Determination of free phenolic acids and antioxidant capacity of methanolic extracts obtained from leaves and flowers of camel thorn (Alhagi maurorum)

The present study comprises the determination of some phenolic acids from the leaves and flowers of Alhagi maurorum by HPLC-DAD, confirmed by LC-MS-APCI. The antioxidant properties and measurements of the total phenolic contents of the extracts were assessed by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging and Folin-Ciocalteu methods, respectively. It was found that the leaf extract had higher antioxidant potential (83.5%) than the flower extract (72.3%). The antioxidant properties and total phenolic contents of the leaves were higher than those of the flowers.     

Tilianin: A Potential Natural Lead Molecule for New Drug Design and Development for the Treatment of Cardiovascular Disorders

Cardiovascular disorders (CVDs) are the leading risk factor for death worldwide, and research into the processes and treatment regimens has received a lot of attention. Tilianin is a flavonoid glycoside that can be found in a wide range of medicinal plants and is most commonly obtained from Dracocephalum moldavica. Due to its extensive range of biological actions, it has become a well-known molecule in recent years. In particular, numerous studies have shown that tilianin has cardioprotective properties against CVDs. Hence, this review summarises tilianin’s preclinical research in CVDs, as well as its mechanism of action and opportunities in future drug development. The physicochemical and drug-likeness properties, as well as the toxicity profile, were also highlighted. Tilianin can be a natural lead molecule in the therapy of CVDs such as coronary heart disease, angina pectoris, hypertension, and myocardial ischemia, according to scientific evidence. Free radical scavenging, inflammation control, mitochondrial function regulation, and related signalling pathways are all thought to play a role in tilianin’s cardioprotective actions. Finally, we discuss tilianin-derived compounds, as well as the limitations and opportunities of using tilianin as a lead molecule in drug development for CVDs. Overall, the scientific evidence presented in this review supports that tilianin and its derivatives could be used as a lead molecule in CVD drug development initiatives.     

Comparative Analysis of Microbial Consortiums and Nanoparticles for Rehabilitating Petroleum Waste Contaminated Soils

Nano-bioremediation application is an ecologically and environmentally friendly technique to overcome the catastrophic situation in soil because of petroleum waste contamination. We evaluated the efficiency of oil-degrading bacterial consortium and silver nanoparticles (AgNPs) with or without fertilizer to remediate soils collected from petroleum waste contaminated oil fields. Physicochemical characteristics of control soil and petroleum contaminated soils were assessed. Four oil-degrading strains, namely Bacillus pumilus ({"type":"entrez-nucleotide","attrs":{"text":"KY010576","term_id":"1248281175"}}KY010576), Exiguobacteriaum aurantiacum ({"type":"entrez-nucleotide","attrs":{"text":"KY010578","term_id":"1248281177"}}KY010578), Lysinibacillus fusiformis ({"type":"entrez-nucleotide","attrs":{"text":"KY010586","term_id":"1248281185"}}KY010586), and Pseudomonas putida ({"type":"entrez-nucleotide","attrs":{"text":"KX580766","term_id":"1159332275"}}KX580766), were selected based on their in vitrohydrocarbon-degrading efficiency. In a lab experiment, contaminated soils were treated alone and with combined amendments of the bacterial consortium, AgNPs, and fertilizers (ammonium nitrate and diammonium phosphate). We detected the degradation rate of total petroleum hydrocarbons (TPHs) of the soil samples with GC-FID at different intervals of the incubation period (0, 5, 20, 60, 240 days). The bacterial population (CFU/g) was also monitored during the entire period of incubation. The results showed that 70% more TPH was degraded with a consortium with their sole application in 20 days of incubation. There was a positive correlation between TPH degradation and the 100-fold increase in bacterial population in contaminated soils. This study revealed that bacterial consortiums alone showed the maximum increase in the degradation of TPHs at 20 days. The application of nanoparticles and fertilizer has non-significant effects on the consortium degradation potential. Moreover, fertilizer alone or in combination with AgNPs and consortium slows the rate of degradation of TPHs over a short period. Still, it subsequently accelerates the rate of degradation of TPHs, and a negligible amount remains at the end of the incubation period.     

Scheduling with earliness–tardiness penalties and parallel machines

This is a summary of the author’s PhD thesis supervised by Francis Sourd and Philippe Chrétienne and defended on 30 January 2007 at the Université Pierre et Marie Curie, Paris. The thesis is written in French and is available from the author upon request. This work is about scheduling on parallel machines in order to minimize the total sum of earliness and tardiness costs. To solve some variants of this problem we propose: an exact method based on continuous relaxations of convex reformulations derived from a 0–1 quadratic program; a heuristic algorithm that relies on a new exponential size neighborhood search; finally, a lower bound method based on a polynomial time solution of a preemptive scheduling problem for which the cost functions of the jobs have been changed into so called position costs functions. Partial funding provided by CONACyT (Mexican Council for Science&Technology).     

