Antifungal and antiovarian cancer properties of α Fe2O3 and α Fe2O3/ZnO nanostructures synthesised by Spirulina platensis

Abstract

Candida albicans (C. albicans) infection shows a growing burden on human health, and it has become challenging to search for treatment. Therefore, this work focused on the antifungal activity, and cytotoxic effect of biosynthesised nanostructures on human ovarian tetracarcinoma cells PA1 and their corresponding mechanism of cell death. Herein, the authors fabricated advanced biosynthesis of uncoated α-Fe₂O₃ and coated α-Fe₂O₃ nanostructures by using the carbohydrate of Spirulina platensis. The physicochemical features of nanostructures were characterised by UV-visible, high resolution transmission electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. The antifungal activity of these nanostructures against C. albicans was studied by the broth dilution method, and examined by 2', 7'-dichlorofluorescein diacetate staining. However, their cytotoxic effects against PA1 cell lines were evaluated by MTT and comet assays. Results indicated characteristic rod-shaped nanostructures, and increasing the average size of α-Fe₂O₃@ZnO nanocomposite (105.2 nm × 29.1 nm) to five times as compared to α-Fe₂O₃ nanoparticles (20.73nm × 5.25 nm). The surface coating of α-Fe₂O₃ by ZnO has increased its antifungal efficiency against C. albicans. Moreover, the MTT results revealed that α-Fe₂O₃@ZnO nanocomposite reduces PA1 cell proliferation due to DNA fragmentation (IC₅₀ 18.5 μg/ml). Continual advances of green nanotechnology and promising findings of this study are in favour of using the construction of rod-shaped nanostructures for therapeutic applications.

Fig. 1

UV spectrum of iron oxide NPs (black line) and iron oxide NPs coated by zinc oxide nanocomposite (red line)

Fig. 2

FTIR spectra for (a) Dried S. platensis (green line), α‐Fe₂ O₃ NPs@ ZnO (red line), and iron oxide NPs (black line), (b) Magnification for low IR region of iron oxide@ZnO nanocomposite

Fig. 3

Carbohydrate test confirmed the presence of violet ring in both (a) Biogenic iron oxide NPs, (b) S. platensis extract

Fig. 4

XRD pattern of (a) Biosynthesised iron oxide NPs, (b) Iron oxide@ZnO nanocomposite

Fig. 5

HRTEM images of (a) , (b) α‐Fe₂ O₃, (c) , (d) α‐Fe₂ O₃ @ZnO nanocomposite biosynthesised by S. platensis extract

Fig. 6

Antimicrobial activities of uncoated αFe₂ O₃ NPs and coated αFe₂ O₃ NPs@ZnO nanocomposite (a) By using agar diffusion method, (b) Against C. albicans, (c) Antifungal activity using broth dilution method

Fig. 7

Live & dead staining, and ROS assay of C. albicans. for live & dead staining (a) Untreated C. albicans, (b) 100 µg/ml of αFe₂ O₃ NPs treated C. albicans, (c) Treated with 100 µg/ml of αFe₂ O₃ @ZnO nanocomposite treated C. albicans. Red and green arrows indicated dead and live cells, respectively

Fig. 8

Determination of size distribution and zeta potential of (a) , (c) Uncoated αFe₂ O₃ NPs, (b) , (d) Coated αFe₂ O₃ NPs@ZnO by using dynamic light scattering

Fig. 9

ROS mechanism for uncoated α‐Fe₂ O₃ NPs and coated α‐Fe₂ O₃ @ZnO antifungal treatments (a) Untreated C. albicans, (b) 100 µg/ml of αFe₂ O₃ NPs treated C. albicans, (c) , (d) 100 µg/ml of αFe₂ O₃ @ZnO nanocomposite treated C. albicans

Fig. 10

(a–d) representative photomicrographs and histogram of cytotoxic effect on PA‐1 cancer cells (a) Untreated PA‐1 cells, (b) Coated α‐Fe₂ O₃ @ZnO at 18.5 µg/ml treated PA‐1 cells, (c) Uncoated α‐Fe₂ O₃ at 25 µg/m treated PA‐1 cells. Arrow indicates the morphological changes in PA‐1 cancer cells, (d) Anti‐proliferative effects of uncoated α‐Fe₂ O₃ NPs, coated α‐Fe₂ O₃ @ZnO on the PA‐1 cancer cells

Fig. 11

Breakage of DNA strands represented by % of DNA tail and length in treated PA‐1 cells compared to untreated PA‐1 cells (a), (b) Treated PA‐1 cells with 15& 20 µg/ml of coated α‐Fe₂ O₃ @ZnO nanocomposite, (c), (d) Treated PA‐1 cells with 20 & 25 µg/ml of uncoated α‐Fe₂ O₃ NPs, compared to untreated PA‐1 cells, * indicates – IC₅₀

Fig. 12

Effect of coated α‐Fe₂ O₃ @ZnO and uncoated α‐Fe₂ O₃ NPs on PA‐1 cells by comet assay (DNA damage) (a) Untreated PA‐1 cells, (b) Treated PA‐1 cell with 20 µg/ml of α‐Fe₂ O₃ @ZnO, (c) Treated PA‐1 cell with 20 µg/ml of α‐Fe₂ O₃, observed after 24 h and stained with EtBr