Boarfish (Capros aper) protein hydrolysate has potent insulinotropic and GLP‐1 secretory activity in vitro and acute glucose lowering effects in mice

Abstract

The anti-diabetic actions of a boarfish protein hydrolysate (BPH) were investigated in cultured cells and mice. A boarfish (Capros aper) muscle protein hydrolysate was generated using the enzymes Alcalase 2.4 L and Flavourzyme 500 L. Furthermore, the BPH was subjected to simulated gastrointestinal digestion (SGID). BPH and SGID samples (0.01-2.5 mg mL À1 ) were tested in vitro for DPP-IV inhibition and insulin and GLP-1 secretory activity from BRIN-BD11 and GLUTag cells, respectively. The BPH and SGID samples, caused a dose-dependent increase (4.2 to 5.3-fold, P < 0.001) in insulin secretion from BRIN-BD11 cells and inhibited DPP-IV activity (IC 50 1.18 AE 0.04 and 1.21 AE 0.04 mg mL À1 ), respectively. The SGID sample produced a 1.3-fold (P < 0.01) increase in GLP-1 secretion. An oral glucose tolerance test (OGTT) was conducted in healthy mice (n = 8), with or without BPH (50 mg/kg bodyweight). BPH mediated an increase in plasma insulin levels (AUC (0-120 min), P < 0.05) and a consequent reduction in blood glucose concentration (P < 0.01), after OGTT in mice versus controls. The BPH showed potent anti-diabetic actions in cells and improved glucose tolerance in mice.Keywords Boarfish protein hydrolysate, dipeptidyl peptidase-IV inhibition, glucagon-like peptide-1, glycaemic control in mice, insulin secretion.

A Narrative Review of the Anti‐Hyperglycemic and Satiating Effects of Fish Protein Hydrolysates and Their Bioactive Peptides

“…[85] Alongside this strong evidence for DPP-4 inhibitory action, several studies have also shown FPH to have strong insulin, GLP-1, and CCK release actions. [31][32][33]39,40,85,86] The in vivo efficacy of FPH has also been reasonably well established. Acutely, all studies investigating an anti-hyperglycemic effect of FPH has found a reduction in blood glucose with doses as low as 50 mg kg −1 bodyweight, [33] and several exhibiting an increase in plasma insulin [33,34] or GLP-1 [34] ; however, Iba et al [34] used extremely high doses of 1.5 g kg −1 and 3 g kg −1 bodyweight which would be impossible to translate to a human trial.…”

“…The inhibition of DPP-4 and prolongation of GLP-1 half-life is of greater interest in the development of functional foods recently as a statement from EFSA concluded that a reduction in post-prandial glucose response "may be considered a beneficial physiological effect as long as insulin responses are not disproportionally increased". [30] FPH were found to cause an increase in insulin secretion in vitro by Harnedy et al [31,32] and Parthsarathy et al [33] Furthermore, Parthsarathy and colleagues and Harnedy et al showed a significant increase in plasma insulin in healthy mice. [31,33] An increase in plasma insulin was also shown by Iba et al [34] ; however, this involved a very high dose (3 g kg −1 bodyweight) which may be difficult to achieve when translating this to human studies.…”

“…[30] FPH were found to cause an increase in insulin secretion in vitro by Harnedy et al [31,32] and Parthsarathy et al [33] Furthermore, Parthsarathy and colleagues and Harnedy et al showed a significant increase in plasma insulin in healthy mice. [31,33] An increase in plasma insulin was also shown by Iba et al [34] ; however, this involved a very high dose (3 g kg −1 bodyweight) which may be difficult to achieve when translating this to human studies. Despite these promising in vivo results, none of the human studies with fish hydrolysates have shown an increase in plasma insulin, while one study showed a decrease in plasma insulin.…”

Antidiabetic Food-Derived Peptides for Functional Feeding: Production, Functionality and In Vivo Evidences

“…In regard to the literature dealing with this topic, Harnedy et al [81] and Parthsarathy et al [98] reported a protein hydrolysate from blue whiting and boarfish with in vitro and in vivo antidiabetic properties, using cell cultures and mice. Similar research was carried out by Jung et al [232] with silk fibroin hydrolysate, and by Hsieh et al [162] with milk proteins.…”

New Bioactive Peptides Identified from a Tilapia Byproduct Hydrolysate Exerting Effects on DPP-IV Activity and Intestinal Hormones Regulation after Canine Gastrointestinal Simulated Digestion

“…Indeed, numerous studies have shown, in vitro as well as in vivo, the beneficial effects of fish hydrolysates on food intake regulation by the stimulation of the gut hormones secretion, in particular CCK and GLP-1 [ 15 , 16 , 17 , 18 ]. Moreover, fish hydrolysates could improve glucose homeostasis by increasing plasma GLP-1, gastric inhibitory peptide, also known as glucose-dependent insulinotropic polypeptide (GIP) increasing insulin secretion and lowering blood glucose [ 19 , 20 ] but also by reducing DPP-IV activity in vitro and in vivo [ 21 , 22 , 23 ].…”