The present paper aims at reviewing and commenting on the analytical methods applied to antioxidant and antioxidant capacity assessment in plant-derived products. Aspects related to oxidative stress, reactive oxidative species' influence on key biomolecules, and antioxidant benefits and modalities of action are discussed. Also, the oxidant-antioxidant balance is critically discussed. The conventional and nonconventional extraction procedures applied prior to analysis are also presented, as the extraction step is of pivotal importance for isolation and concentration of the compound(s) of interest before analysis. Then, the chromatographic, spectrometric, and electrochemical methods for antioxidant and antioxidant capacity determination in plant-derived products are detailed with respect to their principles, characteristics, and specific applications. Peculiarities related to the matrix characteristics and other factors influencing the method's performances are discussed. Health benefits of plants and derived products are described, as indicated in the original source. Finally, critical and conclusive aspects are given when it comes to the choice of a particular extraction procedure and detection method, which should consider the nature of the sample, prevalent antioxidant/antioxidant class, and the mechanism underlying each technique. Advantages and disadvantages are discussed for each method.

https://downloads.hindawi.com/journals/omcl/2016/9130976.pdf

Antioxidant Capacity Determination in Plants and Plant-Derived Products: A Review.

AACR Annual Meeting-- Apr 14-18, 2007; Los Angeles, CA

5537 

Annona glabra (pond apple), a tropical tree growing wild in American and Asian continents, is used in traditional medicine against several human ailments including cancer. To validate the ethanopharmacological claims against cancer, we have investigated the anticancer effects of alcoholic extracts prepared from pond apple leaves, pulp and seeds in human leukemic cell lines. The alcoholic extracts were not cytotoxic to normal human leukocytes. However, extracts were highly cytotoxic to drug sensitive (CEM) and multidrug resistant leukemic (CEM/VLB) cell lines. The seed extract was more potent than leaf and pulp extracts and the cytotoxicity values were significantly lower than that for adriamycin. The seed extract caused a dose-dependent increase in the percentage of sub G/G1 as well as G/G1 population, contributing to the cytotoxicity. The sub G/G1 population increased from 2.2 to 7.0% in CEM and from 1.0 to 10.7% in CEM/VLB cell lines, when the cells treated with 0-10 µg/ml seed extract. Treatment with seed extract induced apoptosis in both sensitive and resistant leukemic cells in a dose-dependent manner with about 27.9% and 20.3% apoptotic cells in CEM and CEM/VLB cells at 10 µg/ml concentrations. The seed extract at 2 and 5 µg/ml doses enhanced cellular daunorubicin accumulation indicating the competitive P-glycoprotein binding ability and drug resistance reversals effect. Treatment of CEM and CEM/VLB cells with seed extracts also up regulated the expression of cyclin kinase inhibitor ( WAF1/p21 ) expression inducing the arrest of cells at G/G1 phase of cell cycle. These results support the traditional use of A. glabra and the alcoholic seed extract appeared is a potent source of anticancer compounds that could be exploited pharmaceutically.

Anticancer effects of Annona glabra plant extracts against human leukemia cell lines

Facile one-step green synthesis of gold nanoparticles (AuNp) using licorice root extract: Antimicrobial and anticancer study against HepG2 cell line

L'objectif de cet article est de realiser une synthese des connaissances relatives au marcottage (aerien et terrestre), acquises durant les vingt-cinq dernieres annees par divers chercheurs oeuvrant principalement sur le continent africain. Elle se base sur les resultats des essais de marcottage realises sur des especes ligneuses et sur les principaux resultats presentes lors de congres et dans des revues (articles et communications), lus pendant ce quart de siecle. Cette synthese se presente sous deux formes: un article et un tableau de 18 pages. D'une part dans le corps du texte, les lecteurs trouveront un resume de la methodologie et des principaux resultats (theses, memoires d'ingenieurs, articles et communications publies jusque fin 2015) des travaux entrepris par divers etudiants et chercheurs confirmes ayant teste les diverses variantes du marcottage en Afrique et, dans certains cas, sur d'autres continents. D'autre part, beaucoup de resultats importants relatifs au marcottage, issus de travaux innovants, mais exterieurs a l'Afrique, sont resumes pour plus de 600 especes ligneuses en quelques mots dans le tableau general, en annexe. (Resume d'auteur)

Plaidoyer en faveur du marcottage pour domestiquer les principales espèces ligneuses africaines

