Khaled Athmouni

Box-Behnken design for extraction optimization of crude polysaccharides from Tunisian Phormidium versicolor cyanobacteria (NCC 466): Partial characterization, in vitro antioxidant and antimicrobial activities

In this study, response surface methodology (RSM) based on Box-Behnken design (BBD) was employed to optimize the aqueous extraction of crude polysaccharides from Tunisian cyanobacteria Phormidium versicolor (NCC 466). The optimal extraction conditions with an extraction yield of 21.56±0.92% were as follows: extraction temperature at 81.05°C, extraction time of 3.99h, and water to raw material ratio of 21.52mLg-1. Crude Phormidium versicolor polysaccharides (CPv-PS) are found to be a hetero-sulfated-anionic polysaccharides that contained carbohydrate (79.37±1.58%), protein (0.45±0.11%), uronic acids (4.37±0.19%) and sulfate (6.83±0.28%). The carbohydrate fraction was composed of arabinose, xylose, ribose, rhamnose, N-acetyl glucosamine, galactose, glucose, mannose, glucuronic acid and saccharose with corresponding mole percentages of 2.41, 14.58, 2.18, 6.23, 7.04, 28.21, 26.04, 3.02, 0.86 and 5.07, respectively. Evaluation of the antioxidant activity in vitro suggested that CPv-PS strongly scavenged radicals, prevented bleaching of β-carotene and reduced activity. Furthermore, the CPv-PS exhibited effective antimicrobial properties.

Chemicals Compositions, Antioxidant and Anti-Inflammatory Activity of Cynara scolymus Leaves Extracts, and Analysis of Major Bioactive Polyphenols by HPLC

Objective. Artichoke (Cynara scolymus L.) was one of the plant remedies for primary health care. The present study was focused on the determination of chemical composition, antioxidant activities, and anti-inflammatory activity and on analyzing its major bioactive polyphenols by HPLC. Methods. Artichoke Leaves Extracts (ALE) were analyzed for proximate analysis and phytochemical and antioxidant activity by several methods such as DDPH, ABTS, FRAP, and beta-carotene bleaching test. The carrageenan (Carr) model induced paw oedema in order to investigate the anti-inflammatory activity. Identification and quantification of bioactive polyphenols compounds were done by HPLC method. The oxidative stress parameters were determined; CAT, SOD, GSH, MDA, and AOPP activities and the histopathological examination were also performed. Results. It was noted that EtOH extract of ALE contained the highest phenolic, flavonoid, and tannin contents and the strongest antioxidants activities including DDPH (94.23%), ABTS (538.75 mmol), FRAP assay (542.62 umol), and β-carotene bleaching (70.74%) compared to the other extracts of ALE. Administration of EtOH extract at dose 400 mg/kg/bw exhibited a maximum inhibition of inflammation induced by Carr for 3 and 5 hours compared to reference group Indomethacin (Indo). Conclusion. ALE displayed high potential as natural source of minerals and phytochemicals compounds with antioxidant and anti-inflammatory properties.

Estrogenic compounds in Tunisian urban sewage treatment plant: occurrence, removal and ecotoxicological impact of sewage discharge and sludge disposal

The occurrence, fate and ecotoxicological assessment of selected estrogenic compounds were investigated at Tunisian urban sewage treatment plant. The influents, effluents, as well as primary, secondary and dehydrated sludge, were sampled and analyzed for the target estrogens to evaluate their fate. All target compounds were detected in both sewage and sludge with mean concentrations from 0.062 to 0.993 μg L−1 and from 11.8 to 792.9 μg kg−1dry weight, respectively. A wide range of removal efficiencies during the treatment processes were observed, from 6.3 % for estrone to 76.8 % for estriol. Ecotoxicological risk assessment revealed that the highest ecotoxicological risk in sewage effluent and dehydrated sludge was due to 17β-estradiol with a risk quotient (RQ) of 4.6 and 181.9, respectively, and 17α-ethinylestradiol with RQ of 9.8 and 14.85, respectively. Ecotoxicological risk after sewage discharge and sludge disposal was limited to the presence of 17β-estradiol in dehydrated-sludge amended soil with RQ of 1.38. Further control of estrogenic hormones in sewage effluent and sludge is essential before their discharge and application in order to prevent their introduction into the natural environment.

