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Background: Oratosquilla woodmasoni is one of the marine squilla species, which is found in the entire Asia-Pacific region. This current study assesses the species as the main basis of both ACEi and antioxidant peptide. Objective: To isolate the ACEi peptide derived from O. woodmasoni and examine its ACE inhibition along with antioxidant potential. Materials and Methods: The squilla muscle protein was hydrolysed using alcalase and trypsin enzymes for 12 hours and tested for DH. The hydrolysates were examined for their ACEi activity and then the best hydrolysate was sequentially purified in various chromatographical methods. The purified peptide was studied for anti-oxidant and functional properties, followed by amino acid sequencing. The purified peptide was also evaluated for its toxicity by in vitro cell viability assay. Results: The DH% was found to be 47.13 ± 0.72% and 89.43 ± 2.06% for alcalase and trypsin, respectively. The alcalase 5th-hour hydrolysate was detected with potent activity (65.97 ± 0.56%) using ACEi assay and was primarily fractionated using ultrafiltration; the maximum inhibitory activity was found with 77.04 ± 0.52% in 3-10 kDa fraction. Subsequently, the fraction was purified using IEC and GFC, in which the AC1-A2 fraction had higher antihypertensive activity (70.85 ± 0.78%). The non-toxic fraction showed hexapeptide HVGGCG with molecular weight 529 Da with great potential of antioxidant activity along with functional property. Conclusion: This peptide could be developed as a potential ACE-inhibitory and antioxidant agent.

Biological waste from marine sources is discarded into various water bodies which leads to dramatic increase in the water pollution near coastal areas. This animal waste consists of bioactive compo...

The current objective was framed on isolation of two angiotensin-I converting enzyme inhibitory peptides from coastal trashes of squilla muscle (Harpiosquilla raphidea) prepared by enzymatic hydrolysis using alcalase, thermolysin and trypsin, which showed the highest degree of hydrolysate in 12th h hydrolysate 87.9 ± 1.6%, 63.1 ± 1.1% and 91.1 ± 2.7% respectively. Among these three hydrolysates, alcalase 5th h (64.8 ± 0.3) and thermolysin 6th h (68.4 ± 1.0) found to be maximum ACE-I inhibition activity. Initial separation was performed by ultra filtration (10–3 kDa) into three different fractions, alcalase (below 3 kDa) fraction observed maximum ACE-I inhibition activity with 75.2 ± 3.5% and thermolysin (3–10 kDa) with 79.5 ± 1.0% inhibition. Further, these two fractions have taken to ion exchange and gel filtration chromatography, the identified ACE-I inhibitory fractions (AC-A2 and TH-A2) also examined for its antioxidant properties. Further, these fractions were determined to be non-toxic against cell lines, functional activities by various assays and characterized into tri peptides MSN (Met-Ser-Asn) and MTH (Met-Thr-His) with a molecular weight of 350 Da and 388 Da respectively using LC–MS/MS. These low molecular weight peptides from natural sources may act as potential ingredient for nutraceutical and pharmaceutical industries.

Antioxidant peptides protect biological macromolecules against radical damages. The use of these peptides was evaluated using free radicals scavenging assays [2,2-diphenyl-1 picrylhydrazyl (DPPH) and hydroxyl] with the help of UV-visible and electron spin resonance (ESR) spectroscopy methods. The Octopus aegina mantle protein were tested upon hydrolysis using gastrointestinal enzymes up to 12 h, where pepsin hydrolysate exhibited superior properties (DPPH: 44.39±0.67% and hydroxyl: 38.84±1.07%) compared with trypsin and α-chymotrypsin. Consequently, the antioxidant activity of the purified hydrolysate increased on a successive purification, and the peptide sequence was determined to be 368.9 Da with Gly-Glu-Tyr amino acids. Tripeptide exerted free radical scavenging efficiency in DNA damage, lipid peroxidation and cellular destruction (MCF7 cells) under stress condition. The results obtained with octopus antioxidant peptide suggested its role as an adjunct in food and pharmaceutical industries.

