Argan Research Articles

Mediterranean agro-pastoral systems and agro-ecology: A cross-analysis of two situations in Corsica and in the argane tree area in Morocco.

Mediterranean agro-pastoral systems and agro-ecology: A cross-analysis of two situations in Corsica and in the argane tree area in Morocco.

In Vitro Root Induction from Argan (Argania spinosa (L.) Skeels) Adventitious Shoots: Influence of Ammonium Nitrate, Auxins, Silver Nitrate and Putrescine, and Evaluation of Plantlet Acclimatization.

Argania spinosa (L.) Skeels is an endangered plant species endemic to Morocco. In recent years, attempts to develop in vitro regeneration systems for this species were made. However, rooting and acclimatization of in vitro plants have been a bottleneck for successful propagation. In the present study, the effects of different concentrations of auxins, putrescine, silver nitrate (AgNO3) and ammonium nitrate on the in vitro rooting of adventitious shoots of two argan genotypes “Mejji” and “R’zwa”, were evaluated. The highest rooting percentages (86.6% in “Mejji” and 84.4% in “R’zwa”) were observed on Murashige and Skoog (MS) medium modified by reducing the ammonium nitrate concentration and supplemented with 1.5 mg L−1 indole-3-butyric acid (IBA), 0.5 mg L−1 1-naphthalene acetic acid (NAA), 2 mg L−1 AgNO3 and 160 mg L−1 putrescine. This medium resulted in the development of a good root system after only 10 days of culture. Plantlet acclimatization was carried out using different substrate mixtures, and high survival rates (100%) were observed when the substrate contained either peat alone or a sand–peat mixture (1:1, w/w). The high percentages of rooting and acclimatization reported in the present study are of high importance for rapid and large-scale propagation of this endangered species.

Understanding anatomical plasticity of Argan wood features at local geographical scale in ecological and archaeobotanical perspectives

The emergence of the Argan tree as an agricultural, pastoral, cultural, economic and ecological keystone species in Southern Morocco is considered to be linked to the settlement of agropastoral communities that favored its expansion. Nevertheless, the use and exploitation of Argan tree is documented by both few medieval written sources and archaeobotanical studies, from a single location, Îgîlîz (Toughmart, Morocco), a famous medieval site of the Anti-Atlas Mountains. Therefore, data remain scarce regarding the type of Argan communities exploited at this period. In order to document this question, a quantitative eco-anatomical approach aiming to understand variations of wood characters involved in sap conduction and reserve storage, is developed from modern samples collected in the area of Îgîlîz. Results show that diameter of branches and environmental factors are the major parameters explaining plasticity of wood anatomical characters. Quantitative eco-anatomical features of Argan archaeological charcoal confronted to two statistical models, allow assessing both the diameter of the branches from which it derives and the agro-ecological conditions of tree growth and development. This preliminary study may be considered as a relevant and pioneering work for the understanding of the eco-history of the Argan tree, and of its use and exploitation during the past.

In Vitro & In Vivo Anti-Hyperglycemic Potential of Saponins Cake and Argan Oil from Argania spinosa.

The Argan tree (Argania spinosa. L) is an evergreen tree endemic of southwestern Morocco. For centuries, various formulations have been used to treat several illnesses including diabetes. However, scientific results supporting these actions are needed. Hence, Argan fruit products (i.e., cake byproducts (saponins extract) and hand pressed Argan oil) were tested for their in-vitro anti-hyperglycemic activity, using α-glucosidase and α-amylase assays. The in-vivo anti-hyperglycemic activity was evaluated in a model of alloxan-induced diabetic mice. The diabetic animals were orally administered 100 mg/kg body weight of aqueous saponins cake extract and 3 mL/kg of Argan oil, respectively, to evaluate the anti-hyperglycemic effect. The blood glucose concentration and body weight of the experimental animals were monitored for 30 days. The chemical properties and composition of the Argan oil were assessed including acidity, peroxides, K232, K270, fatty acids, sterols, tocopherols, total polyphenols, and phenolic compounds. The saponins cake extract produced a significant reduction in blood glucose concentration in diabetic mice, which was better than the Argan oil. This decrease was equivalent to that detected in mice treated with metformin after 2–4 weeks. Moreover, the saponins cake extract showed a strong inhibitory action on α-amylase and α-glucosidase, which is also higher than that of Argan oil.

