Hyaluronic acid from bluefin tuna by-product: Structural analysis and pharmacological activities

The fishing and aquaculture industries generate a huge amount of waste during processing and preservation operations, especially those of tuna. Recovering these by-products is a major economic and environmental challenge for manufacturers seeking to produce new active biomolecules of interest. A new hyaluronic acid was extracted from bluefin tuna's vitreous humour to assess its antioxidant and pharmacological activities. The characterization by infrared spectroscopy (FT-IR), nuclear magnetic resonance ((1D1H) and 2D (1H COSY, 1H/13C HSQC)) and size exclusion chromatography (SEC/MALS/DRI/VD) revealed that the extracted polysaccharide was a hyaluronic acid with high uronic acid content (55.8 %) and a weight average molecular weight of 888 kDa. This polymer possesses significant anti-radical activity and ferrous chelating capacity. In addition, pharmacological evaluation of its anti-inflammatory and analgesic potential, using preclinical models, in comparison with reference drugs (Dexamethasone, diclofenac, and acetylsalicylate of lysine), revealed promising anti-inflammatory activity as well as interesting peripheral and central antinociceptive activity. Therefore, our new hyaluronic acid compound may therefore serve as a potential drug candidate for the treatment of pain sensation and inflammation of various pathological origins.

Antioxidant polysaccharide-enriched fractions obtained from olive leaves by ultrasound-assisted extraction with α-amylase inhibition, and antiproliferative activities

Polysaccharide-rich materials were extracted from the alcohol-insoluble solids of Olea europaea l. **leaves. Structural characteristics were determined by colorimetric techniques, FT-IR, GC-MS, SEC/MALS/VD/DRI, and NMR (1H,13C). The extract and its main macromolecular components were characterized to assess their ability toward antioxidant, α-amylase inhibition, and antiproliferative activities. Results revealed that the ultrasound olive leave extract comprises polysaccharides with uronic acid, galactose, arabinose, and glucose in molar percentages of 11.7%, 11.3%, 7.5%, and 4.9% respectively, constituting 41% of the total mass. In addition, polyphenols (21%) and proteins (9%) are associated with these polysaccharides. Further, the extract showed noticeable ORAC and free radical scavenging abilities, in addition to high in vitro antiproliferative activity against Caco-2 colon carcinoma cell lines. Similarly, the extract exhibited a strong, uncompetitive inhibition of α-amylase by 75% in the presence of the extract with 0.75 µg/mL of concentration. This research concludes that ultrasound extraction method can be used for the extraction of polysaccharide-polyphenol-protein complexes. These conjugates exhibit the potential for combined biological activities resulting from a synergistic effect of its compounds, making them promising ingredients for the development of functional food.

Insights for the control of dried-fruit beetle Carpophilus hemipterus (Nitidulidae) using rosemary essential oil loaded in chitosan nanoparticles

Natural insecticidal products, essentially essential oils and their bioactive compounds are available as an excellent alternative method to control insect pests as well as they are less toxic to human health. However, due to their volatile constituents, encapsulation could be considered as the most suitable solution for their practical application. Therefore, this study aims to explore the insecticidal toxicity of chitosan nanoparticles loaded with Rosmarinus officinalis essential oil against adults of Carpophilus hemipterus. Chitosan nanoparticles were prepared by ionic gelation method with an encapsulation efficiency 41.543.1% and loading capacity 5.24G0.28%. Results revealed that chitosan nanoparticles loaded rosemary oil exhibited interesting insecticidal toxicity towards C. hemipterus adults in stored dates with 50.73% mortality. Overall, this work pointed out that the innovative design method based on chitosan-nanoparticles loaded rosemary oil can be promoted in integrated pest management program for stored date pests.

Extraction, characterization and controlled release application of pectin-like/chitosan hydrogels system loaded Ciprofloxacin

INTRODUCTION

In recent decades, drug delivery applications have extensively utilized hydrogel systems based on natural polymers. Among the numerous biopolymer-based hydrogel drug delivery systems reported, a novel pectin-like substance was extracted from fig leaves and copolymerized with chitosan.

METHOD

The hydrogel was reformed into microspheres using glutaraldehyde (chemical cross-linker) and sodium hexametaphosphate (physical cross-linker). The extracted polysaccharide and the prepared hydrogels were characterized by FTIR, GC/MS, SEC/MALS/DRI as well as XRD, SEM, BET, and thermal analysis. SEM images revealed the formation of porous microspheres with an average size of 50 μm in diameter. Degrees of swelling in pH7 at 35°C have shown the hydrogels reached two to three times their weights. This has been reflected in their ability to load drugs or any other chemicals. The loading formula shows that hydrogels have maximum loading efficiency more than one-third of the weight of hydrogel. The antimicrobial ciprofloxacin was used as a model for loading on prepared hydrogels. The loaded hydrogels were tested for their biological activities against staphylococcus aureus (S. aureus) bacteria. The antimicrobial growth inhibition zone of the cultured (S. aureus) by ciprofloxacin-loaded hydrogel was followed, which shows controlled growth in inhibition zone sizes and for long time intervals. Results showed that the pectin-chitosan hydrogels exhibited significant antibacterial activity against gram - positive bacteria (S. aureus), with an inhibition zone of 45 mm for (CH-co-FLP)/GLU hydrogel.

