Exploring the Antimicrobial, Anticancer, and Apoptosis Inducing Ability of Biofabricated Silver Nanoparticles Using Lagerstroemia speciosa Flower Buds against the Human Osteosarcoma (MG-63) Cell Line via Flow Cytometry

Abstract

Biosynthesized nano-composites, such as silver nanoparticles (AgNPs), can be engineered to function as smart nano-biomedicine platforms for the detection and management of diverse ailments, such as infectious diseases and cancer. This study determined the eco-friendly fabrication of silver nanoparticles using Lagerstroemia speciosa (L.) Pers. flower buds and their efficacy against antimicrobial and anticancer activities. The UV-Visible spectrum was found at 413 nm showing a typical resonance spectrum for L. speciosa flower bud extract-assisted silver nanoparticles (Ls-AgNPs). Fourier transform infrared analysis revealed the presence of amines, halides, and halogen compounds, which were involved in the reduction and capping agent of AgNP formation. X-ray diffraction analysis revealed the face-centered cubic crystals of NPs. Energy dispersive X-ray verified the weight of 39.80% of silver (Ag), TEM analysis revealed the particles were spherical with a 10.27 to 62.5 nm range, and dynamic light scattering recorded the average particle size around 58.5 nm. Zeta potential showed a significant value at -39.4 mV, and finally, thermo-gravimetric analysis reported higher thermal stability of Ls-AgNPs. Further, the obtained Ls-AgNPs displayed good antimicrobial activity against clinical pathogens. In addition, a dose-dependent decrease in the anticancer activity by MTT assay on the osteosarcoma (MG-63) cell line showed a decrease in the cell viability with increasing in the concentration of Ls-AgNPs with an IC₅₀ value of 37.57 µg/mL. Subsequently, an apoptotic/necrosis study was conducted with the help of Annexin-V/PI assay, and the results indicated a significant rise in early and late apoptosis cell populations. Therefore, green synthesized Ls-AgNPs were found to have potent antimicrobial and anticancer properties making them fascinating choices for future bio-medical implementations.

Keywords: Lagerstroemia speciosa flower bud; MG-63 cancer cell line; MTT assay; apoptosis/necrosis; bio-fabricated synthesis; flow cytometry; silver nanoparticles.

Figure 1

(A) Lagerstroemia speciosa plant habit and (B) collected flower buds.

Figure 2

Synthesis of Ls-AgNPs from L. speciosa: (A) pale yellow colored flower bud aqueous extract, (B) 1 mM AgNO₃ solution, (C) change of the color to darkish brown after an incubation period of 24 h, and (D) UV-Visible absorption spectrum of synthesized Ls-AgNPs.

Figure 3

(A) FTIR spectrums of L. speciosa flower bud extract and (B) synthesized Ls-AgNPs showing the presence of functional groups.

Figure 4

XRD pattern of biosynthesized Ls-AgNPs.

Figure 5

EDX spectrum of biosynthesized Ls-AgNPs.

Figure 6

TEM image of biosynthesized Ls-AgNPs.

Figure 7

(A) Zeta potential analysis graph of biosynthesized Ls-AgNPs, and (B) DLS analysis graph of biosynthesized Ls-AgNPs.

Figure 8

Thermo gravimetric analysis curve of biosynthesized Ls-AgNPs.

Figure 9

Antimicrobial activity of Ls-AgNPs biosynthesized from the flower buds extract (A) E.coli, (B) S. aureus, (C) C. albicans, (D) C. glabrata, and (E) graph showing the zone of inhibition for Ls-AgNPs.

Figure 10

MTT assay of different volumes of biosynthesized Ls-AgNPs: (A) untreated cells, (B) standard control, (C) 12.5 μg/mL, (D) 25 μg/mL, (E) 50 μg/mL, (F) 100 μg/mL, (G) 200 μg/mL, and (H) bar graph showing comparative cell viability percentages.

Figure 11

Quadrangular plots showing the Annexin V/PI expression in MG-63 cancer cells: (A) untreated cells, (B) cancer cells treated with Ls-AgNPs, (C) cell cycle arrest of untreated cells, and (D) cell cycle arrest of treated cells.

Figure 12

Schematic representation of possible model mechanism and mode of action of silver nanoparticles in cancer cells.