Multifunctional bioactivity of <i>Moringa oleifera</i> seed acetone extract and its gold nanoparticle formulation: Immunomodulation, anticancer activity, antibacterial properties, acute toxicity, and oxidative stress assessment

Seeds of Moringa oleifera are well-known for their distinct phytochemical composition and potential therapeutic characteristics. This study aimed to explore the biologically active components of M. oleifera seed acetone extract (MSAE) and assess its antibacterial, anticancer, and immunomodulatory effects, both by itself and in conjunction with gold nanoparticles (AuNPs). M. oleifera seeds were dried, ground, and then extracted using acetone to create MSAE. MSAE was used as a capping and reducing agent in the synthesis of AuNPs. High-performance liquid chromatography (HPLC), protein electrophoresis, Fourier transform-infrared (FT-IR), and scanning electron microscopy (SEM) were utilized to characterize the extract and AuNPs. Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Proteus mirabilis and Escherichia coli) microorganisms were used to investigate the antimicrobial effectiveness. The MTT test was harnessed to measure the cytotoxic potentials on colon cancer cells (HT-29). Splenocytes cultures were used to test for immunomodulatory potential. Reactive oxygen species (ROS), gene expression of p53, cell cycle progression, and apoptosis were analyzed. Sprague Dawley rats were used to detect indicators of oxidative stress and acute toxicity. When coupled with AuNPs, MSAE showed considerable effects, especially against B. subtilis (21.19 ± 0.15 mm inhibitory zone), but it did not exhibit any antimicrobial action on its own. In HT-29 cells, MSAE at 1000 µg/mL inhibited growth by 48.50%, with enhanced effects (66.79%) when combined with AuNPs. In addition to inducing apoptosis (21.39%) and G2/M cell cycle arrest (48.35% cells), MSAE increased p53 expression 3.67 times. Immunomodulatory assays revealed dose-dependent effects, with high concentrations stimulating splenic cell growth (2071.03%). Acute toxicity tests showed normal liver/kidney function markers but elevated oxidative stress in MSAE-treated rats, including increased thiobarbituric acid reactive substances (TBARS) and reduced antioxidant capacity. MSAE demonstrates promising anticancer and immunomodulatory properties, particularly when combined with AuNPs. While it lacks standalone antimicrobial activity, its synergy with AuNPs enhances efficacy. The MSAE stimulated apoptosis and the arrest of the cell cycle in tumor cells, likely mediated by p53 upregulation. However, high doses may elevate oxidative stress, warranting further investigation into safety profiles. These findings highlight the power of MSAE as a therapeutic agent; however, further research is required to enhance its applications.