Pharmacological and chemical properties of some marine echinoderms

Echinoderms have attracted the attention of scientists over the past few years after identifying a variety of unique structures endowed by interesting biological properties. However, the Moroccan coast biodiversity is still uninvestigated. In our ongoing attempts to valorize the rich Moroccan marine environment, this study aimed at assessing the antimicrobial activity of extracts obtained from three echinoderms Astropecten irregularis, Luidia sarsi and Ophiura albida against the human pathogens: Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica and Bacillus subtilis. Moreover, their antioxidant activities were tested using standard methods in addition to the antidiabetic activity which has been evaluated in vitro against α-amylase and α-glucosidase enzymes. HPLC-DAD-QTOF-MS analysis revealed a significant content of some phenolic compounds such as pyrogallol, gallic, sinapic, ferulic, p-hydroxybenzoic and salicylic acids whose existence can be related to the endophytic fungi and/or dietary intake whereas GC-MS analysis exhibited diverse chemical structures such as cholesterol, oleic acid and glycerol 1-palmitate

Функціональні зв'язки між ефектами води Нафтуся на канальцеву секреторно-транспортну та імунну системи щурів. Повідомлення 2: Канальцева секреція і параметри спленоцитограми та гемолімфоаденоцитограми

В рамках концепции об общности механизмов функционирования канальцевой секреторно-транспортной и фагоцитарно-лимфоидной систем выявлены существенные связи между скоростью почечной канальцевой секреции и параметрами фагоцитоза, лейкоцитограммы крови, стеноцитогаммы и гемолимфоаденоцитограммы крыс в условиях курсового напаивания их водой Нафтуся per se и в сочетании с цитостатиком или анаболиком.It is shown that increase of canalicular secretion in rats becaused by drinking of water Naftussya accompanied increase massa of haemolymphatic node and contents in its of endothelio-, reticulo-, lymphocytes, eosinophyles and macrophages, blood level lymphocytes, monocytes and segmental nucleare neutrophyles but decrease activity and completion of phagocytose of neutrophyles and level of lymphoblastes in splenocytogramme. The using of cytostatic drug abolishes but anabolic drug potentiates both activating and inhibiting influence of water Naftussya

Antimicrobial Photodynamic Therapy: Study of Bacterial Recovery Viability and Potential Development of Resistance after Treatment

Antimicrobial photodynamic therapy (aPDT) has emerged in the clinical field as a potential alternative to antibiotics to treat microbial infections. No cases of microbial viability recovery or any resistance mechanisms against it are yet known. 5,10,15-tris(1-Methylpyridinium-4-yl)-20-(pentafluorophenyl)-porphyrin triiodide (Tri-Py+-Me-PF) was used as photosensitizer. Vibrio fischeri and recombinant Escherichia coli were the studied bacteria. To determine the bacterial recovery after treatment, Tri-Py+-Me-PF (5.0 μM) was added to bacterial suspensions and the samples were irradiated with white light (40 W m−2) for 270 minutes. Then, the samples were protected from light, aliquots collected at different intervals and the bioluminescence measured. To assess the development of resistance after treatment, bacterial suspensions were exposed to white light (25 minutes), in presence of 5.0 μM of Tri-Py+-Me-PF (99.99% of inactivation) and plated. After the first irradiation period, surviving colonies were collected from the plate and resuspended in PBS. Then, an identical protocol was used and repeated ten times for each bacterium. The results suggest that aPDT using Tri-Py+-Me-PF represents a promising approach to efficiently destroy bacteria since after a single treatment these microorganisms do not recover their viability and after ten generations of partially photosensitized cells neither of the bacteria develop resistance to the photodynamic process

Photodynamic Antimicrobial Chemotherapy in Aquaculture: Photoinactivation Studies of Vibrio fischeri

BACKGROUND: Photodynamic antimicrobial chemotherapy (PACT) combines light, a light-absorbing molecule that initiates a photochemical or photophysical reaction, and oxygen. The combined action of these three components originates reactive oxygen species that lead to microorganisms' destruction. The aim was to evaluate the efficiency of PACT on Vibrio fischeri: 1) with buffer solution, varying temperature, pH, salinity and oxygen concentration values; 2) with aquaculture water, to reproduce photoinactivation (PI) conditions in situ. METHODOLOGY/PRINCIPAL FINDINGS: To monitor the PI kinetics, the bioluminescence of V. fischeri was measured during the experiments. A tricationic meso-substituted porphyrin (Tri-Py(+)-Me-PF) was used as photosensitizer (5 µM in the studies with buffer solution and 10-50 µM in the studies with aquaculture water); artificial white light (4 mW cm(-2)) and solar irradiation (40 mW cm(-2)) were used as light sources; and the bacterial concentration used for all experiments was ≈10(7) CFU mL(-1) (corresponding to a bioluminescence level of 10(5) relative light units--RLU). The variations in pH (6.5-8.5), temperature (10-25°C), salinity (20-40 g L(-1)) and oxygen concentration did not significantly affect the PI of V. fischeri, once in all tested conditions the bioluminescent signal decreased to the detection limit of the method (≈7 log reduction). The assays using aquaculture water showed that the efficiency of the process is affected by the suspended matter. Total PI of V. fischeri in aquaculture water was achieved under solar light in the presence of 20 µM of Tri-Py(+)-Me-PF. CONCLUSIONS/SIGNIFICANCE: If PACT is to be used in environmental applications, the matrix containing target microbial communities should be previously characterized in order to establish an efficient protocol having into account the photosensitizer concentration, the light source and the total light dose delivered. The possibility of using solar light in PACT to treat aquaculture water makes this technology cost-effective and attractive

Engineering of cyclodextrin glucanotransferases and the impact for biotechnological applications

