Protein Hydrolysis as a Way to Valorise Squid-Processing Byproducts: Obtaining and Identification of ACE, DPP-IV and PEP Inhibitory Peptides.

The industrial processing of Argentine shortfin squid to obtain rings generates a significant amount of protein-rich waste, including the skin, which is rich in collagen and attached myofibrillar proteins. This waste is generally discarded. In this study, skin was used as a source of proteins that were hydrolysed using Trypsin, Esperase® or Alcalase®, which released peptides with antioxidant potential and, in particular, antihypertensive (ACE inhibition), hypoglycemic (DPP-IV inhibition) and/or nootropic (PEP inhibition) potential. Among the three enzymes tested, Esperase® and Alcalase produced hydrolysates with potent ACE-, DPP-IV- and PEP-inhibiting properties. These hydrolysates underwent chromatography fractionation, and the composition of the most bioactive fractions was analysed using HPLC-MS-MS. The fractions with the highest bioactivity exhibited very low IC50 values (16 and 66 µg/mL for ACE inhibition, 97 µg/mL for DPP-IV inhibition and 55 µg/mL for PEP inhibition) and were mainly derived from the hydrolysate obtained using Esperase®. The presence of Leu at the C-terminal appeared to be crucial for the ACE inhibitory activity of these fractions. The DPP-IV inhibitory activity of peptides seemed to be determined by the presence of Pro or Ala in the second position from the N-terminus, and Gly and/or Pro in the last C-terminal positions. Similarly, the presence of Pro in the peptides present in the best PEP inhibitory fraction seemed to be important in the inhibitory effect. These results demonstrate that the skin of the Argentine shortfin squid is a valuable source of bioactive peptides, suitable for incorporation into human nutrition as nutraceuticals and food supplements.

Composition and Anticoagulant Potential of Chondroitin Sulfate and Dermatan Sulfate from Inedible Parts of Garfish (Belone belone).

Glycosaminoglycans (GAGs) play a crucial role due to their significant biomedical functions. Chondroitin sulfate (CS) and dermatan sulfate (DS), the main representative family of GAGs, were extracted and purified from garfish (Belone belone) by-products, i.e., skin (GSB), bones (GCB), and heads (GHB), and their composition and anticoagulant activity were investigated. CS/DS were purified by ion-exchange chromatography with yields of 8.1% for heads, 3.7% for skin, and 1.4% for bones. Cellulose acetate electrophoresis was also explored for analyzing the extracted CS/DS. Interestingly, GHB, GSB, and GCB possessed sulfate contents of 21 ± 2%, 20 ± 1%, and 20 ± 1.5%, respectively. Physico-chemical analysis showed that there were no significant differences (p > 0.05) between the variances for sulfate, uronic acid, and total sugars in the GAGs extracted from the different parts of fish. Disaccharide analysis by SAX-HPLC showed that the GSB and GCB were predominately composed of ΔDi-4S [ΔUA-GalNAc 6S] (74.78% and 69.22%, respectively) and ΔDi-2,4S [ΔUA2S-GalNAc 4S] (10.92% and 6.55%, respectively). However, the GHB consisted of 25.55% ΔDi-6S [ΔUA-GalNAc 6S] and 6.28% ΔDi-2,6S [ΔUA2S-GalNAc 4S]. Moreover, classical anticoagulation tests were also used to measure their anticoagulant properties in vitro, which included the activated partial thromboplastin time, prothrombin time, and thrombin time. The CS/DS isolated from garfish by-products exhibited potent anticoagulant effects. The purified CS/DS showed exceptional anticoagulant properties according to this research and can be considered as a new agent with anticoagulant properties.

Identification of ACE I-Inhibitory Peptides Released by the Hydrolysis of Tub Gurnard (Chelidonichthys lucerna) Skin Proteins and the Impact of Their In Silico Gastrointestinal Digestion.

