordance with the zeta potential value. We found that the formulation based on lignin: extract (1:1 ratio) and gelatin: lignin: extract (0.5:0.5:1 ratio) demonstrated photoprotection qualities with a sun protection factor (SPF) ranging from 9.4 to 22.6. In addition, all the hybrid NP-formulations were time-stable with %SPFeff and %UVAPFeff greater than 80% after exposure to 2 h of radiation. These results suggest that the hybrid biopolymer-natural extract improved the photoprotection and photostability properties, as well as the antiradical capacity, of the B. antioquensis extract, and may be useful for trapping high polyphenol content from natural extracts, with potential application in cosmeceutical formulations.

Effect of the Processing Parameters on the Fabrication of MgAl2O4 Foams

Stable MgAl2O4 foams (7–21 vol.%) were manufactured using a natural extract from the pericarp of the soap-nut fruit, saponin being the main component, as the foaming agent. The soap-nut extract is soluble in water, biodegradable, non-toxic, and has similar properties to commercial tensoactives. The stability and characteristics of the porous structure of the ceramic foams were evaluated in terms of the amount of foaming agent, content of MgAl2O4 particles, time and speed of stirring of the slurry, type of agitator, and drying temperature. It was found that the foaming capacity decreased with the percent of foaming agent and ceramic, whereas the time and speed of stirring enhanced the foamability. Foaming trials showed that stirring aqueous slurries with 3 wt.% of soap-nut extract for 2 min at 1070 or 2120 rpm, depending on the type of agitator, produced stable MgAl2O4 foams when drying at 60 °C. The mechanism of foaming is discussed. The foams were sintered at 1400 °C for 1 h under an Ar atmosphere. Observation of the sintered foam structures in the scanning electron microscope revealed nearly spherical cells with very good interconnectivity and strength to be manipulated, making them suitable as preforms for manufacturing Al-based composites by pressureless infiltration.

Correlation of the structural and morphological property of the formation of ZnO nanoparticles using Ricinus Communis extract as a ligand and synthesized through two different precipitating agents

The present work defines the structural and morphological behavior of ZnO nanoparticles (ZnONP) synthesized via using Ricinus Communis (Castor) extracts. Two precipitating agents (bases) were used to regulate the pH (10), in presence of this natural extract the determination of structural, morphological and functional groups availability was performed to evaluate the enhancement in crystallite size, shape formation and colloidal stability of the nanoparticle.

Effect of Dietary Supplementation with a Natural Extract of Sclerocarya birrea on Glycemic Metabolism in Subjects with Prediabetes: A Randomized Double-Blind Placebo-Controlled Study

A randomized, double-blind, placebo-controlled study was conducted with the primary objective of assessing the effect of a natural extract of Sclerocarya birrea on glucose metabolism in subjects with prediabetes. The duration of the study was 90 days. Thirty-three subjects assigned to the experimental group (daily ingestion of 100 mg of the nutraceutical product) and 34 assigned to the placebo group completed the study. There were 36 men and 31 women with a mean age of 32.3 ± 14.1 years. In the area under the curve (AUC) of the oral glucose tolerance test (OGTT), statistically significant decreases in the experimental group at 40 and 90 days as compared with baseline were found, whereas significant changes in the placebo group were not observed. Within-group differences were statistically significant in favor of the experimental group for glucose peak at OGTT, serum insulin, insulin resistance markers, and flow-mediated dilation. Changes in lipid and anthropometric parameters were not observed, although there was a trend for lower cholesterol levels and a decrease in body weight in the experimental group. Decreases in systolic blood pressure were also higher among subjects in the experimental group. This exploratory study confirms the antidiabetic activity of Sclerocarya birrea in prediabetes. Further studies using better measurements of beta-cell function are needed to clarify the underlying mechanisms of the hypoglycemic effect of this natural compound.