http://depot.umc.edu.dz/handle/123456789/4160 2026-06-01T15:18:43Z 2026-06-01T15:18:43Z Khelfi, Sara Zerizer, Sakina Tebibel, Soraya http://depot.umc.edu.dz/handle/123456789/14827 2026-01-27T11:36:12Z 2023-11-18T00:00:00Z

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.

2023-11-18T00:00:00Z Khattabi, Latifa Chettoum, Aziez http://depot.umc.edu.dz/handle/123456789/14820 2026-01-20T13:51:11Z 2023-10-14T00:00:00Z

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.

2023-10-14T00:00:00Z Alloun, Wiem Kacem Chaouche, Noreddine http://depot.umc.edu.dz/handle/123456789/14815 2026-01-19T13:01:01Z 2023-07-20T00:00:00Z

Exploration of Algerian ecosystems for the selection of Actinobacteria belonging to the genus Streptomyces developing potentialities of PGPR and antagonists of wheat phytopathogens Alloun, Wiem; Kacem Chaouche, Noreddine This work aims to isolate Actinobacteria strains with a growth promotion ability and the biocontrol potential of Fusarium culmorum, the wheat root rot-causing fungi. The exploration of terrestrial and aquatic Algerian ecosystems, i.e. the wheat rhizosphere in the Tiffeche region (Souk-Ahras) and the aquatic sediments of Lake Oubeira (El Taref), respectively, resulted in 102 native isolates. Therefore, 37 have morphological and cultural characteristics similar to the genus Streptomyces. These isolates were screened for their plant growth-promoting traits. These activities consist of the production of hydrogen cyanide (HCN), ammonia (NH3), and indole-3- acetic acid (IAA), as well as in vitro antagonism against F. culmorum. Among the auxin family, IAA constitutes a crucial phytohormone regulating specific tropic responses of plants and functions as a chemical signal between host plants and their symbionts. IAA derived from Actinobacteria grown on agricultural waste represents a more economical alternative than its synthetic homologous. Rhizospheric isolate AW 22 was positive for HCN and NH3 production, growth inhibition of F. culmorum with an index of 67.320±8.99% and high IAA content of 23.999±1.126 μg. mL-1 in standard growth conditions on yeast-tryptone broth (YTB) amended with 0.2% (w/v) L-Tryptophan. Thus, the AW22 isolate was selected for a polyphasic chemotaxonomic characterization and the optimization of the production process of this phytohormone. Molecular and phylogenetic analysis identified isolate AW22 as Streptomyces rubrogriseus, and its sequence was deposited in Genbank under accession ID OP176004. Analysis of the putative IAA produced by S. rubrogriseus AW22 on YTB using thin-layer chromatography (TLC) and (HPLC) revealed Rf values equal to 0.69 and a retention time of 3.711 min, equivalent to the authentic IAA. Artificial intelligence-based approaches (i.e. Behnken design from response surface methodology (BBD-RSM) with artificial neural networks (ANNs) coupled with the genetic algorithm (GA)) were employed to bioengineer in vitro and silico a suitable medium for maximum IAA bioproduction. According to the Box Behnken Design matrix, data were based on empirical studies involving the inoculation of AW22 in various cultural conditions and low-cost feedstocks notably, the spent coffee grounds (SCGs). Four input variables comprising L-Trp (X1), incubation T° (X2), initial pH (X3) and SCG concentration (X4) were screened via Plackett-Burman design (PBD) and served as BBD and ANN-GA inputs. The IAA yield constituted the output variable (Y in µg. mL-1). Upon training the model, the optimal conditions suggested by the ANN-GA model were X1= 0.6%, X2= 25.8°C, X3 = 9, X4=30%). An R2 of 99.98%, adding to an MSE of 1.86x10-5 at 129 epochs, postulated higher reliability of the ANN-GA approach in predicting responses, compared with BBD-RSM modeling exhibiting an R2 of 76,28%. Using the process parameters generated by ANN-GA AW 22 achieved a maximum IAA yield of 188.290±0.38 µg. mL-1. This optimization resulted in a 4.55-fold and 4.46- fold increase in IAA secretion after eight days of incubation, corresponding to ANN-GA and BBD-RSM models, respectively. These results confirm the validity of both models in maximizing IAA yield from the multifunctional S. rubrogriseus AW22 isolated for the first time in Algeria.

