Potential of Exopolysaccharide from Porphyridium marinum to Contend with Bacterial Proliferation, Biofilm Formation, and Breast Cancer.

Exopolysaccharide (EPS) from marine microalgae are promising sources of a new generation of drugs. However, lot of them remain to be discovered and tested. In this study, EPS produced by Porphyridium marinum and its oligomers prepared by High Pressure Homogenizer have been tested for different biological activities, i.e., antibacterial, anti-fungal and antibiofilm activities on Candida albicans, as well as for their effects on the viability of murine breast cancer cells. Results have shown that all EPS samples present some biological activity. For antibacterial and antibiofilm activities, the native EPS exhibited a better efficiency with Minimum Inhibitory Concentration (MIC) from 62.5 µg/mL to 1000 µg/mL depending on the bacterial strain. For Candida albicans, the biofilm formation was reduced by about 90% by using only a 31.3 µg/mL concentration. Concerning breast cancer cells, lower molar masses fractions appeared to be more efficient, with a reduction of viability of up to 55%. Finally, analyses of polymers composition and viscosity measurements were conducted on all samples, in order to propose hypotheses involving the activities caused by the intrinsic properties of polymers.

Deciphering the Biological Activities of Dunaliella sp. Aqueous Extract from Stressed Conditions on Breast Cancer: from in Vitro to in Vivo Investigations.

In order to harness local resources to improve well-being and human health, we aim in this study to investigate if the microalgae Dunaliella sp. isolated from the Tunisian coastal zone possesses any anticancer activity. Dunaliella sp. was cultured under normal (DSC) or stressed (DSS) conditions and extracted using different procedures. The biological activity assessment was performed on the Triple Negative Breast Cancer (TNBC) using 4T1 murine cells as a model. Results indicate that: (i) aqueous extract was the most cytotoxic compared to ethanolic and hydroalcoholic extracts; (ii) DSS activity was superior to that of DSC. DSS extracts induced apoptosis rather than necrosis, as evidenced by DNA fragmentation, PARP-1 cleavage and caspase-3 activation. Evaluation in an orthotopic TNBC model validated the anticancer activity in vivo. Intratumoral injection of DSS extract resulted in reduced tumor growth and an enhanced immune system activation. On the transcriptional side, the expression level of the immunosuppressive enzyme Arg-1 was decreased, as well as those of NOS-2 and COX-2 genes. These results suggest a potential anticancer activity of Tunisian Dunaliella sp. deserving further attention.

Microalgae amino acid extraction and analysis at nanomolar level using electroporation and capillary electrophoresis with laser-induced fluorescence detection.

Amino acids play a key role in food analysis, clinical diagnostics, and biochemical research. Capillary electrophoresis with laser-induced fluorescence detection was used for the analysis of several amino acids. Amino acid labeling with fluorescein isothiocyanate was conducted using microwave-assisted derivatization at 80°C (680 W) during only 150 s. Good electrophoretic resolution was obtained using a background electrolyte composed of sodium tetraborate buffer (100 mM; pH 9.4) and ß-cyclodextrin (10 mM), and the limits of quantification were 3-30 nM. The developed capillary electrophoresis with laser-induced fluorescence method was used to analyze amino acids in Dunaliella salina green algae grown under different conditions. A simple extraction technique based on electroporation of the cell membrane was introduced. A home-made apparatus allowed the application of direct and alternating voltages across the electrochemical compartment containing a suspension of microalgae in distilled water at 2.5 g/L. A direct voltage of 12 V applied for 4 min gave the optimum extraction yield. Results were comparable to those obtained with accelerated-solvent extraction. The efficiency of electroporation in destroying microalgae membranes was shown by examining the algae surface morphology using scanning electron microscopy. Stress conditions were found to induce the production of amino acids in Dunaliella salina cells.

Proteomic Analysis of the Chlorophyta Dunaliella New Strain AL-1 Revealed Global Changes of Metabolism during High Carotenoid Production.

The green microalgae Dunaliella genus is known for the production of high added value molecules. In this study, strain AL-1 was isolated from the Sebkha of Sidi El Hani (Sousse, Tunisia). This isolate was identified both morphologically and genetically via 18S rRNA gene sequence as a member of the genus Dunaliella. Strain AL-1 was found to be closely related to Dunaliella salina, Dunaliella quartolecta and Dunaliella polymorpha with more than 97% similarity. Response surface methodology was used to maximize carotenoid production by strain AL-1 by optimizing its growth conditions. The highest carotenoid content was obtained at salinity: 51, light intensity: 189.89 µmol photons·m-2·s-1, and nitrogen: 60 mg·L-1. Proteomic profiling, using two-dimensional gel electrophoresis, was performed from standard and optimized cultures. We detected 127 protein spots which were significantly differentially expressed between standard and optimized cultures. Among them 16 protein spots were identified with mass spectrometry and grouped into different functional categories using KEGG (Kyoto Encyclopedia of Genes and Genomes) such as photosynthetic Calvin cycle, regulation/defense, energy metabolism, glycolysis, and cellular processes. The current study could be of great interest in providing information on the effect of stressful conditions in microalgae carotenoid production.

Flexor Carpi Radialis Muscle: Anatomic Features and Electromyography Technique Under Ultrasound Control.

