Status and Need of Research on Rhizobia and Arbuscular Mycorrhizal Fungi Associated with Leguminous Plants in Saudi Arabia

Most regions of Saudi Arabia are frequently subjected to high temperature and drought spells which destroy natural vegetation and lead to soil erosion and the advance of sand dunes.  The use of legume plants may help to preserve these ecosystems and to slow down desertification processes. Legumes produce extensive, deep root systems with a capacity to develop mycorrhizal and rhizobial symbioses facilitating the plant’s nutrition via enhanced soil nutrients absorption and atmospheric nitrogen fixation, respectively. These associations play a vital role in preserving and even restoring the fertility of poor and eroded soils. Research on tripartite associations of Arbuscular mycorrhizal fungi (AMF), rhizobia and legumes is rare in Saudi Arabia. Little is known about the diversity of these beneficial symbioses in Saudi ecosystems and their beneficial role for the sustainable management of range land. We attempted to explore the present status of research on rhizobia and AMF associated with various legumes in Saudi Arabia. The use of legume plants associated with microbial symbionts may be a useful asset in preserving fragile ecosystems and combating desertification. The identification of adapted and efficient legume-rhizobia-fungi tripartite associations in local ecosystems is of paramount importance for successful ecosystem restoration, rangeland and forest management and agricultural sustainability especially under unfavorable environmental conditions due to soil salinity, drought and heat stress

Development and determination of the stability of cosmetic formulation with incorporation of natural products

Nowadays, natural products are gaining increased popularity as cosmetic ingredients due to their active properties and the different roles they can play in a single cosmetic formula, acting as active ingredients (moisturizers), fragrance (perfumes), excipients (surfactants) and additives (preservatives). The aim of this study is to formulate and subsequently evaluate the stability of an anti-aging gel based on natural product namely, bee pollen, which is used as pigment and active compound due to its intresting properties and essential oil from two varieties of thymus, Portuguese species Thymus zygis zygis and Tunisian species Thymus capitatus applied as natural preservative. The formulations selected were submitted to accelerated stability studies using various physical-chemical parameters such as pH, density, viscosity, themic analysis (freeze and thaw cycles),thermic stress, organoleptic characteristics (odor, color and aspect), UV spectrophotometric analysis, centrifuge test, tests of vibration, texture, spreading resistance and also through light test. The formulation was also evaluated for its resistance and activity against skin microorganisms such as: Staphylococcus aureus, Pseudomonas sp., Escherichia coli. The acute toxicity of the compound incorporated in the base formulation is determined through the evaluation of Brine shrimp (Artemia salina) mobility. The microbiological stability of the formulations is also evaluated through agar diffusion assays using cultures of Escherichia coli, Staphylococcus aureus, Pseudomonas ssp, Bacillus subtilis and Candida albicans. Regarding to the tests were done; centrifuge test and vibration test, there is no evidence of phase separation, which means that the formulation maintains its stability. For pH test, the formulations showed a suitable pH for body skin and no evidence of phase separation. The others tests are being evaluated.info:eu-repo/semantics/publishedVersio

Desenvolvimento e determinação da estabilidade de uma formulação cosmética anti-idade com incorporação de pólen

Atualmente, os produtos apicolas, como ê o caso do pólen, crescem em popularidade como ingredientes cosméticos devido às suas propriedades ativas e aos diferentes papéis que podem desempenhar numa fórmula cosmética, como hidratante, fragrância, excipiente (surfatante), conservante, etc. O pólen de abelha sendo rico em vários aminoácidos essenciais, como metionina, lisina, treonina, histidina, pode ser um nutriente essencial para a pele. Rico em lípidos, ácidos gordos livres essenciais, como o ácido linoleico, y-linolénico e araquídico. O pólen contém ainda minerais: potássio, cálcio, magnésio e fósforo. É fonte de vitaminas hidrossolúveis: vitamina C, vitaminas do complexo B, vitaminas lipossolúveis (vitamina E e p-caroteno) [1]. Vários estudos atribuem propriedades anti-microbianas e antioxidantes, tornando-o um potente suplemento anti-idade para a pele madura [2]. O objetivo deste trabalho foi formular e avaliar a estabilidade de um gel anti-idade baseado em produtos naturais: pólen de abelha (princípio ativo) e óleos essenciais de duas variedades de tomilho, espécie portuguesa Thymus zygis zygis e tunisina Thymus capitatus (conservante natural). A formulação cosmética foi avaliada relativamente ao seu comportamento de fluxo, estabilidade físico-química, atividade anti-microbiana, toxicidade aguda e irritabilidade ocular [3].info:eu-repo/semantics/publishedVersio

