Anti-Proliferative and Anti-Metastatic Effects of Conessine in Human Osteosarcoma Cells: In vitro and in silico Evidence Targeting MMP2 and MMP9

Background: Osteosarcoma is a predominant bone cancer characterised by increased metastatic potential, rapid proliferation, and insufficient clinical prognosis, making it the leading cause of cancer-related morbidity. Finding novel plant-derived therapeutic agents capable of suppressing tumor development and metastasis is a necessary priority. Objectives: The present study demonstrates the potential anticancer and anti-metastatic activity of conessine against MG-63 osteosarcoma cells via various in vitro assays. The study intended to elucidate the mechanism underlying conessine’s action through molecular analysis. Materials and Methods: Examining the cytotoxic effects of conessine on TNF-α-induced and uninduced MG-63 osteosarcoma cells is essential to determine the LC50 value, based on the results of the MTT assay. The antiproliferative effects of conessine were assessed using transwell migration, aggregation, wound healing, and clonogenic assays. The impact of conessine on the β-catenin signalling system and metalloproteinases was examined by indirect ELISA and molecular docking analysis. The tumor microenvironment was induced by TNF-α, which stimulates inflammation. Results: The LC₅₀ value of conessine, estimated using cell viability assays, was 154.83 μg/mL MG-63 cells and 91.948 μg/mL for TNF-α-induced MG-63 cells. Conessine exhibited a significant reduction (p<0.05) in migratory and metastatic activities of osteosarcoma cells even under TNF-α-induced inflammatory conditions. Conessine treatment significantly reduced the relative β-catenin expression by 1.14 units/mg protein, compared with 1.35 units in untreated cells. In silico analysis revealed an effective binding of MMP2 and MMP9 to conessine, characterised by stable hydrogen bonding and hydrophobic interactions. Conclusion: These results demonstrated the significant cytotoxic, anti-proliferative, and anti-metastatic effects of conessine, suggesting a promising alternative medicine for osteosarcoma treatment.