Cissus quadrangularis Linn. Stem Ethanolic Extract Liberates Reactive Oxygen Species and Induces Mitochondria Mediated Apoptosis in KB Cells

BACKGROUND: Cissus quadrangularis Linn. (CQ) commonly known as Hadjod (Family: Vitaceae) is usually distributed in India and Sri Lanka and contains several bioactive compounds responsible for various metabolic and physiologic effects. OBJECTIVE: In this study, the biological effects of CQ ethanolic extract were evaluated by in vitro and supported by in silico analysis on KB oral epidermoid cancer cell line. MATERIALS AND METHODS: Anti-cancer potential of ethanolic extract of CQ stem against KB oral epidermoid cancer cells was evaluated in terms of morphological analysis, nuclei staining, liberation of reactive oxygen species (ROS), cell cycle arrest, mitochondrial membrane potential (MMP) and p53 and Bcl-2 protein expression which reveal the induction of apoptosis along with supporting in silico analysis. RESULTS: Ethanolic extract of CQ stem contains various bioactive compounds responsible for cancer cell morphological alterations, liberation of ROS, G1 phase cell cycle arrest and decreased MMP along with up-regulation of p53 and down-regulation of Bcl-2. By employing in silico approach, we have also postulated that the CQ extract active constituents sequester Bcl-2 with higher affinity as compared to p53, which may be the reason for induction of growth arrest and apoptosis in KB cells. CONCLUSION: Our data indicate that the CQ extract has a remarkable apoptotic effect that suggests that it could be a viable treatment option for specific types of cancers. SUMMARY: Cissus quadrangularis stem ethanolic extract induces apoptosis and cell cycle arrest at G1 phase. It liberates (ROS) and mitochondria mediated apoptosis. It upregulates p53 and down-regulates Bcl-2 protein expression. In silico studies indicates that the active constituents of CQ binds Bcl-2 with higher affinity as compared to p53.