Assessing anticancer, antidiabetic, and antioxidant capacities in green-synthesized zinc oxide nanoparticles and solvent-based plant extracts

Abstract

Cancer and diabetes represent significant challenges in the field of biomedicine, with major and global impacts on public health. Acacia nilotica, commonly called 'gum arabic tree,' is recognized for its unique biomedical properties. The current study aimed to investigate the pharmacological potential of A. nilotica-based zinc-oxide nanoparticles (ZnO-NPs) in comparison to the ethanol and methanol-based extracts against cancer, diabetes, and oxidative stress. Green synthesis of ZnO-NPs was performed using barks of Acacia nilotica. Different techniques for the characterization of ZnO-NPs, including UV-Visible spectroscopy, Scanning Electron Microscopy, Fourier Transmission Infrared (FT-IR) spectroscopy, and X-ray Diffraction (XRD), were utilized. The morphological analysis of ZnO-NPs revealed that the fine NPs have mean particle sizes of 15 ± 1.5 nm. For the solvent based-extraction, leaves and barks were utilized and dissolved into ethanol and methanol for further processing. The MTT assay revealed that the optimum concentration of ZnO-NPs to inhibit the proliferation of liver cancer cell line HepG2 was 100 μg/mL where 67.0 % inhibition was observed; and both ethanol- and methanol-based extracts showed optimum inhibition at 100 μg/mL. The DPPH assay further demonstrated that 250 μg/mL of ZnO-NPs and 1000 μg/mL of both ethanol- and methanol-based extracts, as the optimum concentration for antioxidant activity (with 73.1 %, 68.9 % and 68.2 % inhibition respectively). The α-Glucosidase inhibition assay revealed that 250 μg/mL of ZnO-NPs and 10 μg/mL of both ethanol- and methanol-based extracts as the optimum concentration for antidiabetic activity (with 95 %, 93.7 % and 93.4 % inhibition respectively). The study provided interesting insights into the efficacy and reliability of ZnO-NPs for potential pharmacological application. Further research should be focused on examining specific pathways and the safety of ZnO-NPs in comparison to solvent-based extracts.

Keywords: Acacia nilotica; DPPH assay; HepG2; Liver cancer; α-Glucosidase inhibition assay.

Fig. 1

(a) UV–visible spectrophotometric Analysis of ZnO-NPs, (b) Analysis of functional-groups location of ZnO-NPs using FTIR spectroscopy.

Fig. 2

Scanning Electron Microscopic images of Zinc nanoparticles fabricated using bark extract of Acacia nilotica.

Fig. 3

(a) X-ray diffraction analysis of ZnO-NPs synthesizes from Acacia nilotica,(b) ZnO-NPs average size of particles: estimated to be (15 ± 1.5).

Fig. 4

Comparison between the anti-cancer activity of Zinc oxide nanoparticles and solvent-based plant extracts, 4a)-the anti-cancer activity of ZnO-NPs, 4b) - the anti-cancer activity of ethanol and methanol-based plant extracts using barks and leaves of Acacia nilotica. Values are presented as mean ± SD of three different experiments. Analysis of variance (ANOVA) reveals the significant influence of tested groups; p < 0.0001.

Fig. 5

Comparison between the anti-oxidant activity of Zinc oxide nanoparticles and solvent-based plant extracts, 5a)-the anti-oxidant activity of ZnO-NPs, 5b) - the anti-oxidant activity of ethanol and methanol-based plant extracts using barks and leaves of Acacia nilotica. Values are presented as mean ± SD of three different experiments. Analysis of variance (ANOVA) reveals the significant influence of tested groups; p < 0.0001.

Fig. 6

Comparison between the anti-diabetic activity of Zinc oxide nanoparticles and solvent-based plant extracts, 6a)-the anti-diabetic activity of ZnO-NPs, 6b) - the anti-diabetic activity of ethanol and methanol-based plant extracts using barks and leaves of Acacia nilotica. Values are presented as mean ± SD of three different experiments. Analysis of variance (ANOVA) reveals the significant influence of tested groups; p < 0.0001.