Intrinsic Apoptosis Induction by Codariocalyx motorius: A Natural Hepatoprotective Strategy against HepG2 Cell Proliferation

Background

Globally, liver cancer or hepatocellular carcinoma cases are rising alarmingly and chemotherapeutic agents are used for treatment, they often cause side effects. Codariyocalyx motorius (Houtt.) H. Ohashi, a plant from the Fabaceae family, is traditionally used in Thailand, India and China to treat ailments including cancer-like symptoms. However, this claim lacks scientific validation.

Aim

This study aimed to investigate the effect of aqueous leaf extract of Codariyocaly motorius (ALCM) on liver cancer cells (HepG2) to study its possible mechanism of action for suppressing cell proliferation through activation of intrinsic apoptotic pathway.

Methodology

Qualitative estimation of the component profiling through HPLC and apoptosis induction on HepG2 cell lines was assessed using MTT assay, cellular morphology analysis with AO/EtBr, DAPI stain, ROS generation, quantification of cellular apoptosis by flow cytometry and expression of apoptotic and anti-apoptotic genes by RT-PCR were studied.

Results

During HPLC analysis, four phytocompounds such as gallic acid, rutin, camptothecin and luteolin were quantified. The ALCM exhibited significant anti-proliferative property against HepG2 cancer cell lines with an IC₅₀ of 24.6 µg/mL and reduced their clonogenic potential in a concentration-dependent manner. Furthermore the ALCM showed no adverse toxic effect on Human Embryonic Normal Kidney cells (HEK293). Apoptosis was confirmed through cytometric analysis and microscopic examination of AO/EtBr, DAPI and Annexin V/IP stained cells. Biochemical evidences of apoptosis came from elevating the intracellular ROS level and cell cycle arrest at S and G0/G1 phase. RT-PCR analysis showed that ALCM induced mitochondrial apoptosis in HepG2 cells revealed a concentration-dependent up-regulation of apoptotic genes (Bax and caspase-3) and down regulation of non-apoptotic gene (Bcl-2).

Conclusion

Thus, the present study suggest the remarkable potential of active metabolites in ALCM for the initiation of cell apoptosis through the activation of intrinsic apoptotic pathway in HepG2 cells and thereby serve as promising therapeutic agent for the treatment and management of HCC.