Tub gurnard is a highly abundant fishery species caught as a discard in the Mediterranean Sea. This work proposes its valorisation through the release of potential antihypertensive peptides and glycosaminoglycans (GAGs) through the controlled hydrolysis of tub gurnard skin proteins. Four proteases (Esperase, Alcalase, Trypsin and Pronase E) were used to obtain potent angiotensin converting enzyme I (ACE)-inhibitory hydrolysates. Peptides and GAGs were separated and evaluated for their antihypertensive potential by fluorometry. The peptide-rich fractions derived from the Esperase and Alcalase hydrolysates showed very low IC50 values (47 and 68 µg/mL, respectively). Only the GAGs from the Trypsin and Esperase hydrolysates were relevant ACE inhibitors (63 and 52% at 1 mg/mL, respectively). The peptide composition of the most potent ACE-inhibitory fractions derived from the Esperase and Alcalase hydrolysates (IC50 values of 33 and 29 µg/mL, respectively) was analysed by RP-LC-ESI-MS/MS. The analysis suggests that the ACE-inhibitory activity is related to the peptide hydrophobicity, as well as to the presence of specific residues at any of the last four C-terminal positions. The in silico gastrointestinal digestion of these fractions yielded small peptides with antihypertensive potential.

Isolation and identification of an arabinogalactan extracted from pistachio external hull: Assessment of immunostimulatory activity.

This work studies the extraction and purification of a novel arabinogalactan from pistachio external hull. It was extracted with a simple method from pistachio hull which is considered as unexploited waste. Based on the results of sugar analysis by GC-FID, glycosidic linkage by GC-MS, NMR spectroscopy, and molecular weight by Size Exclusion Chromatography, pistachio hull water soluble polysaccharides (PHWSP) were identified as a type II arabinogalactan (AG), with characteristic terminally linked α-Araf, (α1 â†’ 5)-Araf, (α1 â†’ 3,5)-Araf, terminally linked ß-Galp, (ß1 â†’ 6)-Galp, and (ß1 â†’ 3,6)-Galp. DEPT-135, HSQC, HMBC and COSY NMR data suggested the presence of (ß1 â†’ 3)-Galp mainly branched at O-6 with (ß1 â†’ 6)-Galp chains, α-Araf chains, and terminally linked α-Araf. These AG from pistachio external hulls showed in vitro stimulatory activity for B cells, suggesting their possible use as an immunological stimulant in nutraceutical and biomedical applications.

Preventive effect of Bacillus mojavensis levan against carbon tetrachloride and cisplatin toxicity: in vivo study.

This study is the first to investigate the hepato- and nephron-preventive effect of levan from Bacillus mojavensis (BM-levan) against toxicity induced by carbon tetrachloride (CCl4) and cisplatin. Thirty-six male albino rats weighing between 230 and 250 g were used for this experiment. The groups received multiples doses of BM-levan and were compared to the untreated group. The in vitro and in vivo biological potentials of BM-levan were evaluated by measuring its antioxidant capacity as well as its hepato- and nephron-protective activities in rat models. The investigations highlighted a significant in vitro antioxidant activity indicated by the radical-scavenging capacity, the reducing power, and the total antioxidant activity measurement. In addition, results demonstrate that BM-levan supplementation during 8 weeks (100 mg/kg body weight) significantly (p < 0.05) decreased aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities and remarkably (p < 0.05) attenuated the altered lipid profile by decreasing the levels of triglycerides (TG) and total cholesterol (TC), LDL cholesterol (LDL-C) and by enhancing the HDL cholesterol (HDL-C) content, when compared with the CCl4 group. BM-levan also reduced the content of plasma renal biomarkers (urea, creatinine, and uric acid) in the cisplatin-treated group. Moreover, BM-levan inhibited hepatic and renal oxidative stress generated by CCl4 and cisplatin administration, through the enhancement of the antioxidant catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) and the diminishment of lipid peroxidation. The harmful effects of CCl4 or cisplatin on hepatic and renal histology were found to be decreased by the addition of BM-levan. Therefore, BM-levan has proved promising for biomedical applications thanks to its in vitro and in vivo antioxidant properties.

Hybrid levan-Ag/AgCl nanoparticles produced by UV-irradiation: properties, antibacterial efficiency and application in bioactive poly(vinyl alcohol) films.