RESULT

In vitro, the ciprofloxacin-loaded hydrogels were studied and the cumulative release of ciprofloxacin under suitable conditions was found in a controlled manner and kept release for a long time interval. Data exhibited that the cumulative release profile of ciprofloxacin from the hydrogel demonstrated sustained release over 48 hours, with a value of 6.9% released within the first 24 hours and 7.0 and 6.9% % released at the end of the study for the (CH-co-FLP)/GLU and (CH-co-FLP)/SMP hydrogels, respectively.

CONCLUSION

The novel pectin-chitosan hydrogels hold the potential to enhance the quality of life for numerous patients by minimizing the need for frequent intake of chronic medications.

Effects of Surface Morphology and Type of Cross-Linking of Chitosan-Pectin Microspheres on Their Degree of Swelling and Favipiravir Release Behavior

The cross-linked microspheres were prepared and loaded with Favipiravir SARS-CoV-2 antiviral drug, by copolymerization of chitosan (CS) with a polysaccharide extracted from fresh pomegranate peels. Moreover, glutaraldehyde (Glu) has been used as a chemical cross-linker and sodium hexametaphosphate (SHMP) as a physical cross-linker. The extracted polysaccharide was analyzed, and different techniques have been used. The analyses lead to the conclusion that it is pectin. The surface morphology of the prepared microspheres was studied using a scanning electron microscope, where the size and shape factor (S) of the Glu microspheres showed high values (74.27 μm) and (0.852), respectively, meaning their surfaces tend to be rough, whereas the SHMP microspheres showed a smaller size particle (20.47 μm) and a smaller shape factor (0.748), which gives an indication that the SHMP microspheres have smooth surfaces. The swelling studies have shown that Glu microspheres have a higher degree of swelling, which means SHMP microspheres are more compact. The prepared microspheres have shown a higher loading percentage of Favipiravir antiviral drug in SHMP microspheres (37% w/w) in comparison with Glu microspheres (35% w/w), where the electrostatic interaction between the Favipiravir ions and SHMP anions helps for more loading. The microspheres prepared under different types of cross-linking have shown initial burst release of Favipiravir, followed by a step of controlled release for a certain period of time, whose period depends on the pH of the release medium. Both Glu and SHMP cross-linked microspheres have shown high controlled release times in buffered release solutions at pH = 7.4 and for shorter periods at pH = 1.3 and pH = 9.4, which may be related to the type of electrostatic interactions between drug and polymer systems and their reactions with release solution ions.

Effect of Flavoring with Rosemary, Lemon and Orange on the Quality, Composition and Biological Properties of Olive Oil: Comparative Study of Extraction Processes

The goal of this work was to investigate the impact of the flavoring of some aromatic plants/spices, including rosemary (R), lemon (L) and orange (O) at the concentration of 5% and 35% (w/w) added by 2 methods (conventional maceration and direct flavoring), on quality attributes, chemical changes and oxidative stability of extra virgin olive oil (EVOO). Six flavored oils were obtained (EVOO + O, O + O, EVOO + R, O + R, EVOO + L and O + L). The physicochemical parameters (water content, refractive index, acidity and peroxide value, extinction coefficient, fatty acids, volatile aroma profiles, Rancimat test, phenols and pigments composition) of the flavored oils were investigated. Based on the results obtained, it was observed that flavoring with a conventional process provided increased oxidative stability to the flavored oils, especially with rosemary (19.38 ± 0.26 h), compared to that of unflavored oil. The volatile profiles of the different flavored oils revealed the presence of 34 compounds with the dominance of Limonene. The fatty acid composition showed an abundance of mono-unsaturated fatty acids followed by poly-unsaturated ones. Moreover, a high antioxidant activity, a significant peripheral analgesic effect (77.7% of writhing inhibition) and an interesting gastroprotective action (96.59% of ulcer inhibition) have been observed for the rosemary-flavored oil. Indeed, the flavored olive oils of this study could be used as new functional foods, leading to new customers and further markets.

Chemical Profile of the Pits Oil from the Tunisian 'Alig' Cultivar of Phoenix dactylifera L.: In Vivo Wound Healing Potential Evaluation of a Cream Formulated from the Extracted Oil and Insights from Molecular Docking and SAR Analysis

Since ancient times the oil from date palm pits (Phoenix dactylifera L.) has been used to heal wounds. In order to prove this traditional usage of the pits, this oil was extracted from the pits of the Tunisian cultivar 'Alig' and its physico-chemical properties and the chemical composition were evaluated. The fatty acid profile, evidenced by GC, allowed to classify this oil as an oleic-myristic acid oil with a clear abundance of oleic acid (53.66 %). ¹ H and ¹³ C-NMR as well as FT-IR analyses confirmed the presence of fatty acids in triglyceride forms. Furthermore, in vivo wound healing activity of a cream formulated from the extracted oil was performed, for the first time, using a rat model and was compared to placebo cream and a commercial formulation, MEBO®. This study showed that the test cream promoted the healing of pressure ulcers better than the placebo cream and the MEBO® ointment. The results showed that this vegetable oil is able to improve the healing of infected wounds in rats, thus supporting its traditional use. The contribution of the main oleic, linoleic and myristic acids that can be derived from enzymatic hydrolysis to the healing activity of the whole pits oil was predicted by in silico study and the calculated pharmacokinetics parameters.

