Alpha-Glucosidase Inhibitory Activity of Garcinia lateriflora Blume Leaves

Abstract

Garcinia lateriflora Blume., that belongs to the genus Garcinia, is known to contain polyphenol compounds that are likely to inhibit alpha-glucosidase in the treatment of diabetes mellitus. Therefore, this study aimed to evaluate and acquire the most biologically active fraction from leaves of G. lateriflora in inhibiting alphaglucosidase. The separation of the active fraction was conducted using column chromatography and identified by thin layer chromatography. Alpha-glucosidase inhibitory activity test carried out in vitro using spectrophotometric method with p-nitrophenyl-α-D-glucopiranoside as the substrate. 17 and 12 fractions were obtained from ethyl acetate and methanol extracts, respectively. Fraction 13 (EA13) of ethyl acetate extract and fraction 10 (Me10) of methanol extract were showed the highest percent inhibition compared with the other fraction with IC50 values 8.96 µg/ml and 18.52 µg/ml, respectively. While the IC50 value for Acarbose is 39.53 µg/ml. Furthermore, fraction EA13 is the most active fraction in inhibiting alpha-glucosidase compared with the extract, other fractions, and Acarbose.

In-vitro α-Glucosidase Inhibitory Activity of Litsea petiolata Hk. f

“…α-Glucosidase inhibitory assay: The assay was performed using microplate reader (Versamax ELISA, USA) according to previously study by Mahayasih et al [8]. To obtain 50% inhibition concentration (IC50), 30 µl samples with various concentrations were put in 96 microplate wells, then was added by 36 µl of phosphate buffer pH 6.8 and, as the substrate, 17 µl of 4 mM p-NPG (p-nitrofenil-α-D-glucopiranoside) (Sigma-Aldrich, Switzerland) [8].…”

“…α-Glucosidase inhibitory assay: The assay was performed using microplate reader (Versamax ELISA, USA) according to previously study by Mahayasih et al [8]. To obtain 50% inhibition concentration (IC50), 30 µl samples with various concentrations were put in 96 microplate wells, then was added by 36 µl of phosphate buffer pH 6.8 and, as the substrate, 17 µl of 4 mM p-NPG (p-nitrofenil-α-D-glucopiranoside) (Sigma-Aldrich, Switzerland) [8]. The microplate was inserted into a microplate reader, shaked and incubated at 37 o C for 5 minutes, then was added 17 µl of enzyme α-glucosidase (Saccharomyces cerevisiae, Sigma-Aldrich-Germany) at concentration 0.8 unit/L [8].…”

“…To obtain 50% inhibition concentration (IC50), 30 µl samples with various concentrations were put in 96 microplate wells, then was added by 36 µl of phosphate buffer pH 6.8 and, as the substrate, 17 µl of 4 mM p-NPG (p-nitrofenil-α-D-glucopiranoside) (Sigma-Aldrich, Switzerland) [8]. The microplate was inserted into a microplate reader, shaked and incubated at 37 o C for 5 minutes, then was added 17 µl of enzyme α-glucosidase (Saccharomyces cerevisiae, Sigma-Aldrich-Germany) at concentration 0.8 unit/L [8]. Subsequently re-incubated at 30 o C for 15 minutes, the reaction was then terminated by adding 100 µl of 267 mM Sodium carbonate solution [8].…”

“…The microplate was inserted into a microplate reader, shaked and incubated at 37 o C for 5 minutes, then was added 17 µl of enzyme α-glucosidase (Saccharomyces cerevisiae, Sigma-Aldrich-Germany) at concentration 0.8 unit/L [8]. Subsequently re-incubated at 30 o C for 15 minutes, the reaction was then terminated by adding 100 µl of 267 mM Sodium carbonate solution [8]. The absorbance of the solution was measured with a microplate reader at 400 nm.…”

Preliminary Analysis of the Antidiabetic Activity of Indonesian Polyherbal Formulation

“…where, As represents the absorbance of the test substance while Ac is the absorbance of control. The polyherbal combination with the IC50 value closer to the acarbose (control) was chosen for the animal testing 4,5 .…”