Fig. 1. Inhibition of DPP IV by aronia juice. A. DPP IV inhibitory activity by aronia juice was measured using a synthetic substrate, Gly-Pro-MCA. Values are means ± S.E. n ¼ 4 experiments. Statistically significant: ***p < 0.001. B. DPP IV inhibitory activities in fractions from Spelco column chromatography were measured using a synthetic substrate, Gly-Pro-MCA. Values are means ± S.E. n ¼ 4 experiments. Statistically significant: ***p < 0.001. Not significant: n.s.