A Novel Digestive α-Amylase from Blue Crab (<i>Portunus</i> <i>segnis</i>) Viscera: Purification, Biochemical Characterization and Application for the Improvement of Antioxidant Potential of Oat Flour

This study reports on the purification and characterization of a digestive α-amylase from blue crab (Portunussegnis) viscera designated Blue Crab Amylase (BCA). The enzyme was purified to homogeneity by ultrafiltration, Sephadex G-100 gel filtration and Sepharose mono Q anion exchange chromatography, with the final purification fold of 424.02, specific activity of 1390.8 U mg−1 and 27.8% recovery. BCA, showing a molecular weight of approximately 45 kDa, possesses desirable biotechnological features, such as optimal temperature of 50 °C, interesting thermal stability which is enhanced in the presence of starch, high stability towards surfactants (Tween 20, Tween 80 and Triton X-100), high specific activity, quite high storage and broad pH range stability. The enzyme displayed Km and Vmax values, of 7.5 ± 0.25 mg mL−1 and 2000 ± 23 μmol min−1 mg−1 for potato starch, respectively. It hydrolyzed various carbohydrates and produced maltose, maltotriose and maltotetraose as the major end products of starch hydrolysis. In addition, the purified enzyme was successfully utilized for the improvement of the antioxidant potential of oat flour, which could be extended to other cereals. Interestingly, besides its suitability for application in different industrial sectors, especially food industries, the biochemical properties of BCA from the blue crab viscera provide novel features with other marine-derived enzymes and better understanding of the biodegradability of carbohydrates in marine environments, particularly in invasive alien crustaceans

A Novel Digestive α-Amylase from Blue Crab (Portunus segnis) Viscera: Purification, Biochemical Characterization and Application for the Improvement of Antioxidant Potential of Oat Flour

This study reports on the purification and characterization of a digestive &alpha;-amylase from blue crab (Portunussegnis) viscera designated Blue Crab Amylase (BCA). The enzyme was purified to homogeneity by ultrafiltration, Sephadex G-100 gel filtration and Sepharose mono Q anion exchange chromatography, with the final purification fold of 424.02, specific activity of 1390.8 U mg&minus;1 and 27.8% recovery. BCA, showing a molecular weight of approximately 45 kDa, possesses desirable biotechnological features, such as optimal temperature of 50 &deg;C, interesting thermal stability which is enhanced in the presence of starch, high stability towards surfactants (Tween 20, Tween 80 and Triton X-100), high specific activity, quite high storage and broad pH range stability. The enzyme displayed Km and Vmax values, of 7.5 &plusmn; 0.25 mg mL&minus;1 and 2000 &plusmn; 23 &mu;mol min&minus;1 mg&minus;1 for potato starch, respectively. It hydrolyzed various carbohydrates and produced maltose, maltotriose and maltotetraose as the major end products of starch hydrolysis. In addition, the purified enzyme was successfully utilized for the improvement of the antioxidant potential of oat flour, which could be extended to other cereals. Interestingly, besides its suitability for application in different industrial sectors, especially food industries, the biochemical properties of BCA from the blue crab viscera provide novel features with other marine-derived enzymes and better understanding of the biodegradability of carbohydrates in marine environments, particularly in invasive alien crustaceans

Olive oil by‑product’s contribution to the recovery of phenolic compounds from microalgal biomass: biochemical characterization, anti‑melanogenesis potential, and neuroprotective effect