Argan (Argania spinosa (L.) Skeels) is an endangered and endemic agroforestry species of Morocco highly appreciated for its nutraceutical properties. Herein, the antioxidant activity, total phenolic content and fatty acids were evaluated in different extracts obtained from callus culture, seeds and leaves of four argan genotypes: G25, G36, G41 and G84. Callus induction, proliferation and morphology varied depending on genotype and explant type. The highest callus induction rate (97.5%) was observed in the cotyledon explants of genotype G84. The radical scavenging activity values ranged from 76.5 to 98.1%. The essential oils extracted from calli induced from seedling-derived leaves exhibited a slightly higher radical scavenging activity (91.7%) than those extracted from field-grown leaves (90–91.1%). The total phenolic content ranged from 0.72 mg/g dry weight gallic acid equivalent in the methanolic extracts of G84 callus obtained from seedling-derived leaves to 198.26 mg/g dry weight gallic acid equivalent in the essential oils of G84 seeds. The fatty acid composition varied significantly among the different samples. The essential oils extracted from seeds and callus obtained from cotyledon explants have high contents in oleic and linoleic acids (26–37.9% and 25–36.8%, respectively), while the major fatty acid found in the essential oils of leaves and callus obtained from seedling-derived leaves was eicosenoic acid (18.8–45.4%). The present study showed that argan callus culture could be envisaged for sustainable and continuous production of bioactive compounds, and that each extract analyzed had unique and distinct characteristics. The essential oils and other extracts obtained from argan callus induced in vitro were characterized and were compared with those obtained from seeds and field-grown leaves

Determination of antioxidant activity, total phenolics and fatty acids in essential oils and other extracts from callus culture, seeds and leaves of Argania spinosa (L.) Skeels

/pdf/the-importance-of-behavioral-and-native-factors-on-covid-19-1n1qmbwr.pdf

The Importance of Behavioral and Native Factors on COVID-19 Infection and Severity: Insights from a Preliminary Cross-Sectional Study

Evaluation of antioxidant activities of the edible and medicinal Acacia albida organs related to phenolic compounds

Phenolic constituents and antioxidant activity of Euphorbia retusa Forssk.

The aim of this work was to investigate the physicochemical, nutritional and antioxidant properties of traditionally pressed edible (roasted argan kernels) and beauty (unroasted argan kernels) Algerian argan oil. Oxidative stability and the quality of oils (acidity, peroxide index, K₂₃₂, and K₂₇₀) were slightly affected by roasting process. But, any case, none of the analyzed oils surpassed limits established by Moroccan norms and were labeled as “extra virgin oil.” In addition, the better antioxidant capacities of argan oil prepared from roasted seeds could be explained by a better extractability of carotenoids, phenolics. and tocopherols as compared with unroasted ones. The dominant fatty acids found consisted by oleic acid followed by linoleic, palmitic, and stearic acids and the major triglycerides were principally formed by two or three oleic acid residues. According to our data, the roasting process does not influence the quality of the argan oil and confirm its good stability. PRACTICAL APPLICATIONS: Argania spinosa (Sapotaceae family) is an endemic xero‐thermophilic species from the southwestern region of Algeria (Tindouf countryside) and Morocco. Argan oil is the most important products derived from Argan tree. Despite its wide spread uses and properties, only few studies had been carried out on the traditionally extracted roasted (edible) and unroasted (for beauty uses) Algerian argan oil. Thus, this study aimed to valorize this oil through their physicochemical, nutritional and antioxidant properties in order to situate this local product to the standards and international norm values.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/jfbc.12751

Phytochemical characteristics, antioxidant, and health properties of roasted and unroasted Algerian argan (Argania spinosa) oil

Du fait de leur infime taux de regeneration, des pratiques humaines et du changement climatique, sans intervention efficace, les arganiers repartis dans la Wilaya de Tindouf sont condamnes a disparaitre. La regeneration naturelle dans ces vallees est tres rare et si exceptionnellement elle a lieu, le parcours des caprins et des camelides et l'aridite ambiante ne permettent pas le developpement des plantules. Si la regeneration in situ est a encourager, il est indispensable de prevoir des plantations in et ex situ realisees selon des normes strictes. Les auteurs enumerent les divers problemes qui restent a regler pour la conduite des plantules en pepinieres et en plantations. Les principaux et recents resultats internationaux relatifs aux arganiers sont rappeles dans cet article, notamment en matiere de multiplication vegetative. En conclusion, les auteurs preconisent d'adopter une demarche innovante et raisonnable et un ensemble d'actions que les chercheurs et le Gouvernement algeriens peuvent mener a bien pour sauvegarder l'arganeraie de Tindouf et implanter des vergers (de semis et de clones) ex situ dans des zones climatiques plus arrosees et a l'abri de gelees trop intenses. (Resume d'auteur)

Mohamed Seif Allah Kechebar

Papers

The Importance of Behavioral and Native Factors on COVID-19 Infection and Severity: Insights from a Preliminary Cross-Sectional Study

Evaluation of antioxidant activities of the edible and medicinal Acacia albida organs related to phenolic compounds

Phenolic constituents and antioxidant activity of Euphorbia retusa Forssk.

Phytochemical characteristics, antioxidant, and health properties of roasted and unroasted Algerian argan (Argania spinosa) oil

Démarche à adopter pour sauvegarder le patrimoine génétique de l'arganeraie de Tindouf