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.

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 (1 H 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.

Partial characterization of the edible Spinacia oleracea polysaccharides: Cytoprotective and antioxidant potentials against Cd induced toxicity in HCT116 and HEK293 cells.

Spinacia is an interesting medicinal halophyte plant that is employed as a food and therapeutic agent in traditional medicine. In this work, water-soluble polysaccharides from Spinacia oleracea were extracted and preliminary characterization was established via FT-IR, UV-vis, 1H NMR and SEC/MALS DRI technics. The extracted polysaccharide, with an average molecular mass of 408 kDa, was composed of arabinose, galactose, mannose, glucose, rhamnose and xylose in the molar percentage of 49.3%, 28.1%, 4.9%, 7.8%, 8.2% and 1.7%, respectively. The polysaccharide showed significant antioxidant activity. Moreover, Spinacia polysaccharide, significantly prevented oxidation-induced Cd damage and exhibited a protective effect against Cd cytotoxicity on HEK293 and HCT116 cells, with an important cell viability decrease, an important reduction of MDA production and ROS levels. The outcomes obtained suggest that the Spinacia polysaccharides may be used as an accessible source of natural antioxidants and as potential phytochemicals against kidney and colon cancer.

Wild edible Swiss chard leaves (Beta vulgaris L. var. cicla): Nutritional, phytochemical composition and biological activities.

Nutritional, soluble carbohydrates and aroma volatile profiles of Tunisian wild Swiss chard leaves (Beta vulgaris L. var. cicla) have been characterized. The chemical composition of an ethanol chard leaves extract, as well as its in vitro antioxidant, α-amylase and α-glucosidase inhibition activities were carefully evaluated. The results of the proximate composition showed that total carbohydrate fraction, mainly as dietary fiber were the major macronutrient (2.43 g/100 g fw), being the insoluble dietary fiber the predominant fraction (2.30 g/100 g). In addition, leaves of Beta vulgaris L. were especially rich in Mg, Fe and Ca (4.54, 2.94 and 2.28 mg/100 g fw) and very poor in Na (0.09 mg/100 g fw). Volatile profile revealed that non-terpene derivatives and sesquiterpene hydrocarbons were the essential classes of volatiles in the chard leaves. Myricitrin, p-cumaric acid and rosmarinic acid were characterized. Moreover, the ethanol extract of wild Swiss chard leaves revealed significant antioxidant capacity. Furthermore, a good enzyme inhibitory effects on α-glucosidase and α-amylase activities were observed. These findings highlighted the potential health benefits of wild Swiss Chard as a source of nutritional and bioactive compounds.

Chemo-embolization in the treatment of hepatocellular carcinoma: should we switch to charged particles in our countries? About 102 procedures of a North African radiology center.

BACKGROUND: Hepatocellular carcinoma (HCC) is a public health problem in african countries. The chemoembolization (CE) could represent the only therapeutic strategy. Two methods can be proposed: charged microparticles and lipiodol chemoembolization. The purpose of this study was to compare results, morbidity and survival between charged microparticles and lipiodol chemoembolization. METHODS: A 5 years retrospective, study was conducted including 62 patients with HCC treated by chemioembolization. The efficacy of the treatment was evaluated for patients by performing a computed tomography four to six weeks after the act. We used « European Association for Study of the Liver ¼ criteria to evaluate the therapeutic outcome. RESULTS: A total of 102 sessions of chemoembolization were performed. This was a with charged microparticles in 70 cases (68.6%) and lipiodol chemoembolization in 32 cases (31.3 %). The difference was not significant between the two CE techniques (lipiodol and charged microparticles) in terms of complete and objective response and complications. The mean survival rate was 30 months ± 4 for all techniques combined, with no statistically significant difference in terms of survival time without recurrence between the two chemoembolization techniques. CONCLUSION: The efficacy, morbidity and survival of the two CE techniques to lipiodol or microfilled particles are comparable. The selectivity of the technique is to be taken into consideration. For economic health purposes, the CE lipiodolée appears to be more adapted to the context of the developing African countries.

Characterization of polysaccharides from Prunus amygdalus peels: Antioxidant and antiproliferative activities.

