Functional and antioxidant activity of Ziziphus jujube seed protein hydrolysates

Natural Plant Materials as a Source of Neuroprotective Peptides

In many circumstances, some crucial elements of the neuronal defense system fail, slowly leading to neurodegenerative diseases. Activating this natural process by administering exogenous agents to counteract unfavourable changes seems promising. Therefore, looking for neuroprotective therapeutics, we have to focus on compounds that inhibit the primary mechanisms leading to neuronal injuries, e.g., apoptosis, excitotoxicity, oxidative stress, and inflammation. Among many compounds considered neuroprotective agents, protein hydrolysates and peptides derived from natural materials or their synthetic analogues are good candidates. They have several advantages, such as high selectivity and biological activity, a broad range of targets, and high safety profile. This review aims to provide biological activities, the mechanism of action and the functional properties of plant-derived protein hydrolysates and peptides. We focused on their significant role in human health by affecting the nervous system and having neuroprotective and brain-boosting properties, leading to memory and cognitive improving activities. We hope our observation may guide the evaluation of novel peptides with potential neuroprotective effects. Research into neuroprotective peptides may find application in different sectors as ingredients in functional foods or pharmaceuticals to improve human health and prevent diseases.

Bioactive characterization and optimization of Tamarindus indica seed protein hydrolysate: technology and application of natural enzymes

Tamarind seeds are one of the major sources of different nutrients and minerals and are used as antioxidant components in various food products. Bioactive peptides are released by enzymatic hydrolysis of major food proteins followed by different separation techniques to isolate them from the mixture of other components. Further incorporation of bioactive peptides in various food products may lead to more diversification, fulfilling different nutritional requirements, and promoting health benefits. The objective of this study was to optimize the parameters for the formation of tamarind protein hydrolysates with the use of pepsin and trypsin. It was observed that pepsin and trypsin derived hydrolysate showed the maximum degree of hydrolysis and other bioactive characteristics (DPPH activity, reducing power, ABTS activity, and antidiabetic activity) under optimized conditions. High-performance liquid chromatography was performed for amino acid profiling on trypsin derived protein hydrolysate. From this study, pepsin and trypsin derived hydrolysate can be considered as a rich source of natural antioxidants for developing food formulation.

Physico-chemical properties, antioxidant activity, and ACE inhibitory activity of protein hydrolysates from wild jujube seed

Wild jujube seed protein (WJSP) as one kind of functional food material has attracted much attention due to its highly nutritive and medicinal value in anti-inflammatory and improving immunomodulatory ability. However, owing to its large molecular weight and complex structure, biological activities of WJSP were greatly limited and cannot be fully utilized by the human body. Therefore, how to improve the bioavailability of WJSP and develop promising WJSP nutritious materials is a great challenge. In this work, wild jujube seed protein hydrolysates (WJSPHs) were prepared from WJSP via enzymatic hydrolysis method, and their physico-chemical properties, antioxidant activity, and angiotensin converting enzyme (ACE) inhibitory activity in vitro have been investigated for the first time. SDS-PAGE electrophoresis and size-exclusion chromatographic results indicate that WJSPHs have lower molecular weight distribution (< 5,000 Da) than WJSP. Circular dichroism (CD) spectroscopy and Fourier transform infrared spectroscopy (FTIR) results illustrated that random coil is the main secondary structure of WJSPHs. Antioxidant experiments indicate that WJSPHs exhibit high radicals-scavenging ability of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals (94.60%), 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulfonate) (ABTS⁺ ) radicals (90.84%), superoxide radicals (44.77%), and hydroxyl radicals (47.77%). In vitro, WJSPHs can significantly decrease the accumulation of reactive oxygen species (ROS) and malondialdehyde (MDA), and increase the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in HepG2 cells. Moreover, ACE activity was found that can be significantly inhibited by WJSPHs (73.02%). Therefore, all previously mentioned results suggest that WJSPHs may be a promising antioxidant food to prevent oxidative-related diseases in future. PRACTICAL APPLICATION: This study shows that WJSPHs exhibit high antioxidant activity and ACE inhibitory activity in vitro, which provide potential application value as antioxidant peptides to prevent oxidative-related diseases.

Biologia futura: medicinal plants-derived bioactive peptides in functional perspective-a review

Bioactive peptides (BPs) are 3-20 amino acid residues, with a molecular weight lower than 6 kDa; originated from the breakdown of proteins by endogenous and exogenous peptidases. While intact in protein these peptides do not exert any biological activity, but as they release from their parent protein, they exert various pharmacological activities such as antidiabetic, antihypertensive, anticancerous, anti-inflammatory, antimicrobial, antioxidant, and immunomodulatory. Such peptides exist in all living organism like plants, animals, marine organism and also present in food products derived from them. BPs obtained from dairy food products, cereals, vegetables have been gaining much more importance now-a-days, but little work has been done on bioactive peptides obtained from medicinal plants. Some of the medicinal plants such as Tinospora cordifolia Sterculia foetida, Benincasa hispida, Parkia speciosa, Linum usitatissimum, Salvia hispanica and Ziziphus jujube have been explored for bioactive peptides. Current review is aimed to provide a complete information of medicinal plants derived BPs along with the surge of new materials, new plants which will provide more solutions for handling some of the major human health problems of twenty-first century. This review will also be helpful to researchers in providing valuable information about the extraction, separation, characterization of BPs, their known peptide sequences and various pharmacological activities exerted by medicinal plants-derived bioactive peptides.