Identification of an anti-herpetic compound isolated from Pistacia vera L. male floral buds

Due to the numerous side effects of conventional drugs against herpetic infections and the growing phenomenon of resistance, the researchers turned to natural compounds as a source of new drugs because they are less toxic than the synthetic molecules. This study aimed to analyse the activity of Pistacia vera L. male floral bud extracts, against the replication of herpes simplex virus type 2, as well as to investigate their mode of action, isolate, and identify the active compound. Cell viability and anti-herpes virus activity were performed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and the plaque reduction assay, respectively. Three extracts (ethanolic, aqueous and polysaccharide extracts) were tested, only aqueous and polysaccharide extracts had anti-herpetic activity with a selectivity index of 29.12 and 20.25, respectively. Investigation about the mechanism of action indicated that the two active extracts inhibited the virus replication by direct contact with virucidal selectivity indexes of 39.15 and 32.09, respectively. An active compound was isolated from the aqueous extract using TLC bio-guided assay: it was identified as gallic acid by high-performance liquid chromatography-diode array detection coupled with electrospray ionization mass spectrometry (HPLC-DAD-ESI-MSn). The antiviral activity of Pistacia vera L. has been previously shown. The selectivity index of gallic acid is much lower than that of the active extract from which it has been isolated. Therefore, we can consider the aqueous extract prepared from Pistacia vera L. male floral buds as a promising natural product for treating herpetic diseases.

Characterization of Polysaccharides Sequentially Extracted from Allium roseum Leaves and Their Hepatoprotective Effects against Cadmium Induced Toxicity in Mouse Liver

Allium roseum is one of the medicinal plants of the Liliaceae family, widely used in the food industry and traditional medicine. It is known for its various biological properties, such as its antioxidant, antiviral, antidiabetic, and anti-inflammatory activities. The present work aims to extract the polysaccharides from Allium roseum leaves and evaluate their antioxidant activities and hepatoprotective effects in vivo. Three polysaccharides from the leaves of Allium roseum were sequentially extracted in three media: water, chelating, and basic, respectively. They were characterized by size exclusion chromatography, gas chromatography mass spectrometry, FTIR-ATR, and NMR spectroscopy (1D and 2D). The different polysaccharides principally consist of glucose, galactose, mannose, rhamnose, xylose, and galacturonic acid. The antioxidant activity and hepatoprotective effect of the extracts against Cd-caused oxidative stress in liver mouse were tested. Cd treatment, during 24 h, enhanced significantly lipid peroxidation by a high production of malondyaldehyd (MDA) and superoxide dismutase (SOD) activity. In contrast, catalase activity (CAT) was decreased after the same period of exposure to the metal. The polysaccharides pre-treatment improved the antioxidant defense system to a great degree, mainly explained by the modulating levels of oxydative stress biomarkers (MDA, SOD, and CAT). This research clearly shows that Allium roseum polysaccharides, especially those extracted in aqueous medium, can be used as natural antioxidants with hepatoprotective properties.

Antimicrobial, antioxidant and antileishmanial activities of Ziziphus lotus leaves

The aim of this study was to investigate antimicrobial and antioxidant activities of different fractions obtained from edible Tunisian Ziziphus Lotus leaves of Tozeur region. Different organic extracts were tested: cyclohexane, dichloromethane, ethyl acetate, n-butanol and water. Bio-guided fractionation revealed that dichloromethane fraction is the most active against S. aureus and Methicillin-resistant S. aureus strains. Moreover, this fraction showed the highest antileishmanial activity with IC₅₀ values of 20.55 ± 0.34 μg/mL and 15.37 ± 0.17 μg/mL against L. major and L. infantum, respectively. The potentialities of antibacterial and leishmanicidal activities found in dichloromethane could be explained by the presence of major flavonoids such as catechin, rutin and luteolin 7-O-glucoside as revealed by HPLC system. The observed moderate antifungal activity, which was only given by butanolic fraction against pathogen fungi, may be attributed to the presence of chlorogenic acid. Furthermore, dichloromethane and butanolic fraction showed a good DPPH (2,2-diphenyl-1-picryl hydrazyl) scavenging activity and Ferric reducing power. These results suggest that Ziziphus lotus leaf fractions might be used as antioxidant and antimicrobialagent.

