Doctorat Biologie Animale

Preventive effects of pure vitamin C and Algerian oranges on bowel diseases induced by hyperhomocysteinemia and on cancer cell lines.

2026-01-27T11:36:12Z

Preventive effects of pure vitamin C and Algerian oranges on bowel diseases induced by hyperhomocysteinemia and on cancer cell lines. Khelfi, Sara; Zerizer, Sakina; Tebibel, Soraya Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, are chronic immune-mediated inflammatory diseases of the intestinal tract. Under low vitamin B conditions, homocysteine accumulates and leads to hyperhomocysteinemia and the association between hyperhomocysteinemia and the risk of IBD has been widely studied. The objective of our work is to study the preventive effect of Rosa canina and Citrus sinensis fruits on intestinal inflammation induced by hyperhomocysteinemia in mice. In the first part of this study we determinate two compounds, the polyphenol and flavonoid in fruit extracts of Rosa canina and Citrus sinensis, followed by an evaluation of the antioxidant activity of these fruit extracts by different methods: DPPH, ABTS, GOR, reducing power and CUPRAC. The extracts were then tested in vitro for their anti-inflammatory effect via the bovine serum albumin (BSA) denaturation test. The chemical composition, ascorbic acid content, electrochemical characterization and antioxidant capacity of Rosa canina fruit extract were determined. In addition, the in vitro antioxidant activity of R. canina fruit extract and its protective effect on hydrogen peroxide (H2O2)-stressed human fibroblast cells were evaluated using MTT assay. In the second part, we studied the protective, anti-inflammatory and anti-homocysteinemic effect of the fruits: Citrus sinensis, Rosa canina and vitamin C on the intestinal inflammation induced by high doses of L-methionine during the 21 days in vivo experimental procedure. The levels of plasma inflammatory markers (hs-CRP, homocysteine), reduced glutathione (GSH) and catalase (CAT) in liver tissue were measured, and histological sections of intestinal tissue were examined. The results show that both extracts are rich in polyphenols and have significant antioxidant power. Both extracts prevented the denaturation of BSA in a dose-dependent manner indicating that both extracts have anti-inflammatory activity, which was confirmed by the in vivo anti-inflammatory study. The extract of Rosa.canina fruit indicates the presence of n-hexadecanoic acid, oleic acid and stearic acid, which were identified as the main compounds of this fruit. This fruit is rich in ascorbic acid and has an important antioxidant capacity. Moreover, the results show that Rosa canina fruit extract has a non-toxic effect on the viability of human fibroblasts with a protective effect against oxidative stress induced by hydrogen peroxide on fibroblasts. In addition, treatment with fruits and vitamin C led to a decrease in the level of plasma homocysteine, an increase in the levels of GSH and CAT. This was confirmed by the histological study of the restoration of the integrity of the intestinal epithelium. This study revealed that the fruits of Citrus sinensis and Rosa canina have antioxidant and antiinflammatory powers and can be considered as a natural source to prevent and treat IBD.

Impact of pirimicarb on Neuro-immune-endocrine system sensitivity and the preventive effect of Ephedra alata monjauzeana.

2026-01-20T13:51:11Z

Impact of pirimicarb on Neuro-immune-endocrine system sensitivity and the preventive effect of Ephedra alata monjauzeana. Khattabi, Latifa; Chettoum, Aziez Pesticide users and manufacturers should anticipate exposure to toxicological risks, withal; the general public is not exempted. The use of carbamate insecticides poses a threat to human health, and pirimicarb is the most used carbamate. This research project sought to determine the impact of pirimicarb on the neuroimmune endocrine axis and to evaluate the eventual preventive ability of Ephedra alata monjauzeana. Preliminary in vitro and in vivo investigations were performed to assess the antioxidant, anti-inflammatory and the non-toxic effects of the prepared crude extract from the plant of interest. In addition, LCMS/MS qualitative analysis was conducted for the characterization of the chemical profile. Twenty‐one flavonoids and phenolic acids were identified in the EamCE, this latter exhibited a remarkable antioxidant activity and an interesting anti-inflammatory potential. The tests of toxicity and cytotoxicity indicated our plant as non-toxic and relatively harmless. Moreover, the pirimicarb noxiousness was determined by inducing a subacute toxicity on male wistar rats after a period of 28 days of pirimicarb daily gavage (1/10 of LD50 = 145 mg/kg). The exploration of the noxious effects was realized by various analysis. Behavioral tests were used to evaluate the mood and behavior changes and to estimate the physical performance. Oxidative stress was determined by analyzing some parameters, namely: MDA, GSH SOD and CAT. The measurement of inflammatory and hormonal biomarkers such as blood cells count, IL-1 β level, cortisol and testosterone serum titers were also carried. At the histologic scale, the significance of lesions was specifically examined in the brain and testis. In other respects, traces of pirimicarb in extracts of the same organs were searched using LCMS/MS MRM. Consequently, a considerable status of anxiety and depression was revealed, with a remarkable rise in cortisol, monocytes, IL-1 β (peripheral and cerebral) titers. Likewise, a significant decline in oxidative enzymes and testosterone rate as well as a status of lymphopenia and agranulocytosis were recorded. Additionally, important histological lesions were shown in cerebral cortex and seminiferous tubules. The chromatographic analysis of extracts amples from brain and testis of rats force-fed with pirimicarb provided accurately chromatograms that demonstrated the detection of pirimicarb and approved its accumulation in tissues. The EamCE showed exceptional promising results, as a preventive therapeutic agent, which is characterized by restoring mental and physical performances, enhancing mood, fertility, antioxidant and antiinflammatory activities, and maintaining tissue integrity. In further, we carried another test to confirm the cytotoxic effect of pirimicarb on immune cells where we used human blood cells from healthy donors, to separate neutrophils and reacting them with different concentrations and mixtures of pirimicarb and EamCE. Therefore, pirimicarb induced the reduction of neutrophils viability percentage, in contrast to the enhanced effect of EamCE. Overall, we believe that is pertinent to mention that EamCE possesses euphoric and preventive properties towards pirimicarb negative impacts that are manifested by disrupting the neuro-immune endocrine axis.

