Piperlongumine Induces Apoptosis in Colorectal Cancer HCT 116 Cells Independent of Bax, p21 and p53 Status

Area of Science:

• Natural Product Chemistry
• Cancer Biology
• Pharmacology

Background:

• Colorectal cancer exhibits treatment resistance, often linked to compromised apoptotic and cell-cycle regulatory proteins.
• Piperlongumine (PPLGM), a natural alkaloid from Piper species, demonstrates potential anti-cancer activities.

Purpose of the Study:

• To investigate the efficacy of PPLGM in inducing cell death in colorectal carcinoma HCT 116 cells.
• To assess PPLGM's effects on cells with varying expression of key apoptotic and cell-cycle proteins (Bax, p21, p53).

Main Methods:

• PPLGM was extracted and purified from Piper tuberculatum roots.
• Cell viability assessed via MTT and clonogenic assays; cell death evaluated using acridine orange/ethidium bromide staining and flow cytometry.
• Analysis of PPLGM's interaction with DNA using plasmid cleavage assays and circular dichroism.

Main Results:

• PPLGM induced selective cell death across all tested HCT 116 cell lines, with IC50 values ranging from 10.7 to 13.9 μM.
• Significant increases in late apoptotic cells and alterations in cell-cycle distribution were observed.
• PPLGM demonstrated no direct interaction with plasmid DNA.

Conclusions:

• PPLGM exhibits potent cytotoxic effects on colorectal cancer cells.
• The findings suggest PPLGM as a promising candidate for future colorectal cancer therapeutic development.