Anti-hyperglycemic, antioxidant, and anti-inflammatory activities of extracts and metabolites from Sida acuta and Sida rhombifolia

Abstract

Species of genus Sida are used around the world for a large amount of therapeutic treatments, including hyperglycemia. α-Glucosidase inhibitors are recognized as valuable tools for reducing postprandial hyperglycemia by retarding absorption of glucose. The effect of extracts and isolated compounds of S. acuta and S. rhombifolia on inhibition of α-Glucosidase as primary screening of antihyperglycemic activity was tested using yeast and mammalian α-Glucosidases. When yeast α-Glucosidase was used the acetone extracts of S. acuta and S. rhombifolia showed IC50 values of 8.49 ± 0.66 and 8.10 ± 0.34 μg mL-1, respectively, and the most active compound was p-hydroxyphenethyl trans-ferulate (IC50 19.24 ± 1.73 μmol L-1) followed by β-sitosteryl glucopyranoside (IC50 32.70 ± 1.35 μmol L-1). However, the activity of extracts and isolated compounds decreased significantly when mammalian α-Glucosidase was used, indicating that substrates affinity is higher for type 1 enzymes. The antioxidant and anti-inflammatory activities of extracts and isolates were also tested since many diabetic complications are associated to the oxidative stress and inflammatory immune responses. Acetone extracts were the most active in all evaluations. p-Hydroxyphenethyl trans-ferulate, could be associated to these activities, since it was active in the three evaluations. This effect could be related to its phenolic character.