The visceral mass of the gastropod, Harpa ventricosa was hydrolysed using trypsin, alcalase and pepsin for 12 h to produce protein hydrolysates. Subsequently, the active hydrolysate was observed in the 3rd hour of tryptic hydrolysate (29.17 ± 0.62 and 34.85 ± 0.55 %) using human red blood cell (HRBC) membrane stabilization and albumin denaturation (AD) assays. The active hydrolysate was fractionated by membrane filtration unit, where

Marine organisms provide an intriguing number of bioactive compounds. These bioactive compounds show immunomodulatory, antioxidant, anti-inflammatory and antimicrobial activities. Crabs rank third after shrimps and lobster as seafood delicacies and provide major health benefits when consumed due to presence of proteins, vitamins and unsaturated essential fatty acids. Due to their diverse biological activities, the peptides derived from marine sources may treat various diseases such as migraine, inflammatory bowel disease, rheumatoid arthritis etc. In this study the Crab Leg (CL) muscle was isolated and further hydrolysed using trypsin, alcalase and papain to produce enzymatic hydrolysates. The results obtained from degree of hydrolysis showed that the enzymes significantly cleave the proteins. Furthermore, the HPLC analysis for amino acid compositions of CL showed the sample contained both essential and non-essential amino acids where histidine (%) was highest. In vitro assays for anti-inflammatory activity like Albumin Denaturation (AD) and HRBC Membrane Stabilization (HMS) assay helped to determine the active hour hydrolysate showing the trypsin 3rd hr hydrolysate as having highest activity in CL (90.57 ± 0.95% and 49.94 ± 1.52%). This active hour hydrolysate was purified using gel filtration chromatography and the fractions were determined using AD and HMS assay which resolved fraction Ⅰ to be more active in CL. The low molecular weight peptide sequence was found to be L-G-L-G-A-A-V-L (713.456 Da) by using LC-MS/MS. Further, cell proliferation assay and ELISA were performed for the purified peptide to test the suppression of LPS-mediated induction of COX-2 in RAW264.7 macrophage cells.

In this current investigation, the antioxidant peptides were derived from marine Sepia brevimana mantle by trypsin, α-chymotrypsin and pepsin for 12 h hydrolysis. The active peptides were found in the hydrolysates of trypsin and α-chymotrypsin at the 7th hour and pepsin at the 8th hour. The highest activity was found in trypsin hydrolysate compared to others using various radical scavenging and metal ions transition assays, further the hydrophobic amino acids were observed in more quantity along with other amino acids. Active peptide was purified by consecutive chromatographic techniques and evaluated by DPPH (38.81 ± 1.07%) and reducing power assays (0.478 ± 0.03). The purified peptide exhibited significant inhibition for the linoleic acid auto-oxidation in the model system, protective effect on DNA damage due to hydroxyl radical induction and was non-toxic even at higher concentration. The mass and sequence of the peptide was found to be 679.5 Da and Ile/Leu-Asn-Ile/Leu-Cys-Cys-Asn, respectively. The current results suggested that cuttlefish peptide could be used as natural antioxidant in enhancing antioxidant properties of functional foods and in preventing oxidation reactions in food processing.

Antioxidant peptides were derived from the edible part of Indian squid, Loligo duvauceli, via the use of gastrointestinal enzymes for up to 12 hours. The active α-chymotrypsin hydrolysate exhibited the maximum activity compared to the trypsin and pepsin hydrolysates, as assessed by various radical scavenging and metal chelating assays. Moreover, essential and non-essential amino acids were present in the active hydrolysate. Furthermore, the hydrolysate was purified by ion exchange and gel filtration chromatography using fast protein liquid chromatography (FPLC). The purified peptide exhibited strong free radical scavenging, metal chelation and reducing power abilities that were confirmed with a UV-visible and electron spin resonance (ESR) spectrometer. The peptide also prevented DNA damage and inhibited lipid peroxidation due to its small size (682.5 Da) and content of the high redox potential amino acid sequence Trp-Cys-Thr-Ser-Val-Ser, which was confirmed by ESI-MS/MS. This peptide exhibited no cytotoxic effects on breast cancer cells (MCF7) and scavenged reactive oxygen species at the cellular level under H2O2-induced stress. These results suggest that the peptide derived from squid mantle protein acts as a potent antioxidant against oxidative stress and could be used as an efficient and safer adjunct in food processing.

