Faculty of Natural Sciences, Life and Earth Sciences

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Start date: 2012

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    Effet de la méthode d’extraction aqueuse « macération et décoction » sur les différents composés et l'activité antioxydante des cladodes de l'Opuntia ficus-indica de la région de Ghardaïa
    (Faculté Science de la Nature et de la Vie et Sciences de la Terre - Université de Ghardaïa, 2025) HOUDJEDJE, Asma; BAAMMOUR CHIKH, Hanan
    The young cladodes of Opuntia ficus-indica, consumed as a vegetable, are a valuable source of bioactive compounds and nutrients, and are the subject of our study on their antioxidant activity and nutritional value by analyzing primary and secondary metabolites as well as mineral content. Moisture content, phytochemical composition, mineral analysis, and quantitative determinations: primary metabolites, total polyphenols, total flavonoids, and antioxidant capacity were carried out following established experimental protocols on the dry matter and/or the two aqueous extracts prepared by maceration (Ex M) and decoction (Ex D). The results revealed the presence of flavonoids, polyphenols, alkaloids, free quinones, tannins, terpenes, and reducing compounds, while anthraquinones and saponins were absent. Nutritional analysis showed moisture, fiber, lipid, and ash contents of 92 ± 0,03%, 7,135 ± 0,3%, 1,763 %, and 26,69 ± 0,37%, respectively. Protein content was higher in the maceration extract (14,46 ± 0,01%) than in the decoction extract (10,02 ± 0,02%). Carbohydrates were 56.47% in the dry powder, 49.65% in Ex D, and 55.66% in Ex M. The energy value was low in fresh material (22 kcal/100 g), while the dry matter extracts were much more energetic (273–281 kcal/100 g DM). Total polyphenols and flavonoids were also more abundant in the maceration extract (53,53 ± 0,04 μg GAE/mg and 150,4 ± 0,03 μg RE/mg, respectively) than in the decoction extract. The maceration extract also contained higher levels of minerals, particularly Zn²⁺, Mg²⁺, P, Ca²⁺, and K⁺. Antioxidant activity assessed by the DPPH assay showed a strong IC₅₀, comparable to ascorbic acid, with 42,731 ± 0,46 mg/ml for the maceration extract and 49,643 ± 1,9 mg/ml for the decoction extract. Total antioxidant activity was 35,08 ± 0,06 μg AAE/mg for Ex M and 30,9 ± 0,00 μg AAE/mg for Ex D. According to our study, higher extraction temperatures have a negative impact on the levels of secondary metabolites and nutritional compounds in the aqueous extracts of the cladodes, consequently reducing their antioxidant activity.
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    Valorisation agroalimentaire des dattes par la production de confiture : analyse technico-économique et optimisation du procédé de transformation
    (Faculté Science de la Nature et de la Vie et Sciences de la Terre - Université de Ghardaïa, 2025) DIAF, OMAR; OULAD YAHIA ILYES
    This research aims to evaluate three varieties of dates (Ghars, Azerza, Timdjouhart) to select the most suitable for producing a healthy, high-quality date jam, by leveraging abundant raw material supply, developing new industrial production methods, and supporting the economy. A series of chemical and physical analyses were carried out, examining pH, electrical conductivity, water content, dry matter, ash content, sugar content (Brix), titratable acidity, along with microbiological analyses, to determine the variety best suited nutritionally and technologically. Results showed the pH ranged from 5.83 for Ghars, 6.18 for Azerza, and 5.97 for Timdjouhart, values close to neutrality, which are good for food preservation. Electrical conductivity was highest in Ghars (1208 µS/cm), followed by Timdjouhart (1177), and lowest in Azerza (1072), reflecting differences in mineral salt concentration. Regarding moisture, Timdjouhart had the lowest water content (35%) compared to Ghars (39%) and Azerza (38%), favoring higher sugar concentration and a firmer texture for the jam. Dry matter was highest in Timdjouhart (65%), then Azerza (62%), and Ghars (61%), an important advantage that reduces cooking time and preserves nutrients. Ash content was 4.5% in Ghars, versus only 3% in Azerza and Timdjouhart. Brix measurements, indicating soluble sugar concentration, showed Ghars and Timdjouhart reaching a high, identical rate (53.5%), significantly higher than Azerza (46%), offering natural sweetness and better preservation. Titratable acidity was highest in Timdjouhart (0.203), followed by Azerza (0.159), then Ghars (0.121), ensuring a good balance between sweetness and acidity and limiting microbial growth. In light of these results, Timdjouhart appears the most suitable variety for producing a healthy, high-quality date jam. It combines high dry matter content, which reduces cooking time, rich sugar content for natural sweetness and good preservation, and balanced acidity providing pleasant flavor and microbiological safety. These features make Timdjouhart the ideal choice for a nutritious jam with firm texture and harmonious taste.