Foodborne diseases caused by resistance of microorganisms to multiple antimicrobial agents have emerged as a major public health concern around the world. The search for potential antimicrobials has resulted in the emergence of metal nanoparticles for protection against these infections. In this study an eco-friendly and green approach was used to biosynthesize hybrid Ag/AgCl nanoparticles (NPs), using levan from Bacillus mojavensis as a stabilizing/reducing agent, with a high efficiency against a broad spectrum of foodborne bacteria as well as biofilm formations. The morphology and physicochemical characteristics of levan-Ag/AgCl NPs were investigated by transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-vis spectroscopy (UV), dynamic light scattering (DLS) and thermogravimetric analysis (TGA). The hybrid levan-Ag/AgCl was evaluated for antibacterial activity against foodborne pathogenic bacteria (Escherichia coli, Klebsiella pneumoniae, Salmonella enterica, Pseudomonas aeruginosa, Staphylococcus aureus, Micrococcus luteus, Listeria monocytogenes, Enterococcus faecalis, Bacillus subtilis and Bacillus thuringiensis). The study demonstrated the strong efficiency of hybrid levan-Ag/AgCl NPs as a potent inhibitor against all tested strains, with much higher activity against Gram-negative than Gram-positive bacteria. Furthermore, bacterial strains were found to be highly sensitive to hybrid levan-Ag/AgCl NPs in comparison to the tested antibiotics. As a possible application of levan-Ag/AgCl NPs as an additive in packaging, PVA films with different amounts of hybrid levan-Ag/AgCl NPs were prepared by casting and their antibacterial, mechanical, and optical properties and ability to expand the shelf life of beef meat were explored. Interestingly, the amount of Ag leached out from films was below the permissible limit. This work demonstrates the strong antibacterial action of hybrid levan-Ag/AgCl NPs and their potential use in bioactive packaging material.

Multidirectional insights on polysaccharides from Schinus terebinthifolius and Schinus molle fruits: Physicochemical and functional profiles, in vitro antioxidant, anti-genotoxicity, antidiabetic, and antihemolytic capacities, and in vivo anti-inflammatory and anti-nociceptive properties.

The aim of the current study was to compare crude polysaccharides extracted from Schinus terebinthifolius Raddi (PSTF) and S. molle L. (PSMF) fruits based on their structures, physicochemical characteristics, monosaccharide composition, as well as in vitro and in vivo assays. The extraction yield of PSTF (4.26%) was higher than that of PSMF (3.56%). Remarkable variability was detected in the content of carbohydrates (80.64 ± 0.98%), protein (1.80 ± 0.28%), fat (0.04 ± 0.005%) and ash (6.32 ± 0.26%). FT-IR assay and 1H and 13C NMR spectroscopy revealed that fruits extract showed similar structural characteristics. Thin layer chromatography together with HPLC-RID analysis showed that the monosaccharide composition varied significantly between species. Both contained arabinose (40.55-42.03%) galacturonic acid (31.21-41.15%), and fucose (10.90-17.63%), but PSTF had glucose (9.13%) whereas PSMF had galactose (7.40%). Functional analyses demonstrated that samples exhibited favorable water- and oil-retention capacity, emulsifying properties, and foaming qualities. PSTF exhibited the highest antioxidant effects. Both of them showed a remarkable in vitro antidiabetic effect. PSMF highly mitigated H2O2-induced hemolysis and exhibited ~80% antihemolytic activity. The extracted polysaccharides showed potent inhibitory activity against AAPH-induced plasmid DNA damage. PSTF and PSMF revealed interesting in vivo antinociceptive and anti-inflammatory capacities.

Chondroitin/dermatan sulfate purified from corb (Sciaena umbra) skin and bone: In vivo assessment of anticoagulant activity.

