The Cytotoxic and Anti-proliferative Activity of High Molecular Weight Pectin and Modified Citrus Pectin

Background: Pectin is a heterogeneous polysaccharide mainly present in citrus fruits and has different biological activities.Objective: High molecular weight Citrus Pectin and modified citrus pectin (MCP) were tested for their cytotoxic, anti-proliferative, and anti-oxidant activity.Methods: The cytotoxicity of pectin was studied against HaCaT cell line (human keratinocyte cell line) using Trypan blue method and LDH-cytotoxicity assay. Anti-proliferative activity was assayed using a WST-1 proliferation kit. Antioxidant activity was determined using the DPPH scavenging assay.Results: MCP and Pectin both reduced the viability of HaCaT cells in a dose dependent manner; however MCP was found to be more cytotoxic than high molecular weight citrus pectin since it had a lower IC50 (300ug/ul). At non-cytotoxic concentrations, the viability of cells decreased with increase of concentration of MCP as determined by the WST-1. MCP exhibited a higher antioxidant effect than pectin (SC50 at a concentration range between 2 and 4mg/ml).Conclusion: This study suggests that MCP exhibits a stronger cytotoxic and anti-proliferative effect on HaCaT cell line than pectin. The most probable explanation of this observation is the different effect due to the variable molecular weight and exposed side-chains of MCP and high molecular weight citrus pectin.