Pectic polysaccharides from edible halophytes: Insight on extraction processes, structural characterizations and immunomodulatory potentials

The preparation, chemical properties and bio-activities of polysaccharides derived from halophytes have gained an increasing interest in the past few years. Phytochemical and pharmacological reports have shown that carbohydrates are important biologically active compounds of halophytes with numerous biological potentials. It is believed that the mechanisms involved in these bio-activities are due to the modulation of immune system. The main objective of this summary is to appraise available literature of a comparative study on the extraction, structural characterizations and biological potentials, particularly immunomodulatory effects, of carbohydrates isolated from halophytes (10 families). This review also attempts to discuss on bioactivities of polysaccharides related with their structure-activity relationship. Data indicated that the highest polysaccharides yield of around 35% was obtained under microwave irradiation. Structurally, results revealed that the most of extracted carbohydrates are pectic polysaccharides which mainly composed of arabinose (from 0.9 to 72%), accompanied by other monosaccharides (galactose, glucose, rhamnose, mannose and xylose), significant amounts of uronic acids (from 18.9 to 90.1%) and some proportions of fucose (from 0.2 to 8.3%). The molecular mass of these pectic polysaccharides was varied from 10 to 2650 kDa. Hence, the evaluation of these polysaccharides offers a great opportunity to discover novel therapeutic agents that presented especially beneficial immunomodulatory properties. Moreover, reports indicated that uronic acids, molecular weights, as well as the presence of sulfate and unmethylated acidic groups may play a significant role in biological activities of carbohydrates from halophyte species.

Optimization of extraction with salicylic acid, rheological behavior and antiproliferative activity of pectin from Citrus sinensis peels

A Box-Behnken design was used to optimize extraction temperature, extraction time and concentration of the salicylic acid to obtain a maximum polysaccharide yield from Citrus sinensis peels. The optimal settings were: extraction time 3 h, extraction temperature 80 °C and concentration of the salicylic acid 1.5%. Under these conditions, the experimental yield and uronic acid content were 11.74% and 66.9% respectively. Preliminary characterization was performed via FT-IR, SEC/MALS/VD/DRI and GC-MS after hydrolysis. SEC analysis showed that the extracted polysaccharide had a weight average molar mass of 350 kDa and an intrinsic viscosity of 640 mL/g. The GC-MS results revealed that the extracted polysaccharide was composed of arabinose 56.7%, galactose 17.8%, xylose 13.8%, rhamnose 5.1%, mannose 2.5% and glucose 1.5% suggested a rhamnogalacturonan pectin type I with a degree of esterification of 50.9% (IRTF). The flow curve and the dynamic frequency sweep were obtained at 10, 20, 30 and 40 g/L in water and at 30 g/L in presence of CaCl₂ or NaCl at 1 mol/L. The solutions showed shear-thinning behavior fitted with Ostwald-De Waele model, except 10 g/L with a Newtonian behavior. The apparent viscosity and, the G' and G" moduli increase with PACO concentration in agreement with a slow-down of the dynamic chain. In the presence of CaCl₂ or NaCl the reduction of electrostatic repulsions between pectin chains decreases the rheological parameters. The effect is less sensitive with CaCl₂ due to intermolecular interactions. The antiproliferative activity of the extracted pectin on human Caco-2 and Hep-2 cells was very interesting with an IC₅₀ 1.4 and 1.8 μg/mL respectively.

Protective effect assessment of Moringa oleifera against cadmium-induced toxicity in HCT116 and HEK293 cell lines

The cadmium (Cd) is considered one of the widespread toxic metals in the aquatic and terrestrial environments, which is due to its long half-life, non-degradable characteristic, and toxicity. Aqueous extract of freeze-dried Moringa oleifera (Moringaceae family) leaves was examined for protective effect and antioxidant power against Cd toxicity. The results revealed that Moringa aqueous extract (MAE) has contents of total polyphenols and flavonoids about 30.14 mg GAE/g and 18.35 mg QE/g respectively. Furthermore, phenolic compounds in leaves of Moringa were studied using a high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS). Results showed that the largest number of phenolic compounds determined in leaves of Moringa belongs to flavonoids. Moreover, biological properties were determined by radical scavenging capacity (DPPH) and ferric-reducing power (FRAP). Cytoprotective effect and antioxidant power of Moringa extract were assessed using the mitochondrial activity testing method (MTT test), malondialdehyde (MDA), and reactive oxygen species (ROS) production. Results indicate that Moringa aqueous extract have a significant (i) proliferative, (ii) antioxidant, and (iii) cytoprotective effect on HCT116 and HEK293 cells against metal toxicity.

Dietary administration effects of exopolysaccharide from potential probiotic strains on immune and antioxidant status and nutritional value of European sea bass (Dicentrarchus labrax L.)

