Chemical and Biological Properties of Sodium Alginates Isolated from Tow Brown Algae Dictyopteris Membranaceae and Padina Pavonica

Polysaccharides are known to have interesting biological activities. To date polysaccharides extracted from Tunisian seaweed have not been fully studied. In this paper we tried to isolate sodium alginate from two brown algae and evaluate their biological activities. Two brown seaweeds Dictyopteris membranaceae and Padina pavonica were treated with selective solvents to extract sodium alginate. Analyses were performed to determine their IR spectra, uronic acid’s content and biological properties (antioxidant and gastroprotective activities). Results showed that sodium alginate extracted from D. membranaceae contained 65% of uronic acid while this extracted from P. pavonica contained only 9% of uronic acid. These polysaccharides showed also variation in the structure and the activities. Sodium alginate extracted from D. membranaceae had the highest antioxidant activity with ED50 of 20µg/ml in the DPPH test. Additionally, this polysaccharide had the most important gastroprotective activity with a percent of 97% at dose 50mg/kg. Our finding suggested that sodium alginates extracted from D. membranaceae and P. pavonica could be used as a natural source of antioxidant and gastroprotective agents. &nbsp

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Physico-chemical characterization and pharmacological evaluation of sulfated polysaccharides from three species of Mediterranean brown algae of the genus Cystoseira

International audienceBackgroundSeaweed polysaccharides are highly active natural substances having valuable applications. The present study was conducted to characterize the physico-chemical properties of sulphated polysaccharides from three Mediterranean brown seaweeds (Cystoseira sedoides, Cystoseira compressa and Cystoseira crinita) and to evaluate their anti-radical, anti-inflammatory and gastroprotective activities.MethodsThe different rates of neutral sugars, uronic acids, L-fucose and sulphate content were determined by colorimetric techniques. The different macromolecular characteristics of isolated fucoidans were identified by size exclusion chromatography equipped with a triple detection: multiangle light scattering, viscometer and differential refractive index detectors, (SEC/MALS/VD/DRI). Anti-inflammatory activity was evaluated, using the carrageenan-induced rat paw edema test in comparison to the references drugs Acetylsalicylate of Lysine and Diclofenac. The gastroprotective activity was determined using HCl/EtOH induced gastric ulcers in rats and to examine the antioxidant effect of fucoidans in the three species, the free radical scavenging activity was determined using 1,1-diphenyl-2-picrylhydrazyl.ResultsThe pharmacological evaluation of the isolated fucoidans for their anti-inflammatory, and their gastroprotective effect established that these products from C. sedoides, C. compressa and C. crinita exhibited a significant anti-inflammatory activity at a dose of 50 mg/kg, i.p; the percentages of inhibition of the oedema were 51%, 57% and 58% respectively. And, at the same dose, these fucoidans from C. sedoides and C. compressa showed a significant decrease of the intensity of gastric mucosal damages compared to a control group by 68%, whereas, the fucoidan from C. crinita produced a less gastroprotective effect. Furthermore, the isolated fucoidans exhibited a radical scavenging activity.ConclusionThe comparative study of fucoidans isolated from three species of the genus Cystoseira showed that they have similar chemicals properties and relatives anti-radical, anti-inflammatory and gastroprotective activities which are found to be promising

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

International audienceAlginates 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 147,000 g/mol while it was 85,000 g/mol for alginate from Cystoseira compressa (ACC) and 58,000 g/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 50 mg/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

Characterization of sulfated polysaccharide from Laurencia obtusa and its apoptotic, gastroprotective and antioxidant activities

International audienceThis study was designed to characterize the physico-chemical properties of the sulfated polysaccharide (SP) isolated from the red alga Laurencia obtusa and to evaluate its apoptotic, gastroprotective and antioxidant activities.The different macromolecular characteristics of SP were determined by size exclusion chromatography combined with multi-angle laser light-scattering detection (SEC-MALLS), Fourier transform infrared spectroscopy (FTIR) analysis and nuclear magnetic resonance spectroscopy (1H NMR and 13C NMR). The native molecular weight of the extracted polysaccharide is high (≥336,900 g·mol−1). It showed high amounts of sulfated groups (28.2%) and low levels of proteins. It was found to be a potent inducer of apoptosis on acute monocytic leukaemia THP-1cell lines with EC50 value of 53 μg·mL−1. Furthermore, a significant gastroprotective effect (p < 0.01) was also observed with a gastric ulcer inhibition of 63.44%, 78.42% and 82.15% at the doses 25, 50 and 100 mg·kg−1, respectively. In addition, SP significantly increased glutathione levels (GSH) and decreased the concentration of thiobarbituric acid-reactive substances (TBARS) in EtOH/HCl-damaged gastric mucosa in rats; it also exhibited an important antioxidant activity in vitro. Therefore, SP, derived from the red alga Laurencia obtusa, may have a potential therapeutic effect against acute myeloid leukaemia and a beneficial potential as gastroprotective and antioxidant natural product