Oxidative stress and chronic inflammation interplay with the pathogenesis of cancer. Breast cancer in women is the burning issue of this century, despite chemotherapy and magnetic therapy. The management of secondary complications triggered by post-chemotherapy poses a great challenge. Thus, identifying target-specific drugs with anticancer potential without secondary complications is a challenging task for the scientific community. It is possible that green technology has been employed in a greater way in order to fabricate nanoparticles by amalgamating plants with medicinal potential with metal oxide nanoparticles that impart high therapeutic properties with the least toxicity. Thus, the present study describes the synthesis of Titanium dioxide nanoparticles (TiO2 NPs) using aqueous Terenna asiatica fruit extract, with its antioxidant, anti-inflammatory and anticancer properties. The characterisation of TiO2 NPs was carried out using a powdered X-ray diffractometer (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray diffraction (EDX), high-resolution transmission electron microscopy (HR-TEM), dynamic light scattering (DLS), and zeta-potential. TiO2 NPs showed their antioxidant property by scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals in a dose-dependent manner with an IC50 value of 80.21 µg/µL. To ascertain the observed antioxidant potential of TiO2 NPs, red blood cells (RBC) were used as an in vitro model system. Interestingly, TiO2 NPs significantly ameliorated all the stress parameters, such as lipid peroxidation (LPO), protein carbonyl content (PCC), total thiol (TT), superoxide dismutase (SOD), and catalase (CAT) in sodium nitrite (NaNO2)-induced oxidative stress, in RBC. Furthermore, TiO2 NPs inhibited RBC membrane lysis and the denaturation of both egg and bovine serum albumin, significantly in a dose-dependent manner, suggesting its anti-inflammatory property. Interestingly, TiO2 NPs were found to kill the MCF-7 cells as a significant decrease in cell viability of the MCF-7 cell lines was observed. The percentage of growth inhibition of the MCF-7 cells was compared to that of untreated cells at various doses (12.5, 25, 50, 100, and 200 µg/mL). The IC50 value of TiO2 NPs was found to be (120 µg/mL). Furthermore, the Annexin V/PI staining test was carried out to confirm apoptosis. The assay indicated apoptosis in cancer cells after 24 h of exposure to TiO2 NPs (120 µg/mL). The untreated cells showed no significant apoptosis in comparison with the standard drug doxorubicin. In conclusion, TiO2 NPs potentially ameliorate NaNO2-induced oxidative stress in RBC, inflammation and MCF-7 cells proliferation.