A randomized controlled trial to compare the effectiveness and safety of adsorbent lotion containing tapioca starch, spent grain wax, Butyrospermum parkii extract, argania spinosa kernel oil, aloe barbadensis, rosehip oil, and allantoin with a low-potency topical corticosteroid in the treatment of intertrigo.

Intertrigo is an inflammatory skin-fold condition. Candida infections may occur concurrently or afterward. Topical corticosteroids may reduce inflammation but exacerbate Candida infections. The treatment is contentious. To evaluate the efficacies and safety of adsorbent lotion containing tapioca starch, spent grain wax, Butyrospermum parkii extract, argania spinosa kernel oil, aloe barbadensis, rosehip oil, and allantoin for the treatment of mild-to-moderate intertrigo, relative to 1% hydrocortisone cream. This randomized, double-blinded study enrolled 40 intertrigo patients. Twice daily, 20 patients applied adsorbent lotion while the remainder used 1% hydrocortisone cream. Efficacy evaluation, skin biophysical measurements, skin tolerability, safety, and visual analog scale (VAS) patient-satisfaction scores were evaluated at baseline and Week 2. The adsorbent lotion showed higher complete cure rates for color, partial epidermal loss, papules/pustules/vesicles/patches, dryness, and scaling than the corticosteroid without statistical significance. Adsorbent lotion demonstrated significantly higher reduction in pruritus than the corticosteroid treatment. Reduction of erythema level using Mexameter and VAS patient-satisfaction scores were not statistically different between adsorbent lotion and hydrocortisone cream. No adverse effects or superimposed infections were reported. The anti-inflammatory efficacies of adsorbent lotion and low-potency steroid were equivalent. The lotion was safe and produced excellent pruritus reduction. Patient satisfaction was high.

The Comparative Study of Efficacy between Cream Containing Spent Grain Wax, Shea Butter, Argania spinosa Kernel Oil, Tapioca Starch, and 1% Hydrocortisone Cream in The Treatment of Intertrigo

Background: Intertrigo is a common skin problem. Although there was no standard treatment due to few clinical studies, topical corticosteroids, and drying agents such as talcum are usually used to treat intertrigo, and the side effects of these agents should be monitoring. Objective: To compare the efficacy between cream containing spent grain wax, shea butter, Argania spinosa kernel oil, Tapioca starch, and 1% hydrocortisone cream for the treatment and prevention of intertrigo. Materials and Methods: Fifty-eight lesions from 18 intertrigo patients were randomized into two groups, HCC group, which is the 1% hydrocortisone cream and STIMU-TEX AS group, which is the combination cream of spent grain wax, shea butter, Argania spinosa kernel oil, and tapioca starch. The evaluations were performed at baseline, the first week, the second week, and the fourth week via scoring of skin redness, pruritus, excoriation, Dermatology Life Quality Index (DLQI), and patient satisfaction. The adverse events were also recorded. Results: All participants completed the protocol. At the end of the study, 27 of 29 lesions were completely cured in the HCC group, and 25 of 29 lesions cured in the STIMU-TEX AS group. Although the number of complete remissions of the STIMU-TEX AS group was inferior to the HCC group, it was not statistically significant. There was no relapse within two weeks after completing the treatment. Conclusion: The outcomes showed no statistically significant difference between both groups; thus, the cream may be considered as an alternative treatment and prevention of intertrigo. Keywords: Intertrigo, Spent grain wax, Shea butter, Argania spinosa kernel oil, Tapioca starch

