Inhibitory Potential of Red Cabbage against Digestive Enzymes Linked to Obesity and Type 2 Diabetes

Assays of the inhibitory potential against enzymes involved in carbohydrate and lipid digestion (a-amylase, alpha-glucosidase, and lipase) as well as the total contents of phenolics and anthocyanins, anthocyanin profile, and antioxidant capacity revealed significant differences (p < 0.05) between five varieties of red cabbage. Among the varieties, the highest inhibitory activity against alpha-glucosidase (IC50 = 3.87 +/- 0.12 mg dry weight (DW) of cabbage/mL) and lipase (IC50 = 1.57 +/- 0.06 mg DW/mL) was exhibited by the Koda variety, which showed the highest antioxidant capacity in ABTS (Trolox equivalent antioxidant capacity (TEAC) = 141 +/- 4.71 mu mol/g DW) and ferric-reducing antioxidant power (TEAC = 125 +/- 1.94 mu mol/g DW) assays and had the highest total phenolics level (19.6 +/- 0.48 mg/g DW). The highest total anthocyanin content (12.0 +/- 0.16 mg/g DW) and inhibitory activity against a-amylase (IC50 = 69.0 +/- 3.65 mg DW of cabbage/mL) was shown by the Kissendrup variety. The anthocyanin profiles of these two varieties were characterized by the highest percentages of diacylated cyanidin derivatives. There was no correlation between the contents of phenolic compounds and lipase inhibitory activity, but inhibition of alpha-amylase was correlated with concentrations of monoacylated and diacylated anthocyanins, while inhibition of alpha-glucosidase increased with total phenolics and diacylated anthocyanins levels.