Isorhamnetin Influences the Viability, Superoxide Production and Interleukin-8 Biosynthesis of Human Colorectal Adenocarcinoma HT-29 Cells In Vitro

Isorhamnetin has gained research interest for its anti-inflammatory, anti-proliferative and chemoprotective properties. In this study, human colon adenocarcinoma cells were cultured in the presence or absence of different isorhamnetin concentrations (5–150 μM) for 24 h or 48 h of cultivation to explore the impact on several parameters of viability/proliferation (mitochondrial function using an MTT test, metabolic activity, cell membrane integrity and lysosomal activity using a triple test). The intracellular generation of superoxide radicals using an NBT test and ELISA analysis was performed to observe the biosynthesis of interleukin 8 (IL-8) in cells stimulated with zymosan, as well as in basal conditions. The antiproliferative activity of isorhamnetin was demonstrated by significantly reduced values of mitochondrial and metabolic activity, integrity of cell membranes and lysosomal activity. Its high prooxidant potential was reflected by the significantly elevated generation of superoxides even in cells with low viability status. The anti-inflammatory effect of isorhamnetin was evident due to decreased IL-8 production, and the most significant decline in IL-8 concentration was observed after 24 h treatment in cells with induced inflammation. We demonstrated that isorhamnetin can suppress the proliferation of HT-29 cells, and this effect was correlated with pro-oxidative and anti-inflammatory activity of isorhamnetin.