Doctorat (Biochimie)

Obésité, asthme, maladies bucco-dentaires et confinement

2025-02-20T00:00:00Z

Obésité, asthme, maladies bucco-dentaires et confinement Debbache, Afnane; Rouabah, Leïla Obesity poses a growing threat to public health in Algeria. The onset of obesity is influenced by a complex interplay of factors, with chronic diseases playing a significant role. Furthermore, asthma and obesity, both inflammatory conditions, have a detrimental impact on oral health. Concurrently, physical activity, crucial for preventing these pathologies, has been severely disrupted by the SARS-CoV-2 pandemic lockdowns. This comprehensive study aims to elucidate the multifaceted causes of obesity in Algeria and develop effective control strategies, as well as analyze the impact of the SARS-CoV-2 lockdown on the physical and mental health of algerians. The first section of this work, conducted among 70 asthmatic patients and 60 healthy controls from Constantine, aimed to explore the links between asthma, obesity, and the occurrence of periodontitis, whose inflammatory state was measured by assessing CRP (Creactive protein), ESR (erythrocyte sedimentation rate), and eosinophil count. The analysis revealed that females were more predisposed to uncontrolled asthma (p < 0.044) and obesity (p < 0.028). Additionally, snacking emerged as a significant factor in weight gain (p < 0.004). Moreover, the use of inhaled corticosteroids to treat asthma was associated with increased weight gain (p < 0.047) and poorer oral health (p < 0.026). Similarly, significant correlations were observed between inflammation (CRP) and poor asthma control (p< 0.046), as well as between eosinophil count and poor asthma control (p < 0.001). The second part of this work, a retrospective study of SARS-CoV-2 patient records, revealed a significant male predominance among patients who developed severe forms of the disease (p < 0.005). These patients also had significantly higher levels of C-reactive protein (CRP) (p < 0.000). Our final section, conducted on a sample of the algerian population, assessed the impact of the SARS-CoV-2 lockdown on physical activity levels. The analysis, based on the IPAQ and GPAQ questionnaires and the calculation of the total MET (min/week) activity score, revealed a significant decrease in physical activity at all intensity levels during the lockdown. More specifically, participants initially classified as highly active and moderately active experienced a drastic reduction in their physical activity to (551.42 ± 1212.27) METmin/week and (60.38 ± 134.44) MET-min/week respectively (p < 0.000). These findings suggest that the lockdown-imposed restrictions led to a substantial decline in regular physical activity among initially active individuals. Concurrently, the study also observed an increase in snacking habits during the lockdown. This three-pronged study has shed valuable light on critical public health issues in Algeria. The findings obtained could have significant implications for patient management and the promotion of healthy lifestyles.

Extraction, purification des lectines à partir des plantes médicinales

2023-01-24T00:00:00Z

Extraction, purification des lectines à partir des plantes médicinales Messai, Alima; Necib, Youcef Lectins are ubiquitous proteins, non-immune origin, with several biological properties. The purpose of this work was to purify and characterize the lectin from Ruta montana roots and Peganum harmala seeds and to study their antiproliferative activity. Lectins from two plants were extracted by three different methods, distilled water at pH 4, sodium chloride (NaCl), phosphate buffered saline (PBS). Ruta montana lectin was purified by ultrafiltration and ammonium sulfate precipitation, followed by gel filtration chromatography. While Peganum harmala lectin was purified by ultrafiltartion and gel filtration chromatography. The characterization of Ruta montana lectin shows that it have a monomeric structure with a molecular weight of 28.8 kDa, it lost its activity at 70°C for 30 min and stable in neutral pH, and shows specificity to human erythrocytes type B, Its activity is inhibited by galactose and glucose. Peganum harmala lectin was composed of three identical subunits, each with a molecular mass of 70.53 kDa. The activity of this lectin was stable between pH 4.2 and pH 9, their incubation at 80°C for 10 min led to irreversible denaturation. It agglutinated all human erythrocyte ABO, its activity was not inhibited by the presence of monosaccharides, such as galactose, mannose, fructose, sucrose, and glucose. Ruta montana lectin has antiproliferative activity on Caco-2 cell lines and stimulates cell proliferation of THP-1 cell lines. Peganum harmala lectin has a dosedependently high inhibitory effect on Caco-2 cell lines and no effect on THP-1 cell lines.