Biodiversité des Collemboles (Arthropoda ; Hexapoda) de divers habitats naturels du Constantinois.

2025-12-16T14:20:45Z

Biodiversité des Collemboles (Arthropoda ; Hexapoda) de divers habitats naturels du Constantinois. Lachi, Noureddine; Hamra-Kroua, Salah In order to improve the biodiversity knowledge of Algerian springtails, a hundreds of samples were collected from many forests, caverns and caves meadow, in different bioclimatic stages during the years 2018-2020. 85 species and morpho-species were encountered in forest samples, spread over 15 families and 53 genera, which the mountain range of Jijel presents an exceptional biodiversity in endemic, rare and of biogeographical interest species. Among these species, 05 are probably new to science, Edoughnura sp., second species of the genus Edoughnura endemic to the Edough massif, Deutonura sp., close to Deutonura zana endemic to Edough and Collo mountains, Protanura sp., endemic to the Jijel massif, Tetracanthella sp., found exclusively in moss and Heteromurus sp., was collected from several forest stations in Jijel. 04 new species for Algeria and North Africa fauna appear in the list : Microgastrura duodecimoculata, Proctostephanus cf. cidi, Entomobrya marginata and Isotomurus sp2. 02 other species remarkable for their biogeographic status are present in the surveyed localities : Sensillanura austriaca endemic to the Northern Alps and the Collo massif and Kenyura sp., new species for science, belongs to the genus Kenyura, which all the species known to date are endemic to the tropical zone Afro-American. The statistical results obtained from the samples in the forest of Bouraoui Belhadef, reveal the presence of a great specific richness of taxonomic interest in the samples of rotten wood, litter and moss than the soil. 06 cave species not yet identified at the specific level, were harvested during the prospection of 04 caves in North-East Algeria. 03 species new to science belong to the same genus Orchesella and another species probably new to science of the genus Etomobrya, all were collected near the caves. Several interesting species are being identified and descripted, which allow us to expect new discoveries.

Interrelations entre les gènes CYP450 et la réponse à l'hormonothérapie adjuvante chez la femme en pré-ménopause dans le cancer du sein.

2025-12-16T12:04:04Z

Interrelations entre les gènes CYP450 et la réponse à l'hormonothérapie adjuvante chez la femme en pré-ménopause dans le cancer du sein. Boucenna, Amira; Boudaoud, Kadidja; Satta, Dalila Tamoxifen, a selective estrogen receptor modulator acts as an anti-estrogen in ER+ breast cancer. It inhibits competitively the binding of estradiol to their receptors, the efficacy depends on its active metabolites, particularly endoxifen that is metabolized primarily by CYP2D6, CYP3A5, and CYP2C19 enzymes. The variability in the enzyme activity related to genetic polymorphisms that affect plasma concentrations of the metabolites, thus the efficacy and toxicity of the treatment. Nevertheless, contradictory results provided by many studies which do not currently allow predicting the relevance of CYP450 genotyping before prescription of tamoxifen. In our study, we evaluated the correlation between the main metabolites of tamoxifen and the incidence of relapses after 5 years of tamoxifen treatment as adjuvant, in a cohort of premenopausal Algerian patients with ER+ breast cancer. In addition, a molecular study is conducted to test the impact of pharmacogenetics of CYP2D6, CYP2C19 and CYP3A5 on the pharmacokinetics of tamoxifen. The analyzes revealed significant variability in plasma concentrations of tamoxifen and its metabolites in 143 patients that were included in our series. The genotyping of the CYP2D6, CYP2C19 and CYP3A5 genes was established for 100 samples by OpenArray® technique, based on real-time PCR that allows a high throughput genotyping. In this study we also highlighted the role of CYP2D6, thus plasma endoxifen levels under therapeutic threshold (C< 5.9 ng/ml) was observed in homozygous subjects with reduced alleles (red/red), nul alleles (nul/nul) or heterozygous subjects for the altered alleles (red/nul). In the pharmacodynamics study, our results indicate that patients with PM and IM phenotypes for the CYP2D6 gene are more likely to developed relapses during or post treatment with tamoxifen. Our research, the first performed in Algeria, provides crucial results on the influence of genetic factors, mainly CYP2D6 and to a minor degree CYP3A5 and CYP2C19, on non-genetic parameters (age, as well as clinical and pathological parameters such as tumor size, grade and stage), on the pharmacokinetics and pharmacodynamics of tamoxifen in the context of adjuvant treatment of hormone-positive breast cancer, and thus can be provided as support when introducing hormone therapy in ER+ breast cancer protocol. The best strategy to optimize tamoxifen treatment would consist of an adaptation of doses according to the CYP2D6 genotype accompanied by a TDM of endoxifen once the state of equilibrium reached.