The antioxidant activity of protein hydrolysates prepared from the skin of Sphyraena barracuda (Seela fish) and Lepturacanthus savala (Ribbon fish), using the commercial enzymes pepsin, trypsin, and papain were determined. The protein hydrolysate showed high antioxidant activity in which trypsin hydrolysate of the skin of both seela and ribbon fish proved good DPPH scavenging activity with 66 and 60% (p < 0.05), respectively. These active hydrolysates were purified using fast protein liquid chromatography on ion exchange and gel filtration chromatography procedure and the active purified fractions were determined using electron spin resonance spectrophotometer against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radicals. Further the purified fractions were analyzed for amino acid composition using high performance liquid chromatography and it consisted of antioxidant inducing amino acids along with a considerable quantity of essential amino acids.

In the present study, bioactive peptide was isolated from protein hydrolysate of Nemipterus japonicus backbone hydrolysed by trypsin. Functional properties like solubility, emulsifying, and foaming capacities of protein hydrolysate were governed by pH. Protein hydrolysate was fractionated by DEAE XK 26/20 anion exchange chromatography followed by G-25 gel filtration chromatography. The fractions collected were tested for radical scavenging properties on DPPH, hydroxyl, and superoxide radicals by electron spin resonance spectrometer. Amino acid composition of a potent fraction was rich in glutamic acid (21.20 g/100 g), lysine (37.50 g/100 g), aspartic acid (5.8 g/100 g), arginine (5.4 g/100 g), and glycine (2.84 g/100 g). Moreover, the potent fraction showed no cytotoxicity on Vero cell lines till 0–100 μg/ml with CC50 = 94 μg/ml, whereas it exerted a significant antitumor property against HepG2 cell line with an IC50 value of 61.1 μg/ml.

Summary To assess the antioxidant properties of fish protein hydrolysate from giant kingfish Caranx ignobilis (Forsskal, 1775), muscle and skin were obtained using various proteases (papain, pepsin, trypsin and α-chymotrypsin), respectively. Antioxidant activities of the resulting hydrolysates were evaluated using 2, 2-diphenyl-1-picrylhydrazyl radical scavenging activity, reducing power and metal chelating activity. Among the hydrolysates, peptic of muscle (37 ± 1.0; 0.290 ± 0.012; 63.30 ± 0.57) and tryptic of skin (36.2 ± 1.0; 0.190 ± 0.110; 63 ± 0.57) hydrolysates, which had the highest free radical scavenging activity, was subjected to purification using Sephadex G-25. The fractionated hydrolysates were superior to the original hydrolysates in the antioxidative activity tested. The active fractions (MF2 and SF2) effectively inhibited lipid peroxidation in linoleic acid emulsion system, and the activity was compared with α-tocopherol. The amino acid profile of MF2 and SF2 showed a high level of essential amino acids, and the most abundant amino acids were in the order His (12.01% and 7.08%), Phe (7.05% and 6.18%) and Lys (6.76% and 4.74%). Conclusively, C. ignobilis muscle and skin hydrolysates could be a promising rich source of natural antioxidants.

The current study aims at the isolation and characterization of the peptides, believed to have antioxidant activity, from Conus betulinus by using different types of enzymes. The body and viscera of C. betulinus were treated with three enzymes viz. trypsin, pepsin and papain to obtain peptide hydrolysates. The activities of the hydrolysates were analyzed by DPPH and hydroxyl radical assay by using electron spin resonance (ESR) device. Active hydrolysates were purified using ion exchange chromatography followed by gel filtration chromatography. The activity of the separated fractions was analyzed by ESR; in which the result showed that trypsin hydrolysate of body (28.48 and 76.00%) and viscera (38.45 and 83.00%) respectively have high activity than the other hydrolysates. The HPLC result of purified fraction showed, presence of active amino acids viz., metheonine, cystine, histidine etc. This purified peptide has more antioxidant activity that could reduce the excess free radicals in body in order to prevent free radical induced diseases.

