Phytochemical-assisted biosynthesis of nanomaterial’s offers an eco-friendly alternative to traditional methods. This study presents the synthesis of silver(Ag-NPs) and nickel oxide nanoparticles (NiO-NPs) using cress seed mucilage polysaccharides (CSMP) as a reducing, stabilizing, and capping agent. AgNO3and NiNO3 served as precursors in the hot plate combustion method. Characterization of the NPs was conducted using UV-visible and Fourier transform infrared (FT-IR) spectroscopy. The biocompatibility of Ag-NPs and NiO-NPs was confirmed through hemolysis assays, showing no toxicity at low concentrations. Cytotoxicity assessments revealed CC50 values greater than10,000 µg/mL for CSMP, 2346 µg/mL for Ag-NPs, and 1987 µg/mL for NiONPs ,indicating their safety at lower concentrations. The antioxidant activity of the NPs, evaluated using the DPPH assay, showed Ag-NPs stabilizing DPPH radicals by 85.67 ± 1.01% at 400 µg/mL, comparable to ascorbic acid (96.91 ±2.05%). Ag-NPs also exhibited significant inhibition of a-amylase (89.03 ±3.71%) and a-glycosidase (90.83 ± 3.54%) at 400 µg/mL, surpassing NiO -NPs and CSMP, and approaching the effectiveness of the standard drug acarbose. Antibacterial assays demonstrated that both Ag-NPs and NiO-NPs effectively inhibited the growth of Pseudomonas aeruginosa, Klebsiella pneumoniae, Haemophilus influenzae, and Escherichia coli. These findings suggest that CSMP offers a sustainable and effective method for the green synthesis of bioactive Ag-NPs and NiO-NPs with potential applications in biomedicine and agriculture.