Synthesis and Characterization of Biogenic Silver Nanoparticles using Medicinally important Nigella sativa L. (black Cumin) and their Antioxidant, Anti‑inflammatory, and DNA Cleavage Potentials

Introduction: The application of nanotechnology in herbal medicine offers promising prospects for drug delivery by enabling targeted, controlled, and efficient delivery of medicinal ingredients, potentially minimizing side effects and improving treatment outcomes. Nigella sativa L. (black Cumin) seed infusions are useful in Asian and African ethnomedicines in remedying stress and inflammatory-related ailments. Objective: On this premise, black Cumin-based silver nanoparticles (BC-Ag NP) were developed and evaluated for their biological potential. Materials and Methods: Silver nanoparticles (AgNPs) were green synthesized using the seed aqueous extract of black cumin (BC). The BC-AgNPs were characterized using scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), highresolution transmission electron microscopy analysis (HRTEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). The biological potential of the NPs was based on NO, H₂O₂, •OH, and O₂ •– radical scavenging antioxidant, egg albumin denaturation (anti-inflammatory), and DNA cleavage assay methods. Results: The SEM and FESEM revealed spherical-to-cubical-shaped ultrafine BC-Ag NPs with a size of less than 100 nm. The HR-TEM micrograph confirmed each NP to be spherical in shape and within the 10-50 nm range. The X-ray diffractogram showed the crystallinity of the NPs with a sharp peak at 38.12° [reflection index (111)] at an average size of 47 nm. The transformation of metallic silver into elemental silver was validated by EDX analysis, with 97.58% elemental Ag at ~3 keV acute curve. The BC-Ag NPs showed dose-dependent antioxidant activity, with IC50 of 87.56 ± 1.54 and 110.5 ± 2.27 μg/mL against H₂O₂ and O₂ ._ free radicals, respectively. The anti-inflammatory activity of the NPs was one-third the potency of Diclofenac sodium (standard drug) at IC₅₀ of 103.44 ± 5.35 μg/mL. Finally, the BC-Ag NPs acted as chemical nucleases to cleave DNA at a 20 mg/mL concentration for 120 minutes. Conclusion: This study has shown that AgNPs biosynthesized with black Cumin seed extract possess notable antioxidant, anti-inflammatory, and DNA cleavage properties and, thus, may be a useful nanomaterial for efficient pharmaceutical delivery.