Efecto inhibitorio de un extracto acuoso de las hojas de Allophylus cominia (L.) Sw sobre las proteínas tirosina fosfatasa 1B y dipeptidil peptidasa IV
Introduction: Allophylus cominia (L.) Sw is a Cuban medicinal plant used by traditional medicine for the treatment of diabetes with unknown mechanisms of action. Objective: to evaluate the effect of Allophylus cominia (L.) Sw leaves aqueous extract and its fractions on protein tyrosine phosphatase 1B (PTP1B) and dipeptidyl peptidase IV (DPPIV) enzymatic activity, as therapeutic targets of type 2 diabetes. Methods: the aqueous extract of A. cominia leaves was successively partitioned with organic solvents mixtures, thus increasing polarity in order to obtain ten fractions. The extract and its fractions were tested for their possible antidiabetic activity on therapeutic targets of type 2 diabetes: PTP1B and DPPIV. The enzymatic inhibition assays were performed and the inhibitory activity was calculated with the fluorescence values using an excitation wavelength of 360 nm and an emission wavelength of 460 nm. Results: the aqueous extract from A. cominia inhibited the enzymatic activity of PTP1B and DPPIV according to the concentration, being IC50 values equal to 0.69 μg/mL and 344.3 μg/mL, respectively. Several fractions were detected as potent PTP1B inhibitors. The most polar fractions AcF9 and AcF10 were more active, showing IC50 values of 4.4 µg/mL and 3.8 µg/mL respectively. The fractions showed a slight DPPIV inhibition, being fractions AcF6, AcF9 and AcF10 the most active, exhibiting inhibition percentages of 52.0 %, 39.0 % and 40.0 % respectively. Conclusions: A. cominia aqueous extract and its polar fractions (AcF9 and AcF10) have antidiabetic properties in vitro and are promissory candidates for development of new drugs with inhibitory activity of PTP1B and DPPIV for type 2 diabetes treatment