Programmed cell death in Argania spinosa fruit endocarp development

Argania spinosa, belongs to the family Sapotaceae is endemic to the South western Algeria in northen Tindouf. This species plays essential local ecologi-cal and economical roles. The fruit seeds are used to produce precious oil that is, mainly used in cooking and believed to have medicinal properties (antiproliferative, Hypolipidemic, hypocholesterolemic, antiatherogenic, an-tiradical). However, this valorization of the argan trees raises a problem. The major challenge for current territory planning is to enhance the propagation of argan trees in natural conditions. Natural seeds propagation is scarce. The argan endocarp is hard and thick, resulting in an obstacle to germination. In this study, we have carried out in-depth anatomical investigation of endo-carp of A. spinosa using Electron Microscopy to clarify the exogenous dor-mancy observed in argan seeds. This study demonstrated that the cell walls of sclerenchyma cells, before the cell dies, frequently undergo secondary modifications, such as lignification. Sclerenchyma cells are dead because thick cell walls perform the mechanical function. It’s constituted of characte-ristic cells with thick lignified layer, with a porous structure. It’s protects seed against desiccation. The protoplast is no longer needed, there for its eliminated. The sclerenchyma cells appear to have a cell death program, in which the coupled. Physical or chemical treatments can be recommended to effectively eliminate integumentary inhibition of A. spinosa in areas in which biodiversity is threatened.

Protective effect of argan oil on DNA damage in vivo and in vitro

Background: Iron-overload is a well-known cause for the development of chronic liver diseases and known to induce DNA damage. Material and methods: The protective effect of argan oil (AO) from the Argania spinosa fruit and olive oil (OO) (6% AO or OO for 28 days) was evaluated on a mouse model of iron overload (3.5mg Fe2+/liter) and in human fibroblasts where DNA damage was induced via culture under hyperoxia (40% oxygen). Results: Iron treatment induced DNA damage in liver tissue while both oils were able to decrease it. We confirmed this effect in vitro in MRC-5 fibroblasts under hyperoxia. A cell-free ABTS assay suggested that improvement of liver toxicity by both oils might depend on a high content in tocopherol, phytosterol and polyphenol compounds known for their antioxidant potential. The antioxidant effect of AO was confirmed in fibroblasts by reduced intracellular peroxide levels after hyperoxia. However, we could not find a significant decrease of genes encoding pro-inflammatory cytokines (TNFα, IL-6, IL-1β, COX-2) or senescence markers (p16 and p21) for the oils in mouse liver. Conclusion: We found a striking effect of AO by ameliorating DNA damage after iron overload in a mouse liver model and in human fibroblasts by hyperoxia adding compelling evidence to the protective mechanisms of AO and OO.

Comparison and correlation of phytochemical content with antioxidant potential of different parts of Argan tree, Argania spinosa L.

The Argan tree or Argania spinosa L. is a plant in the Sapotaceae family. It is an endemic tree from Morocco. This study aims to evaluate the phytochemical and antiradical potential of different parts of Argan for the further valorization of this organic material. Seeds, kernels, pulps, leaves, and branches were targeted for this purpose and were soxhlet extracted with methanol. Amongst the different parts, leaves displayed the greatest DPPH radical scavenging ability with an IC50 value (4.37 µg mL-1) close to that of ascorbic acid (1.97 µg mL-1). This observation was true for the ABTS assay as well. Accordingly, leaf extract was also the highest in polyphenols content (TPC) content, while seeds recorded the lowest value. The results were not so different for the flavonoid content, where leaf extract recorded the highest content. The leaves and branch of Agran seem to be the richest in antioxidant agents, as shown by the gathered data and results. Hence, it could be used as an important source of natural antioxidants.

The use of payments for environmental services in the development of sustainable tourism in the Arganeraie Biosphere Reserve in Morocco

The Arganeraie (forests of argan trees) is one of the most important natural resources of Morocco but it faces a serious risk of degradation or even extinction. It is therefore essential to develop a model of sustainable tourism that can help to preserve this natural heritage, especially given the ever growing number of tourists. The purpose of this article is to analyze the concept of “payments for environmental services” (PES) as a method of collecting revenue to create a sustainable and structured touristic offering and to preserve the natural heritage in the region of Souss-Massa. This exploratory study is based on qualitative data collected during interviews with 80 tourists visiting Souss-Massa. It was found that the respondents were interested in the natural attributes of sites they visited and expressed their willingness to protect this natural heritage by paying for environmental services.

