Green-synthesized silver nanoparticles from Zingiber officinale extract: antioxidant potential, biocompatibility, anti-LOX properties, and in silico analysis

Abstract

Introduction: Zingiber officinale extract has emerged as a compelling candidate for green synthesis of nanoparticles, offering diverse applications across medicine, cosmetics, and nutrition. This study delves into the investigation of in vitro toxicity and explores the biomedical utility of green-synthesized silver nanoparticles derived from ginger extract (GE-AgNPs).

Methods: We employed established protocols to evaluate in vitro aspects such as antioxidant capacity, anti-inflammatory potential, and biocompatibility of GE-AgNPs. Additionally, molecular docking was employed to assess their anti-lipoxygenase (anti-LOX) activity.

Results: Our findings highlight that the extraction of ginger extract at a pH of 6, utilizing a cosolvent blend of ethanol and ethyl acetate in a 1:1 ratio, yields heightened antioxidant capacity attributed to its rich phenolic and flavonoid content. In the context of silver nanoparticle synthesis, pH 6 extraction yields the highest quantity of nanoparticles, characterized by an average size of 32.64 ± 1.65 nm. Of particular significance, GE-AgNPs (at pH 6) demonstrated remarkable efficacy in scavenging free radicals, as evidenced by an IC₅₀ value of 6.83 ± 0.47 µg/mL. The results from the anti-LOX experiment indicate that GE-AgNPs, at a concentration of 10 µg/mL, can inhibit LOX activity by 25%, outperforming ginger extract which inhibits LOX by 17-18%. Notably, clionasterol exhibited higher binding energy and enhanced stability (-8.9 kcal/mol) compared to nordihydroguaiaretic acid. Furthermore, a cell viability study confirmed the safety of GE-AgNPs at a concentration of 17.52 ± 7.00 µg/mL against the L929 cell line.

Conclusion: These comprehensive findings underscore the significant biomedical advantages of GE-AgNPs and emphasize their potential incorporation into cosmetic products at a maximum concentration of 10 µg/mL.

Keywords: Anti-LOX; Antioxidant; Biocompatibility; Silver nanoparticles; Zingiber officinale.

Fig. 1

A DPPH radical scavenging activity of ginger extracts, B DPPH radical scavenging activity of GE-AgNPs, C ABTS radical scavenging activity of ginger extracts, D ABTS radical scavenging activity of GE-AgNPs. Standard deviations, calculated from triplicate determinations of each concentration, are represented by the bars. Trolox (yellow) and ascorbic acid (purple) served as references, while red, orange, blue, and green bars corresponded to pH 7, pH 6, pH 5 of ethyl acetate: ethanol cosolvents, and water extract, respectively

Fig. 2

A Vials containing silver nitrate with colorless and AgNPs synthesized from ginger extract with water and various pH cosolvents. B UV–visible range spectra of the synthesized AgNPs using ginger extract in water and a 50:50 ethanol and ethyl acetate cosolvent at different pH levels

Fig. 3

particle size histogram of silver nanoparticles with reducing agents of aqueous ginger extract (A1), cosolvent ginger extract in pH 5 (A2), pH 6 (A3), pH 7 (A4) and surface charge distribution with reducing agents of aqueous ginger extract (B1), cosolvent ginger extract in pH 5 (B2), pH 6 (B3), pH 7 (B4)

Fig. 4

Transmission electron microscopy (TEM) of silver nanoparticles with reducing agents of aqueous ginger extract (A1), cosolvent ginger extract in pH 5 (A2), pH 6 (A3), pH 7 (A4) and EDS spectrum with reducing agents of aqueous ginger extract (B1), cosolvent ginger extract in pH 5 (B2), pH 6 (B3), pH 7 (B4)

Fig. 5

Fourier transform infrared spectra of silver nitrate (blue) and silver nanoparticles from ginger (red)

Fig. 6

The morphology of L929 cell line: A co-cultured with ginger extracts and (B) silver nanoparticles. Cell viability of L929 Cells: C co-cultured with ginger extracts and (D) silver nanoparticles. Incubated for 24 h with aqueous ginger extract (red), cosolvent ginger extract at pH 5 (green), pH 6 (blue), pH 7 (orange), compared with untreated (Control) and toxic control (Triton-X-100). Scale bar: 250 µm

Fig. 7

Molecular docking conformation of (A) positive control as nordihydroguaiaretic acid, and ginger extracts containing (B) 6-gingerol, (C) 6-shogaol, (D) butan-2-one, 4-(3-hydroxy-2-methoxyphenyl)-, (E) Alpha-curcumene, (F) diacetoxy-6-gingerdiol, (G) 6-isoshogaol, (H) 3-decanone,1-(4-hydroxy-3-methoxyphenyl)-, (I) 8-shogaol, (J) (S)-8-gingerol, (K) 1-(4-hydroxy-3-methoxyphenyl)tetradec-4-en-3-one, and (L) clionasterol at active site of LOX

Fig. 8

linoleic acid was employed as the substrate to investigate the potential inhibition of lipoxygenase (LOX) activity. Gallic acid (GA), utilized as a positive control, alongside silver nanoparticles synthesized from ginger extracted using co-solvent represented by AgNPs(Co), silver nanoparticles synthesized from ginger extracted using water depicted by AgNPs(W), ginger extracted using water (W), and ginger extracted using co-solvent (Co) were tested at concentrations of 10 g/mL (red bars) and 100 µg/mL (green bars). Notably, all tested compounds exhibited inhibitory effects on the enzyme activity. Error bars in the graph signify the standard deviation from the mean, and each bar represents the average result derived from three independent experimental trials