Prunus amygdalus is used in the folk medicine that proved the interest of this plant which cures many diseases. Many researchers are interested to valorize almond waste (hull and shell) and to evaluate their biological and pharmacological activities. In this work, polysaccharides from Prunus amygdalus shell were extracted sequentially by water, ammonium oxalate and hydrochloric acid. The monosaccharide composition of polysaccharides fractions was performed by GC-MS. Water-soluble polysaccharide was found to be the most effective extracting agent with an extracted yield of 9%. The acid Soluble Polysaccharides (ASP) exhibited the highest galacturonic acid content (31.95%), the highest polysaccharides extractability (88.57%) and the lowest degree of esterification (31.76%). The different polysaccharides fractions were characterized by FTIR, 1H NMR and SEC/MALS/VD/DRI. The antioxidant tests (DPPH, ABTS and FRAP) indicated that ASP showed even better antioxidant activities. Moreover, the result of the antiproliferative activity against Caco-2 and B-16 cells showed that ASP exhibited strong cytotoxicity ability which confirmed that the Prunus amygdalus peels may comprise the natural raw materials for new drug and functional food.

Optimized extraction of pectin-like polysaccharide from Suaeda fruticosa leaves: Characterization, antioxidant, anti-inflammatory and analgesic activities.

Box-Behnken design (BBD) was performed via ultrasound-assisted system to optimize extraction yield and total antioxidant ability of polysaccharides from Suaeda fruticosa. Three independent variables were studied: temperature, time and pH with optimal settings 90 °C, 37 min and 2.9, respectively. Under these settings, isolation yield and total antioxidant activity were 34.0% and 31.8 mg ascorbic acid equivalent/g material, respectively. Furthermore, preliminary structure study was carried out using UV-vis analysis, Fourier transform infrared spectroscopy (FT-IR) and Nuclear magnetic resonance (1D (1H, 13C NMR) and 2D (1H, 1H COSY, 1H/13C HSQC)) methods Size exclusion chromatography (SEC) determination revealed that polysaccharide extracted had an average molecular weight of 240 kDa. Chemical composition analyses showed that extracted polysaccharide was a pectin-like polysaccharide with uronic acid content (47.5%) and neutral monosaccharides (52.5%) constituted mainly of arabinose, mannose, galactose, rhamnose, glucose and xylose in the molar percentage of 48.63%, 5.85%, 29.42%, 7.96%, 6.54% and 1.60%, respectively. This sugar composition was typical of that of a galactoarabinan. Importantly, the optimum polysaccharide possesses significant potentials in antioxidant activity effect. Moreover, pharmacological investigation of extracted polysaccharide revealed a good anti-inflammatory effect and interesting peripheral as well as central antinociceptive activities.

Value of water enema computed tomography in elderly symptomatic patients.

BACKGROUND AND STUDY AIMS: Colonoscopy remains the gold standard for the examination of the colon. However, its use in the elderly is not well tolerated, and there is often a need for general anaesthesia, thus increasing the risk, especially if there are co-morbidities. Water enema computed tomography has been suggested to be a satisfactory alternative as a non-invasive, fast and effective means for the diagnosis of colorectal supra-centimetric lesions. The aim of our study was to assess the performance of water enema computed tomography as first-line examination by calculating its negative predictive value (NPV) for the diagnosis of supra-centimetric lesions in symptomatic elderly referred to colonoscopy. PATIENTS AND METHODS: This was a prospective study including 57 symptomatic patients older than 65 years. All patients were explored by water enema computed tomography at first, followed by colonoscopy, and responded to a questionnaire on the tolerance to the preparation and both procedures. RESULTS: The mean age of patients was 73 years. The M:F sex ratio was 1.59. The most frequent indication for colonoscopy was bowel disorders associated with abdominal pain (30%). Water enema computed tomography allowed the diagnosis of tumours (n = 2), polyps (n = 6), diverticulosis (n = 7), inflammatory wall thickening (n = 1) and extra-colic lesions (n = 28). NPV of water enema computed tomography for supra-centimetric lesions was 96.5%. Sensitivity and specificity were 87.3% and 98%, respectively. However, for sub-centimetric lesions, water enema computed tomography had a low sensitivity estimated at 6%, specificity at 89.9%, positive predictive value at 91.9% and NPV at 27.7%. CONCLUSION: Water enema computed tomography has proven to be a valuable and non-invasive method indicated as a first-line examination in case of colonic symptoms in the elderly to diagnose supra-centimetric lesions.