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    Etude de l’effet de stress hydrique sur les variétés de petit pois(pisumsativum L)
    (Faculté Science de la Nature et de la Vie et Sciences de la Terre - Université de Ghardaïa, 2025) Beldjoudi, Maroua; Bouregba, Maroua
    An experimental study was conducted in 2025 at the Faculty of Natural, Life, and Earth Sciences in Ghardaïa, aiming to evaluate the effect of water deficit on two pea varieties (Kelvedon and Onward) through four irrigation levels (5%, 10%, 15%, 20% ). Statistical analyses revealed that water stress led to a significant decrease in the studied morphological and physiological parameters, including leaf number, stem and root length, as well as the fresh and dry weight of both aerial and underground parts, reflecting the direct negative impact of water shortage on pea growth and productivity.
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    Caractérisation des sols agricoles dans une région aride : cas de Mansoura (Ghardaïa)
    (Faculté Science de la Nature et de la Vie et Sciences de la Terre - Université de Ghardaïa, 2024) ACHOUR, Tarek; MEKECHTI, Chouaib
    This study was conducted in the Saharan commune of Mansoura, in the south of the province of Ghardaïa, with the aim of characterizing the physicochemical properties of agricultural soils and assessing the impact of cropping systems on their quality. Using 48 soil samples collected from various types of agricultural land (cereals, olive trees, palm trees) and uncultivated control plots, several parameters were analyzed, including pH, electrical conductivity (EC), calcium carbonate (CaCO₃) content, organic matter (OM), and texture. The results revealed high spatial variability between the study sites. Soil pH was generally neutral to slightly alkaline (7.185 to 7.795), which is characteristic of arid environments, although there were differences between plots depending on agricultural practices. Electrical conductivity revealed moderate to high salinity levels (0.2885 dS/m to 8.595 dS/m), particularly in olive groves (8.595 dS/m), suggesting salt accumulation due to insufficiently controlled irrigation. CaCO₃ content (3.92% to 17.54%) varies considerably, reflecting a local geological influence, with higher levels in some areas with calcareous substrates. As for organic matter (2.13% to 3.10%), it is generally low, reflecting the low biological productivity of arid soils, but a few plots show a significant improvement where sustainable practices (organic amendments, crop rotations) are implemented. Texturally, the majority of soils have a sandy to sandy- clayey texture, which reduces their water and nutrient retention capacity, and poses a major constraint to the sustainability of agricultural systems. Overall, the results confirm that soil quality in this region is strongly influenced by agricultural practices and highlight the urgent need to adopt sustainable management strategies to preserve soil fertility, optimize water use, and improve the resilience of agroecosystems to the extreme climatic conditions specific to arid zones.
