@article {540, title = {Antioxidative Properties of Blighia sapida K.D. Koenig Stem Bark Extract and Inhibitory Effects on Carbohydrate Hydrolyzing Enzymes Associated with Non-Insulin Dependent Diabetes Mellitus}, journal = {Pharmacognosy Journal}, volume = {10}, year = {2018}, month = {January 2018}, pages = {376-383}, type = {Original Article}, chapter = {376}, abstract = {

Background and Aim: In Africa, the fruit, seed, leaf, and stem of Blighia sapida K.D. Koenig are used as remedy for a range of diseases. This study characterized the phytochemicals, assessed the antioxidant and inhibitory properties of the stem bark of Blighia sapida. Materials and Methods: Samples were consecutively extracted using ethanol solvent and investigated for phenol content, DPPH radical scavenging abilities, iron chelation, reducing power, \α-amylase and \α-glucosidase activities as markers of in vitro anti-diabetic activities. Phytochemicals were analyzed using gas chromatography-mass spectrometry (GC-MS) analysis. Results: The extract had radical scavenging capabilities, iron chelation and reducing power. Furthermore, the results reveal the extract had considerably high \α-glucosidase and \α- amylase inhibitory activities as the concentration increases with IC50 values of 4.17 \± 0.24 mg/mL and 5.30 \± 1.25 mg/mL, respectively. Enzyme kinetic studies indicated that the extract displayed uncompetitive inhibitor for \α-glucosidase and was a competitive inhibitor of \α-amylase. The ethanolic extract is rich in several aromatic phenolic compounds and long chain aliphatic acids. Conclusion: These results reveal the bark possessed antioxidant as well as \α -glucosidase and \α -amylase inhibitory activities.

}, keywords = {Antidiabetic, antioxidant activity, Blighia sapida K D Koenig, α-amylase, α-glucosidase}, doi = {10.5530/pj.2018.2.63}, url = {http://fulltxt.org/article/494}, author = {Oluwafemi Adeleke Ojo and Basiru Olaitan Ajiboye and Oluwatosin Debbie Imiere and Oluwatosin Adeyonu and Israel Olayide and Adewale Fadaka} } @article {772, title = {Inhibitory Actions of Lagerstroemia speciosa (L.) Pers. Aqueous and Ethanolic Leaf Extracts against Carbohydrate-digesting Enzymes}, journal = {Pharmacognosy Journal}, volume = {10}, year = {2018}, month = {November 2018}, pages = {s113-s118}, type = {Original Article}, chapter = {s113}, abstract = {

Context: The leaves of Lagerstroemia speciosa (L.) Pers. (banaba) have been consumed traditionally in several Southeast Asian countries for the treatment of diabetes mellitus. The plasma glucose lowering actions of this medicinal plant were proposed to be linked with several mechanisms of action. However, its inhibitory actions against \α-amylase and \α-glucosidase, which play a major role in the regulation of postprandial plasma glucose, have not been clearly established. Aims: This study thus aimed to investigate the effects of Lagerstroemia speciosa (L.) Pers. aqueous and ethanolic leaf extracts (LSA and LSE extracts, respectively) on in vitro carbohydrate-digesting enzyme activities and enzyme kinetics. Settings and Design: In vitro carbohydrate-digesting enzyme activity assay. Materials and Methods: The activities of \α-amylase and \α-glucosidase were indicated by the amounts of maltose and p-nitrophenol generated in the reactions, respectively. Statistical analysis used: The data were analysed by using one-way ANOVA, followed by Bonferroni post-hoc test. Results: The LSA extract significantly inhibited both \α-amylase and \α-glucosidase enzymes with the IC50s of 1.21\±0.16 and 49.71\±0.86 \μg/mL, respectively. Meanwhile, the LSE extract selectively inhibited \α-amylase activity (IC50 = 22.21\±4.00 \μg/mL) with no apparent inhibition against \α-glucosidase activity. Both LSA and LSE extracts inhibited \α-amylase enzyme in a mixed inhibition manner whilst the LSA extract also acted as a mixed inhibitor against \α-glucosidase enzyme. The extracts possessed higher binding affinities toward the enzymes, indicated by the lower Ki values, when compared to acarbose (positive control). Conclusion: These results suggest the potential use of the extracts for a control of postprandial plasma glucose.

}, keywords = {Diabetes mellitus, Lagerstroemia speciosa (L.) Pers., α-amylase, α-glucosidase}, doi = {10.5530/pj.2018.6s.22}, author = {Wanwisa Khunawattanakul and Passakorn Boonma and Ronnarit Kampetch and Achida Jaruchotikamol and Benjamart Cushnie and Sakulrat Rattanakiat and Pawitra Pulbutr} }