The present work deals with the extraction and purification of chondroitin sulfate/dermatan sulfate from skin (CSG) and bone (CBG) of corb (Sciaena umbra). Electrophoresis of these polymers in barium acetate buffer on cellulose acetate revealed two fractions similar to dermatan sulfate and chondroitin sulfate. The in vivo anticoagulant activity of both chondroitin sulfate/dermatan sulfate (CS/DS) were evaluated, at 25 and 75 mg kg-1 of body weight (b.w), using activated partial thromboplastin time (aPTT), prothrombine time (TT) and thrombin time (PT) tests. Results showed that aPTT of CSG and CBG at 75 mg kg-1 of b.w were prolonged by 1.59 and 1.48-fold respectively, compared with the control. Further, toxicity studies on liver performed by the catalytic activity of transaminases in plasma, oxidative stress markers and hepatic morphological changes demonstrated that CSG and CBG at both doses are not toxics. In summary, the higher activity and lower toxicity of both CS/DS, especially at 25 mg kg-1 of b.w, recommended these compounds as a better drug candidate.

Oil from hake (Merluccius merluccius): Characterization, antioxidant activity, wound healing and anti-inflammatory effects.

The aim of this work was to evaluate some biological properties of hake head oil (HHO) as well its lipid composition. The fatty acid profiles showed a dominance of unsaturated fatty acids overtaking 55% of the total fatty acids. Omega-3 polyunsaturated fatty acid profiles exhibited a dominance of EPA (eicosapentaenoic acid) (3.96%) and DHA (docosahexaenoic acid) (25.39%). The antioxidant activity was determined through two different assays: DPPH scavenging activity and ß-carotene bleaching by linoleic acid assay. Eighteen mice were excised on their back and divided into 3 groups, treated with sterile saline, commercial healing cream and HHO, respectively. The wound closure rate, the hydroxyproline contents and the histopathology evolution in skin tissue were elaborated. Also, the anti-inflammatory activity was studied by carrageenan-induced mouse paw edema. Mice were divided into 3 groups treated respectively with sterile saline, anti inflammatory drug reference and HHO. The anti-inflammatory evaluation of HHO in mice exhibited an important inhibition of carrageenan-induced hind paws edema, as confirmed by the histological analysis, the superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) level. HHO displayed a significant wound healing effect probably due to the anti-inflammatory and antioxidant activities of its EPA and DHA contents. The overall results proved that HHO might be favorable drugs who exert a great therapeutic potential wound healing and anti-inflammatory effects in animal model.

Purification, compositional analysis, and anticoagulant capacity of chondroitin sulfate/dermatan sulfate from bone of corb (Sciaena umbra).

Chondroitin sulfate/dermatan sulfate (CS/DS) were isolated and purified for the first time from the bone of corb (Sciaena umbra) (CBG) and their chemical composition and anticoagulant activity were assessed. Infrared spectrum and agarose-gel electrophoresis for extracted CS/DS were also investigated. The results showed that the purified CS/DS obtained at a yield of 10% contains about 31.28% sulfate and an average molecular mass of 23.35 kDa. Disaccharide analysis indicated that CBG was composed of monosulfated disaccharides in positions 6 and 4 of the N-acetylgalactosamine (8.6% and 40.0%, respectively) and disulfated disaccharides in different percentages. The charge density was 1.4 and the ratio of 4:6 sulfated residues was equal to 4.64. Chondroitinase AC showed that the purified CS/DS contained mainly 74% CS and 26% DS. Moreover, the new CS/DS extracted from bone of corb showed a strong anticoagulant effect through activated partial thrombosis time (aPTT), thrombin time (TT) and prothrombin time (PT). In fact, CBG prolonged significantly (p < 0.05), aPTT and PT about 2.62 and 1.26 fold, respectively, greater than that of the negative control at a concentration of 1000 µg/mL. However, TT assay of CBG was prolonged 3.53 fold compared with the control at 100 µg/mL. The purified CS/DS displayed a promising anticoagulant potential, which may be used as a novel and soothing drug.

Glycosaminoglycans from grey triggerfish and smooth hound skins: Rheological, Anti-inflammatory and wound healing properties.

