Preparation, typical structural characteristics and relieving effects on osteoarthritis of squid cartilage type II collagen peptides.

The promoting effects of collagen and its derivatives on bone health have been uncovered. However, the structure and effects of type II collagen peptides from squid cartilage (SCIIP) on osteoarthritis still need to be clarified. In this study, SCIIP was prepared from squid throat cartilage with pretreatment by 0.2 mol/L NaOH at a liquid-solid ratio of 10:1 for 18 h and hydrolyzation using alkaline protease and flavourzyme at 50 °C for 4 h. The structure of SCIIP was characterized as a molecular weight lower than 5 kDa (accounting for 87.7 %), a high glycine level of 35.0 %, typical FTIR and CD features of collagen peptides, and a repetitive sequence of Gly-X-Y. GP(Hyp)GPD and GPAGP(Hyp)GD were separated and identified from SCIIP, and their binding energies with TLR4/MD-2 were - 8.4 and - 8.0 kcal/mol, respectively. SCIIP effectively inhibited NO production in RAW264.7 macrophages and alleviated osteoarthritis in rats through the TLR4/NF-κB pathway. Therefore, SCIIP exhibited the potential for application as an anti-osteoarthritis supplement.

Stem-Cell-Regenerative and Protective Effects of Squid (Symplectoteuthis oualaniensis) Skin Collagen Peptides against H2O2-Induced Fibroblast Injury.

Recently, there has been a growing interest in collagen peptides derived from marine sources for their notable ability to protect skin cells against apoptosis induced by oxidants. Therefore, the current study aimed to investigate the fundamental properties of collagen peptides, including their physicochemical, thermal, structural, stem-cell-regenerative, and skin-cell-protective effects, in comparison to commercial collagen peptides. The acid-soluble (ASC) and pepsin-soluble (PSC) collagens exhibited three distinct bands on SDS-PAGE, namely α (α1 and α2), ß, and γ chains, confirming a type I pattern. The thermal profiles obtained from TG and DSC analyses confirmed the denaturation of PSC and ASC at temperatures ranging from 51.94 to 56.4 °C and from 52.07 to 56.53 °C, respectively. The purified collagen peptides were analyzed using SDS-PAGE and MALDI-TOF mass spectrometry, revealing a mass range of 900-15,000 Da. Furthermore, the de novo peptide sequence analysis confirmed the presence of the Gly-X-Y repeating sequence in collagen peptides. Collagen peptide treatments significantly enhanced HFF-1 cell proliferation and migration compared to the control group. ELISA results confirmed the potential interactions between collagen peptides and HFF-1 cells through α2ß1, α10ß1, and α11ß1 integrin receptors. Notably, collagen peptide treatment effectively restored the proliferation of HFF-1 cells damaged by H2O2. Consequently, the advantageous characteristics of squid skin collagen peptides highlight their promising role in regenerative medicine.

Lipidomics profile and volatile compounds of squids (Illex argentinus, Ommastrephes Bartram and Dosidicus gigas) in the Argentine, North Pacific Ocean, Equator and Peru by UPLC-triple TOF-MS and HS-SPME-GC-O-MS.

Comprehensive lipid and volatile compound analyses were performed with squids collected from four varied geographical locations to discriminate the regional characteristics. A total of 1442 lipid molecules and 110 volatiles were detected in the squid muscle samples. There were significant differences in the lipid profiles between Argentine squid (Illex argentinus, AGT), North Pacific Ocean squid (Ommastrephes Bartram, NPO), Equatorial squid (Dosidicus gigas, EQ), and Peruvian squid (Dosidicus gigas, PR) muscle. Phosphatidylcholines (14.64%), triacylglycerols (12.42%), and ceramides (10.97%) were the main lipid components. The contents of polyunsaturated fatty acid in phospholipids and in glycerolipids were 30.35-52.05% and 18.11-25.15%, respectively. The volatiles in squids exhibited significant regional variation; 1-pentanol and 1-octanol, 2-ethyl-1-hexanol and terpinen-4-ol, 2,7-ethyl-1-hexanol, 3-methy-1-butanol and 2-propyl-1-pentanol were identified as characteristic flavor compounds in AGT, NPO, EQ, and PR, respectively. Sphingomyelin, phosphatidylserine, phosphatidylethanolamine, and ceramide were strongly correlated with volatiles in squid muscle. Our study is a reference for the lipid nutritional value and flavor compounds of squids.

