Pigeon pea penta- and hexapeptides with antioxidant properties also inhibit renin and angiotensin-I-converting enzyme activities.

Pigeon pea protein was sequentially digested with pepsin followed by pancreatin and the hydrolysate separated into 18 fractions using reversed-phase high-performance liquid chromatography. Fractions were analyzed for in vitro antioxidant properties (radical scavenging, metal chelation, and ferric iron reducing ability) in addition to inhibition of renin and angiotensin-converting enzyme (ACE). The most active fractions were analyzed by mass spectroscopy followed by identification of 10 peptide sequences (7 pentapeptides and 3 hexapeptides). All the peptides showed a wide range of multifunctional activity by scavenging hydroxyl (31.9-66.8%) and superoxide (25.6-100.0%) radicals in addition to ACE inhibition (7.4-100%) with significant (p < .05) differences between the peptides. AGVTVS, TKDIG, TSRLG, GRIST, and SGEKI were the most active; however, AGVTVS had the highest hydrophobic residue and exhibited the strongest activity against ACE, renin as well as superoxide and hydroxyl radicals. PRACTICAL APPLICATIONS: There is an increasing attraction of researchers to food peptides especially from legume proteins. Enzymatic digestion as well as high performance liquid chromatography (HPLC) purification has become an important process used to separate peptides with significant biological activities and health-promoting effects. There is useful information regarding the bioactive and functional (in vitro antioxidant, antidiabetic, in vitro/in vivo antihypertensive) properties of hydrolyzed and ultra-filtered pigeon pea fractions but scant research output still exists for purified peptides from pigeon pea establishing their therapeutic potential. The present study aimed to separate peptide fractions from pigeon pea hydrolysate and identify available amino acid sequences from the parent protein. Therefore, peptide sequences generated from the most bioactive fractions showed prospects for the expanded industrial utilization of pigeon pea. Further promoting its application as functional ingredient or additive for alleviating angiotensin-converting enzyme-related diseases.

Multigrain porridge possesses superior nutritional quality, its consumption alleviates hyperglycemia, hypercholesterolemia and oxidative stress in obese-diabetic wistar rats.

There is an increased utilization of wholegrain cereals in food formulations considering their richness in essential nutritional and biological properties. In this study, each component (amaranth, acha and pearl millet) of the multigrain blend was individually pre-fermented. Thereafter, the pre-fermented grain flours were optimized to obtain two unique blends (90:5:5 and 47.98: 26.68:25.34) containing high protein content (~23% and 17%) and low glycemic index (~43). The optimum blends were processed into instant porridges (PR1, PR2) and analyzed for its nutritional composition, blood glucose lowering ability, antioxidant enzyme and tissue/serum biochemical makers modulatory ability in obese-diabetic animals. The porridge showed significant nutritional profile, consumption of formulated multigrain porridge reduced blood glucose level (by 62% and 66%), upregulated the antioxidant defense system to near normal levels likewise, significantly reduced serum biochemical parameters. Thus, suggests that the multigrain blends/porridge is nutrient-dense possessing beneficial effect to maintain antioxidant levels in the diabetic condition with potential to attenuate oxidative damage. PRACTICAL APPLICATIONS: Prolonged feeding with high-fat diet induces hypercholesterolemia in experimental animals. Further interperitoneal injection of streptozotocin induces experimental diabetes with a cascade of oxidative stress related complications in serum and tissue parameters. Porridge is a traditional meal while multigrain porridge is a nutrient dense meal which may exert curative effect. In this work, it was shown that dietary intervention with multigrain porridge product promoted positive weight control, portrayed hepatoprotective effect as shown by the elevated levels of biomarker (ALT, AST, ALP) and antioxidant enzymes (CAT, SOD, GPx) as well as modulation of serum lipid profile (total cholesterol, triglycerides, high density lipoprotein-cholesterol). Thus, the multigrain porridge may be a functional food product to combat hypercholesterolemia and hyperglycemia especially PR1 which appeared to be more efficient than PR2 in modulating oxidative stress, conferring hypoglycemic effect and lowering lipid levels in obese-diabetic rats model studied.

Shallot-enriched amaranth-based extruded snack influences blood glucose levels, hematological parameters, and carbohydrate degrading enzymes in streptozotocin-induced diabetic rats.

Diabetes mellitus affects different age groups, and it is popularly managed using synthetic drugs; however, recent research efforts focus on dietary intervention especially the use of fiber rich crops to circumvent the effects of drugs. Developed shallot-enriched amaranth-based extruded snacks, namely: GCB, Amaranth: shallot: soy cake (55:25:20) %; TYD, Amaranth: shallot: soy cake (75:14.81:10.19)%; DZU, Amaranth: shallot: soy cake (60.43:25:14.57)%; and JKL, Amaranth: shallot: soy cake (70:25:5)%, were evaluated for proximate composition, total phenol and flavonoid contents. Snacks ability to modulate carbohydrate hydrolyzing enzymes in streptozotocin induced diabetic rats were also investigated. AMT (100% amaranth grain extrudate) and CCS (commercial shallot-enriched snack) served as control. Protein contents of snacks provided up to 25% of daily protein requirements for adult. Snacks exhibited high total phenol and flavonoid contents. Animals fed with snacks showed ameliorative effects on hematological parameters, attenuates elevation of enzyme activities in kidney and liver homogenates, and displayed decreased α-glucosidase/α-amylase activities. PRACTICAL APPLICATIONS: Dietary intervention is capable of circumventing the adverse effects of synthetic drugs in the management of diabetes mellitus. The study established that developed shallot-enriched amaranth-based extruded snacks possess significant ability to hamper the activities of key carbohydrate hydrolyzing enzymes in streptozotocin induced diabetic rats, hence, has potential as a functional nutritious snack to curtail hyperglycemia and prevent diabetic complications.

