Germinated chickpea protein ficin hydrolysate and its peptides inhibited glucose uptake and affected the bitter receptor signaling pathway in vitro.

The objective of this study was to evaluate germinated chickpea protein hydrolysate (GCPH) in vitro for its effect on markers of type 2 diabetes (T2D) and bitter taste receptor expression in intestinal epithelial cells. Protein hydrolysate was obtained using ficin, and the resulting peptides were sequenced using LC-ESI-MS/MS. Caco-2 cells were used to determine glucose uptake and extra-oral bitter receptor activation. Three peptides, VVFW, GEAGR, and FDLPAL, were identified in legumin. FDLPAL was the most potent peptide in molecular docking studies with a DPP-IV energy of affinity of -9.8 kcal mol-1. GCPH significantly inhibited DPP-IV production by Caco-2 cells (IC50 = 2.1 mM). Glucose uptake was inhibited in a dose-dependent manner (IC25 = 2.0 mM). A negative correlation was found between glucose uptake and PLCß2 expression in Caco-2 cells (R value, -0.62). Thus, GCPH has the potential to be commercialized as a functional ingredient.

Optimization, identification, and comparison of peptides from germinated chickpea (Cicer arietinum) protein hydrolysates using either papain or ficin and their relationship with markers of type 2 diabetes.

The objective was to optimize and compare the production of antidiabetic peptides from germinated chickpea isolated protein using either papain or ficin. Kabuli chickpeas were germinated for 2, 4 and 6 days. Proteins were isolated, and peptides were produced based on a central composite design selecting human dipeptidyl peptidase (DPP-IV) inhibition as a response. Peptide sequencing was performed to identify and evaluate the physiochemical, biochemical and bitterness properties. DPP-IV inhibition using papain was 84.66 ± 8.72%, with ficin being 72.05 ± 1.20%. The optimum hydrolysate conditions were 6 days germination, 1:10 E/S, and 30 min ficin hydrolysis; SPGAGKG, GLAR, and STSA were identified. Pure SPGAGKG had relatively high affinity for DPP-IV (-7.2 kcal/mol) and α-glucosidase inhibition (-5.9 kcal/mol), with an IC50 of 0.27 mg/mL for DPP-IV inhibition. Peptides in the chickpea hydrolysate inhibited markers of T2D, indicating that the optimal conditions could be used to prepare a functional food ingredient.

Identification and Comparison of Peptides from Chickpea Protein Hydrolysates Using Either Bromelain or Gastrointestinal Enzymes and Their Relationship with Markers of Type 2 Diabetes and Bitterness.

The chickpea (Cicer arietinum L.) is one of the most important pulses worldwide. The objective was to identify, compare and evaluate peptides from chickpea hydrolysates produced by two enzymatic treatments. The antidiabetic potential and bitterness of the peptides and induction of bitter receptors were identified in silico. Proteins were isolated from the Kabuli variety. Peptides were produced from the proteins using a simulated digestive system (pepsin/pancreatin, 1:50 Enzyme/Protein, E/P), and these peptides were compared with those produced via bromelain hydrolysis (1:50 E/P). The protein profiles, sequences and characteristics of the peptides were evaluated. The biochemical inhibition and molecular docking of dipeptidyl peptidase-IV (DPP-IV), α-amylase and α-glucosidase were also studied. The molecular docking identified peptides from enzymatic hydrolysis as inhibitors of DPP-IV. The high hydrophobicity of the peptides indicated the potential for bitterness. There was no correlation between peptide length and DPP-IV binding. Peptides sequenced from the pepsin/pancreatin hydrolysates, PHPATSGGGL and YVDGSGTPLT, had greater affinity for the DPP-IV catalytic site than the peptides from the bromelain hydrolysates. These results are in agreement with their biochemical inhibition, when considering the inhibition of sitagliptin (54.3 µg/mL) as a standard. The bitter receptors hTAS2R38, hTAS2R5, hTAS2R7 and hTAS2R14 were stimulated by most sequences, which could be beneficial in the treatment of type 2 diabetes. Chickpea hydrolysates could be utilized as functional ingredients to be included in the diet for the prevention of diabetes.

Relationship of phenolic composition of selected purple maize (Zea mays L.) genotypes with their anti-inflammatory, anti-adipogenic and anti-diabetic potential.

This study aimed to investigate the associations between phenolic composition of selected purple maize genotypes and their anti-inflammatory, anti-adipogenic and anti-diabetic properties in vitro. Anthocyanin-rich water extracts (PMWs) from 20 purple maize genotypes were evaluated in RAW 264.7 macrophages and 3T3-L1 adipocytes under different conditions. Cyanidin-3-O-glucoside (C3G), pelargonidin-3-O-glucoside (Pr3G), peonidin-3-O-glucoside (P3G) and corresponding acylated forms were major anthocyanins in PMW, accompanied by ten tentatively identified non-anthocyanin phenolics. Correlation studies showed that C3G, P3G, and derivatives, but not Pr3G and its acylated form contributed to the biological properties of PMW. Besides anthocyanins, quercetin, luteolin, and rutin were the dominant anti-inflammatory and anti-diabetic components, in terms of down-regulating pro-inflammatory mediator production in inflamed macrophages and adipocytes, modulating diabetes-related key enzymes and improving insulin sensitivity in insulin-resistant adipocytes. Quercetin and phenolic acids, especially vanillic acid and protocatechuic acid, were closely associated with anti-adipogenic properties of PMW via inhibition of the preadipocyte-adipocyte transition.