The electromyographic assessment of the flexor carpi radialis muscle (FCRM) in the context of an upper limb extensors' deficiency helps physicians in differentiating radial nerve damage from C7 radicular impairment. Ultrasound (US)-guided electromyography (EMG) is mandatory to locate this muscle, particularly in the case of muscle atrophy, denervation, and neuromuscular disorders. The aim of this manuscript is to illustrate the anatomical specific features of the FCRM and the technical procedure of FCRM EMG with US guidance.

Clinical Significance of Anatomic Peculiarities and Ultrasound-Guided Electromyography of the Posterior Tibial Muscle.

The posterior tibial muscle (PTM) is a key muscle in diagnosing the level of the neurologic lesion that causes steppage gate that is a paralysis of nervous origin of the muscles ensuring the foot dorsiflexion. The aim of this manuscript is to illustrate the anatomical peculiarities of the PTM, the ultrasound (US) anatomy of the infero-posterior part of the leg, and the technique of US-guided electro-neuro-myography (ENMG) of the PTM, which is considered a key muscle in the diagnosis of the neurological lesion causing steppage gate. The US-guided ENMG of the PTM is technically easy and safe for young practitioners provided there is a good knowledge of US anatomy of the infero-posterior part of the leg.

Importance of Anatomic Peculiarities and Ultrasound-Guided Electromyography of the Extensor Indicis Proprius Muscle.

The extensor indicis proprius muscle (EIPM) is considered a key muscle in the assessment of the level of the neurologic lesion causing any motor or sensory medio-cubital impairment of the hand. The aim of this study is to illustrate the anatomical peculiarities of the EIPM, the ultrasound (US) anatomy of the inferoposterior part of the forearm, and the technique of US-guided electromyography (EMG) of the EIPM. The US-guided EMG of the EIPM is technically easy and safe for young practitioners, provided there is a good knowledge of US anatomy of the inferoposterior part of the forearm.

Production and structure prediction of amylases from Chlorella vulgaris.

Amylases are enzymes required for starch degradation and are naturally produced by many microorganisms. These enzymes are used in several fields such as food processing, beverage, and medicine as well as in the formulation of enzymatic detergents proving their significance in modern biotechnology. In this study, a three-stage growth mode was applied to enhance starch production and amylase detection from Chlorella vulgaris. Stress conditions applied in the second stage of cultivation led to an accumulation of proteins (75% DW) and starch (21% DW) and a decrease in biomass. Amylase activities were detected and they showed high production levels especially on day 3 (35 U/ml) and day 5 (22.5 U/ml) of the second and third stages, respectively. The bioinformatic tools used to seek amylase protein sequences from TSA database of C. vulgaris revealed 7 putative genes encoding for 4 α-amylases, 2 ß-amylases, and 1 isoamylase. An in silico investigation showed that these proteins are different in their lengths as well as in their cellular localizations and oligomeric states though they share common features like CSRs of GH13 family or active site of GH14 family. In brief, this study allowed for the production and in silico characterization of amylases from C. vulgaris.

Protective Role of Spirulina platensis Against Bifenthrin-Induced Reprotoxicity in Adult Male Mice by Reversing Expression of Altered Histological, Biochemical, and Molecular Markers Including MicroRNAs.

: The potential reprotoxicity of bifenthrin remains unclear if only the common clinical indicators of reproductive disease are examined. The present study aimed to investigate the efficacy of Spirulina platensis, a microalga rich in antioxidant compounds, against bifenthrin-induced testicular oxidative damage in male mice. At the first, we demonstrate that administration of bifenthrin resulted in a decline of testosterone level and in deterioration of sperm quality that was correlated with significant transcription changes of some specific mRNA and microRNA involved in cholesterol transport, testosterone synthesis, and spermatogenesis. At the biochemical level, we found that oxidative stress was obvious in the bifenthrin group, as evidenced by increase in malondialdehyde (MDA), protein carbonyls (PCO), reactive oxygen species (ROS), and nitrite oxide (NO) that was correlated with activation of genes related to mitochondrial apoptotic signal pathways. We then brought, for the first time to our knowledge, solid and complete experimental evidences that administration of mice with Spirulina extract was sufficient to protect against deleterious effects BF in testicular tissues by abrogating the change in antioxidant enzyme activities; the increase in MDA, PCO, and NO concentrations; and the altered expression level of miRNA and mRNA involved in spermatogenesis. We finally demonstrate that Spirulina restores the production of testosterone in mice as well as epididymal sperm viability and motility. These results suggest a potential antitoxic activity of Tunisian Spirulina deserving further attention.

Cyanobacteria as source of marine bioactive compounds: Molecular specific detection based on Δ9 desaturase gene.

The blue-green microalga, Arthrospira sp., isolated from the sea of Kssour Essef in Mahdia (Tunisia), was purified and then identified both morphologically and genetically based on 16S rRNA gene sequence. Following physicochemical analysis, the prokaryotic microalga tested represented a competitive source of pigments and showed a considerable rate in protein (64%) which was confirmed by FTIR measurement. The lipid content (4%) was quantified by the gravimetric method and the intracellular lipid bodies were detected with the Nile red staining. Using gas chromatography coupled with flame ionization detector, the fatty acid profile revealed the presence of 27.4% and 32.88% of monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs), respectively. Given the richness of the isolated microalga in unsaturated fatty acids, we have developed a SYBR Green real time PCR method for the specific identification of Arthrospira sp. Δ9 desaturase gene. This current method will be of great value for carrying out high-throughput studies like cloning, heterologous expression and structure-function relationship analysis.