An efficient regeneration pathway through adventitious organogenesis for the endangered Argania spinosa (L.) Skeels

An efficient in vitro propagation system through adventitious organogenesis is reported for argan (Argania spinosa (L.) Skeels). Seed germination of two argan genotypes, ‘Mejji’ and ‘R’zwa’, was evaluated under different treatments. Afterwards, the effects of different factors on adventitious shoot bud induction, shoot multiplication, elongation and rooting were evaluated. The findings of this study showed that soaking argan seeds in GA3 during 12 h speeds germination increases the germination percentage. Besides, the use of a sucrose-free medium, without ammonium and with a low nitrate concentration significantly increased the germination percentage. To induce organogenesis, different seedling-derived explants were used. However, epicotyl segments were the only explants capable of regenerating adventitious shoot buds. Highest organogenesis percentage (79.17%) was observed in genotype ‘Mejji’ on Murashige and Skoog (MS) medium containing 2 mg L−1 6-benzylaminopurine (BAP) under dark conditions. Adventitious shoot bud multiplication was performed on MS medium supplemented with different combinations of BAP and GA3. The highest number of adventitious shoot buds per explant (4.0) was observed on MS medium containing 1 mg L−1 BAP and 2 mg L−1 GA3. Regarding in vitro root induction, it was found that combining indole-3-butyric acid (IBA) and putrescine is necessary for rhizogenesis. The highest rooting percentage (56.66% in genotype ‘R’zwa’) was observed on MS medium supplemented with 1.5 mg L−1 IBA and 160 mg L−1 putrescine, with an average number of 2.74 roots per shoot and an average root length of 1.93 cm. The regenerated plantlets were successfully acclimatized and showed normal growth and development.

Remotely Sensed Phenology Monitoring and Land-cover Classification for the Localization of the Endemic Argan Tree in the Southern-west of Morocco

ABSTRACT Argania spinosa also known as the argan tree is an endemic plant of Morocco. Despite having the ability to subsist in extreme drought conditions, it is threatened by soil land clearing, overexploitation, and absence of natural regeneration, causing a worrying decline in both spatial extent and density. The spatial extent of dryland forests is debated, as estimates of forest areas in drylands are uncertain. The present study aims to map and locate the spatial distribution of the argan trees at Smimou community located in Essaouira province, south-eastern Morocco, using satellite images and a double-classification process to overcome separability problems. The work focuses on the characterization and comparison of the unique phenological patterns of argan with the other present land-cover classes. NDVI products were derived from a Sentinel-2 time-series covering one year (2018 to 2019), then ground samples were used to extract phenological profiles at parcel level then at tree level, to feed representative calibration samples to Support Vector Machine classifier. The outcome was integrated with an elevation model in a Decision Tree to reclassify mixed areas. The results indicated an F1-score and an overall accuracy of 91.27% and 92.60% respectively, a promising technique for updating argan extent at national scale.

Comparative Oil Composition Study of the Endemic Moroccan Olive (Olea europaea subsp. maroccana) and Wild Olive (var. Sylvestris) in Central West Morocco

