A promising method for cancer therapy is the coating of magnetic nanoparticles with carboxy methylcellulose. In a research project, hydroalcoholic extract of Cinnamomum camphora leaves was used to demonstrate the production of magnetic nanoparticles (MNPs); MNPs were coated with carboxymethyl cellulose to form carboxymethyl cellulose-coated magnetic nanoparticles (CMNPs)were formed. Preliminary phytochemical screening of C. camphora confirmed the presence of flavonoids, carbohydrates, phenolic compounds, and proteins. Phenolics 280.59 (mg/g), flavonoids 15.46 (mg/g), proteins 1.9 (mg/mL) and total carbohydrates 293.80 (mg/g) were all quantified. To confirm the formation of MNPs and CMNPs, UV–visible (UV–vis) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) were used. Peaks were observed at 232 nm and 240 nm, respectively. The largest absorption peaks were observed in MNPs and CMNPs, respectively. The particles were spherical in shape and less than 10 (nm) in diameter. The potential scavenging activity of biosynthesized MNPs and CMNPs was evaluated by the ABTS and DPPH assays, and the inhibition values IC50 were 141.3 ± 3.0 and 61.67 ± 2.5 (µg/mL) for ABTS and 176.1 ± 4.0 and 70.92 ± 3.0 (µg/mL) for DPPH, respectively (p ≤ 0.05). Furthermore, the cytotoxicity test results showed that the HCT-116 human colon cancer cell line had the lowest IC50 value of 20 (µg/mL) for CMNP, followed by the HepG2 hepatocellular carcinoma cell line with an IC50 value of 33 (µg/mL) for CMNP, indicating that the cytotoxic effect on colon cancer cells is stronger than on liver cancer cells. Molecular docking studies have revealed that CMNPs target and bind to apoptotic protein, enhancing their bioactivity and cytotoxic effects on cancer cells. Furthermore, our findings suggest that the induction of apoptosis may be responsible for the anticancer effects of CMNPs.Graphical abstract