Antimicrobial and In Vitro Cytotoxic Efficacy of Biogenic Silver Nanoparticles (Ag-NPs) Fabricated by Callus Extract of Solanum incanum L

Abstract

The in vitro callus induction of Solanum incanum L. was executed on MS medium supplemented with different concentrations of auxin and cytokinin utilizing petioles and explants of leaves. The highest significant fresh weights from petioles and leaf explants were 4.68 and 5.13 g/jar for the medium supplemented with1.0 mg L^-1 BA and 1.0 mg L^-1 2,4-D. The callus extract of the leaves was used for the green synthesis of silver nanoparticles (Ag-NPs). Analytical methods used for Ag-NPs characterization were UV-vis spectroscopy, Fourier Transform Infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and Transmission Electron Microscopy (TEM). Spherical, crystallographic Ag-NPs with sizes ranging from 15 to 60nm were successfully formed. The FT-IR spectra exhibited the role of the metabolites involved in callus extract in reducing and capping Ag-NPs. The biological activities of Ag-NPs were dose-dependent. The MIC value for Staphylococcus aureus, Bacillus subtilis, and Escherichia coli was 12.5 µg mL^-1, while it was 6.25 µg mL^-1 for Klebsiella pneumoniae, Pseudomonas aeruginosa, and Candida albicans. The highest inhibition of phytopathogenic fungi Alternaria alternata, Fusarium oxysporum, Aspergillus niger, and Pythium ultimum was 76.3 ± 3.7, 88.9 ± 4.1, 67.8 ± 2.1, and 76.4 ± 1.0%, respectively at 200 µg mL^-1. Moreover, green synthesized Ag-NPs showed cytotoxic efficacy against cancerous cell lines HepG2, MCF-7 and normal Vero cell line with IC₅₀ values of 21.76 ± 0.56, 50.19 ± 1.71, and 129.9 ± 0.94 µg mL^-1, respectively.

Keywords: Solanum incanum L.; antimicrobial; callus aqueous extract; in vitro cytotoxicity; phytopathogenic fungi; silver nanoparticles.

Figure 1

Field picture of Solanum incanum L. collects from Wadi Al Khilb, Al-Baha area, KSA.

Figure 2

Callus induction from leaves (A) and petioles (B) of Solanum incanum L. after five weeks of culture on MS medium supplemented with 2.4-D (1.0 mg L⁻¹) and BA (1.0 mg L⁻¹).

Figure 3

Characterization of green synthesized Ag-NPs using callus aqueous extract of S. incanum L. (A) UV-vis spectroscopy of biosynthesized Ag-NPs; (B) FT-IR spectra of callus aqueous extract and green synthesized Ag-NPs.

Figure 4

XRD pattern of Ag-NPs synthesized by callus aqueous extract of S. incanum L.

Figure 5

(A) Transmission Electron Microscopy (TEM) image; (B) particle size distribution; (C)Scanning Electron Microscopy (SEM); (D) EDX spectrum of Ag-NPs synthesized by callus extract of S. incanum L.

Figure 6

The antimicrobial activity of Ag-NPs synthesized by callus extract of S. incanum L. Data are statistically different at p ≤ 0.05, (n = 3); error bars are means ± SD (Standard deviation). For each treatment, bars with different letters indicate significantly different values at a significance level of p ≤ 0.05.

Figure 7

The activity of Ag-NPs synthesized using the callus extract of S. incanum L. against phytopathogenic fungi. Data are statistically different at p ≤ 0.05, (n = 3); error bars are means ± SD (standard deviation). The standard deviation is less than the size of the symbols if no error bars are seen.

Figure 8

Morphological change of two cancerous cells, HepG2 and MCF-7 due to exposure to different concentrations of Ag-NPs synthesized by callus aqueous extract of S. incanum L.

Figure 9

In vitro cytotoxic effects of Ag-NPs fabricated with the callus extract of S. incanum L. against two cancerous cells HepG2 and MCF-7. The data are statistically different at p ≤ 0.05, (n = 3); error bars are means ± SE (standard error).