Six wild olive subspecies (Olea europaea L.) are currently recognised globally, with two taxa cooccurring in the argan tree area in Central West Morocco: the widespread Mediterranean subspecies europaea var. Sylvestris (the so-called oleaster) and the microendemic subspecies maroccana. Despite its taxonomic and ecological importance, the chemical composition of subsp. maroccana oil remains poorly known. Therefore, the aim of this study is to investigate the oil content and the chemical composition of subsp. maroccana and var. Sylvestris as well as comparing their proprieties during two consecutive years (2017 and 2018) from the same geographical area. The fatty acid and the sterol compositions were analysed using gas chromatography. Additionally, the tocopherol content was determined using high-performance liquid chromatography. The total amount of unsaturated fatty acids was higher in maroccana (85.24%) than that in oleasters (79.05%). Additionally, the tocopherol and phytosterol content of the maroccana oil (1232.35 mg/kg and 312.75 mg/100 g, resp.) was approximately twofold higher than in oleasters (661.35 mg/kg and 210.06 mg/100 g, resp.). Analysis of variance and principal component analysis (PCA) of the chemical composition highlighted a significant difference between the quantitative and qualitative properties of their oil. Finally, these findings suggest that maroccana oil could be considered as a potential source of vitamin E, essential fatty acids, and sterols and can provide a nutraceutical oil for the local population. While this work contributes to the study of olive tree biodiversity, further investigations are still necessary to guide the putative nutraceutical use of subspecies maroccana.

Climate and land-use effects on hydrological and vegetation signals during the last three millennia: Evidence from sedimentary leaf waxes in southwestern Morocco

The southwest of Morocco is considered to be an area of refuge within the Mediterranean region, hosting the endemic tropical Argan tree. This region is presently subject to severe droughts, desertification and land degradation, and likely facing increased climate variability and socio-economic stress in the future. Here, we use the stable hydrogen and carbon isotope composition (δD and δ13C) of plant-waxes in a high-resolution marine sediment core (GeoB8601-3) collected off Cape Ghir in southwestern Morocco, in combination with published data on pollen and XRF element ratios from the same archive. We aim to reconstruct the hydroclimate and vegetation history during the last 3000 years. Stable carbon isotope compositions of leaf waxes (δ13Cwax) show that natural vegetation in southwestern Morocco consists of C3 plants. Minor variations in δ13Cwax were positively correlated to changes in stable hydrogen isotope compositions of leaf waxes (δDwax) before 700 CE. Changes in rainfall amounts and water use efficiency indicate a clear vegetation response to precipitation changes and thus to climate forcing. After 700 CE, δDwax and δ13Cwax became de-coupled suggesting that the plant wax discharge and their isotope signals were no longer solely controlled by climate; the waxes likely mainly originate from the lowlands and carry an enriched (dry) δD signal but a depleted 13C signature. The depletion of δ13Cwax correlates with the increase of Argan pollen concentration in the record. The period between ~700 and 900 CE coincides with the Arabization of Morocco which had an impact on the demographic composition of the country leading to new agricultural habits and, as a result, on the land-use triggering a higher erosion of lowland material by the Souss River.

Floristic biodiversity, biogeographical significance, and importance of Morocco's Arganeraie Biosphere Reserve.

The coastal and subcoastal areas of west-central Morocco (Safi to Draa River, the Souss Valley, and the southern part of the western High Atlas and northern and southern slopes of the western Anti-Atlas) are characterized by typical Infra-Mediterranean vegetation ranking them amongst the important of the remarkable borderlands of North Africa. The flora is determined by complex historical and environmental factors occurring since the Tertiary period. The originality of this sector is due to the presence of the argan tree (Argania spinosa (L.) Skeels), Moroccan gum (Acacia gummifera Willd), olive trees (Olea europaea L. subsp. maroccana (Greuter & Burdet) P. Vargas & al.), a thermophilic flora adapted to an arid climate with several endemic species. This flora constitutes the final barrier against the desert and is of environmental and socioeconomical interest. Leaves and fruits provide forage material, while wood is used for fuel. Argan fruits are collected for their oily constitutes and for nutritional, cosmetic, and medicinal properties. Additionally, many species of Argan ecosystems are used in medicine and cosmetics. Recognizing its ecological value and local economic importance, the Argan region was declared a UNESCO Biosphere Reserve in 1998. Despite their biogeographical, historical, and socioeconomic value, vegetation structures in west-central Morocco are vulnerable and threatened by human activities. They exhibit high levels of degradation due to increasing clearance, overgrazing, and overexploitation. The area requires high conservation priority and sustainable management strategies for key species and genetic diversity.

