TY - JOUR
T1 - Citrus bioflavonoids dipeptidyl peptidase-4 inhibition compared with gliptin antidiabetic medications
AU - Gupta, Ankit
AU - Jacobson, Glenn A.
AU - Burgess, John R.
AU - Jelinek, Herbert F.
AU - Nichols, David S.
AU - Narkowicz, Christian K.
AU - Al-Aubaidy, Hayder A.
N1 - Funding Information:
The project was funded by the internal grant scheme of the School of Medicine, University of Tasmania.
Funding Information:
The project was funded by the internal grant scheme of the School of Medicine , University of Tasmania .
Publisher Copyright:
© 2018 Elsevier Inc.
PY - 2018/9/3
Y1 - 2018/9/3
N2 - This study compared dipeptidyl peptidase-4 (DPP-4) inhibitory activity of citrus bioflavonoid nutraceuticals compared with three gliptins. Citrus bioflavonoid standards and three commercially available citrus bioflavonoid supplements (Thompson's Super Bioflavonoid Complex®(SB), Ethical Nutrients Bioflavonoids Plus Vitamin C®(EN), and Country Life Citrus Bioflavonoids and Rutin®(CB)) were considered in this study. Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis was undertaken to identify and quantitate the citrus bioflavonoids present in each supplement. The DPP-4 inhibitory activity was determined by fluorometric assay. All of the tested individual citrus flavonoids demonstrated DPP-4 inhibitory activity, with IC50 values ranging from 485 μM (rutin) to 5700 μM (hesperitin and eriodictyol). Similarly, the flavonoid supplements had IC50 values of 16.9 mg/mL (EN), 3.44 mg/mL (SB) and 2.72 mg/mL (CB). These values compare with gliptin IC50 values of 0.684 μM (sitagliptin), 0.707 μM (saxagliptin) and 2.286 μM (vildagliptin). The supplement flavonoid content varied from 11.98% (CB) to 5.26% (EN) and 14.51% (SB) of tablet mass, corresponding to daily flavonoid doses of around 300, 150 and 400 mg, respectively, with CB and SB containing rutin at levels of 7.0% and 7.5% of tablet mass, respectively. While our data demonstrated that citrus bioflavonoid based supplements do possess DPP-4 inhibitory activity, they are several orders of magnitude less potent than gliptins. Further studies using higher concentrations of citrus bioflavonoids, as well as investigations into antioxidant properties which may add additional benefit are warranted.
AB - This study compared dipeptidyl peptidase-4 (DPP-4) inhibitory activity of citrus bioflavonoid nutraceuticals compared with three gliptins. Citrus bioflavonoid standards and three commercially available citrus bioflavonoid supplements (Thompson's Super Bioflavonoid Complex®(SB), Ethical Nutrients Bioflavonoids Plus Vitamin C®(EN), and Country Life Citrus Bioflavonoids and Rutin®(CB)) were considered in this study. Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis was undertaken to identify and quantitate the citrus bioflavonoids present in each supplement. The DPP-4 inhibitory activity was determined by fluorometric assay. All of the tested individual citrus flavonoids demonstrated DPP-4 inhibitory activity, with IC50 values ranging from 485 μM (rutin) to 5700 μM (hesperitin and eriodictyol). Similarly, the flavonoid supplements had IC50 values of 16.9 mg/mL (EN), 3.44 mg/mL (SB) and 2.72 mg/mL (CB). These values compare with gliptin IC50 values of 0.684 μM (sitagliptin), 0.707 μM (saxagliptin) and 2.286 μM (vildagliptin). The supplement flavonoid content varied from 11.98% (CB) to 5.26% (EN) and 14.51% (SB) of tablet mass, corresponding to daily flavonoid doses of around 300, 150 and 400 mg, respectively, with CB and SB containing rutin at levels of 7.0% and 7.5% of tablet mass, respectively. While our data demonstrated that citrus bioflavonoid based supplements do possess DPP-4 inhibitory activity, they are several orders of magnitude less potent than gliptins. Further studies using higher concentrations of citrus bioflavonoids, as well as investigations into antioxidant properties which may add additional benefit are warranted.
KW - Citrus bioflavonoids
KW - Dipeptidyl peptidase-4
KW - Dipeptidyl peptidase-4 inhibitory assay
KW - Gliptins
KW - Ultra performance liquid chromatography
UR - http://www.scopus.com/inward/record.url?scp=85048158685&partnerID=8YFLogxK
U2 - 10.1016/j.bbrc.2018.04.156
DO - 10.1016/j.bbrc.2018.04.156
M3 - Article
C2 - 29698678
AN - SCOPUS:85048158685
SN - 0006-291X
VL - 503
SP - 21
EP - 25
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 1
ER -