Purification, molecular docking and in vivo analyses of novel angiotensin-converting enzyme inhibitory peptides from protein hydrolysate of moth bean (Vigna aconitifolia (Jacq.) Màrechal) seeds.

The moth bean is a high-protein food legume. Enzymatic hydrolysates of food proteins demostrate health benefits. Search for diet related food protein hydrolysates is therefore within the scope of functional foods. Present study asertains to produce, screen and identify natural ACE-I inhibitory peptides derived from moth bean seed protein hydrolysates. The extracted protein was hydrolysed using alcalase, chymotrypsin, flavourzyme, papain, pepsin and trypsin respectively. Alcalase achieved the greatest degree of hydrolysis and ACE inhibition. The highest ACE-I inhibitory activity was exhibited by the peptide with the lowest molecular weight i.e. <3 kDa (IC50 11.19 ± 0.15 µg/mL). This was further separated by FPLC, followed by mass spectrometry. Molecular docking analysis showed the peptides IAWDFR and ADLPGLK bind to active sites whereas DKPWWPK and AVIPNAPNLR to non-active sites of the ACE molecule. In vivo administration of MBP hydrolysate to dexamethasone-induced hypertensive rats reduced their systolic blood pressure (125 ± 0.76 mmHg) compared with positive control (155 ± 3.13 mmHg). Moth bean protein peptides exhibit functional nutraceutical properties with adequate antihypertensive activity.

Variations in the antioxidant and free radical scavenging under induced heavy metal stress expressed as proline content in chickpea.

This study pertains to the effects of heavy metal salts viz., copper (Cu), manganese (Mn), lead (Pb) and zinc (Zn) on the chickpea accession ICC-4812. The salts were given as treatments to the chickpea seeds at various ascending levels of doses till proving toxic. The treatment of 24 h soaked and swollen seeds were then extended to 7 days duration from the date of treatment. Atomic absorption spectrophotometric analysis of bioassay tissue Cicer, showed maximum uptake of 9.41 mg/g and minimum of 1.65 mg/g tissue dry weight for Pb and Zn respectively. The study reveals that enhanced antioxidant responses are associated with substantial proline accumulation indicating induced stress. Ferric reducing antioxidant power assay measuring antioxidant activity was highest in the chickpea seedling treated with Zn, whereas, free radical scavenging activity was highest in the treatments with Mn. The total phenolic and flavonoid contents ranged between 0.24-0.97 and 0.27-1.00 mg/g of dry matter content respectively. Higher Pb and Zn doses seem to elicit higher proline levels therefore, suggesting an extreme condition of induced abiotic stress. Dose dependent protein oxidation coupled with DNA degradation was observed in all treatments, depicting genotoxicity. Unweighted pair-group method arithmetic average analysis presented similarity coefficients between the treatments.

Chickpea (Cicer arietinum L.) Lectin Exhibit Inhibition of ACE-I, α-amylase and α-glucosidase Activity.

BACKGROUND: Diabetes and hypertension are the major health concern and alleged to be of epidemic proportions. This has made it a numero uno subject at various levels of investigation. Glucosidase inhibitor provides the reasonable option in treatment of Diabetes Mellitus (DM) as it specifically targets post prandial hyperglycemia. The Angiotensin Converting Enzyme (ACE) plays an important role in hypertension. Therefore, inhibition of ACE in treatment of elevated blood pressure attracts special interest of the scientific community. Chickpea is a food legume and seeds contain carbohydrate binding protein- a lectin. Some of the biological properties of this lectin hitherto been elucidated. METHODS: Purified by ion exchange chromatography, chickpea lectin was tested for its in vitro antioxidant, ACE-I inhibitory and anti-diabetic characteristic. RESULTS: Lectin shows a characteristic improvement over the synthetic drugs like acarbose (oral anti-diabetic drug) and captopril (standard antihypertensive drug) when, their IC50 values are compared. Lectin significantly inhibited α-glucosidase and α-amylase in a concentration dependent manner with IC50 values of 85.41 ± 1.21 µg/ml and 65.05 ± 1.2 µg/ml compared to acarbose having IC50 70.20 ± 0.47 value of µg/ml and 50.52 ± 1.01 µg/ml respectively. ß-Carotene bleaching assay showed antioxidant activity of lectin (72.3%) to be as active as Butylated Hydroxylanisole (BHA). In addition, lectin demonstrated inhibition against ACE-I with IC50 value of 57.43 ± 1.20 µg/ml compared to captopril. CONCLUSION: Lectin demonstrated its antioxidant character, ACE-I inhibition and significantly inhibitory for α-glucosidase and α-amylase seems to qualify as an anti-hyperglycemic therapeutic molecule. The biological effects of chickpea lectin display potential for reducing the parameters of medically debilitating conditions. These characteristics however needs to be established under in vivo systems too viz. animals through to humans.

Biochemical diversity evaluation in chickpea accessions employing mini-core collection.

The seeds of chickpea provide an exceptional source of dietary proteins and is one of the important legumes in both developed and developing countries over the world. The available germplasm of cultivated chickpea is deficient in desired biochemical signatures. To identify new sources of variations for breeding, reduced subsets of germplasm such as mini-core collection can be explored as an effective resource. In the present investigation, mini-core collections consisting of 215 accessions of chickpea were extensively evaluated for tapping biochemical diversity. Analysis included ten biochemical parameters comprising total protein, total free amino acids, phytic acid, tannin, total phenolics, total flavonoids, lectin, DPPH radical scavenging activity, in vitro digestibility of protein and starch. The spectrum of diversity was documented for total protein (4.60-33.90%), total free amino acids (0.092-9.33 mg/g), phytic acid (0.009-4.06 mg/g), tannin (0.232-189.63 mg/g), total phenolics (0.15-0.81 mg/g), total flavonoids (0.04-1.57 mg/g), lectin (0.07-330.32 HU/mg), DPPH radical scavenging activity (26.74-49.11%), in vitro protein digestibility (59.45-76.22%) and in vitro starch digestibility (45.63-298.39 mg of maltose/g). The principal component analysis revealed association of chickpea higher protein content to the lower level of total phenolics and flavonoid contents. The dendrogram obtained by unweighted pair group method using arithmetic average cluster analysis grouped the chickpea accessions into two major clusters. This is the first comprehensive report on biochemical diversity analysed in the mini-core chickpea accessions. The ultimate purpose of conducting such studies was to deliver information on nutritional characteristics for effective breeding programmes. Depending on the objectives of the breeding aforesaid accessions could be employed as a parent.