Hairless canary seeds (Phalaris canariensis L.) as a potential source of antioxidant, antihypertensive, antidiabetic, and antiobesity biopeptides

Rising consumer concerns with synthetic drugs to treat non-communicable diseases (NCDs) have promoted a shift towards using natural biological active constituents that offer similar health benefits. Hairless canary seed (Phalaris canariensis L) is an emerging crop traditionally used in Mexico to treat NCDs. Peptides liberated during simulated digestion of canary seed protein are believed to be responsible for their biological activity; however, no studies have shown the effect of controlled protein hydrolysis using commercial proteases on canary seed protein’s biological activity. Therefore, this study aimed to explore the in vitro antihypertensive, antidiabetic, and anti-obesity activity of canary seed peptides derived from proteolysis with Alcalase®. Protein fractions were primarily composed of prolamins (54.07 ± 1.8%), glutelins (32.19 ± 3.18%), globulins (5.97 ± 0.52%) and albumins (5.97 ± 0.52%). The < 3 kDa and 3–10 kDa peptide fractions showed the highest inhibition capacity (p < 0.05) towards angiotensin-converting enzyme (IC50= 0.028–0.032 mg/mL) lipase (IC50= 2.15–2.27 mg/mL), α-glucosidase (IC50= 0.82–1.15 mg/mL), and dipeptidyl-peptidase-IV (IC50= 1.27–1.60 mg/mL). Additionally, these peptide fractions showed high antioxidant activity against DPPH (134.22–150.66 μmol TE/mg) and ABTS (520.92–813.33 μmol TE/mg). These results provide an insight into the potential development of functional foods using commercial enzymatic hydrolysis of canary seed proteins for treating hypertension, type-2 diabetes, and obesity.

Extraction and Characterization of Antioxidant Peptides from Fruit Residues

Fruit residues with high protein contents are generated during the processing of some fruits. These sustainable sources of proteins are usually discarded and, in all cases, underused. In addition to proteins, these residues can also be sources of peptides with protective effects against oxidative damage. The revalorization of these residues, as sources of antioxidant peptides, requires the development of suitable methodologies for their extraction and the application of analytical techniques for their characterization. The exploitation of these residues involves two main steps: the extraction and purification of proteins and their hydrolysis to release peptides. The extraction of proteins is mainly carried out under alkaline conditions and, in some cases, denaturing reagents are also employed to improve protein solubilization. Alternatively, more sustainable strategies based on the use of high-intensity focused ultrasounds, microwaves, pressurized liquids, electric fields, or discharges, as well as deep eutectic solvents, are being implemented for the extraction of proteins. The scarce selectivity of these extraction methods usually makes the subsequent purification of proteins necessary. The purification of proteins based on their precipitation or the use of ultrafiltration has been the usual procedure, but new strategies based on nanomaterials are also being explored. The release of potential antioxidant peptides from proteins is the next step. Microbial fermentation and, especially, digestion with enzymes such as Alcalase, thermolysin, or flavourzyme have been the most common. Released peptides are next characterized by the evaluation of their antioxidant properties and the application of proteomic tools to identify their sequences.

Natural Peptides in Drug Discovery Targeting Acetylcholinesterase

Acetylcholinesterase-inhibitory peptide has gained much importance since it can inhibit acetylcholinesterase (AChE) and increase the availability of acetylcholine in cholinergic synapses, enhancing cholinergic transmission in pharmacological treatment of Alzheimer’s disease (AD). Natural peptides have received considerable attention as biologically important substances as a source of AChE inhibitors. These natural peptides have high potential pharmaceutical and medicinal values due to their bioactivities as neuroprotective and neurodegenerative treatment activities. These peptides have attracted great interest in the pharmaceutical industries, in order to design potential peptides for use in the prophylactic and therapy purposes. Some natural peptides and their derivatives have high commercial values and have succeeded in reaching the pharmaceutical market. A large number of peptides are already in preclinical and clinical pipelines for treatment of various diseases. This review highlights the recent researches on the various natural peptides and future prospects for AD management.

Bioactive characteristics and optimization of tamarind seed protein hydrolysate for antioxidant-rich food formulations

Tamarind seed has been a source of valuable nutrients such as protein (contains high amount of many essential amino acids), essential fatty acids, and minerals which are recognized as additive to develop perfect balanced functional foods. The objective of present work was to optimize the process parameters for extraction and hydrolysis of protein from tamarind seeds. Papain-derived hydrolysates showed a maximum degree of hydrolysis (39.49%) and radical scavenging activity (42.92 ± 2.83%) at optimized conditions such as enzyme-to-substrate ratio (1:5), hydrolysis time (3 h), hydrolysis temperature (65 °C), and pH 6. From this study, papain hydrolysate can be considered as good source of natural antioxidants in developing food formulations.

Bioactive L acidissima protein hydrolysates using Box-Behnken design

This study examines the extraction and hydrolysis of proteins using single factor and Box-Behnken Design (BBD). From single factor tests, optimised extraction parameters were 1% alkali concentration, 40 °C temperature, 60 min time, and 1:20 solid to alkali ratio. Under these conditions; 924.31 mg/g of total protein was obtained from Limonia acidissima (L acidissima). The maximum degree of hydrolysis was 39.82% at pH 2, enzyme to substrate ratio 2.5% (w/w), and hydrolysis time was 42.41 min using BBD design. L acidissima seed protein hydrolysate showed 32.94% DPPH and 88.18% of ABTS activity at concentration of 100 µg/ml and 1 mg/ml, respectively. Reducing power of 0.16 and metal chelating activity of 87.39% was obtained from 5 mg/ml protein hydrolysates. This implied that L acidissima seed protein hydrolysate could be utilised in protein rich product or as protein supplements.