2023-07-20T00:00:00Z Gares, Maroua Kacem Chaouche, Noreddine Evidente, Antonio http://depot.umc.edu.dz/handle/123456789/14813 2026-01-19T11:58:15Z 2023-07-17T00:00:00Z

Recherche de micro-organismes producteurs d’hémi-cellulases à partir de la biomasse lignocellulosique ; valorisation des hémicelluloses dans les domaines des bio-polymères et les fermentations non agroalimentaires. Gares, Maroua; Kacem Chaouche, Noreddine; Evidente, Antonio The main objective of this work is to search for microorganisms capable of degrading lignocellulosic biomass by lignocellulosic enzymes and more particularly, hemicellulase. The exploration of soil samples from two forests and a former landfill in Constantine (Algeria), resulted in the selection of 16 microbial isolates. A single mold isolate (MGA) was selected for its high cellulase and hemicellulase activity. Molecular identification of MGA revealed it to be Aspergillus fumigatus ON226990. The selected strain was subsequently subjected to a scaling-up study to test its ability to grow and produce hemicellulase on a large scale. A. fumigatus showed an ability to grow in a liquid medium based on xylose as substrate, in 250 mL Erlenmeyer flasks, 2 and 20 liter bioreactors. In addition, three shaking speeds: 350, 500 and 650 rpm were tested in the 2 L bioreactor in order to follow the impact of the shear effect on the morphology of A. fumigatus. Indeed, this strain showed a certain ""robustness"" to the shear that can occur on an industrial scale; by increasing the agitation speed to 500 rpm, the mold forms free micro-pellets ensuring a good homogeneity in the culture medium. On the other hand, at agitation speeds lower than 300 rpm, the mycelium develops as macro-pellets. Furthermore, according to HPLC analyses, A. fumigatus showed a very high potential for production of endo-1,4-β-xylanase and xylan 1,4-β xylosidase during using corn xylan as substrate in a 2-L bioreactor fermentation. The production process in liquid medium, remains very expensive because of the high price of pure substrate. Therefore, the interest is redirected to the valorization of Stipa tenacissima (Alfa) as raw material for the production of hemicellulase by A. fumigatus. It is important to emphasize that this work is the first to have exploited Alfa as a raw material for the production of enzymes without pretreatment by A. fumigatus. For this purpose, the polymers of dried and ground esparto samples were analyzed by chemical methods (strong and dilute acid). Indeed, the results obtained by HPLC analysis show that this herb is mainly composed of 46-44% of cellulose and 12.5-13.33% of hemicellulose. On another aspect, experiments were statistically planned with the Box-Behnken design to optimize the production of xylanase and cellulase by A. fumigatus, using Alfa as the only carbon source, where the inputs are; pH, temperature, humidity and incubation time. The optimal conditions established by the response surface method for maximum xylanase production (841.78 U/gds) are: pH; 4.5, temperature; 30 °C, humidity; 89.19% and a fermentation time of 144 h, and for maximum cellulase production (74.41 U/gds): pH; 6, temperature; 31.61 °C, humidity; 90% for 144 h incubation. Subsequently, 11 factors, including organic and inorganic nitrogen sources, carbon and phosphorus sources, were screened using the Plackett-Burman design to investigate their influence on xylanase production. Malt extract, MgSO4, NaNO3 and (NH4)2SO4 were selected for further optimization using the Central-Composite design. The maximum xylanase production under the optimized conditions is 1659.41 U/gds, which represents a nearly 3-fold increase over the first xylanase production before optimization. Furthermore, the enzyme activity produced by A. fumigatus under the optimized conditions, is more efficient than that of commercial enzymes. This enzyme complex also showed its efficiency in the saccharification of Alfa, wheat straw, oat straw and wheat bran, compared to the saccharification of these substrates by commercial hemicellulase. A saccharification rate of 35.82% was observed with wheat bran, oat straw (25.91%), Alfa (21.29%) and wheat straw (2.29%) after 24 h of incubation. Finally, a cost-effectiveness study confirmed the value of xylanase production by A. fumigatus; enzyme production with Alfa is 3 times cheaper than with pure commercial xylan.

2023-07-17T00:00:00Z