Antioxidant properties, glycemic indices, and carbohydrate hydrolyzing enzymes activities of formulated ginger-based fruit drinks.

The global prevalence of hyperglycemia has been attributed to unhealthy lifestyle and diet. The study assessed the antioxidant properties, glycemic indices, and carbohydrate hydrolyzing enzymes activities of ginger-based fruit drinks. Drinks prepared from blends of ginger (G), pineapple (P), and apple (A) at varied ratios-G50:P40:A10, G50:P30:A20, G50:P20:A30, G50:P10:A40, G100, and a commercial ginger drink (control) were analyzed for phenolic distribution and antioxidant properties using 2,2-diphenyl-1-picrylhydrazyl [DPPH] and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) [ABTS] radical scavenging abilities. The ferric reducing antioxidant property (FRAP), the glycemic indices and carbohydrate hydrolyzing enzymes activities were also investigated. G50:P10:A40 exhibited the highest phenolic distribution, highest DPPH● , ABTS●+ scavenging abilities as well as FRAP. All formulated ginger-based drinks exhibited low glycemic indices, the G50:P10:A40 showed the strongest inhibition against carbohydrate hydrolyzing enzymes. G50:P10:A40 blend may be suitable for the control of hyperglycemia and some degenerative conditions linked with oxidative stress. PRACTICAL APPLICATIONS: Unchecked activities of reactive oxygen species (ROS) are linked to health disorders such as diabetes mellitus, hypertension, cancer, neurodegenerative, and inflammatory diseases. A practical approach to the management of the deleterious effect of ROS is through the consumption of foods rich in nutritional antioxidants. Ginger (Zingiber officinale) is grown globally for its edible rhizome which has varied utilization in culinary and medicinal applications. Drinks produced from blends of ginger, pineapple, and apple were able to scavenge free radicals and able to exhibit hypoglycemic effects by inhibiting carbohydrate hydrolyzing enzymes. The Ginger-based fruit drinks would, therefore, be an effective functional dietary drink in the management and prevention of diabetes mellitus.

Thermoase-hydrolysed pigeon pea protein and its membrane fractions possess in vitro bioactive properties (antioxidative, antihypertensive, and antidiabetic).

Enzymatic hydrolysis can liberate bioactive peptides from protein materials, thus, pigeon pea was hydrolysed using thermoase. Crude hydrolysate (PPHT) was subjected to ultrafiltration using different molecular weight cutoffs to collect <1, 1-3, 3-5, 5-10, and >10 kDa peptide fractions. Fractions were analysed for in vitro antioxidative, antihypertensive, and antidiabetic properties. The peptide fractions had stronger DPPH• scavenging and renin inhibition when compared to PPHT. In contrast, ACE inhibition was stronger for the PPHT and <1 kDa peptide fraction while activity decreased as peptide size increased. The <1 kDa peptide also showed significantly stronger ferric reducing antioxidant power, OH• scavenging and inhibition of linoleic acid oxidation when compared to PPHT. α-amylase and α-glucosidase were inhibited by all the peptide fractions, though the 3-5 and >10 kDa had higher values. We conclude that the PPHT and peptide fractions could serve as potential ingredients to formulate antihypertensive and antidiabetic functional foods and nutraceuticals. PRACTICAL APPLICATIONS: Oxidative stress promotes the generation of free radicals, which have a significant impact in the pathogenesis of human chronic diseases such as cardiovascular impairment, cancer, and diabetes. Peptides generated from enzymatic hydrolysis of proteins have been identified to impart beneficial health effects. In this work, we showed that a thermoase digest of pigeon pea protein as well as the fractionated peptides had strong antioxidant properties in addition to exhibiting inhibitory activities against renin and angiotensin converting enzyme, the main therapeutic targets for antihypertensive agents. The peptide products also inhibited α-amylase and α-glucosidase activities, providing potential ingredients that can be used to formulate antidiabetic functional foods.

Antioxidant properties, ACE/renin inhibitory activities of pigeon pea hydrolysates and effects on systolic blood pressure of spontaneously hypertensive rats.

Legumes are rich sources of protein in human diet and their consumption has been associated with the prevention of chronic diseases attributable to their bioactive components. Pigeon pea (Cajanus cajan) is an underutilized legume with relatively high protein content (~24%). Protein hydrolysates were prepared from pea isolate by enzymatic hydrolysis using pepsin and pancreatin. Hydrolysates were evaluated for their amino acid composition, antioxidant properties, in vitro and in vivo antihypertensive properties. The hydrolysates had high hydrophobic amino acids, especially isoleucine, phenylalanine, and leucine. Pepsin-pancreatin-hydrolyzed pea protein (PPHPp) showed significantly higher ability to scavenge DPPH˙ while pancreatin-hydrolyzed pea protein (PPHPa) had higher ˙OH, ABTS˙+ scavenging, Fe3+ reducing and linoleic acid peroxidation inhibition. PPHPp exhibited superior angiotensin-converting enzyme inhibition (61.82%) while PPHPa showed higher renin inhibition (14.28%). PPHPp exhibited strong antihypertensive effect, showing an instantaneous systolic blood pressure lowering effect (-26.12 mmHg) within 2-h post-oral administration. Pigeon pea protein hydrolysate (especially from pancreatin digest) could therefore, be a promising source of bioactive peptides and potential ingredient for formulation of functional foods against oxidative stress and hypertension.