We have investigated the antioxidant activity of protein hydrolysates prepared from backbones of two commercially important fishes; seela (Sphyraena barracuda) and ribbon fish (Lepturacanthus savala). Pepsin and trypsin hydrolysates were found more potent to inhibit lipid peroxidation in case of ribbon and seela fish respectively and were further purified by using fast protein liquid chromatography on anion exchange and gel filtration chromatography. The active peaks after gel filtration chromatography of seela fish was able to scavenge 2,2-diphenyl-1-picryhydrazyl and hydroxyl radicals by 61 ± 2.3 and 58.7 ± 2.3% and ribbon fish hydrolysate by 60.0 ± 2.6 and 55.6 ± 1.8% as measured by ESR spectroscopy. And the active fractions showed presence of both essential and non-essential amino acids with high percentages of arginine (11.95 and 12.76%) and lysine (13.49 and 13.89%).

Summary In our present investigation, Nemipterus japonicus and Exocoetus volitans backbone protein were hydrolysed by proteases like trypsin and pepsin, respectively. The protein hydrolysates were purified by different chromatographic methods, and the resulted purified peptides were analysed for their amino acid sequences by electrospray ionisation–MS/MS. The analysis of peptides showed sequences as Gly-His-Met-Ser (451.8 Da) and Leu-Glu-Val-Lys-Pro (596.9 Da) for N. japonicus and E. volitans muscle, respectively. The presence of hydrophobic amino acids contributes more to the antioxidant activities of peptides than other amino acids. Moreover, sequence of amino acids in peptides plays an important role in their antioxidant activities.

The sulphated polysaccharide from the widespread Tridax procumbens plant was studied for the anticoagulant, antiherpetic and antibacterial activity. The anticoagulant activity was determined by the activated partial thromboplastin time assay. The sulphated polysaccharide from T. procumbens represented potent anticoagulant reaching the efficacy to heparin and chondroitin sulphate. Moreover, the sulphated polysaccharide extracted from T. procumbens was found non-toxic on Vero cell lines up to the concentration of 200 μg/ml. Sulphated polysaccharide exhibited detectable antiviral effect towards HSV-1 with IC(50) value 100-150 μg/ml. Furthermore, sulphated polysaccharide from T. procumbens was highly inhibitory against the bacterial strains Vibrio alginolyticus and Vibrio harveyi isolated from oil sardine.

The antioxidant activity of marine clam, Meretrix casta (Chemnitz) protein hydrolysates prepared from different organs (body, foot and viscera), using the commercial enzymes (pepsin, trypsin and papain) were determined. The protein hydrolysate had a high antioxidant activity where, pepsin hydrolysate of viscera and trypsin hydrolysate of body and foot showed good activity. The viscera pepsin hydrolysate and foot trypsin hydrolysates were purified using FPLC on ion exchange and gel filtration chromatography procedure and activity was determined by DPPH radical scavenging and reducing ability assays. Further the amino acid content of the purified fractions was analyzed using HPLC. Active fractions contained good quantity of both essential and non-essential amino acids.

Summary The aim of this study was to evaluate antioxidant, antiproliferative and antimicrobial properties of flying fish (Exocoetus volitans) backbone hydrolysed by three different enzymes namely papain, pepsin and trypsin. The in vitro antioxidant potencies of hydrolysates and purified peptides against 1, 1-diphenyl-2-picrylhydrazyl, superoxide and hydroxyl radicals were evaluated by electron spin resonance spectroscopy. The peptic protein hydrolysate showed maximum free radical scavenging potential and lipid peroxidation inhibition and was further purified by DEAE XK 26/20 anion exchange chromatography followed by G-25 gel permeation chromatography. The amino acid composition of potent purified fraction was determined by HPLC, contains essential and nonessential amino acids with glutamic acid (24.10%), lysine (23.62%), glycine (12.05%) and threonine (10.41%) as the dominant amino acids. The potent purified fraction was tested for cell cytotoxicity on Vero and Hep G2 cell lines. It was found that fraction IIIb did not show any cytotoxic effect for Vero cell lines and exerted a significant antiproliferative effect on Hep G2 cell lines.