Biomolecules of Algerian propolis

2023-05-11T00:00:00Z

Biomolecules of Algerian propolis Boulechfar, Safia; Zellagui, Amar This study aimed to investigate the chemical composition and the biological properties of propolis collected from different regions of Algeria. The total bioactive content, antioxidant, antienzymatic, antimicrobial, toxicity and anticancer effects were evaluated. The chemical composition of propolis extracts and essential oils (EOs) was also analyzed. The results demonstrated the richness of propolis extracts in phenolic and flavonoid compounds. Antioxidant tests (DPPH, ABTS, alkaline DMSO, CUPRAC, ferric reducing power and β-carotene-linoleic acid tests) revealed the strong radical scavenging, ion reducing and lipid peroxidation inhibition abilities of the extracts, whereas EOs were the least active. Anti-enzymatic assays against acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and -glucosidase showed that all propolis extracts possessed a potent inhibitory effect on α-glucosidase better than acarbose and revealed the ability of extracts to inhibit BChE more effectively than AChE. However, the tested oil was more effective on AChE than BChE. The antimicrobial assay indicated that all extracts were mainly active against Gram-positive bacteria and yeast. The inhibition of bacterial growth by propolis extracts and EOs was found to be through bactericidal or bacteriostatic mechanism, whereas the inhibition of yeast growth was through fungicidal or fungistatic mode. The toxicity test against brine shrimp larvae indicated that propolis extracts possess moderate toxic properties. In addition, anticancer effect of propolis extracts on HepG2 human hepatocellular carcinoma cells (HepG2) determined using CCK-8 assay revealed the strong cytotoxic activity of the extracts against HepG2 with IC50 values ranged from 12.22±0.05 to 60.39±1.82 µg/mL. The GC-MS analysis of three EOs allowed the identification of a total of 112 compounds, in which α-pinene, limonene, trans-pinocarveol, α-terpinenyl acetate and δ-Cadinene were common between the three oils. The LC-MS/MS analysis of propolis extracts that showed potent anticancer effect revealed the richness of these extracts in phenolic acids such as caffeic and ferulic acids, and flavonoids such as kaempferol, apigenin and quercetin. These findings indicate the importance of Algerian propolis as a source of bioactive principles for the development of pharmaceutical products.

Diversité génétique des variétés d’arachides (Arachis hypogaea) en Algérie.

2022-11-02T00:00:00Z

Diversité génétique des variétés d’arachides (Arachis hypogaea) en Algérie. Djeghim, Hanane; Khelifi, Douadi The knowledge and characterization of plant genetic resources are major challenges for our country to protect and enhance our genetic heritage. Peanut (Arachis hypogaea L) is one of the cultivated plants with a narrow genetic base, hence the interest in prospecting, rescuing, and characterizing germplasm of this species. The present study aimed to assess, for the first time, the genetic diversity and population structure of Algerian peanut accessions originated from four geographic regions in the north and south of the country using 40 agro-morphological descriptors, 11 microsatellite markers and seed storage proteins. Findings showed a high genetic diversity between studied accessions for all the markers and confirmed the presence of two subspecies of A. hypogaea in the studied collection results confirm also the important role of conarachine I fraction to distinguished between these subspecies. Furthermore, PCA results were revealed that leaflet size (length and width), seed shape and size, oil content, and branching pattern were the principal characters to discriminate the screened A. hypogaea accessions. Besides that, molecular analysis was exhibited 86 alleles with a mean number of 7.545 alleles per locus. Genetic structure analysis showed a strong population at K=2, separating accessions according to their geographic origin (North and south) with some exceptions. Unweighted Pair Group Method with Arithmetic Averages (UPGMA) results were consistent with the results from the structure and PCA analysis dividing the studied collection into two clusters based on the subspecies affiliation of accessions. Moreover, Analysis of Molecular Variance (AMOVA) revealed high genetic variation within individuals (90.7%) and low genetic differentiation between subspecies (10,3%) and among populations (8.9%). On the other hand, peanut is accounted as one of the most cause of food allergy and anaphylaxis choc. Despite this, studies of peanut allergy didn’t make the subject of intensive interest in Algeria. The objective of this research, was to evaluate the allergenicity of six peanut accessions using Balb/c mouse model. Serum specific IgE, IgG and IgG1 antibodies against peanut proteins were presented a high level. Furthermore, the histological analysis of jejunal sections were showed a lot of damages and inflammatory cells infiltration. These results were traduced the success of sensitized protocol used. Findings reports also that accessions belonging to the subspecies hypogaea especially Timimoune and El Oued 1 were the most hypoallergenic accessions compared with those belonging to the fastigiata subspecies. During the different parts of this research Saharan Algerian peanut accessions were presented the best characteristics, namely agro-morphological traits and hypoallergenic character. Thus, we suggest the use of these accessions for cultivation and industry in order to benefit of their agronomical quality and fighting against peanut allergy problem.