Argan Tree (Argania spinosa (L.) Skeels) Mapping Based on Multisensor Fusion of Satellite Imagery in Essaouira Province, Morocco

Tree species identification and their geospatial distribution mapping are crucial for forest monitoring and management. The satellite‐based remote sensing time series of Sentinel missions (Sentinel‐1 and Sentinel‐2) are a perfect tool to map the type, location, and extent of forest cover over large areas at local or global scale. This study is focused on the geospatial mapping of the endemic argan tree (Argania spinosa (L.) Skeels) and the identification of two other tree species (sandarac gum and olive trees) using optical and synthetic aperture radar (SAR) time series. The objective of the present work is to detect the actual state of forest species trees, more specifically the argan tree, in order to be able to study and analyze forest changes (degradation) and make new strategies to protect this endemic tree. The study was conducted over an area located in Essaouira province, Morocco. The support vector machine (SVM) algorithm was used for the classification of the two types of data. We first classified the optical data for tree species identification and mapping. Second, the SAR time series were used to identify the argan tree and distinguish it from other species. Finally, the two types of satellite images were combined to improve and compare the results of classification with those obtained from single‐source data. The overall accuracy (OA) of optical classification reached 86.9% with a kappa coefficient of 0.84 and declined strongly to 37.22% (kappa of 0.29) for SAR classification. The fusion of multisensor data (optical and SAR images) reached an OA of 86.51%. A postclassification was performed to improve the results. The classified images were smoothed, and therefore, the quantitative and qualitative results showed an improvement, in particular for optical classification with a highest OA of 89.78% (kappa coefficient of 0.88). The study confirmed the potential of the multitemporal optical data for accurate forest cover mapping and endemic species identification.

Comparative assessment of total phenolics content and in vitro antioxidant capacity variations of macerated leaf extracts of Olea europaea L. and Argania spinosa (L.) Skeels

The present study aims to ascertain the potency of Olea europaea L. and Argania spinosa (L.) Skeels leaves extracts in natural phenolic compounds of variable antioxidant properties. The obtained extracts were investigated for their total phenolic and total flavonoid content, total antioxidant activity (TAC), as well as evaluated for their ferric reducing capacity (FRAP), β-carotene bleaching inhibition capacity, and for the radical scavenging activity through the extent of their abilities to scavenge the DPPH• and ABTS+ radicals. Antioxidant contents and capacities were expressed as mg/g DW, IC50, and as (%) inhibition in percentage. Total phenolic content was ranged between 378.10 ± 2.05 to 22.51 ± 0.07 mg/g DW in argan samples and from 226.50 ± 1.32 to 15.02 ± 0.04 mg/g DW in olive samples, expressed as gallic acid equivalents and shown in the decreasing order: methanolic extracts > aqueous extracts > ethyl acetate extracts. Moreover, for both plant species; the highest reducing and antiradical power as well as the greatest total antioxidant capacities, were obtained by the methanolic leave extracts. Whilst the most distinguished β-carotene bleaching inhibition was observed for aqueous extracts of olive (90.67%) and argan (87.39%) macerated leaves. With this highly revealed antioxidant power of the extracts, it was significantly linked to the important correlations between the in vitro executed assays and the total phenolic (TP) and total flavonoid (TF) contents detected. Based on the obtained results, it could be concluded that argan and olive leaves display promising antioxidant capacities to potentially serve as rich sources of phenolic compounds with variable antioxidant properties.