The use of biological immunostimulants is considered a valuable practice to improve culture conditions in aquaculture sector that may help to increase production and maintain healthy environment. We undertook this study in order to evaluate the potential effect of the administration of two exopolysaccharides (EPS) "EPLB" and "EPB" derived from potential probiotic strains on immune and antioxidant status of European sea bass (Dicentrarchus labrax L.) larvae. In order to find out if the EPSs have an effect on the biochemical composition during the trial period, the nutritional value has been evaluated. The results revealed that expression levels of immune-relevant genes (infg, Il1b, Il8, Il6 and tcr-β) in the gut and head kidney and the scavenging enzymes (cat, sod, gr) genes in the liver were modulated. In fact, the dietary supplementation with the tested EPSs, significantly enhances the expression of immune-associated genes in the head-kidney, particularly infg and tcrβ, as well as catalase gene in liver. During the period of study, EPSs administration did not affect the fatty acid profiles of larvae, which is balanced. This is confirmed by the Docosahexaenoic acid / Eicosapentaenoic acid ratio and demonstrates that EPLB and EPB can be administrated without any negative effect on biochemical composition of European sea bass. The present findings provided evidence that the tested EPSs with antibacterial and antioxidant activities can enhance immune response without negative effect on the biochemical composition. The used EPSs can be considered as a good source of natural functional aquafeed ingredients for European sea bass.

Protective potential effects of fucoidan in hepatic cold ischemia-rerfusion injury in rats

The necessity to increase the efficiency of organ preservation has pushed physicians to consider the use of pharmacological additives in preservation solutions to minimize ischemia reperfusion injury. Here, we evaluated the effect of fucoidan, sulfated polysaccharide from brown seaweed, as an additive to IGL-1 (Institut Georges Lopez) preservation solution. Livers from Wistar rats were preserved for 24 h at 4 °C in IGL-1 solution, enriched or not with fucoidan (100 mg/L). Thereafter, they were subjected to reperfusion (2 h, at 37 °C) using an isolated perfused rat liver model. The addition of fucoidan to IGL-1 solution reduced hepatic injury (AST, ALT) and improved liver function compared to IGL-1 solution without fucoidan. In addition, we noted a significant increase in the phosphorylation of AMPK, AKT protein kinase and GSK3-β, leading to a reduction in VDAC phosphorylation, as well as a reduction in apoptosis (caspase 3), mitochondrial damage, oxidative stress and endoplasmic reticulum (ER) stress markers. Furthermore, ERK1/2 and P38 MAPKs phosphorylation significantly decreased after supplementation of IGL-1 solution with fucoidan. In conclusion, the supplementation of IGL-1 solution with fucoidan maintained liver graft integrity and function through the prevention of the ER stress, oxidative stress and mitochondrial dysfunction. Fucoidan could be considered as potential natural therapeutic agent to alleviate graft injury.

An Acetylcholinesterase Inhibition-Based Biosensor for Aflatoxin B1 Detection Using Sodium Alginate as an Immobilization Matrix

In this study, we investigated a novel aflatoxin biosensor based on acetylcholinesterase (AChE) inhibition by aflatoxin B1 (AFB1) and developed electrochemical biosensors based on a sodium alginate biopolymer as a new matrix for acetylcholinesterase immobilization. Electrochemical impedance spectroscopy was performed as a convenient transduction method to evaluate the AChE activity through the oxidation of the metabolic product, thiocholine. Satisfactory analytical performances in terms of high sensitivity, good repeatability, and long-term storage stability were obtained with a linear dynamic range from 0.1 to 100 ng/mL and a low detection limit of 0.1 ng/mL, which is below the recommended level of AFB1 (2 µg/L). The suitability of the proposed method was evaluated using the samples of rice supplemented with AFB1 (0.5 ng/mL). The selectivity of the AChE-biosensor for aflatoxins relative to other sets of toxic substances (OTA, AFM 1) was also investigated.

Antioxidant Activity Improvement of Apples Juice Supplemented with Chitosan-Galactose Maillard Reaction Products

Chitosan-galactose Maillard reaction (CG) were prepared by heating at 100 °C for 3 hrs in a model system containing chitosan (CH) and 1%, 1.5% and 2% (w/v) of galactose. The results showed that the absorbance at 294 and 420 nm, the fluorescence intensity and the color differences of CG Maillard reaction products (MRPs) increased significantly with the increase of galactose concentration, which indicated the development of MRPs. In addition, FT-IR analysis showed that the degree of deacetylation of CG-MRPs was reduced with the increasing galactose ratio by the schiff base (-C=N) formation, indicating that the galactose has been attached to the amino group of chitosan. Likewise, the antioxidant activities (DPPH, chelating ability and reducing power) of CG-MRPs were investigated. Notably, the effect of galactose concentration in CG-MRPs was found to enhance the antioxidant activity, indicating that CG-2% exhibited the highest antioxidant activity in the range of 0.25-2.0 mg/mL. Furthermore, the apple juice supplemented with CG-MRPs could significantly improve the antioxidant activities, and CG-2% in apple juice showed the better antioxidant capacity at the concentration of 1.0 mg/mL. Thus, we conclude that CG-MRPs addition may greatly improve the antioxidant quality of apple juice.