The present study aims to evaluate for the first time the wound healing and in vivo anti-inflammatory effects of glycosaminoglycans from skins of smooth hound (SHSG) and grey triggerfish (GTSG). Thermal analysis of GTSG and SHSG was evaluated using differential scanning calorimetry (DSC). The rheologie properties and water absorption capacity of two gels prepared from SHSG and GTSG were also studied. The application of GTSG and SHSG based gels on dermal full-thickness excision wounds in a mouse model, enhanced significantly wound healing activity and a total closure was achieved after eleven days of wound induction for SHSG. Further, histological examination of biopsies showed advanced tissue regeneration, characterized by the presence of well-organized stratum of both derma and epidermis. The anti-inflammatory evaluation of GTSG and SHSG in mice showed a significant inhibition of edema paw, after 5 h of carrageenan injection. The edema inhibition was 91.6% and 90% for SHSG and GTSG, respectively at the dose of 50 mg/kg. Furthermore, the histological evaluation and the superoxide dismutase, catalase and malondialdehyde level in muscle tissue were investigated. In summary, this work demonstrates that both GTSG and SHSG could be promising drugs with good wound healing and anti-inflammatory effects in animal model.

Chondroitin sulfate/dermatan sulfate from corb (Sciaena umbra) skin: Purification, structural analysis and anticoagulant effect.

In this study, chondroitin sulfate/dermatan sulfate was isolated and purified from the skin of corb (Sciaena umbra) (CSG) with a yield of 6.2%. Chemical and structural analysis showed that CSG consisted of high sulfate content 28.74% and an average molecular weight of 15.46 KDa. The separation of CSG by agarose-gel electrophoresis revealed the presence of DS and CS. Structural analysis of the purified CS/DS by means of SAX-HPLC after treatment with specific chondroitinases showed that this polymer was composed of nonsulfated disaccharide, monosulfated disaccharides and disulfated disaccharides in various percentages. The results also suggest that the percentage of CS and DS recovred in CSG were 24% and 76%, respectively. Anticoagulant activity in vitro was measured in plasma using classical anticoagulation tests: activated partial thromboplastin time (aPTT), thrombin time (TT) and prothrombine time (PT) tests. The findings thus indicated that the purified CS/DS exhibits a remarkably high anticoagulant effect.

Physicochemical properties of water-soluble polysaccharides from black cumin seeds.

In the present work, water-soluble polysaccharides were isolated from black cumin seeds. Polysaccharides were characterized by their carbohydrate composition, molecular weight, thermal stability and by FTIR, NMR spectroscopy and X-ray diffraction. The surface, the functional and the antioxidant properties of black cumin water-soluble polysaccharides (BCWSP) were also investigated. BCWSP consisted mainly of galacturonic acid (30.20%), glucuronic acid (17.66%) and neutral sugar (22.99%). BCWSP was composed of high peak molecular weight. The FTIR spectrum obtained for BCWSP showed two most important absorptions, at 1659 and 1085 cm-1, which corresponded to COO- of uronic acids and pyranose form, respectively. NMR spectroscopy data suggested that the BCWSP is probably a rhamnogalacturonan backbone with galactan and arabinan side chains. X-ray pattern revealed the semi-crystalline behavior of BCWSP. WHC and OHC of BCWSP were relatively high and varied with temperatures. The polysaccharide zeta potential was greatly affected by pH. Results indicated that the decrease of surface tension has influenced foaming and emulsifying capacities. The DPPH radical scavenging activity of the BCWSP was 63.25% at 1 mg/mL. The BCWSP displayed moderate reductive, ß carotene bleaching and chelating abilities. Overall, our results suggested that BCWSP could be used as alternative additives in food and non-food products.

Identification and molecular docking of novel ACE inhibitory peptides from protein hydrolysates of shrimp waste.

