School of Medicine, University of Tasmania, Hobart, TAS, Australia 7000.
School of Medicine, University of Tasmania, Hobart, TAS, Australia 7000; Department of Diabetes & Endocrinology, Royal Hobart Hospital, Hobart, TAS, 7000, Australia.
Biochem Biophys Res Commun. 2018 Sep 3;503(1):21-25. doi: 10.1016/j.bbrc.2018.04.156. Epub 2018 Jun 9.
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 IC values ranging from 485 μM (rutin) to 5700 μM (hesperitin and eriodictyol). Similarly, the flavonoid supplements had IC values of 16.9 mg/mL (EN), 3.44 mg/mL (SB) and 2.72 mg/mL (CB). These values compare with gliptin IC 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.
本研究比较了二肽基肽酶-4（DPP-4）抑制活性的柑橘类生物类黄酮营养保健品与三种gliptins。在这项研究中考虑了柑橘类生物类黄酮标准品和三种市售的柑橘类生物类黄酮补充剂（Thompson's Super Bioflavonoid Complex（SB），Ethical Nutrients Bioflavonoids Plus Vitamin C（EN）和 Country Life Citrus Bioflavonoids and Rutin（CB））。采用超高效液相色谱-串联质谱（UPLC-MS/MS）分析方法鉴定和定量每种补充剂中的柑橘类生物类黄酮。通过荧光测定法测定 DPP-4 抑制活性。所有测试的单个柑橘类黄酮均表现出 DPP-4 抑制活性，IC 值范围为 485 μM（芦丁）至 5700 μM（橙皮苷和圣草酚）。同样，黄酮类补充剂的 IC 值为 16.9 mg/mL（EN），3.44 mg/mL（SB）和 2.72 mg/mL（CB）。这些值与 gliptin 的 IC 值（西他列汀为 0.684 μM，沙格列汀为 0.707 μM，维格列汀为 2.286 μM）相比。补充剂中类黄酮的含量从片剂质量的 11.98%（CB）到 5.26%（EN）和 14.51%（SB）不等，分别对应于每天约 300、150 和 400mg 的类黄酮剂量，其中 CB 和 SB 中芦丁的含量分别为片剂质量的 7.0%和 7.5%。虽然我们的数据表明基于柑橘类生物类黄酮的补充剂确实具有 DPP-4 抑制活性，但它们的效力比 gliptins 低几个数量级。需要进一步研究使用更高浓度的柑橘类生物类黄酮以及调查可能增加额外益处的抗氧化特性。
