Table 1.
Dry yield, Total Phenolic Content (TPC), Total tannin Content (TTC) and Total Flavonoid Content (TFC) of test materials.
Figure 1.
SCE SCD and SCEC exhibited alpha-glucosidase inhibitory property.
(A) Yeast alpha glucosidase inhibition. (B) Rat intestinal alpha glucosidase inhibition. Values are means ± SD; n = 3. SCE, S. cochinchinensis (SC) ethanol extract; SCD, SC dichloromethane fraction and SCEC, SC ethyl acetate fraction.
Figure 2.
DPP-IV and PTP-1B inhibitory property of SCE and SCEC.
(A) DPP-IV inhibition by SCE & SCEC. SCEC IC50- 87.63±1.88 µg/mL and SCE IC50- 269.98±2.95 µg/mL. Values are means ± SD; n = 3. (B) PTP-1B inhibitory property of SCE & SCEC. SCEC IC50- 55.83±1.24 µg/mL and SCE IC50- 159.10±1.91 µg/mL. Values are means ± SD; n = 3. SCE, S. cochinchinensis (SC) ethanol extract and SCEC, SC ethyl acetate fraction.
Table 2.
IC50 values of antioxidant (DPPH, ABTS and hydroxyl radical scavenging) and metal chelation assays.
Figure 3.
Fluorescence quantification and SEM microstructure analysis of advanced glycation end products revealed the antiglycation property of SCE SCEC and SCEL.
(A) Quantification of fluorescence intensity of glycated products in presence of various concentrations of SCE, SCEC and SCEL (100, 500, 1000 µg/mL) under 2 different time intervals (day1 & day7) in terms of relative fluorescence units (RFU). Quercetin (100 µM) was used as reference compound. RFU are normalized to 100. Values are means ± SD; n = 3. *represents groups differ significantly from day 1 control group (P≤0.05) and ≠represents groups differ significantly from day 7 control group (P≤0.05). (B) Representative SEM microstructures of glycated products formed under various groups of day1 experiments (a–h), (a, control; b, quercetin 100 µM, c & d, SCE 100 µg/mL and SCE 1000 µg/mL; e & f, SCEC 100 µg/mL and SCEC 1000 µg/mL and g & h, SCEL 100 µg/mL and SCEL 1000 µg/mL. All samples were visualized at 16000× magnification.
Figure 4.
SCE and SCEC fractions protected HepG2 cells against ROS generation during hyperglycemia.
Analysis of high glucose induced intracellular ROS levels in HepG2 cells by DCFDA method. Cultured HepG2 cells were treated with SCE or SCEC in the presence of high glucose (HG; 25 mM) for 24 h and then incubated with H2DCFDA. The results are shown as (A) the quantitative analysis of fluorescence from three independent experiments. Values are means ± SD; n = 3. *represents groups differ significantly from HG group (P≤0.05). (B) Representative microscopic scans a–i (a, vehicle control; b, high glucose (HG); c, HG+Quercetin; d–f, HG+10 µg, 50 µg and 100 µg SCE; g–i, HG+10 µg, 50 µg and 100 µg SCEC). All samples were visualized at 20× magnification.
Figure 5.
Pancreatic beta cell proliferation potential of SCE in RIN-m5F and MIN-6 cells.
(A) Beta cell proliferation potential of SCE in RIN-m5F cells. (B) Beta cell proliferation potential of SCE in MIN-6 cells. Results are normalised to 100 based on control readings. Values are means ± SD; n = 3. *represents groups differ significantly from control group (P≤0.05).
Figure 6.
Glucose uptake and adipocyte differentiation studies in all 5 extracts.
(A) 2-deoxy glucose uptake in L6 myotubes. Cells were incubated for 16 h with different extracts (100 µg/mL) or standards. After incubation myotubes were left untreated (white bars) or stimulated with 100 nM insulin (black bars) for 20 min, followed by the determination of 2-DG uptake. Results are expressed as fold stimulation over control basal. Metformin (10 mM) & rosiglitazone (20 µM) were the standards. Values are means ± SD; n = 3. *represents groups differ significantly from basal control group (P≤0.05). ≠represents groups differ significantly from insulin control group (P≤0.05). (B) Quantification of triglyceride content in differentiating 3T3-L1 adipocytes treated with different extracts (30 µg/mL) or rosiglitazone (10 µM) for 8 days by oil red O staining. Data are expressed as the means ± SD; n = 3; * represents groups differ significantly from MDI positive group (P≤0.05). MDI−ve, media without 3-isobutyl-1-methylxanthine (IBMX), dexamethasone & insulin; MDI+ve, media with IBMX, dexamethasone & insulin and Ros 10 µM, rosiglitazone 10 µM.
Figure 7.
Estimation of adipogenesis in SCE tretment.
(A) Cellular morphology. (Panels a–f) Micrographs (×10) showing (a) MDI negative, (b) MDI positive (vehicle control) (c) differentiating 3T3-L1 adipocytes treated for 8 days with rosiglitazone (10 µM), and (d–f) various concentrations of SCE (10, 25 and 50 µg/mL, respectively). DMSO (0.1%, vehicle) in differentiation media served as the vehicle control group i.e MDI positive. (B) Glycerol-3-phosphate dehydrogenase activity in various groups (MDI positive, rosiglitazone at 10 µM) and various concentrations of SCE (10, 25 and 50 µg/mL, respectively). (C) Diacyl glycerol -3 phosphate activity in various groups (MDI positive, rosiglitazone at 10 µM) and various concentrations of SCE (10, 25 and 50 µg/mL, respectively). (D) The triglyceride content in various groups (MDI positive, rosiglitazone at 10 µM) and various concentrations of SCE (10, 25 and 50 µg/mL, respectively). (E) Adiponectin level in various groups (MDI positive, rosiglitazone at 10 µM) and various concentrations of SCE (10, 25 and 50 µg/mL, respectively). Results are normalised to 100 based on control readings. Data are expressed as the means ± SD; n = 3. *Represents groups that differ significantly from the MDI positive (vehicle control) group (P≤0.05).
Figure 8.
The antihyperglycemic effect of SCE in normal rats, mild diabetic rat model (SLM) and streptozotocin-induced diabetic rat model (STZ-S) after sucrose administration.
(A) The glycemic response curve and (B) incremental AUC0–120 min in normal rats. (C) The glycemic response curve and (D) incremental AUC0–120 min in SLM model. (E) The glycemic response curve and (F) incremental AUC0–1440 min in STZ-S model. Data are expressed as the mean ± SD, n = 6. * represents groups differ significantly from control group (p<0.05). SCE, S. cochinchinensis (SC) ethanol extract.