The effect of enzymatic hydrolysis by Savinase on the interfacial properties and antihypertensive activity of shrimp waste proteins was evaluated. The physicochemical characterization, interfacial tension, and surface characteristics of shrimp waste protein hydrolysates (SWPH) using different enzyme/substrate (E/S) (SWPH5 (SWPH using E/S = 5), SWPH15 (SWPH using E/S = 15), and SWPH40 (SWPH using E/S = 40)) were also studied. SWPH5, SWPH15, and SWPH40 had an isoelectric pH around 2.07, 2.17, and 2.54 respectively. SWPH5 exhibited the lowest interfacial tension (68.96 mN/m) followed by SWPH15 (69.36 mN/m) and SWPH40 (70.29 mN/m). The in vitro ACE inhibitory activity of shrimp waste protein hydrolysates showed that the most active hydrolysate was obtained using an enzyme/substrate of 15 U/mg (SWPH15). SWPH15 had a lower IC50 value (2.17 mg/mL) than that of SWPH5 and SWPH40 (3.65 and 5.7 mg/mL, respectively). This hydrolysate was then purified and characterized. Fraction F1 separated by Sephadex G25 column which presents the best ACE inhibition activity was then separated by reversed-phase high performance liquid chromatography. Four ACE inhibitory peptides were identified and their molecular masses and amino acid sequences were determined using ESI-MS and ESI-MS/MS, respectively. The structures of the most potent peptides were SSSKAKKMP, HGEGGRSTHE, WLGHGGRPDHE, and WRMDIDGDIMISEQEAHQR. The structural modeling of anti-ACE peptides from shrimp waste through docking simulations results showed that these peptides bound to ACE with high affinity.

ß-Chitin and chitosan from squid gladius: Biological activities of chitosan and its application as clarifying agent for apple juice.

Chitin is the second most abundant polysaccharide in biomass after cellulose and the term chitosan usually refers to a family of polymers obtained after chitin deacetylation. The aim of this work was the preparation and the characterization of chitin and chitosan from the gladius (pen) of the European squid (Loligo vulgaris). A high level of deproteinization (more than 80%) was recorded using Alcalase® with an enzyme/protein ratio of 10U/mg. The demineralization of the gladius was completely achieved within 8h at room temperature in HCl. 13C NMR, FTIR, and XRD diffractograms of prepared chitin and chitosan were taken and then degree of deacetylation of chitosan was calculated using 13C CP/MAS-NMR Spectroscopic. Further, in vitro antioxidant capacity of chitosan was evaluated on 1,1-diphenyl-2-picrylhydrazyl method (IC50=3.2mgmL-1) and the ß-carotene bleaching assay (IC50=3.3mgmL-1). Antimicrobial activity was also investigated and assays indicated that prepared chitosan exhibited marked inhibitory activity against all microbial strains tested. Additionally, chitosan was tested such as clarifying agent for apple juice and showed powerful clarification capability, without affecting nutritional value. Furthermore, the results suggested that prepared chitosan could be used as alternative additive in pharmaceutical preparations and food industry.

Purification, structural characterization and antiproliferative properties of chondroitin sulfate/dermatan sulfate from tunisian fish skins.

Chondroitin sulfate/dermatan sulfate GAGs were extracted and purified from the skins of grey triggerfish (GTSG) and smooth hound (SHSG). The disaccharide composition produced by chondroitinase ABC treatment showed the presence of nonsulfated disaccharide, monosulfated disaccharides ΔDi6S and ΔDi4S, and disulfated disaccharides in different percentages. In particular, the nonsulfated disaccharide ΔDi0S of GTSG and SHSG were 3.5% and 5.5%, respectively, while monosulfated disaccharides ΔDi6S and ΔDi4S were evaluated to be 18.2%, 59% and 14.6%, 47.0%, respectively. Capillary elecrophoresis analysis of GTSG and SHSG contained 99.2% and 95.4% of chondroitin sulfate/dermatan sulfate, respectively. PAGE analysis showed a GTSG and SHSG having molecular masses with average values of 41.72KDa and 23.8KDa, respectively. HCT116 cell proliferation was inhibited (p<0.05) by 70.6% and 72.65% at 200µg/mL of GTSG and SHSG respectively. Both GTSG and SHSG demonstrated promising antiproliferative potential, which may be used as a novel, effective agent.

Globularia alypum methanolic extract improves burn wound healing process and inflammation in rats and possesses antibacterial and antioxidant activities.