Structure élémentaire de l’arganeraie Argania spinosa L. Skeels de Tindouf (Sahara occidental algérien) / Elementary structure of the argan forest Argania spinosa L. Skeels of Tindouf (Algerian western Sahara)

The argan tree is well adapted to drought conditions in Algerian western Sahara. The argan forest of Tindouf has a structure of coppice on stumps, characterized by an average height of 4.7m. Regeneration by dense resprouts represents 43% for 1,192 inventoried trees. The mother trees of Argania spinosa have a significant potential to resprout in coppice or suckers, thus forming crowns around mounds on beds of wadis. It should be noted that 21% of the trees are damaged by illegal cutting. The average spacing between the trees is around 13m. The argan tree retains a large volume of soil input with an average of 23.6 ± 36.3m3/ stump in the form of mounds. Linear regression analysis revealed an increasing relationship between mound volume and the number of stems per stump. Thanks to its powerful root system, the argan tree accumulates additional soil and contributes to the slow mechanism of sedimentation of micro-horizons, constituting mounds around the feet of trees.

Effect of hydric and light stress on biomass, nutrient uptake and enzymatic antioxidants of Argania spinosa seedlings

Sunlight and water are factors that affect seedling development. However, the effects of acclimatization of seedlings to sunlight and water stress remain poorly understood. This study aimed to examine the interactive effects of acclimatization to light and water stress on argan tree (Argania spinosa) seedlings in nurseries. An experiment was conducted with 504 seedlings using two sunlight treatments (L1 and L2, i.e. 100% and 60% of full sunlight, respectively), and three watering treatments (well-watered, moderate stress and severe stress, i.e. 100%, 50% and 25% of field capacity, respectively). According to our results, water stress treatments caused a reduction in total biomass accumulation, nitrogen and phosphorus uptake. Water stress significantly increased other macroelements, H2O2 and MDA levels and antioxidant enzyme activities compared to well-watered seedlings. Seedlings grown under moderate shade (L2) showed higher macroelement uptake, which probably contributed to the increase in total biomass in all water treatments. The highest membrane stability index (MSI) values, H2O2 and MDA levels and lowest antioxidant enzyme activities were recorded in acclimatized argan seedlings under moderate shading (L2). These results suggest that moderate shade can effectively prevent stress caused by light excess and can also mitigate the harmful effects of water stress on A. spinosa seedlings.

Quantification of secondary metabolites and the evaluation of the in vitro antioxidant activity of the Argan tree of eastern Morocco

Argania Spinosa (L.) Skeels is an endemic species of Morocco that belongs to the Sapotaceae family and which recommends a warm climate, and most of its trees are grown in tropical regions. This population is highly concentrated in the southwest of Morocco but is also found as a relic in the eastern region of the country. This work aims to valorize the different parts of the Argan plant (Leaves, branches, and for the first-time flower-buds) grown in two sites of eastern Morocco, Oujda (820885,945; 455262,165 Meters) and Chouihiya (755725,636; 477 008,053 Meters) coordinate system: nord Maroc, and this by the quantification of different secondary metabolites such as polyphenols, flavonoids, and tannins. The investigation of their antioxidant activity was assessed using two different technics, the free radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) and the ferric reducing power (FRAP). The crude extracts were obtained by soaking the different parts of Argania Spinosa L. in a hydroalcoholic solution (70%) for 48 h.The quantitative evaluation of the various secondary metabolites of the different studied parts of the plant showed that flower-buds and leaves from Oujda are the highly rich with polyphenols, and flavonoids respectively, Fb-O :498,9 ± 20,08 µg Eq AG/mg DW; Le-O :71,2 ± 0,8 µg Eq QE/mg DW. On the other hand, the results obtained reveals that the tannins are very concentrated in flower-buds from Chouihya 212,4 ± 5,8 µg Eq CA/mg DW. It was also found that the different secondary metabolites vary between the two regions studied and different organs. All the extracts for the two regions showed interesting antioxidant activities compared to the Ascorbic acid used as a standard for the DPPH and the FRAP. The antiradical activity of the crude extract of the flower-buds from Oujda showed the best IC50 with a value of 64,68 ± 3,5 µg/ml, while the leaves from Oujda showed the smallest IC50 value 208,33 ± 5,08 µg/ml in the ferric reducing power test comparing to the other parts of the plant. The antioxidant activities varied significantly according to both regions and organs.