Bayesian modeling of forestry data with R using optimization and simulation tools

Data generated in forestry biometrics are not normal in statistical sense as they rarely follow the normal regression model. Hence, there is a need to develop models and methods in forest biometric applications for non-normal models. Due to generality of Bayesian methods it can be implemented in the situations when Gaussian regression models do not fit the data. Data on diameter at breast height (dbh), which is a very important characteristic in forestry has been fitted to Weibull and gamma models in Bayesian paradigm and comparisons have also been made with its classical counterpart. It may be noted that MCMC simulation tools are used in this study. An attempt has been made to apply Bayesian simulation tools using \textbf{R} software.     

Evaluation of the Expression of Amyloid Precursor Protein and the Ratio of Secreted Amyloid Beta 42 to Amyloid Beta 40 in SH-SY5Y Cells Stably Transfected with Wild-Type,Single-Mutant and Double-Mutant Forms of the APP Gene for the Study of Alzheimer’s Disease Pathology

Neuroblastoma cell lines such as SH-SY5Y are the most frequently utilized models in neurodegenerative research, and their use has advanced the understanding of the pathology of neurodegeneration over the past few decades. In Alzheimer’s disease (AD), several pathogenic mutations have been described, all of which cause elevated levels of pathological hallmarks such as amyloid-beta (Aβ). Although the genetics of Alzheimer’s disease is well known, familial AD only accounts for a small number of cases in the population, with the rest being sporadic AD, which contains no known mutations. Currently, most of the in vitro models used to study AD pathogenesis only examine the level of Aβ42 as a confirmation of successful model generation and only perform comparisons between wild-type APP and single mutants of the APP gene. Recent findings have shown that the Aβ42/40 ratio in cerebrospinal fluid (CSF) is a better diagnostic indicator for AD patients than is Aβ42 alone and that more extensive Aβ formation, such as accumulation of intraneuronal Aβ, Aβ plaques, soluble oligomeric Aβ (oAβ), and insoluble fibrillar Aβ (fAβ) occurs in TgCRND8 mice expressing a double-mutant form (Swedish and Indiana) of APP, later leading to greater progressive impairment of the brain. In this study, we generated SH-SY5Y cells stably transfected separately with wild-type APP, the Swedish mutation of APP, and the Swedish and Indiana mutations of APP and evaluated the APP expression as well as the Aβ42/40 ratio in those cells. The double-mutant form of APP (Swedish/Indiana) expressed markedly high levels of APP protein and showed a high Aβ2/40 ratio compared to wild-type and single-mutant cells.     

Sensitive and selective determination of peptides,PG and PGP,using a novel fluorogenic reagent 4-chlorobenzene-1,2-diol

A novel fluorometric method was developed for the sensitive and selective detection of Pro-Gly (PG) and Pro-Gly-Pro (PGP) using 4-chlorobenzene-1,2-diol (4-CBD) as a fluorogenic reagent. The reaction was performed at 37°C for 30 min in the presence of a borate buffer (pH 7.0) and sodium periodate. The resulting fluorescence intensity was measured using a spectrofluorometer with excitation and emission wavelengths of 450 nm and 535 nm. To obtain a stable fluorescent signal and maximise its intensity, different reaction conditions such as the concentrations of the reagents, the reaction time, and the pH were optimised. Under the optimised conditions, a linear relationship was obtained between fluorescence intensity and peptide concentrations from 1.0–40.0 µmol L^?1 with a limit of detection of 1.0 µmol L^?1 (S/N = 3). Both PG and PGP generated a strong signal out of all the peptides tested and no other biogenic substances such as amino acids or proteins produced any fluorescence. The reaction thus developed is simple, rapid, selective, and sensitive. It can be applied to the determination of peptides as biomarkers or substrates.     

Ultraviolet Radiation Exposure and its Impacts on Cutaneous Phosphorylation Signaling in Carcinogenesis: Focusing on Protein Tyrosine Phosphatases†

Sunlight exposure is a significant risk factor for UV-induced deteriorating transformations of epidermal homeostasis leading to skin carcinogenesis. The ability of UVB radiation to cause melanoma, as well as basal and squamous cell carcinomas, makes UVB the most harmful among the three known UV ranges. UVB-induced DNA mutations and dysregulation of signaling pathways contribute to skin cancer formation. Among various signaling pathways modulated by UVB, tyrosine phosphorylation signaling which is mediated by the action of protein tyrosine kinases (PTKs) on specific tyrosine residues is highly implicated in photocarcinogenesis. Following UVB irradiation, PTKs get activated and their downstream signaling pathways contribute to photocarcinogenesis by promoting the survival of damaged keratinocytes and increasing cell proliferation. While UVB activates oncogenic signaling pathways, it can also activate tumor suppressive signaling pathways as initial protective mechanisms to maintain epidermal homeostasis. Tyrosine dephosphorylation is one of the protective mechanisms and is mediated by the action of protein tyrosine phosphatases (PTPs). PTP can counteract UVB-mediated PTK activation and downregulate oncogenic signaling pathways. However, PTPs have not been studied extensively in photocarcinogenesis with previous studies regarding their inactivation induced by UVB. This current review will summarize the recent progress in the protective function of PTPs in epidermal photocarcinogenesis.