Use of A Hydroalcoholic Extract of Moringa oleifera Leaves for the Green Synthesis of Bismuth Nanoparticles and Evaluation of Their Anti-Microbial and Antioxidant Activities

Abstract

The employment of plant extracts in the synthesis of metal nanoparticles is a very attractive approach in the field of green synthesis. To benefit from the potential synergy between the biological activities of the Moringa oleifera and metallic bismuth, our study aimed to achieve a green synthesis of phytochemical encapsulated bismuth nanoparticles using a hydroalcoholic extract of M. oleifera leaves. The total phenolic content in the M. oleifera leaves extract used was 23.0 ± 0.3 mg gallic acid equivalent/g of dried M. oleifera leaves powder. The physical properties of the synthesized bismuth nanoparticles were characterized using UV-Vis spectrophotometer, FT-IR spectrometer, TEM, SEM, and XRD. The size of the synthesized bismuth nanoparticles is in the range of 40.4–57.8 nm with amorphous morphology. Using DPPH and phosphomolybdate assays, our findings revealed that the M. oleifera leaves extract and the synthesized bismuth nanoparticles possess antioxidant properties. Using resazurin microtiter assay, we also demonstrate that the M. oleifera leaves extract and the synthesized bismuth nanoparticles exert potent anti-bacterial activity against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, and Enterococcus faecalis (estimated MIC values for the extract: 500, 250, 250, and 250 µg/mL; estimated MIC values for the bismuth nanoparticles: 500, 500, 500, and 250 µg/mL, respectively). Similarly, the M. oleifera leaves extract and the synthesized bismuth nanoparticles display relatively stronger anti-fungal activity against Aspergillus niger, Aspergillus flavus, Candida albicans, and Candida glabrata (estimated MIC values for the extract: 62.5, 62.5, 125, and 250 µg/mL; estimated MIC values for the bismuth nanoparticles: 250, 250, 62.5, and 62.5 µg/mL, respectively). Thus, green synthesis of bismuth nanoparticles using M. oleifera leaves extract was successful, showing a positive antioxidant, anti-bacterial, and anti-fungal activity. Therefore, the synthesized bismuth nanoparticles can potentially be employed in the alleviation of symptoms associated with oxidative stress and in the topic treatment of Candida infections.

Quaternary Trimethyl Chitosan Chloride Capped Bismuth Nanoparticles with Positive Surface Charges: Catalytic and Antibacterial Activities

“…1c). Das and coworkers recently revealed that BiNPs had a distinctive absorption peak at 270 nm, which is almost identical to the absorption band found in our study [24]. Similarly, a prior study found a UV-Vis absorption peak at 285 nm in nanometer-sized bismuth particles [27].…”

“…Row 12 was used as a control (medium and bacterial inoculums). Following the incubation period, each well of the microtiter plate was filled with 30 mL (0.015%) resazurin solution and incubated at 37°C for 2 to 4 h to observe color change [20,23,24]. MBC was also calculated by collecting the contents of wells in three plates with concentrations greater than the MIC value.…”

Antioxidant and Antibacterial Activities of Magnesium Oxide Nanoparticles Prepared using Aqueous Extract of Moringa Oleifera Bark as Green Agents

“…Antioxidant activity of Moringa oleifera bark aqueous extract (BEM) and MgONPs was evaluated through (2,2-diphenyl-1-picrylhydrazyl) DPPH radical testing in accordance with the procedure described by Das et al [29], using ascorbic acid as reference. DPPH 0.1 mM solution is was prepared by dissolving in ethanol.…”

“…Different methods are used to qualitatively test phytochemical compounds contained in moringa oleifera (BEM) extracts. The test method used refers to the report Das et al [29], Qualitative evaluations of several chemical contents are shown in Table 1. Table 1 shows BEM containing phytochemical compounds such as alkaloids, flavonoids, saponins, and phenolics.…”

“…Total phenolic and flavonoid levels in bark water extracts are lower than total phenolic and flavonoid levels in water extracts of other M. oleifera plants that have been previously reported. Siddhuraju and Becker [30] reported total phenolic content in leaves is 74.30 ± 9.00 (µg / mg GAE), while Mohammed and Manan [31] reported total phenolic content in ore is 101.79 ± 2.89 (µg / mg GAE). The total flavonoid content in leaf water extract was reported by Okumu et al [32] amounted to 79.13 ± 13.04 (µg / mg CE).…”