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    Prédiction de la toxicité de Docetaxel par le dosage de l'Alpha-1-Glycoprotéine Acide dans le cancer du sein
    (Faculté Science de la Nature et de la Vie et Sciences de la Terre - Université de Ghardaïa, 2024) DJEROUNI, Mohamed
    Background: Docetaxel is a cytotoxic drug used in different types of cancer. However, the tolerance is marked by hematological toxicity especially neutropenia. Distribution of Docetaxel is assured by lipoproteins, albumin and α1-acid glycoprotein. It is demonstrated that docetaxel clearance was related to α1-acid glycoprotein level. Increased estrogen level is associated with decreased plasmatic concentration of α1-acid glycoprotein, and unbound docetaxel is correlated with α1-acid glycoprotein. In fact, this study solves the hypothesis that women who have a decreased levels of α1-acid glycoprotein are more exposed to develop severe toxicities of docetaxel chemotherapy. Patients: Women diagnosed with breast cancer undergoing chemotherapy by docetaxel Methods: Pretreatment dosage of α1-acid glycoprotein and check in of the neutropenia and adverse events of Docetaxel Results: Thirty patients are included in the study, 23 patients (76,66%) developed neutropenia. α1-acid glycoprotein is correlated to neutropenia (Khi2 18.3, p<0,0001) Conclusion: α1-acid glycoprotein Level can be considered as independent factor to Docetaxel toxicity, results to be confirmed by more investigations with large sample.
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    Évaluation de quelques activités biologiques des extraits aqueux et polysaccharidiques de dattes (Phoenix dactylifera L.) de la région de Ghardaïa
    (Faculté Science de la Nature et de la Vie et Sciences de la Terre - Université de Ghardaïa, 2025) ABISMAIL HEDJOUDJA, Nacer; ABDELAZIZ, Aissa
    The richness of dates in bioactive compounds makes them a valuable natural source of molecules with therapeutic potential, particularly in the prevention and management of metabolic diseases such as type 2 diabetes. This study assessed the antioxidant and antidiabetic activities of aqueous (EAT, EAO) and polysaccharide (EPT, EPO) extracts of two local date varieties from Ghardaïa, T’dalet and Ouarous. Extraction yields revealed high rates for aqueous extracts 59.63% for T’dalet and 62.31% for Ouarous, reflecting the richness of these fruits in water-soluble compounds, while polysaccharide extracts showed modest yields 9.8% and 11.02%, respectively. Nevertheless, it should be noted that, despite being lower than those of the aqueous extracts, these yields are substantial and rank among the highest reported in the literature. Antioxidant activity, assessed by the DPPH and FRAP tests, showed that the polysaccharide extracts generally possessed a higher antioxidant power than the aqueous extracts, with lower IC50 values 1.65 ± 0.13 mg/mL for EPT and 2.34 ± 0.37 mg/mL for EPO in the DPPH test; 1.48 ± 0.06 and 1.53 ± 0.14 mg/mL in the FRAP test, although still lower than the efficacy of vitamin c 0.0027 mg/mL. Regarding antidiabetic activity, measured by the α-amylase inhibition test, the extracts showed IC50 values between 0.57 and 1.07 mg/mL, reflecting a significant inhibition of the enzyme. Compared to acarbose, the reference drug, whose IC50 reported in the literature generally varies between 0.1 and 0.5 mg/mL, date extracts are in an interesting efficacy zone: the aqueous extract of the Ouarous variety (0.57 ± 0.09 mg/mL) is close to the performance of the control, while the other extracts show a slightly lower activity. These results suggest that local dates, particularly the Ouarous variety, constitute a promising source of natural compounds with antioxidant and antidiabetic potential, which can serve as a basis for the development of food supplements or functional ingredients for the prevention and management of type 2 diabetes.