The focus of the study was to investigate the antioxidant activity of hydrolyzed muscle protein of Nemipterus japonicus and Exocoetus volitans. The trypsin protein hydrolysates of both fish showed maximum free radical scavenging potential and lipid peroxidation inhibition. Furthermore, it was purified by chromatographic methods followed by the lipid peroxidation inhibition; free radical scavenging assay was performed before and after purification. The purified peptide fractions of N. japonicus and E. volitans exhibited higher activity against polyunsaturated fatty acids (PUFA) peroxidation which was similar to natural antioxidants like α-tocopherol. Free radical scavenging potencies were measured by electron spin resonance technique (ESR). The purified peptide of E. volitans quenched free radicals (DPPH, hydroxyl, and superoxide) slightly more than N. japonicus. The amino acid composition of both fish protein hydrolysates showed variations in their ratio. The purified peptides were tested for cell cytotox...

Body, foot and viscera of Donax cuneatus (Linnaeus) were hydrolyzed using commercial proteases (pepsin, trypsin and papain) and tested for their antioxidant activity by DPPH scavenging ability and reducing power assays. In comparison between all the hydrolysates, papain viscera (28.513 ± 0.165 & 0.186 ± 0.008) and foot (33.567 ± 0.132 & 0.166 ± 0.013) hydrolysates showed highest DPPH and reducing power ability respectively. The active hydrolysates were purified with DEAE- cellulose followed by Sephadex G-25 columns connected to FPLC. Further, the isolated active fractions were loaded onto HPLC for their amino acid profiling and found with the presence of potential amino acids viz., histidine, cysteine, alanine etc. These results suggest that the isolated antioxidant peptide from viscera and foot hydrolysate of D. cuneatus can be used in treating human diseases where free radicals and oxidative damage are involved.

In the present study, protein of muscles of commercially important marine fishes Nemipterus japonicus and Exocoetus volitans were extracted by trypsin and their hydrolysis conditions viz., temperature, time, and enzyme to substrate concentration on degree of hydrolysis were studied by response surface methodology. The optimum values for N. japonicus was found as temperature, 30°C, hydrolysis time of 100 min an enzyme/substrate concentration of 1.59% whereas, for E. volitans muscle protein, optimum hydrolysis conditions were temperature, 30°C, hydrolysis time of 115 min and enzyme/substrate concentration of 1.67%. Furthermore, amino acid sequence of antioxidant peptides derived after chromatographic purification was identified by ESI–MS/MS. The analysis of peptides showed sequences as Glu-Ser-Asp-Arg-Pro (620.3 Da) and Gly-Trp-Met-Gly-Cys-Trp (747.3) for N. japonicus and E. volitans muscle, respectively. The peptides contained important antioxidant amino acids and acted as good antioxidant peptides to scavenge free radicals.

Functional properties and antioxidant activity of pink perch (Nemipterus japonicus) muscle hydrolysed by three different enzymes papain, pepsin and trypsin were studied. The protein hydrolysates produced by trypsin had an excellent solubility (98%) compared to pepsin (77%) and papain hydrolysate (74%). Conversely, the emulsifying activity index (ESI) and foaming abilities were affected by pH. DPPH radical scavenging ability, reducing power and metal chelating activity of protein hydrolysates increased with increase in concentration. Lipid peroxidation was strongly inhibited by 64% by protein hydrolysates produced by trypsin. The results revealed that the functional properties and antioxidant activities of pink perch were greatly affected by the enzymes used.