Exploiting specific properties of squid pens for the preparation of oligochitosan hydrochloride.

Herein, we describe in first the application of squid pens for the preparation of pharmaceutical-grade oligochitosan hydrochloride with the physicochemical characteristics corresponding with the requirements of the European Pharmacopoeia. It is shown that the use of specific properties of squid pens as a source of parent chitosan allows preparing the product with a high yield at relatively moderate process conditions used for squid pens treatments and chitosan depolymerization.

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.

Exploring the potential of chitosan/aragonite biocomposite derived from cuttlebone waste: Elaboration, physicochemical properties and in vitro bioactivity.

Cuttlefish bone biowaste is a potential source of a composite matrix based on chitin and aragonite. In the present work, we propose for the first time the elaboration of biocomposites based on chitosan and aragonite through the valorization of bone waste. The composition of the ventral and dorsal surfaces of bone is well studied by ICP-OES. An extraction process has been applied to the dorsal surface to extract ß-chitin and chitosan with controlled physico-chemical characteristics. In parallel, aragonite isolation was carried out on the ventral side. The freeze-drying method was used to incorporate aragonite into the chitosan polymer to form CHS/ArgS biocomposites. Physicochemical characterizations were performed by FT-IR, SEM, XRD, 1H NMR, TGA/DSC, potentiometry and viscometry. The ICP-OES method was used to evaluate in vitro the bioactivity level of biocomposite in simulated human plasma (SBF), enabling analysis of the interactions between the material and SBF. The results obtained indicate that the CHS/ArgS biocomposite derived from cuttlefish bone exhibits bioactivity, and that chitosan enhances the bioactivity of aragonite. The CHS/ArgS biocomposite showed excellent ability to form an apatite layer on its surface. After three days' immersion, FTIR and SEM analyses confirmed the formation of this layer.

Cryomilling-assisted high purity ß-chitin extraction from Uroteuthis edulis pens.

We report on the extraction of ß-chitin from pens (or Gladius) of Uroteuthis edulis, a squid species prevalent in the Pacific coastal regions of East Asia. In particular, we employ cryogenic mechanical grinding (or cryomilling) as a pre-treatment process for the raw squid pens. We show that the cryomilling step enables an effective pulverization of the raw materials, which facilitates the removal of protein residues allowing the extraction of high-purity ß-chitin with a high acetylation degree (∼97 %) and crystallinity (∼82 %). We also demonstrate that the Uroteuthis edulis extract ß-chitin affords a free-standing film with excellent optical transmittance and mechanical properties.

Development of an efficient hemostatic material based on cuttlefish ink nanoparticles loaded in cuttlebone biocomposite.

