A molecular connection of Pterocarpus marsupium, Eugenia jambolana and Gymnema sylvestre with dipeptidyl peptidase-4 in the treatment of diabetes

Figures & data

Figure 1. Dissociation kinetics of P. marsupium (PM), E. jambolana (EJ) and G. sylvestre (GS) with dipeptidyl peptidase-4 (DPP-4). DPP-4 was pre-incubated with each extract (1000 µg/mL), and the enzyme reaction was initiated by adding substrate. Fluorescence intensities were measured every 5 min for a total of 10 h. The values were the mean of triplicate studies.

Table 1. Effect of extracts on DPP-4 inhibition and kinetics.

Extract	IC50	Koff	EI half-life
P. marsupium	273.73 ± 12	1.49	462.3
E. jambolana	278.94 ± 16	2.18	317.2
G. sylvestre	773.22 ± 19	4.50	153.8

IC₅₀ expressed in µg/mL. K_off -- dissociation constant and expressed as ×10⁻³/s. EI half-life -- Enzyme inhibitory half-life and expressed in minute.

Figure 2. Effect of extracts on plasma active glucagon-like peptide-1 levels in streptozotocin-induced diabetic rats. Graph represented as mean ± SD (n = 6). Two way ANOVA followed by Bonferroni post test was applied. ***p < 0.001, **p < 0.01 vs negative control. (a) P. marsupium (PM), (b) E. jambolana (EJ) and (c) G. sylvestre (GS).

Figure 3. Effect of extracts on the area under the plasma active glucacon-like peptide-1 concentration time curve. The graph is represented as mean ± SD (n = 6). One way ANOVA followed by Bonferroni multiple comparison test. **p < 0.01 versus negative control. (a) P. marsupium at 2 h, (b) E. jambolana at 2 h and (c) G. sylvestre at 1.5 h.