Phyto-mediated biosynthesis of silver nanoparticles using Aloe barbadensis Miller leaves gel with improved antibacterial, anti-fungal, antioxidant, anti-inflammatory, anti-diabetic, and anti-cancer activities

Abstract

An effective topical therapeutic agent requires a multifunctional attribute such as antibacterial, antioxidant, and anti-inflammatory efficacy. The green-synthesized metallic and metallic oxide nanoparticles have shown significant applicability in this regard. Hence a biosynthesis of silver nanoparticles (AgNPs) using Aloe barbadensis miller leaf gel was fabricated and evaluated for effect of imperative influences such as temperature, time, and concentration of reactant on AgNPs synthesis. Furthermore, the biomimetic qualities were assessed to ensure the safety and efficacy. The synthesis of stabilized and capped AgNPs presented a UV–vis–based plasmonic resonance at ∼ 400 nm. The reduction of silver nitrate was further confirmed by the shift in FTIR spectra for -OH around 2870 cm⁻¹. SEM and TEM images revealed cubic shape of the AgNPs. Whereas X-ray diffraction pattern indicated crystalline structure (crystallite size of ∼ 31.14 nm) with an inter-planar spacing value of 2.77, 1.96, and 1.67 Å for (200), (220), and (311) planes, respectively. In addition, AgNPs indicated a steady dispersion, homogeneity, and strong anionic zeta potential (∼ 35.4 mV). The results of antibacterial and antifungal activity demonstrated the potential of phyto-synthesized AgNPs in mitigation of infection associated with tested bacterial strain Bacillus subtilis, Bacillus megaterium, Shigella flexneri, Trichoderma viride, Aspergillus niger, and Penicillium crysogenum. Moreover, the results of hydrogen peroxide-based scavenging, anti-inflammatory, and anti-diabetic study revealed that the biosynthesized AgNPs exhibit an improved biomimetic attribute. Additionally, the biocompatibility assay demonstrated > 80 % of CaCO-2 and L-929 cells viability at 1.67 μg/mL and 3.35 μg/mL, respectively. The anticancer activity of synthesized AgNPs against epithelium-like phenotype oral squamous carcinoma cells (CLS-354/WT) displayed IC₅₀ of 11.58 μg/mL. The results indicate that biogenic produced AgNPs may find suitable use as a potential therapeutic agent due to multifunctional attribute.