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    Synthèse bibliographique des travaux sur le régime alimentaire du criquet pèlerin Schistocerca gregaria (Forskål, 1775) (Orthoptera - Cyrtacanthacridinae) en Algérie
    (Faculté Science de la Nature et de la Vie et Sciences de la Terre - Université de Ghardaïa, 2025) HADJ MAHAMMED, Zineb
    The study of the diet of the desert locust (Schistocerca gregaria) was carried out in distinct biotopes: in the Algerian Sahara (central and southern), Adrar, Biskra, and Ouargla. In the Algerian Sahara, the desert locust consumed 32 of the 97 plant species inventoried (32.99%), belonging to 17 of the 34 botanical families present (50%), with a marked preference for Poaceae, followed by Asclepiadaceae, Asteraceae, Zygophyllaceae, and Amaranthaceae. In the Adrar region, the desert locust consumed 31 of the 61 plant species inventoried (50.81%) and 14 of the 24 botanical families present (58.33%), with a strong preference for Poaceae (12 species), followed by Amaranthaceae and Cucurbitaceae (3 species each), which reflects a good capacity for adaptation to the local flora. In the Biskra region, the desert locust consumed 34 of the 35 plant species inventoried (97.14%) and 14 of the 15 botanical families present (93.33%), with a clear preference for Poaceae (13 species), followed by Amaranthaceae (5 species) and Asteraceae (3 species), which demonstrates a strong dietary plasticity in an environment rich in plant resources. In the Ouargla region, the desert locust consumed 10 of the 26 plant species inventoried (38.46%) and 4 of the 9 botanical families present (44.44%), with a clear dominance of Poaceae (7 species), while Asteraceae, Fabaceae and Polygonaceae are represented by a single species each, reflecting a more restricted diet linked to less diverse vegetation.
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    Etude de l’extraction des glycosides de stéviol à partir de Stevia et évaluation de leur efficacité en tant qu’édulcorants naturels.
    (Faculté Science de la Nature et de la Vie et Sciences de la Terre - Université de Ghardaïa, 2025) BAHMANE, Touria; CHEBIHI, Nawal Khadîdja
    Stevia rebaudiana, better known as Stevia, is a plant native to South America. It is distinguished by its high content of steviol glycosides (Stevioside and Rebaudioside A), compounds with intense sweetening power, as well as the presence of essential nutrients beneficial to the body. Used as a natural alternative to sugar, Stevia is a zero-calorie solution that helps limit the harmful effects of overconsumption of sugar. In this study, we performed an extraction of steviol glycosides by decoction, infusion, and starting with washing and drying of Stevia leaves. We also performed a dosage of total sugars. Our results reveal that the nutritional composition of stevia leaves was As follows: lipids 7%, ash 12.39%, humidity83.46, For the extraction of stevioside, we used the infusion and decoction methods, as well as distilled water as a solvent. For the infusion, we soaked 150 g of the plant in 4 L of distilled water at 80 °C. Then, we filtered and soaked a second time with 2 L of distilled water. Then, we filtered and soaked a third time with 1 L of distilled water. After soaking, we obtained: 4 liters at 16.16 mg/ml, 2 liters at 8.2 mg/ml and 1 liter at 1.08 mg/ml. For the decoction, we boiled 150 g of the plant in 4 liters of distilled water at 80 °C, then filtered and boiled a second time with 2 liters of distilled water, then filtered and boiled a third time with 1 liter of distilled water. In the decoction, we obtained: 4 liters 36 mg/ml, 2 liters 33.6 mg/ml, 1 liter 28 mg/ml. For electrocoagulation: infusion 1 liter of 10.22 mg/ml, 2 liters 33 mg/ml, 4 liters 39 mg/ml, decoction 1 liter 27 mg/ml, 2 liters 15 mg/ml, 4 liters 20 mg/ml. The amount of stevioside after lyophilization: infusion 1 liter 2.1412%, 2 L 1.5812%, 4 L 2.1410%, decoction 1 L 2.6715%, 2 L 2.6720%, 4 L 2.6722%. For electrocoagulation: infusion 1 L: 1.5511%, 2 L: 0.3398%, 4 L: 1.1214%, decoction 1 L: 1.0664%, 2 L: 0.6094%, 4 L: 2.2147%. Finally, we conducted a taste test to determine the sweetness and acceptability of the sterilized stevioside sweetener. We sweetened two components: hot coffee and cold plain yogurt. Fifteen tasters tested the sweetness levels (low, medium, and high) and compared them to white sugar to determine acceptability. The results were as follows: Steviol provides sufficient sweetness at a small dose. Optimal dose: 0.02-0.03% for yogurt, 0.01-0.02% for coffee. Secondary taste: grassiness is the most prominent (especially in coffee). Consumer acceptance: 75-82% acceptance rate for steviol, compared to 85-92% for sugar. Taste tests with different concentrations (0.01%, 0.02%, 0.03%) to determine the optimal percentage for each product.