Burns are known as one of the most common and destructive forms of injury with a vast spectrum of consequences. Despite the discovery of various antibacterial and antiseptic agents, burn wound healing still has remained a challenge to modern medicine. Plants have been considered as potential agents for prevention and treatment of disorders in recent years. Globularia alypum L. (GA) is widely used in folk medicine against skin diseases and abscesses, however there is no scientific evidence justifying its use. This study aimed to evaluate the wound healing and anti-inflammatory effect, the antibacterial and antioxidant activities, as well as the chemical compositions of GA methanolic extract (GAME). Chemical compounds of GAME were examined by GC-MS. Wound healing effect was assessed by second-degree burn wounds in rats, anti-inflammatory activity was studied by carrageenan-induced rat paw edema, antioxidant activity was estimated by the DPPH, reducing power and ß-carotene tests and antimicrobial activity was tested against 6 bacteria. A total of 17 compounds were identified. GAME-treated rats showed an improvement in healing process and carrageenan-induced hind paws edema as assessed by histological and biochemical investigations, compared to the control. A significant antioxidant and antibacterial activities were also observed in GAME-treated rats. GAME revealed a burn wound healing activity probably due to the anti-inflammatory, antimicrobial and antioxidant activities of its phytochemical contents. Thus, this study confirms its traditional use, however further more precise studies are needed for future clinical application.

Chitin and chitosan from the Norway lobster by-products: Antimicrobial and anti-proliferative activities.

Chitin was recovered through enzymatic deproteinization of the Norway lobster (Nephrops norvegicus) processing by-products. The obtained chitin was characterized and converted into chitosan by N-deacetylation, the acid-soluble form of chitin. Chitosan samples were then characterized by Fourier transform infrared spectroscopy (FTIR) and 13 Cross polarization magic angle spinning nuclear magnetic resonance (CP/MAS)-NMR spectroscopy. The antimicrobial activity and anti-proliferative capacity of chitosan were evaluated. Antimicrobial activity assays indicated that prepared chitosan exhibited marked inhibitory activity against the bacterial and fungal strains tested. Further, cytotoxic effects of chitosan samples on human colon carcinoma cells HCT116 was evaluated using the MTT assay. Chitosan showed the antiproliferative capacity against the colon-cancer-cell HCT116 in a dose dependent manner with IC50 of 4.6mg/ml. Indeed, HCT116 cell proliferation was significantly inhibited (p<0.05) between 13.5 and 67.5% at 0.5-6mg/mL of chitosan after 24h of cell treatment. The chitosan showed high antitumor activity which seemed to be dependent on its characteristics such as acetylation degree.

Purification, identification and structural modelling of DPP-IV inhibiting peptides from barbel protein hydrolysate.

Inhibition of DPP-IV may improve glycemic control in diabetics by preventing the rapid breakdown and there by prolonging the physiological action of incretin hormones. Barbel muscle protein hydrolysate (BMPH) was noted to exhibit DPP-IV inhibitory activity, with an IC50 value of 1.94mg/mL. It was fractionated into five major fractions (FI-FV) by size exclusion chromatography using a Superdex peptide. The FIII fraction was noted to display the highest inhibitory activity, with an IC50 value of 1.23mg/mL, and was, therefore, further fractionated by RP-HPLC. Four major peptide sub-fractions were selected. The results revealed that the SF4 sub-fraction showed the highest DPP-IV inhibitory activity, with an IC50 value of 0.21mg/mL. This sub-fraction was submitted to RP-HPLC, ESI-MS, and ESI-MS/MS analyses. The findings indicated that SF4 consisted of two peptides (IC50=96µg/mL), namely PP1 and PP2, whose structures were identified as Trp-Ser-Gly (330Da) and Phe-Ser-Asp (349Da), respectively. This is the first report of these sequences from barbel proteins. The structural modelling through docking simulations results with DPP-IV showed that the Trp-Ser-Gly peptide bound to DPP-IV with high affinity. Overall, the results suggested that BMPH can be considered as a promising natural source of DPP-IV inhibitory peptides.