Effects of Carpobrotus edulis Extract on Oxidative Stress and 158N Oligodendrocyte Death

OBJECTIVE

Age-related diseases, including neurodegenerative diseases, are associated with oxidative stress and lipid peroxidation, and increase the levels of cholesterol auto-oxidation products such as 7β-hydroxycholesterol (7β-OHC). Thus, it is imperative to identify agents that can prevent 7β-OHC-induced side-effects.

METHODS

We evaluated the potential protective effects of Carpobrotus edulis ethanol-water extract (EWe) on murine oligodendrocytes (158N) cultured in the absence or presence of 7β-OHC (20 μg/mL, 24 h). The cells were incubated with EWe (20-200 µg/mL) 2 h before 7β-OHC treatment. Mitochondrial activity and cell growth were evaluated with the MTT assay. Photometric methods were used to analyze antioxidant enzyme [catalase (CAT) and glutathione peroxidase (GPx)] activities and the generation of lipid and protein oxidation products [malondialdehyde (MDA), conjugated diene (CD), and carbonylated proteins (CPs)].

RESULTS

Treatment with 7β-OHC induced cell death and oxidative stress (reflected by alteration in CAT and SOD activities). Overproduction of lipid peroxidation products (MDA and CDs) and CPs was also reported. The cytotoxic effects associated with 7β-OHC were attenuated by 160 μg/mL of EWe of C. edulis. Cell death induced by 7β-OHC treatment was ameliorated, GPx and CAT activities were restored to normal, and MDA, CD, and CP levels were reduced following C. edulis extract treatment.

CONCLUSION

These data demonstrate the protective activities of C. edulis EWe against 7β-OHC-induced disequilibrium in the redox status of 158N cells, indicative of the potential role of this plant extract in the prevention of neurodegenerative diseases.

Highly Sensitive Voltammetric Glucose Biosensor Based on Glucose Oxidase Encapsulated in a Chitosan/Kappa-Carrageenan/Gold Nanoparticle Bionanocomposite

In this work, an enzymatic sensor, based on a bionanocomposite film consisting of a polyelectrolyte complex (PEC) (Chitosan/kappa-carrageenan) doped with gold nanoparticles (AuNPs) encapsulating glucose oxidase (GOD) deposited on a gold electrode (Au) for glucose sensing, is described. Using the electrocatalytic synergy of AuNPs and GOD as a model of enzyme, the variation of the current (µA) as a function of the log of the glucose concentration (log [glucose]), shows three times higher sensitivity for the modified electrode (283.9) compared to that of the PEC/GOD modified electrode (93.7), with a detection limit of about 5 µM and a linearity range between 10 µM and 7 mM. The response of the PEC/AuNPs/GOD based biosensor also presents good reproducibility, stability, and negligible interfering effects from ascorbic acid, uric acid, urea, and creatinine. The applicability of the PEC/AuNPs/GOD based biosensor was tested in glucose-spiked saliva samples and acceptable recovery rates were obtained.

Chitosan/beidellite nanocomposite as diclofenac carrier

Chitosan (CS) and purified sodium beidellite (Na-Bd) were used to obtain a nanocomposite able to carry anionic pharmaceutical ingredients. Diclofenac sodium (DS) was chosen as a model drug and was loaded by intercalation solution technique. Solid state characterization of the resultant hybrids was performed, including X-ray diffraction, Fourier transformed infrared spectroscopy, Thermal analysis and high resolution transmission electron microscopy coupled with energy dispersive X-Ray analysis. Drug loading capacity and encapsulation efficiency were quantified by measuring equilibrium concentration by UV-Vis spectroscopy at 276 nm. Solid-state characterization of the samples confirmed both chemical and physical interaction of DS with the nanocomposites. High drug loading along with a modified cumulative release of the drug in simulated intestinal fluid was obtained. The developed clay/polymer hybrids can act as potential candidates for the design of modified dosage forms of anionic drugs.

Optimization of polysaccharides extraction from quince peels: partial characterization, antioxidant and antiproliferative properties

In this study, Box-Behnken Design was used to optimize the ultrasonic extraction of polysaccharides from quince peels (QPPs) by ascorbic acid and the effect of extraction temperature, extraction time and pH was evaluated. Under optimized conditions of temperature 90 °C, 60 min sonication time and pH = 3.26, the extraction yield, the galacturonic acid yield and the concentration of sample required to scavenge 50% of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic) acid (ABTS) values of QPPs were respectively 10.25%, 3.86% and 1.35 mg/mL. The QPPs extracted under optimum conditions was characterized by Fourier transform infrared spectroscopy (FTIR), Nuclear magnetic resonance (¹H NMR) and Size exclusion chromatography (SEC/MALS/VD/DRI). The monosaccharide analysis revealed that arabinose was the most abundant, followed by galactose, glucose, mannose and xylose. Moreover, QPPs showed significant antioxidant activities (2,2-diphenyl-1-picrylhydrazyl (DPPH) and Ferric- reducing antioxidant power (FRAP)) and reduced viability of human Caco-2 and murine B-16 cell lines in a dose-dependent manner. Hence QPPs could be used as antitumor agent in functional foods andpharmaceutical industries.

