Determinación del potencial inhibitorio de la fracción alcaloidal de Psychotria pilosa sobre xantina oxidasa y radical superóxido mediante autografía.

Abstract

The research aimed to determine the inhibitory potential of the alkaloidal fraction of P.pilosa on xanthine oxidase and superoxide radical by autography. The alkaloidal extract of the P. pilosa leaves was obtained from maceration with methanol, after the use of organic solvents (ethyl ether and ethyl acetate) and pH changes, reaching a yield of 0.07%. The study was conducted at different concentrations of the alkaloidal fraction (1, 10, 50, 100 µg) using methanol as solvent. The autographic tests were carried out in 6x4 cm TLC plates, using the "dot blot" technique, approximately 10 µL of each total alkaloid solution was seeded. When evaluating the antioxidant activity of P. pilosa using the DPPH method, ascorbic acid was used as a reference. The models were used to determine the superoxide radical scavenging capacity: riboflavin, light, tetrazolium nitro blue (NBT) and NADH, phenazine methosulfate (PMS), tetrazolium nitro blue (NBT). In both methods, the standard used was taxifolin, while to evaluate the inhibitory potential of xanthine oxidase, xanthine was used as a substrate, and allopurinol was a positive control. Thus, these methods helped discriminate between a pure XO inhibitor and a O_2^(.-) sensor. Thin-layer chromatography (TLC) was carried out using chloroform/triethylamine/ methanol as a mobile phase in proportions (6: 0.5: 0.6) and developed without chemical treatment at 254 nm. Qualitative and quantitative data were reflected in the intensity of the color and diameter of the halos, respectively; The GelAnalyzer program was used to obtain the results of the inhibition areas. The results showed that the P. pilosa alkaloidal fraction has a superoxide radical scavenging capacity for the B2 / light / NBT and NADH / PMS / NBT systems. In contrast, it does not exhibit xanthine oxidase inhibition. It is recommended to conduct studies of structural elucidation of alkaloids using chromatographic and spectroscopic techniques.