Cyclodextrin glucanotransferases (CGTases) are industrially important enzymes that produce cyclic α-(1,4)-linked oligosaccharides (cyclodextrins) from starch. Cyclodextrin glucanotransferases are also applied as catalysts in the synthesis of glycosylated molecules and can act as antistaling agents in the baking industry. To improve the performance of CGTases in these various applications, protein engineers are screening for CGTase variants with higher product yields, improved CD size specificity, etc. In this review, we focus on the strategies employed in obtaining CGTases with new or enhanced enzymatic capabilities by searching for new enzymes and improving existing enzymatic activities via protein engineering

Geographic distribution of MERS coronavirus among dromedary camels, Africa

We found serologic evidence for the circulation of Middle East respiratory syndrome coronavirus among dromedary camels in Nigeria, Tunisia, and Ethiopia. Circulation of the virus among dromedaries across broad areas of Africa may indicate that this disease is currently underdiagnosed in humans outside the Arabian Peninsula

Fail-safe digital implementation of indirect field oriented controlled induction motor drive

International audienc

Staphylococcus aureus photodynamic inactivation mechanisms by rose bengal: use of antioxidants and spectroscopic study

Abstract This study aims to follow the photodynamic and spectroscopic properties of dianionic rose Bengal disodium salt (RB) on Staphylococus aureus (S. aureus) in phosphate buffer solution (PBS) at pH 7.3. It focused on: (1) the effect of several reactive oxygen species (ROS) antioxidants used [such as sodium azide (NaN3), l-tryptophan (l-Trp) and d-mannitol] on the RB photodynamic efficiency as a mean to identify the main ROS attributed, and (2) the possible interactions of the RB with the important singlet oxygen quencher used namely tryptophan and/or between the dye and the bacteria S. aureus thanks to a spectroscopic study. The results showed that 20 µM of RB and 10 min of visible light (50 mW/cm2) with a light fluence dose of 30 J/cm2 are crucial for a good photodynamic action, achieving a reduction of 79.4% in the viability. Rose Bengal photodynamic action was in part inhibited by D-mannitol and l-Trp, indicating the mediation by.OH and 1O2, respectively. The high inhibition of the RB activity against S. aureus by l-Trp is not due only to its singlet oxygen quencher ability but it is mainly due to the interaction between RB and l-Trp as shown spectrophotometrically

Destruction photodynamique des oeufs de Taeniidés et de Toxocara sp. dans l'eau

Dans le but de mettre en évidence l'effet de la photosensibilisation sur les formes de résistance de parasites, qui se retrouvent dans des eaux partiellement épurées ou brutes à des concentrations variables, nous avons été amenés à les isoler dans de l'eau distillée. Ceci nous a permis de rendre compte des effets directs qu'ils peuvent contracter lors de la photosensibilisation et de mieux gérer les différents paramètres qui y interviennent. Dans le présent travail, nous nous sommes intéressés à l'étude des mécanismes photodynamiques de la photosensibilisation sur des formes infectantes de parasites (notamment oeufs de Taeniidés et Toxocara sp.), par photosensibilisants (RB, BM, T4MPyP) libres dans la solution ou fixés sur support par une résine. Ainsi, nous avons contribué à élucider les processus photoinactivateurs des oeufs d'helminthes en fonction des différentes conditions expérimentales. Nous avons étudié dans un premier temps, l'effet photosensibilisant notamment selon le mécanisme Type I de la photosensibilisation (autres espèces réactives de l'oxygène tel que le radical hydroxyle -OH), Type II (production de l'1O2) et par effet contact, de 3 composés appartenant à différents groupes de colorants [rose bengale (RB), bleu de méthylène (BM), porphyrine tétracationique (T4MPyP)], mis en solution dans de l'eau distillée en présence d'une suspension d'oeufs de parasites. L'observation microscopique a montré que les pourcentages d'oeufs de Taeniidés fracturés dans de l'eau distillée, atteignaient 31,5 % pour une concentration relativement élevée de l'ordre de 450 ± 49 oeufs par ml en suspension avec la T4MPyP (20 µM), après 120 min d'exposition à la lumière visible artificielle sous une intensité lumineuse instantanée de 500 W.m2. Le pourcentage le plus élevé est obtenu en présence de la T4MPyP, suivi du RB et du BM. Ces mêmes résultats ont montré que les oeufs de Taeniidés sont plus sensibles à la photosensibilisation que les oeufs de Toxocara sp. Par ailleurs, pour distinguer la prédominance des réactions de Type II faisant intervenir l'oxygène singulet des autres entités radicalaires, des expérimentations ont été entreprises avec des Ps fixés sur support (photosensibilisation indirecte). Les Ps sont fixés par une résine sur les parois du réacteur. Les résultats ont montré que la T4MPyP fixée permet d'enregistrer des pourcentages de fracturation des oeufs de Taeniidés de l'ordre de 30 ± 2 % après 60 min d'exposition à la lumière visible artificielle (500 W.m2), suivie du RB et du BM. Dans les mêmes conditions, des pourcentages de fracturation moins importants ont été obtenus pour les oeufs de Toxocara sp. notamment durant les trois premières heures d'exposition aux irradiations visibles artificielles. Les Ps fixés sur les parois du réacteur, sans entrer en contact direct avec la cible, arrivent à endommager les oeufs de Taeniidés et de Toxocara et à provoquer leur cassure. Ces observations dans l'eau distillée, pourraient mettre en évidence le deuxième mécanisme de réaction de la photosensibilisation (Type II). En plus, les oeufs de Toxocara étaient devenus plus sensibles par rapport aux oeufs de Taeniidés et ceci à la suite d'une prolongation du temps d'exposition à la lumière