7β-hydroxycholesterol-induced cell death, oxidative stress, and fatty acid metabolism dysfunctions attenuated with sea urchin egg oil

Some oxysterols resulting either from enzymatic oxidation or autoxidation of cholesterol are associated with age-related diseases including neurodegenerative diseases. Among these oxysterols, 7β-hydroxycholesterol (7β-OHC) is often found at increased levels in patients. It is therefore important to identify molecules or mixtures of molecules to prevent 7β-OHC-induced side effects. Consequently, murine oligodendrocytes (158N) were cultured in the absence or presence of 7β-OHC (20 μg/mL, 24 h) with or without a natural oil extracted from sea urchin (Paracentrotus lividus) eggs known for its biological activity. Firstly, the chemical composition of this oil was determined using ³¹P NMR and GC-MS. Secondly, this oil was used to reduce 7β-OHC-induced side effects. To this end, the oil (160 μg/mL) was added to the culture medium of 158N cells 2 h before 7β-OHC. The effects of 7β-OHC with or without the oil on cell viability were studied with the MTT test. Photometric methods were used to analyze antioxidant enzyme activities, superoxide dismutase (SOD) and glutathione peroxidase (GPx), as well as the generation of lipid peroxidation products (malondialdehyde (MDA), conjugated dienes (CDs)) and protein oxidation product (carbonylated proteins (CPs)). Gas chromatography was used to determine the fatty acid profile. With 7β-OHC, an induction of cell death associated with oxidative stress (alteration of GPx and SOD activities) was observed; an overproduction of lipid peroxidation products (MDA and CDs) and CPs was also revealed. Sea urchin egg oil attenuated 7β-OHC-induced cytotoxicity: 7β-OHC-induced cell death was reduced, GPx and SOD activities were normalized, and lower levels of MDA, CDs and CPs were produced. In addition, whereas a disturbed fatty acid profile was observed with 7β-OHC, similar fatty acid profiles were found in control cells and in cells cultured with 7β-OHC associated with sea urchin egg oil. These data demonstrate the protective activities of sea urchin egg oil against 7β-OHC-induced side effects on 158N cells, supporting the concept that this oil may have benefits in the prevention of neurodegenerative diseases.

Dawson-type polyoxometalate nanoclusters confined in a carbon nanotube matrix as efficient redox mediators for enzymatic glucose biofuel cell anodes and glucose biosensors

Two new inorganic-organic hybrid materials based on heteropolyoxometalates (POMs): (C₄H₁₀N)₆[P₂Mo₁₈O₆₂]·4H₂O (P₂Mo₁₈) and (C₆H₈NO)₄[H₂P₂W₁₈O₆₂]·6H₂O (P₂W₁₈) are reported as mediators for electron transfer between FAD-dependent glucose dehydrogenase (FAD-GDH) and a multiwalled carbon nanotube (MWCNT) matrix for glucose biofuel cell and biosensor applications. These polyoxometalates were chosen due to their promising redox behavior in a potential range for mediated electron transfer with the glucose oxidizing enzyme, FAD-GDH. P₂Mo₁₈ and P₂W₁₈ were immobilized on 1-pyrenemethylamine (PMA) functionalized MWCNT deposits. After immobilization of FAD-GDH, the P₂W₁₈-modified MWCNT electrode demonstrated mediated electron transfer and provided a catalytic current density of 0.34 mA cm^-2 at 0.2 V vs SCE with an open circuit potential (OCP) of -0.08 V vs SCE. A 10-fold increase in catalytic current to 4.7 mA cm^-2 at 0.2 V vs SCE and a slightly lower OCP of -0.10 V vs SCE was observed for an equivalent electrode modified with P₂Mo₁₈.The apparent superiority of P₂Mo₁₈ is related, at least in part, to its improved incorporation in the MWCNT matrix compared to P₂W₁₈. Both POM-modified bioanodes showed exceptional stabilities with 45% of their initial performances remaining after 15 days. The mediated electron transfer capacities of the POMs were also evaluated in a glucose sensor setup and showed very satisfying performances for glucose detection, including a sensitivity of 0.198 mA mol L^-1 cm^-2, a satisfying linear range between 1 mmol L^-1 and 20 mmol L^-1, and good reproducibility for the P₂Mo₁₈ electrode.

GC-EI-MS identification data of neutral sugars of polysaccharides extracted from Zizyphus lotus fruit

Gas chromatography coupled to mass spectrometer (GC–MS) was used to identify and to quantify neutral sugars that constitute the water soluble polysaccharides from Zizyphus lotus fruit. The trimethylsilyl (TMS) method was successfully used for derivatization of the monosaccharides units of extracted polysaccharides that were released by hydrolysis method. Sugars were identified based on their retention times compared with those of standards and the NIST MS Spectral Library. All sugars were quantified in TIC (Total Ion Current) mode using calibration curves. Data is related to “Optimization extraction of polysaccharide from Tunisian Zizyphus lotus fruit by response surface methodology: Composition and antioxidant activity” (Mkadmini Hammi et al., 2016) [1].