Recently, the use of microalgae in the treatment of olive mill wastewater as a safe method for reducing pollutants has gained more attention. However, the contribution of such by-product to the improvement of the pharmacological properties addressing the health benefits of Scenedesmus sp., as a cosmetic remedy or food ingredient, is not sufficiently available. To address this issue, Scenedesmus sp. was cultivated in BG11 medium enriched or not with 20% of ultra-filtrated olive mill wastewater (UFOMW) and polyphenols were then extracted, identified, and quantified by HPLC–DAD analysis. Their antioxidant capacity, enzymatic inhibition, potential in inhibiting lysozyme aggregation, B16 and HeLa cell proliferation, cytotoxic effect against healthy cells, and their intracellular anti-melanogenic effect were assessed, up to our knowledge, for the first time in this study. The addition of UFOMW enhanced the production and apparition of some phenolic compounds with low cytotoxicity on normal versus cancer cells. UFOMW improved the antioxidant capacity and promoted melanogenesis, enzyme, and lysozyme inhibition. Interestingly, Scenedesmus sp. cultured in the presence of UFOMW may provide a valuable source of safe antioxidants with an enhanced biological potential that can be commercially exploited in the food and/or pharmaceutical industries.This work was supported by the PEER project-Cycle 6, USAID-NAS, Grant number 308, “Evaluation of algal treatment options for olive mill wastewater to produce energy and biofertilizer.

Contribution of major polyphenols to the antioxidant profile and cytotoxic activity of olive leaves

Aims: This study was designed to investigate the phytochemical profile and the cytotoxic activities of the eco-friendly extracts of olive leaves from Chemlali cultivar. Materials and Methods: The Phenolic composition of olive leaves extracts, the antioxidant activity and the cytotoxic effects against MCF-7 and HepG2 cells were determined. Results: Olive leaves extracts showed relevant total polyphenols contents. Oleuropein was the major detected phenolic compound reaching a concentration of 16.9 mg/ml. The antioxidant potential of the studied extracts varied from 23.7 to 46.5mM Trolox equivalents as revealed by DPPH and ABTS assays. Cytotoxicity experiments showed similar trends for both HepG2 and MCF-7 cells with the infusion extract being the most active. Conclusion: This study denotes that olive leaves may have great potential as endless bioresource of valuable bioactive compounds which may have a wide application. - 2019 Bentham Science Publishers.This work was supported by the Tunisian Ministery of Higher Education and Scientific Research under the contract program for Laboratory of Environmental Bioprocesses at Centre of Biotechnology of Sfax. This work was also partially supported by the JICA/JST Science and Technology Research Partnership for Sustainable Development (SATREPS) Project (A6A24087): �Valorization of Bio-resources in Semi-arid and Arid Land for Regional Development''.Scopu

Pistacia lentiscus L. Distilled Leaves as a Potential Cosmeceutical Ingredient: Phytochemical Characterization, Transdermal Diffusion, and Anti‐Elastase and Anti‐Tyrosinase Activities

The present work was performed to investigate the phenolic composition of P. lentiscus L. distilled leaves (PDL) and examine its potential against certain key enzymes related to skin aging. High‐pressure liquid chromatography coupled to mass spectrometry (HPLC‐MS) and various separation procedures combined with nuclear magnetic resonance (NMR) and MS analysis were performed to isolate and identify compounds present in the ethyl acetate extract (EAE) of PDL. A high amount of flavonol glycoside was detected in EAE. Indeed, quercetin‐3‐O‐rhamnoside (FC), myri-cetin‐3‐O‐rhamnoside (FM2), and kaempferol‐3‐O‐rhamnoside (FB2) were isolated from EAE, and are present in high quantities of 10.47 ± 0.26, 12.17 ± 0.74, and 4.53 ± 0.59 mg/g dry weight, respec-tively. A transdermal diffusion study was carried out to determine the EAE‐molecules that may transmit the cutaneous barrier and showed that FM2 transmits the membrane barrier with a high amount followed by FC. EAE, FM2, and FC were tested against tyrosinase and elastase enzymes. Moreover, intracellular tyrosinase inhibition and cytotoxicity on skin melanoma cells (B16) were evaluated. The results indicated that EAE, FC, and FM2 have important inhibitory activities com-pared to the well‐known standards, at non‐cytotoxic concentrations. Therefore, they could be excel-lent agents for treating skin pigmentation and elasticity problems.The authors are grateful to the Qatar National Research Fund (QNRF) for funding and supporting the M-NEX Project (grant no. BFSUGI01-1120-170005) in Qatar. The M-NEX is a project of the Collaborative Research Area Belmont Forum (no. 11314551)

