Inhibition Potencies Of Guava Leaf Extracts And Synthetic Triazole Compounds On Protein Tyrosine Phosphatase 1B (PTP1B) And Dipeptidyl Peptidase-IV (DPP-IV) Enzymes

• Main Author: Rezka Larasati
• Other Authors: Tsai, Henry, J.
• Format: Others
• Language: en_US
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/13930302262140466112

碩士 === 亞洲大學 === 保健營養生技學系碩士班 === 99 === Diabetes mellitus (DM) is a chronic disease that is characteristic of hyperglycemia with various etiologies. The rising prevalence of diabetes mellitus has fueled an intensified search for new therapeutic treatments. Dipeptidyl peptidase IV (DPP-IV) and protein tyrosine phosphatase 1b (PTP1B) are two major enzymes that have recently emerged as biological targets for anti-diabetic compound development. The validation of specific inhibitor to PTP1B and DPP-IV is required for treating diabetes. Guava leaf has been used as a folk medicine traditionally because of its hypoglycemic effect. The 1,2,4-triazole is a synthetic compound that appears in the structure of various natural products and has attracted attention due to their diverse biological activities in pharmaceutical and agrochemical fields. The objectives of this study are to evaluating inhibitory potential of guava leaf extracts on PTP1B enzyme and the inhibition potency of synthetic 1,2,4-triazole compounds on PTP1B and DPP-IV enzymes. We have obtained water fraction of guava leaf extracts and fourteen 1,2,4-triazole compounds. We assessed the inhibitory activity associated with the water fraction of guava leaf extracts on PTP1B and their selectivity over T-cell protein tyrosine phosphatase (TCPTP) using enzymatic assays. Similarly, we tested the inhibitory activity of each triazole compounds on PTP1B and DPPIV enzymes. Results showed that fraction 5 of guava leaf extracts has the best inhibitory activity with the IC50 values of 0.160±0.013 µg/ml and provided 2-folds selectivity over T-cell protein tyrosine phosphatase (TCPTP). Compound 4 of trizole compounds has the strongest PTP1B inhibitory activity in vitro with the IC50 values of 25 µM. Compound 4 and 12 exhibited the strongest DPP-IV inhibitory activities with the IC50 values of 10 µM and 5 µM, respectively. The results from this experiment indicated that water fraction of guava leaf extracts and synthetic 1,2,4-triazole compounds have strong potency as inhibitor of PTP1B and DPP-IV enzymes.