Green Synthesis and Characterization of Silver Nanoparticles Using Anchusa Officinalis: Antimicrobial and Cytotoxic Potential

Abstract

Objective: Anchusa officinalis L. (A. officinalis) is a herbaceous traditional medicinal plant used in the treatment of some diseases. The presence of its medicinal properties suggested that A. officinalis (AO) leaf extract could be used as a coating agent for the environmentally friendly production of silver nanoparticles (AgNPs).

Methods: The synthesized biogenic silver nanoparticles (AO-AgNPs) were characterized using different techniques. The antimicrobial activity of AgNPs against common bacterial pathogenic strains was determined by the minimum inhibitory concentration (MIC) method. The presence of phytochemicals was determined by LSMS/MS. The MTT assay was used to investigate AO-AgNPs' cytotoxic activity in malignant (LnCap, Caco2, MDA-MB2, A549) and healthy (HEK-293) cell lines.

Results: LC-MS/MS analysis detected the presence of rich phytochemicals that may be responsible for reduction reactions. Biogenic AO-AgNPs exhibited effective inhibition of the growth of pathogenic microorganisms at low concentrations. The most effective antimicrobial activity was measured as 0.5 µg/mL MIC against S. aureus, E. coli, and C. albicans. Moreover, AO-AgNPs showed significant inhibition on the growth of cancerous cell lines, especially at a concentration of 25 μg/mL. On the contrary, it was determined that the inhibition rate decreased in the growth of healthy cell lines due to the increase in concentration. The lowest EC₅₀ values were determined as 15.15 µg/mL in A549 cells.

Conclusion: The obtained results showed that AO could be an important source for the synthesis of AgNPs. Especially their ability to inhibit the growth of antibiotic-resistant pathogenic bacteria at low concentrations compared to common antibiotics indicates that AO-AgNPs can be used as biomedical agents in various areas. Moreover, their suppressive effect on cancerous cell lines showed that they have the potential to be used as an anticancer agent, but due to their proliferative effect on healthy cell lines, care should be taken in determining the appropriate dose.

Keywords: Ag NPs; Anchusa officinalis; antimicrobial activity; biochemical composition; cytotoxic activity; green synthesis.

Figure 1

A schematic diagram of the biogenic Ag NP synthesis steps, characterization, and antimicrobial applications.

Figure 2

Places where Anchusa officinalis plant samples were collected (collections).

Figure 3

LC-ESI-MS/MS analysis chromatogram of Anchusa officinalis extract.

Figure 4

The ultraviolet-visible (UV-vis) spectrum of silver nanoparticles that were produced using A. officinalis.

Figure 5

FTIR spectra of pure AO leaf aqueous extract (A) and AO-capped Ag NPs (B).

Figure 6

XRD diagrams of biosynthesized AO-Ag.

Figure 7

Different magnifications SEM (A–C), and TEM (D–E) images of biologically synthesized silver nanoparticles by Anchusa officinalis leaf aqueous extract.

Figure 8

EDX data of AgNPs synthesized with leaf extract of Anchusa officinalis plant.

Figure 9

The results of the TGA-DTA study obtained from biogenic silver nanoparticles.

Figure 10

Zeta potential analysis of AgNPs obtained from the leaves of the Anchusa officinalis plant.

Figure 11

Continued.

Figure 11

Viability rates of MDA-MB231, LnCap, A549, Caco-2, and HEK293 cell lines 24 hours after interaction with AO-Ag NPs.