Influence of the uronic acid composition on the gastroprotective activity of alginates from three different genus of Tunisian brown algae

Alginates from three genus of Tunisian brown algae were isolated and characterized by size exclusion chromatography and Solid-state NMR spectroscopy. Alginate from Padina pavonica (APP) had the highest molecular weight (Mw) with 147,000g/mol while it was 85,000g/mol for alginate from Cystoseira compressa (ACC) and 58,000g/mol for alginate from Dictyopteris membranaceae (ADM). The mannuronate (M) to guluronate (G) ratios were estimated from spectral deconvolution of the 13C CP/MAS spectra and the results has shown that all the extracts are mannuronic acid-rich alginates with M/G ratio increased in the order ADM - ACC - APP. An interesting gastroprotective effect was observed for the extracts; ADM and ACC exhibited the highest inhibition of gastric lesions, at 50mg/kg, with 83.41% and 75.39% respectively. Otherwise, it has been shown that the gastroprotective effect of alginates depends mainly on their uronic acid composition.

Recovery of Phenolic Compounds and Carbohydrates from Hydro-ethanolic Extract of Zizyphus lotus Fruit using Ultrafiltration Process

Cross flow ultrafiltration (UF) using a cellulose membrane (cut off of 5 kDa) was employed to separate phenolic compounds from carbohydrates of hydro-ethanolic extract obtained fromZizyphus lotusfruit. The performance of the UF membrane was evaluated in terms of permeate flux, fouling index and retention values of total phenolic compounds, carbohydrates and uronic acid contents. The results showed that at VRF of 4.5, the membrane gave the highest rejections towards carbohydrates (99.89 %) and uronic acids (82.8 %) and the lowest average rejection of total phenolic compounds (3.12 %). Moreover, the permeate fraction exhibited the highest 2,2-diphenyl-1-picrylhydrazyl free radical scavenging ability and total antioxidant capacity with 0.036 mg.mL−1and 102.145(mgGAE.g−1DM), respectively. This result is due to the presence of phenolic compounds (gallic acid, syringic acid, catechin, quercetin and kaempferol) as identified by HPLC system. Besides, a low rejection values of the UF membrane concerning these compounds were confirmed by liquid chromatography analyses.

Effect of ultrasonic degradation of hyaluronic acid extracted from rooster comb on antioxidant and antiglycation activities

CONTENT

Recently, low-molecular-weight hyaluronic acid (LMWHA) has been reported to have novel features, such as free radical scavenging activities, antioxidant activities and dietary supplements.

OBJECTIVE

In this study, hyaluronic acid (HA) was extracted from rooster comb and LMWHA was obtained by ultrasonic degradation in order to assess their antioxidant and antiglycation activities.

MATERIALS AND METHODS

Molecular weight (Mw) and the content of glucuronic acid (GlcA) were used as the index for comparison of the effect of ultrasonic treatment. The effects on the structure were determined by ultraviolet (UV) spectra and Fourier transform infrared spectra (FTIR). The antioxidant activity was determined by three analytical assays (DPPH, NO and TBARS), and the inhibitory effect against glycated-BSA was also assessed.

RESULTS

The GlcA content of HA and LMWHA was estimated at about 48.6% and 47.3%, respectively. The results demonstrate that ultrasonic irradiation decreases the Mw (1090-181 kDa) and intrinsic viscosity (1550-473 mL/g), which indicate the cleavage of the glycosidic bonds. The FTIR and UV spectra did not significantly change before and after degradation. The IC50 value of HA and LWMHA was 1.43, 0.76 and 0.36 mg/mL and 1.20, 0.89 and 0.17 mg/mL toward DPPH, NO and TBARS, respectively. Likewise LMWHA exhibited significant inhibitory effects on the AGEs formation than HA.

DISCUSSION AND CONCLUSION

The results demonstrated that the ultrasonic irradiation did not damage and change the chemical structure of HA after degradation; furthermore, decreasing Mw and viscosity of LMWHA after degradation may enhance the antioxidant and antiglycation activity.

Microwave-assisted extraction and pharmacological evaluation of polysaccharides from Posidonia oceanica

Microwave-assisted extraction was employed for the isolation of polysaccharides from Posidonia oceanica (PPO). The extracting parameters were optimized adopting response surface methodology. The highest polysaccharide yield (2.55 ± 0.09%), which is in concordance with the predicted value (2.76%), was obtained under the following conditions: extraction time 60 s, liquid–solid ratio of 50:1 (mL/g) and power of 800 W. This polysaccharide, with molecular weight of 524 KDa, characterized by gas chromatography–mass spectrometry showed that PPO was mainly composed of galactose, glucose, and arabinose with molar percentages 25.38, 24.37, and 21.64%, respectively. The pharmacological evaluation of PPO using animal models at the dose of 100 mg/kg indicated a significant anti-inflammatory activity with a percentage of inhibition of edema of 54.65% and a significant antinociceptive activity with 78.91% inhibition of writhing for peripheral analgesic activity and an increase in the hot plate reaction time for central analgesic activity.