Traumatic hemorrhage is one of the main causes of mortality in civilian and military accidents. This study aimed to evaluate the effectiveness of cuttlefish bone (cuttlebone, CB) and CB loaded with cuttlefish ink (CB-CFI) nanoparticles for hemorrhage control. CB and CB-CFI were prepared and characterized using different methods. The hemostasis behavior of constructed biocomposites was investigated in vitro and in vivo using a rat model. Results showed that CFI nanoparticles (NPs) are uniformly dispersed throughout the CB surface. CB-CFI10 (10 mg CFI in 1.0 g of CB) showed the best blood clotting performance in both in vitro and in vivo tests. In vitro findings revealed that the blood clotting time of CB, CFI, and CB-CFI10 was found to be 275.4 ± 12.4 s, 229.9 ± 19.9 s, and 144.0 ± 17.5 s, respectively. The bleeding time in rat liver injury treated with CB, CFI, and CB-CFI10 was 158.1 ± 9.2 s, 114.0 ± 5.7 s, and 46.8 ± 2.7 s, respectively. CB-CFI10 composite resulted in more reduction of aPTT (11.31 ± 1.51 s) in comparison with CB (17.34 ± 2.12 s) and CFI (16.79 ± 1.46 s) (p < 0.05). Furthermore, CB and CB-CFI10 exhibited excellent hemocompatibility. The CB and CB-CFI did not show any cytotoxicity on human foreskin fibroblast (HFF) cells. The CB-CFI has a negative surface charge and may activate coagulation factors through direct contact with their components, including CaCO3, chitin, and CFI-NPs with blood. Thus, the superior hemostatic potential, low cost, abundant, simple, and time-saving preparation process make CB-CFI a very favorable hemostatic material for traumatic bleeding control in clinical applications.

Detection and quantification of biogenic amines in cephalopod using dansyl chloride pre-column derivatization-HPLC and their production.

The accurate detection of biogenic amines (BAs) is an important means of ensuring the quality and safety of cephalopod seafood products. In this study, the pre-column derivatization of high-performance liquid chromatography (HPLC) was optimized using dansyl chloride (Dns-Cl) to detect BAs in octopus, cuttlefish, and squid. The reasons for the formation of BAs were investigated by assessing their decarboxylase activity and the rates of decomposition. The findings demonstrated that using Dns-Cl to optimize pre-column derivatization enabled the separation of nine different BAs. The detection limits ranged from 0.07 to 0.25 mg/L, and the results exhibited a high level of linearity (R2 ≥ 0.997). The decarboxylase activity and biodegradation rate positively correlated with the formation of BAs at temperatures below 0°C. Notably, the decarboxylase activity of octopus, cuttlefish, and squid exhibited a significant increase with prolonged storage time, and formyltransferase and carbamate kinase may be the key decarboxylase in cephalopod products. These findings serve as a valuable reference for further investigations into the mechanisms behind BAs production and the development of control technologies for BAs in cephalopod products. This study has successfully demonstrated the effectiveness of the Dns-Cl pre-column derivatization-HPLC method in accurately and efficiently detecting BAs in octopus, cuttlefish, and squid. Moreover, it highlights the influence of decarboxylase content and biodegradation rate on the formation of BAs. Importantly, this method can serve as a reference for detecting BAs in various seafood products.

Integrated extraction, structural characterization, and activity assessment of squid pen protein hydrolysates and ß-chitin with different protease hydrolysis.

Squid pen (SP) is a valuable source of protein and ß-chitin. However, current research has primarily focused on extracting ß-chitin from SP. This study innovatively extracted both SP protein hydrolysates (SPPHs) and SP ß-chitin (SPC) simultaneously using protease hydrolysis. The effects of different proteases on their structural characteristics and bioactivity were evaluated. The results showed that SP alcalase ß-chitin (SPAC) had the highest degree of deproteinization (DP, 98.19 %) and SP alcalase hydrolysates (SPAH) had a degree of hydrolysis (DH) of 24.47 %. The analysis of amino acid composition suggested that aromatic amino acids accounted for 17.44 % in SPAH. Structural characterization revealed that SP flavourzyme hydrolysates (SPFH) had the sparsest structure. SPC exhibited an excellent crystallinity index (CI, over 60 %) and degree of acetylation (DA, over 70 %). During simulated gastrointestinal digestion (SGD), the hydroxyl radical scavenging activity, ABTS radical scavenging activity, Fe2+ chelating activity, and reducing power of the SPPHs remained stable or increased significantly. Additionally, SPFC exhibited substantial inhibitory effects on Staphylococcus aureus and Escherichia coli (S. aureus and E. coli), with inhibition circle diameters measuring 2.4 cm and 2.1 cm. These findings supported the potential use of SPPHs as natural antioxidant alternatives and suggested that SPC could serve as a potential antibacterial supplement.