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    Évaluation de l’effet herbicide de deux Euphorbiacées : Caractérisation phytochimique et évaluation de l’impact sur la germination d’une espèce adventice.
    (Faculté Science de la Nature et de la Vie et Sciences de la Terre - Université de Ghardaïa, 2025) DAHOU, Manel; SOUILEM, Messaouda
    As part of the valorization of Saharan plant resources and the search for bio-control methods, this study focuses to evaluate the herbicidal effect of two species from the Euphorbiaceae family such as Euphorbia guyoniana and Euphorbia retusa. The study encompasses both a phytochemical analysis of aqueous leaf extracts and an évaluation of their effects on seed germination. Particular attention was given to the weed species Malva aegyptiaca and to an important cereal crop, durum wheat (Triticum durum). The extracts were obtained using the reflux method, yielding 6.5% for E. guyoniana and 6% for E. retusa. Phytochemical screening revealed richness in bioactive secondary metabolites. Some compounds are absent in specific extracts, including alkaloids in E. guyoniana and saponins in E. retusa. The biological evaluation under controlled conditions showed significant inhibition of Malva aegyptiaca seed germination , whereas wheat germination was not significantly affected according to Probit. Interestingly, low extract concentrations exhibited stimulatory effects on root and shoot growth. This study highlights the selective bioherbicidal potential of Euphorbia extracts and their promise as natural alternatives to synthetic herbicides in sustainable agriculture.
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    Etude épidémiologique rétrospective des méningites bactériennes au niveau de la wilaya de Ghardaïa
    (Faculté Science de la Nature et de la Vie et Sciences de la Terre - Université de Ghardaïa, 2025) DJEBRIT, BOUCHRA
    Meningitis is an inflammatory process, generally of infectious origin, that affects the meninges. It is classified according to its cause into viral, bacterial, fungal, and parasitic meningitis. Although less common, bacterial meningitis remains the most severe form, with high mortality and neurological morbidity rates, despite advances in diagnosis and treatment. The aim of this study was to assess the frequency, describe the cytobacteriological and clinical characteristics, and identify the main pathogens responsible for bacterial meningitis. A retrospective study conducted over a four-year period (January 2020 to August 2025) included 42 hospitalized patients who were managed for confirmed or suspected bacterial meningitis, based on cytobacteriological and biochemical cerebrospinal fluid (CSF) analysis, at the microbiology laboratories of three hospitals in the Wilaya of Ghardaïa: the Specialized Hospital "EHS Mother and Child" Gaddi Bakir in the neonatology and pediatrics departments of Ghardaïa, the Public Hospital Establishment Tirichine Brahim (EPH of Ghardaïa), and the Public Hospital Establishment 18 February (EPH of Metlili).The results showed that the overall male-to-female ratio was 1.625 in favor of males (61.90%). Infants under 2 years of age were the most affected (47.62%); in this age group, the main clinical signs included fever (100%), bulging fontanelle (50.5%), hypotonia (50%), and vomiting (44.4%). In patients aged 2 years and older, the main clinical signs were fever (100%) and headache (84.61%), followed by meningeal irritation signs, including neck stiffness (61.54%), Kernig’s, and Brudzinski's signs (61.53%). Cerebrospinal fluid cyto-biochemical analysis revealed a predominance of turbid appearance (64.1%), hyperleukocytosis (leukocytes > 500) in 57.14% of cases, hypoglycorrhachia (71.43%), and hyperproteinorrachia (90.48%). The causative pathogen was identified in 10 patients (23.8%), with the majority of patients showing negative CSF cultures. The main isolated pathogen was Streptococcus pneumoniae (90%), while Klebsiella pneumoniae was isolated in one patient. In total, 7 patients out of 42 with bacterial meningitis died, yielding a mortality rate of 16.6%. In light of these findings, bacterial meningitis predominantly affects infants and remains a severe condition with considerable mortality. Streptococcus pneumoniae continues to be the leading pathogen in bacterial meningitis.