In Situ Biosynthesis of Reduced Alpha Hematite (α-Fe2O3) Nanoparticles by Stevia Rebaudiana L. Leaf Extract: Insights into Antioxidant, Antimicrobial, and Anticancer Properties

Abstract

In the present study, we utilized Stevia rebaudiana L. (SRLe) extract to in situ biosynthesize nanoscale alpha hematite (α-Fe 2 O 3 ) nanoparticles (NPs) with potent antioxidant, antimicrobial, and anticancer properties. SRLe-α-Fe 2 O 3 was characterized using physiochemical analyses, including UV/Vis, FTIR, XRD, DLS, EDX, SEM, and TEM studies. Among tested solvents, CHCl 3 /MeOH (2:1 v / v ) SRL extract (least polar solvent) contained the highest EY, TPC, and antioxidant capacity of ~3.5%, ~75 mg GAE/g extract, and IC 50 = 9.87 ± 0.7 mg/mL, respectively. FTIR confirmed the engagement of coating operation to the colloidal α-Fe 2 O 3 NPs. TEM, SEM, and DLS revealed that SRLe-α-Fe 2 O 3 has a spherical shape, uniform size distribution with aggregation for an average size of ~18.34 nm, and ζ = −19.4 mV, forming a repulsive barrier that helped to improve stability. The synthesized nanoparticles displayed considerable antibacterial activity against E. coli and S. aureus bacterial growth, and exhibited superior activity against the A549 lung cancer cell lines. These findings indicate that the increased availability of bioactive substances with antioxidant properties of SRLe makes it a potentially interesting material for the preparation of biologically active compounds and green synthesis of nanoparticles.

Eggshell-Mediated Hematite Nanoparticles: Synthesis and Their Biomedical, Mineralization, and Biodegradation Applications

“…The free scavenging radical activity (RSA) improved with the concentration of iron oxide NPs, as shown in Figure 11. Eggshell-mediated hematite NPs showed 95% of RSA, which was higher, as reported earlier [48]. Ascorbic acid was used as the control and exhibited 96% antioxidant activity.…”

Novel Copper Oxide Bio-Nanocrystals to Target Outer Membrane Lectin of Vancomycin-Resistant Enterococcus faecium (VREfm): In Silico, Bioavailability, Antimicrobial, and Anticancer Potential

“…According to earlier investigations, the oleuropein exists in high concentrations compared to other phenolic components as observed by the HPLC chromatogram of olive leaf extract [25,26]. Oleuropein, a highly unstable molecule that quickly breaks down into the more polarizable hydroxytyrosol (C 8 H 10 O 3 ) in organic solvents, may have played a role in the capping action CuO-NS underwent in the current work to modify high-energy planes (atoms).…”

Antimicrobial properties in nanoparticles synthesized by biogenic route

“…En cuanto a las nanopartículas de óxido de hierro (FeO) y ZnO, las investigaciones de [24], [28], [30], [32], [44] obtuvieron resultados similares, con volúmenes de extractos menores a 15 mL, obteniendo dimensiones entre los 7-21 nm. A pesar de ello, los estudios [19]- [22], [33], [45] difieren pues al aplicar volúmenes de extracto mayores, obtuvieron nanoestructuras de similar tamaño.…”

“…Los estudios mencionan distintos mecanismos de acción, como la interacción electrostática entre la nanoestructura y la membrana celular [21], [31], [34], [41], [43], a pesar de ello [24], [30] recalcan la rigidez de la membrana de las bacterias gram negativas debido a la presencia de peptidoglucano, lípidos y lipoproteínas; la literatura también considera la digestión del ADN [35], [44].…”