Biological activities evaluation of enantiopure isoxazolidine derivatives: in vitro, in vivo and in silico studies

A series of enantiopure isoxazolidines (3a–c) were synthesized by 1,3-dipolar cycloaddition between a (−)-menthone-derived nitrone and various terminal alkenes. The screened compounds were evaluated for their antioxidant activity by two in vitro antioxidant assays, including β-carotene/linoleic acid bleaching, and inhibition of lipid peroxidation (thiobarbituric acid reactive species, TBARS). The results revealed that compound 3b (EC50 = 0.55 ± 0.09 mM) was the most potent antioxidant as compared to the standard drug (EC50 = 2.73 ± 0.07 mM) using the TBARS assay. Furthermore, the antimicrobial activity was assessed using disc diffusion and microdilution methods. Among the synthesized compounds, 3c was found to be the most potent antimicrobial agent as compared to the standard drug. Subsequently, the acute toxicity study has also been carried out for the newly synthesized compounds and the experimental studies revealed that all compounds were safe up to 500 mg/kg and no death of animals were recorded. The cytotoxicity of these compounds was assessed by the MTT cell proliferation assay against the continuous human cell lines HeLa and compound 3c (GI50 = 46.2 ± 1.2 μM) appeared to be more active than compound 3a (GI50 = 200 ± 2.8 μM) and 3b (GI50 = 1400 ± 7.8 μM). Interestingly, all tested compounds displayed a good α-amylase inhibitory activity in competitive manner with IC50 values ranging between 23.7 and 64.35 μM when compared to the standard drug acarbose (IC50 = 282.12 μM). In addition, molecular docking studies were performed to understand the possible binding and the interaction of the most active compounds to the α-amylase pocket.info:eu-repo/semantics/publishedVersio

Revalorization of wild: Asparagus stipularis Forssk. as a traditional vegetable with nutritional and functional properties

The nutritional values and phytochemical composition of young shoots of wild Asparagus stipularis Forssk. from Tunisia were determined in this study. The antioxidant (tested by four different in vitro assays) and antiproliferative properties (against human tumour cell lines) of aqueous and hydroalcoholic extracts of the young shoots were also investigated. The obtained results indicated that the young shoots are a potential source of valuable nutrients and dietary fiber, and their hydroalcoholic extract showed marked antioxidant and antiproliferative activities in all tested assays. The major phenolic compound, characterized by using a high-performance liquid chromatograph coupled with diode-array and mass spectrometer detectors, in both extracts was diferuloyl glycerol. Our results reinforce the interest in recovering the traditional culinary uses of this wild plant, with potential functional properties, which can be included in the modern diet as an alternative to the variety of vegetables normally used.Thanks are due to the ALIMNOVA research group (project UCM-252/2017), the Foundation for Science and Technology (FCT, Portugal) and the FEDER Program PT2020 for financial support to CIMO (UID/AGR/00690/2013) and R. Calhelha, and to A. Fernandes (SFRH/BPD/114753/2016), as well as to the Spanish MINECO for financial support to GIP-USAL (Project AGL2015-64522-C2-2-R).info:eu-repo/semantics/publishedVersio

Pseudomonas rhizophila S211, a New Plant Growth-Promoting Rhizobacterium with Potential in Pesticide-Bioremediation

