Antioxidant and Anti-inflammatory Activities Mediate the Radioprotective Effect of Trianthema portulacastrum L. Extracts

Background: Ionizing radiation (IR) generates reactive oxygen species (ROS), which leads to oxidative stress that often leads to inflammatory responses in organisms. Objective: Trianthema portulacastrum L., a plant commonly growing in India, is rich in antioxidant phytochemicals. This is responsible for scavenging free radicals and may provide radioprotective and anti-inflammatory effects in response to ionizing radiation. Methods: The effect of T. portulacastrum extracts was studied in hepatic cells, which are susceptible to radiation-induced damage and in macrophages, which are the primary inflammatory cells of the body. Results: T. portulacastrum stem extracts showed efficient free radical scavenging activity in hepatocytes and decreased radiation-induced lipid peroxidation in cell and mitochondrial membranes. Treatment of irradiated cells with T. portulacastrum stem extracts enhanced cell viability at lower concentration and reduced cell viability at higher concentration. Treatment with low concentration of T. portulacastrum stem extract also reduced cellular ROS generation and increased the concentration of cellular anti-oxidant, glutathione. T. portulacastrum extracts also showed remarkable anti-inflammatory properties in macrophages activated by the inflammatory agonist bacterial lipopolysaccharide (LPS). The extract reduced nitric oxide (NO) production and suppressed the expression of inflammatory genes. Conclusion: Together, these observations demonstrated a potential radioprotective role of T. portulacastrum extract mediated by both its antioxidant activity on hepatic epithelial cells and its anti-inflammatory activity on immune cells.