Identification of compound heterozygous patients with primary hyperoxaluria type 1: clinical evaluations and in silico investigations

Abstract Background Primary hyperoxaluria type 1 (PH1) is an autosomal recessive inherited disorder of glyoxylate metabolism in which excessive oxalates are formed by the liver and excreted by the kidneys. Calcium oxalate crystallizes in the urine, leading to urolithiasis, nephrocalcinosis, and consequent renal failure if treatment is not initiated promptly. Mutations in the AGXT gene which encodes the hepatic peroxisomal enzyme alanine:glyoxylate aminotransferase are responsible of PH1. In the present work, we aimed to analyze AGXT gene and in silico investigations performed in four patients with PH1 among two non consanguineous families. Methods Exhaustive gene sequencing was performed after PCR amplification of coding exons and introns boundaries. Bioinformatic tools were used to predict the impact of AGXT variants on gene expression as well as on the protein structure and function. Results Direct sequencing of all exons of AGXT gene revealed the emergence of multiple mutations in compound heterozygous state in the two studied families. Two patients were compound heterozygous for the c.731 T > C, c.32C > T, c.1020A > G and c.33_34insC and presented clinically with recurrent urinary tract infection, multiple urolithiasis and nephrocalcinosis under the age of 1 year and a persistent hyperoxaluria at the age of diagnosis. The two other patients presenting a less severe phenotypes were heterozygous for c.731 T > C and homozygous for the c.32C > T and c.1020A > G or compound heterozygous for c.26C > A and c.65A > G variants. Conclusion In Summary, we provided relevance regarding the compound heterozygous mutations in non consanguineous PH1 families with variable severity

Pistacia lentiscus by-product as a promising source of phenolic compounds and carotenoids: Purification, biological potential and binding properties

The hydro-distilled leaves of Pistacia lentiscus are considered as an agricultural residue and of no commercial value yet. In this study, chromatographic purification of a methanolic fraction of P. lentiscus L. (lentisk) distilled leaves yielded pure compounds, including Quercitrin (QUE) and Loliolid (LOL) which are characterized, for the first time, in the lentisk leaves’ residue. The inhibitory potential of QUE and LOL was investigated against tyrosinase and acetylcholinesterase activities using enzymatic assays and lysozyme fibrillation through Thioflavin-T fluorescence assay. Their binding mode to Bovine Serum Albumin (BSA) was also assessed by several spectroscopic analyses. Results show that QUE was more potent to inhibit enzyme activity than LOL. Besides, the Thioflavin-T assay confirmed that only QUE was able to block the fibril formation at a concentration of 25 μg/mL. Furthermore, the BSA quenching mechanism by QUE and LOL is a static process with conformational changes in BSA. Interestingly, our findings may provide novel insights into the potentiality of lentisk to be used as a bioresource for the generation of Quercitrin and Loliolid which can be commercially exploited in the field of cosmeceuticals and nutraceuticals

Biotransformation of the fluoroquinolone, levofloxacin, by the white-rot fungus Coriolopsis gallicaCoriolopsis\ gallica

International audienceThe wastewater from hospitals, pharmaceutical industries and more generally human and animal dejections leads to environmental releases of antibiotics that cause severe problems for all living organisms. The aim of this study was to investigate the capacity of three fungal strains to biotransform the fluoroquinolone levofloxacin. The degradation processes were analyzed in solid and liquid media. Among the three fungal strains tested, $Coriolopsis\ gallica$ strain CLBE55 (BRFM 3473) showed the highest removal efficiency, with a 15% decrease in antibiogram zone of inhibition for Escherichia coli cultured in solid medium and 25% degradation of the antibiotic in liquid medium based on high-performance liquid chromatography (HPLC). Proteomic analysis suggested that laccases and dye-decolorizing peroxidases such as extracellular enzymes could be involved in levofloxacin degradation, with a putative major role for laccases. Degradation products were proposed based on mass spectrometry analysis, and annotation suggested that the main product of biotransformation of levofloxacin by $Coriolopsis\ gallica$ is an N-oxidized derivative