A number of Pseudomonas strains function as inoculants for biocontrol, biofertilization, and phytostimulation, avoiding the use of pesticides and chemical fertilizers. Here, we present a new metabolically versatile plant growth-promoting rhizobacterium, Pseudomonas rhizophila S211, isolated from a pesticide contaminated artichoke field that shows biofertilization, biocontrol and bioremediation potentialities. The S211 genome was sequenced, annotated and key genomic elements related to plant growth promotion and biosurfactant (BS) synthesis were elucidated. S211 genome comprises 5,948,515 bp with 60.4% G+C content, 5306 coding genes and 215 RNA genes. The genome sequence analysis confirmed the presence of genes involved in plant-growth promoting and remediation activities such as the synthesis of ACC deaminase, putative dioxygenases, auxin, pyroverdin, exopolysaccharide levan and rhamnolipid BS. BS production by P. rhizophila S211 grown on olive mill wastewater based media was effectively optimized using a central-composite experimental design and response surface methodology (RSM). The optimum conditions for maximum BS production yield (720.80 ± 55.90 mg/L) were: 0.5% (v/v) inoculum size, 15% (v/v) olive oil mill wastewater (OMWW) and 40◦C incubation temperature at pH 6.0 for 8 days incubation period. Biochemical and structural characterization of S211 BS by chromatography and spectroscopy studies suggested the glycolipid nature of the BS. P. rhizophila rhamnolipid was stable over a wide range of temperature (40–90◦C), pH (6–10), and salt concentration (up to 300mM NaCl). Due to its low-cost production, emulsification activities and high performance in solubilization enhancement of chemical pesticides, the indigenous BS-producing PGPR S211 could be used as a promising agent for environmental bioremediation of pesticide-contaminated agricultural soils

Rhaponticum acaule (L) DC essential oil: chemical composition, in vitro antioxidant and enzyme inhibition properties

Background: α-glucosidase is a therapeutic target for diabetes mellitus (DM) and α-glucosidase inhibitors play a vital role in the treatments for the disease. Furthermore, xanthine oxidase (XO) is a key enzyme that catalyzes hypoxanthine and xanthine to uric acid which at high levels can lead to hyperuricemia which is an important cause of gout. Pancreatic lipase (PL) secreted into the duodenum plays a key role in the digestion and absorption of fats. For its importance in lipid digestion, PL represents an attractive target for obesity prevention. Methods: The flowers essential oil of Rhaponticum acaule (L) DC (R. acaule) was characterized using gas chromatography-mass spectrometry (GC-MS). The antioxidant activities of R. acaule essential oil (RaEO) were also determined using 2,2’-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), reducing power, phosphomolybdenum, and DNA nicking assays. The inhibitory power of RaEO against α-glucosidase, xanthine oxidase and pancreatic lipase was evaluated. Enzyme kinetic studies using Michaelis-Menten and the derived Lineweaver-Burk (LB) plots were performed to understand the possible mechanism of inhibition exercised by the components of this essential oil. Results: The result revealed the presence of 26 compounds (97.4%). The main constituents include germacrene D (49.2%), methyl eugenol (8.3%), (E)-β-ionone (6.2%), β-caryophyllene (5.7%), (E,E)-α-farnesene (4.2%), bicyclogermacrene (4.1%) and (Z)-α-bisabolene (3.7%). The kinetic inhibition study showed that the essential oil demonstrated a strong α-glucosidase inhibiton and it was a mixed inhibitor. On the other hand, our results evidenced that this oil exhibited important xanthine oxidase inhibitory effect, behaving as a non-competitive inhibitor. The essential oil inhibited the turkey pancreatic lipase, with maximum inhibition of 80% achieved at 2 mg/mL. Furthermore, the inhibition of turkey pancreatic lipase by RaEO was an irreversible one. Conclusion: The results revealed that the RaEO is a new promising potential source of antioxidant compounds, endowed with good practical applications for human health. Keywords: α-glucosidase, Antioxidant activity, Chemical composition, Pancreatic lipase inhibition, Rhaponticum acaule essential oil, Xanthine oxidase

Posture et Occlusion (quelles relations?)

AIX-MARSEILLE2-BU Méd/Odontol. (130552103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Comparative study of kinetic and interfacial properties of a novel Rhizopus oryzae

We compared several kinetic and interfacial properties of a lipase from a novel strain of Rhizopus oryzae (ROLw) with ROL29 lipase. In contrast to ROL29, ROLw was able to hydrolyze triolein emulsion in the absence of any additive, like bovine serum albumin (BSA). Furthermore, unlike Rhizopus oryzae lipase (ROL29), kinetic study of ROLw lipase shows linear dependency when using tributyrin emulsion as substrate. ROLw can tolerate, more efficiently than ROL29, the accumulation of long-chain free fatty acids at the interface when olive oil emulsion was used as substrate. The critical surface pressure πc of penetration into phosphatidyl choline from egg yolk films was found to be 23 mN/m with ROLw, in contrast to a value of 10 mN/m obtained with ROL29. The effect of calcium ion and synthetic detergent on the two lipases was studied. In contrast to ROL29, ROLw was activated in the presence of 100 lmoles TX-100. No significant difference on the two lipase activity was observed in presence or absence of calcium ion