Biogenic green synthesis of MgO nanoparticles using Saussurea costus biomasses for a comprehensive detection of their antimicrobial, cytotoxicity against MCF-7 breast cancer cells and photocatalysis potentials

Abstract

Distinct morphological MgO nanoparticles (MgONPs) were synthesized using biomasses of Saussurea costus roots. The biomass of two varieties of Saussurea costus (Qustal hindi and Qustal bahri) were used in the green synthesis of MgONPs. The physical and chemical features of nanoparticles were confirmed by spectroscopic and microscopic techniques. The surface morphology of the obtained nanoparticles was detected at different magnifications by SEM and TEM microscopy and the size of nanoparticles were found to be 30 and 34 nm for Qustal hindi and Qustal bahri, respectively. The antimicrobial activity of the prepared MgONPs was screened against six pathogenic strains. The synthesized nanoparticles by Qustal bahri biomass exerted significant inhibition zones 15, 16, 18, 17, 14, and 10 mm against E. coli, P. aeruginosa, C. tropicalis and C. glabrata, S. aureus and B. subtilis as compared to those from Qustal hindi 12, 8 and 17 mm against B. subtilis, E. coli and C. tropicalis, respectively. MgONPs showed a potential cytotoxicity effect against MCF-7 breast cancer cell lines. Cellular investigations of MgONPs revealed that the prepared nanoparticles by Qustal bahri exhibited high cytotoxicity against MCF-7 cancer cell lines. IC50 values in MCF-7 cells were found to be 67.3% and 52.1% for MgONPs of Saussurea costus biomasses, respectively. Also, the photocatalytic activity of MgONPs of each Saussurea costus variety was comparatively studied. They exhibited an enhanced photocatalytic degradation of methylene blue after UV irradiation for 1 h as 92% and 59% for those prepared by Qustal bahri and Qustal hindi, respectively. Outcome of results revealed that the biosynthesized MgONPs showed promising biomedical potentials.

Fig 1

(A) UV-Vis, (B) FT-IR and (C) XRD spectra of MgONPs synthesized with S.costus (Qustal hindi and Qustal bahri) biomasses, respectively.

Fig 2

(a and b), (c and d) are the TEM and SEM images of MgONPs synthesized by S.costus (Qustal hindi and Qustal bahri) biomasses, respectively.

Fig 3

(A) EDS analysis (B) DLS and Zeta potential of MgONPs synthesized by S.costus (Qustal hindi and Qustal bahri), respectively.

Fig 4. Antimicrobial activity of MgONPs synthesized by S. costus (Qustal hindi and Qustal bahri) against four bacterial strains.

Fig 5

Minimum bactericidal concentrations (μg mL^-1) of the MgONPs (Qustal bahri) against (a) E. coli (b) P. aeruoginosa. Results are expressed as Mean ± SD of triplicate experiments.

Scheme 1. Schematic diagram of the mechanism of antibacterial and cytotoxicity potential of MgONPs.

Fig 6. SEM images of untreated and treated with MgONPs (Qustal bahri) and altered shape of E. coli and P. aeruginosa.

Fig 7. Antifungal activity of MgONPs synthesized by S. costus biomasses against C. tropicalis and C. glabrata.

Fig 8

Anticancer effect of MgONPs on MCF-7 cells (A) MTT analysis to estimate the cytotoxicity (B) LHD assay to detect the membrane integrity and (C) microscopic images describing morphological changes.

Fig 9

(A) Light microscope showing DNA fragmentation in MCF-7 cells, (B) Fluorescence microscopic images of MCF-7 cells treated with CM-H2 DCFDA, intracellular ROS indicator after treatment with MgONPs (C) quantification of ROS level using fluorescence spectroscopy, (D) Fluorescence microscopic images of MCF-7cells treated with JC-1 staining to assess the mitochondrial membrane potential (ΔΨm) after treatment with the MgONPs for 24 h in comparison with Piacitaxel (40×) (E) Bar diagram illustrating the percentage of cells with disrupted MMP.

Fig 10

Antiproliferative effect of MgONPs at its IC₅₀ in MCF-7 cells as depicted by (A) AO/EtBr double staining (B) quantification of apoptotic population (C) DAPI staining (D) Wound healing showing inhibition of cellular migration in MgONPs treated group of MCF-7 cells.

Fig 11. Catalytic effect of MgONPs calculated as % of MB dye degradation in the presence of UV radiation and sunlight.