The Potential of a Brown Microalga Cultivated in High Salt Medium for the Production of High-Value Compounds

Amphora sp. was isolated from the Sfax Solar Saltern and cultivated under hypersaline conditions. It contains moderate rates of proteins, lipids, sugars, and minerals and a prominent content of bioactive compounds: polyphenols, chlorophyll a, carotenoids, and fatty acids. The analysis of fatty acids with GC/MS showed that the C16 series accounted for about 75% of Amphora sp. lipids. Saturated fatty acids whose palmitic acid was the most important (27.41%) represented 41.31%. Amphora sp. was found to be rich in monounsaturated fatty acids with dominance of palmitoleic acid. It also contains a significant percentage of polyunsaturated fatty acids with a high amount of eicosapentaenoic acid (2.36%). Among the various solvents used, ethanol at 80% extracted the highest amounts of phenols and flavonoids that were 38.27 mg gallic acid equivalent and 17.69 mg catechin equivalent g−1 of dried extract, respectively. Using various in vitro assays including DPPH and ABTS radicals methods, reducing power assay, and β-carotene bleaching assay, the 80% ethanolic extract showed high antioxidant activity. A strong antibacterial activity was checked against Gram-positive bacteria (Staphylococcus aureus and Micrococcus luteus) and Gram-negative bacteria (Klebsiella pneumoniae and Salmonella enterica). These results are in favor of Amphora sp. valorization in aquaculture and food and pharmaceutical industries.

Phenolic compounds analysis, antioxidant, and hepatoprotective effects of Periploca angustifolia extract on cadmium-induced oxidative damage in HepG2 cell line and rats

Abstract A total of five components (Catechin, Caffeic acid, Ferulic acid, Rosmarinic acid, and Amentoflavone) were identified in Periploca angustifolia leaf methanolic extract. This extract did not cause any cytotoxic effect on HepG2 cell line within the range of concentrations tested (0–400 µg mL−1). Thus, pre-treatment with 100 µg mL−1 of P. angustifolia leaf methanolic extract (PAE) significantly (p < .05) protective HepG2 cells against cytotoxicity induced by cadmium exposure. However, Cd-intoxication significantly (p < .05) increased alanine and aspartate amino transferases serum activities (ALT and AST) and bilirubin content by 1.85-, 1.13-, and 3.55-fold, respectively. The levels of hepatic antioxidant parameters including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were significantly (p < .05) decreased in Cd-intoxicated rats with concomitant enhancement of lipid peroxidation. Our results showed that P. angustifolia leaf methanolic extract can induce antioxidant effects and also exerts beneficial effects for the treatment of Cd-induced hepatotoxicity.

Optimization, antioxidant properties and GC/MS analysis of Periploca angustifolia polysaccharides and chelation therapy on cadmium-induced toxicity in human HepG2 cells line and rat liver

The extraction of Periploca polysaccharides (PAPS) was optimized using the response surface methodology. The influence of solvent, liquid-solid ratio and extraction time on polysaccharide yield was evaluated using a full factorial design (23). Also, PAPS extract did not induce a cytotoxic effect on HepG2 cells within the range of tested concentrations (0-250μgmL-1). Herein, the pre-treatment with PAPS extract (100μgmL-1) reduced cell mortality. Furthermore, the in vivo antioxidant activity of PAPS extract was investigated in rats. The oral administration of 250mgkg-1 body weight of PAPS extract administered above a period of 10 weeks to cadmium chloride (CdCl2) induced toxicity in male Wistar rats, markedly decreased the content of MDA and protein damage in liver tissue, and enhanced liver function parameters (ALAT, ASAT and bilirubin), as well as the activities of hepatic antioxidant status (SOD, CAT, GPx and GSH). Finally, the examination of liver histopathology confirmed that PAPS ameliorate the alteration of liver tissue caused by exposition to cadmium.

