ACETONIC EXTRACT FROM FEIJOA SELLOWIANA BERG. FRUITS INHIBITS PROLIFERATION AND MODULATES BRUSH BORDER MEMBRANE ENZYME ACTIVITIES IN HUMAN INTESTINAL EPITHELIAL CELLS

Background and aim: Feijoa sellowiana fruits grow throughout the Mediterranean area and are used for human food. These fruits and especially the acetonic extract have been shown to possess biological activities, such as antioxidant and anti-cancer properties. We aim to investigate the effects of the acetonic extract of Feijoa sellowiana fruits on the viability, proliferation and brush border membrane enzyme activities of the epithelial intestinal cells. Material and methods: Caco-2 cells were seeded into a 6-wells multiwells plate and cultured with appropriate medium. At confluence, cells were star- vated for 24h and then exposed to the acetonic extract (500 ug/mL), for 24h and 48h. Brush border membrane enzymes lactase and sucrase activity, cell proliferation and viability were measured with the modified Dahlqvist method, bromodeoxyuridine incorporation assay and MTT vitality test, respectively. Cells with medium alone were used as control. Data are expressed as mean ± SD. Results: Compared to control conditions, the acetonic extract significantly increased lactase activity, both after 24h (+7.1 ± 1.0 fold increase vs control, p < 0.05) and 48h (+2.9 ± 0.8 fold increase vs control, p < 0.05) and sucrase acivity, both after 24h (+3.2 ± 0.7 fold increase vs control, p < 0.05) and 48h (+3.6 ± 0.8 fold increase vs control, p < 0.05). The acetonic extract signifi- cantly decreased proliferation respect to control, both after 24h (0.17 ± 0.01 vs 0.23 ± 0.01 450–540nm; p < 0.01) and 48h (0.22 ± 0.02 vs 0.39 ± 0.03 450– 540nm; p < 0.01). After 24h, the acetonic extract had no effects on cells viability, while after 48h, the acetonic extract significantly increased viability respect to control (+50 ± 7% increase vs control, p < 0.05). Conclusions: We demonstrate that the treatment with the acetonic extract from Feijoa sellowiana fruits improves lactase and sucrase activity in intestinal epithelial cells. We also show that the acetonic extract inhibits cell proliferation and have no cytotoxic effects. These changes induced by the acetonic extract in the brush border enzyme activity may be exploited in case of enzymatic deficit of lactase and sucrase