Polysaccharides from Phormidium versicolor (NCC466) protecting HepG2 human hepatocellular carcinoma cells and rat liver tissues from cadmium toxicity: Evidence from in vitro and in vivo tests

The in vitro antioxidant, cytotoxic and cytoprotective properties and in vivo hepatoprotective activities of crude polysaccharides extracted from cyanobacteria Phormidim versicolor NCC466 (CFv-PS) were investigated. The CFv-PS, identified as heteropolysaccharides with molecular weight of 63.79kDa, exhibited relatively strong antioxidant activity, in a concentration-depended manner, in vitro assays. Additionally, CFv-PS did not induce cytotoxic effect on HepG2 human hepatocellular carcinoma cells within the range of tested concentrations (25-150μg·mL-1) while preventing them against Cd. Moreover, in rats subjected to Cd-induced hepatotoxicity, CFv-PS pretreatment significantly (P<0.05) reduced the level of ALAT, ASAT, biliburin, MDA, protein carbonyl and DNA damage, and markedly increased enzyme activities in liver tissues. These findings suggest that the cyanobacteria Phormidium versicolor is a potential source of natural products possessing antioxidant, cytoprotective and hepatoprotective properties.

Optimization, antioxidant potential, modulatory effect and anti-apoptotic action in of Euphorbia bivonae polysaccharides on hydrogen peroxide-induced toxicity in human embryonic kidney cells HEK293

For the first time, we have determined the effect of solvent, liquid-solid ratio and extraction time on polysaccharides yield was evaluated using a full factorial design (23). In this present investigation, a total of 7 molecules were determined in this species. In our analysis saccharose was the dominant monosaccharides. Arabinose, pyranose, fructose, glucose, inositol, saccharose and trehalose found in E. bivonae. The results of the in vitro antioxidant assay showed that the EBPS have higher antioxidant capacity. Accordingly, the HEK293 cells pre-treated with EBPS compounds (100 μg·mL-1) enhanced cell viability against H2O2 exposure. Our results revealed that H2O2-exposure induced a significant increase in intracellular ROS and lipid peroxidation in HEK293 cells. Additionally, the H2O2-induced alteration in HEK293 cells morphology, was ameliorated by EBPS treatment. In addition, EPBS pre-treated cells significantly enhanced the activities of HEK293 cells antioxidant status (SOD, CAT, GPx and GSH) that were decreased after hydrogen peroxide exposure.

Development of catechin–phospholipid complex to enhance the bioavailability and modulatory potential against cadmium-induced oxidative stress in rats liver

Abstract The natural flavonoid (catechin) has been shown to possess a multitude of pharmacological activities. However, oral administrated catechin (CT) failed to fulfil its therapeutic potential due to poor absorption and low bioavailability. Thus, is a pressing need to develop a new approach from to increase its intestinal absorption and improved bioavailability. In this work, we intended the increase the bioavailability of CT by preparing catechin-phospholipid complex (CT–PH) and evaluate the protective effect of CT–PH complex against cadmium caused liver injuries in rats. Oral bioavailability of CT and CT–PH complex was evaluated in rats and the plasma CT was estimated by HPLC analysis. The greater absorption of CT–PH complex rats indicated that improved bioavailability. Liver function markers, lipid peroxidation, protein oxidation, antioxidant status and histopathological changes were determined in normal and treated rats. Moreover, biochemical analysis and histopathological examinations indicated that CT–PH provided better protection to rat liver than free CT.

Effect of 17α-Ethinylestradiol Exposure on Phycocyanin Metabolite Production and Antioxydant System of Phormidium Versicolor NCC466

With the growing release of endocrine dustrupting chemicals such as 17α-ethinylestradiol (EE2) into aquatic ecosystems in recent years (Belhaj et al. in Environ Sci Pollut Res 24(8):7392–7402, 2015), concerns have been raised about their potential toxicity to aquatic organism.