Hanen Najjaa

Antioxidant and Antimicrobial Activities of Allium roseum L. “Lazoul,” A Wild Edible Endemic Species in North Africa

Total polyphenolic contents (TPC), antioxidant and antibacterial activities of bulb, leaf and flower extracts of the North African endemic plant Allium roseum were studied using three different solvents. Flower and leaf TPCs were found significantly higher than that of bulb with the highest values in methanolic extracts reaching 736.65 ± 88.67 and 749.54 ± 129.15 mg catechol equivalent/100 g of dry material, respectively. The same trend was observed for antioxidant potentials using DPPH. and ABTS.+ scavenging methods. Moreover, the A. roseum phenolic extracts strongly inhibited the growth of a range of microorganisms. Multivariate analysis showed that the extraction solvent and the plant material significantly affected the quantity and bioactivity of the phenolics. Almost all extracts exhibited antioxidant and antibacterial activity; however, the highest values were found in the methanolic extracts of leaves and flowers. These results provide the basis for the use of this edible spontaneous species for functional food ingredients and/or supplements.

Arthrophytum scoparium inhibits melanogenesis through the down-regulation of tyrosinase and melanogenic gene expressions in B16 melanoma cells

Melanin performs a crucial role in protecting the skin against harmful ultraviolet light. However, hyperpigmentation may lead to aesthetic problems and disorders such as solar lentigines (SL), melasma, postinflammatory hyperpigmentation and even melanoma. Arthrophytum scoparium grows in the desert in the North African region, and given this type of environment, A. scoparium exhibits adaptations for storing water and produces useful bioactive factors. In this study, the effect of A. scoparium ethanol extract (ASEE) on melanogenesis regulation in B16 murine melanoma cells was investigated. Cells treated with 0.017% (w/v) ASEE showed a significant inhibition of melanin biosynthesis in a time‐dependent manner without cytotoxicity. To clarify the mechanism behind the ASEE‐treated melanogenesis regulation, the expressions of tyrosinase enzyme and melanogenesis‐related genes were determined. Results showed that the expression of tyrosinase enzyme was significantly decreased and Tyr, Trp‐1, Mitf and Mc1R mRNA expressions were significantly down‐regulated. LC‐ESI‐TOF‐MS analysis of the extract identified the presence of six phenolic compounds: coumaric acid, cinnamic acid, chrysoeriol, cyanidin, catechol and caffeoylquinic acid. The melanogenesis inhibitory effect of ASEE may therefore be attributed to its catechol and tetrahydroisoquinoline derivative content. We report here that ASEE can inhibit melanogenesis in a time‐dependent manner by decreasing the tyrosinase protein and Tyr, Trp‐1, Mitf and Mc1R mRNA expressions. This is the first report on the antimelanogenesis effect of A. scoparium and on its potential as a whitening agent.

Allium Roseum L. Extract Exerts Potent Suppressive Activities on Chronic Myeloid Leukemia K562 Cell Viability Through the Inhibition of BCR-ABL, PI3K/Akt, and ERK1/2 Pathways and the Abrogation of VEGF Secretion

ABSTRACT Use of plant extracts, alone or combined to the current chemotherapy as chemosensitizers, has emerged as a promising strategy to overcome tumor drug resistance. Here, we investigated the anticancer activity of Allium roseum L. extracts, a wild edible species in North Africa, on human Chronic Myeloid Leukemia (CML) K562 cells. The dehydrated aqueous extract (DAE) disturbed the cell cycle progression and induced the apoptosis of K562 cells. Chemical analysis of DAE showed a diversity of organosulfur compounds S-alk(en)yl-cysteine sulfoxides (RCSO) and high amount of allicin, suggesting that such molecule may be behind its antitumor effect. DAE was efficient in inhibiting K562 cell viability. DAE inhibitory effect was associated with the dephosphorylation of the BCR-ABL kinase and interfered with ERK1/2, Akt, and STAT5 pathways. Furthermore, we found that DAE-induced inactivation of Akt kinase led to the activation of its target FOXO3 transcription factor, enhancing the expression of FOXO3-regulated proapoptotic effectors, Bim and Bax, and cell cycle inhibitor p27. Finally, we found that DAE reduced the secretion of vascular endothelial growth factor. Overall, our data suggest that A. roseum extract has great potential as a nontoxic cheap and effective alternative to conventional chemotherapy.

Différences et similitudes des métabolites secondaires chez deux espèces du genre Allium, Allium roseum L. et Allium ampeloprasum L

Abstract This study deals with the valorisation of medicinal and aromatic Allium to find new bioactive natural products. The phytochemical analyses of A. roseum and A. ampeloprasum powders and their aqueous and organic extracts are achieved. The results show that these species are characterized by the presence, among their components, of three precursors of organosulphurous volatile compounds. They are methiin, isoalliine and alliine in A. roseum and isoalliin and methiin in A. ampeloprasum. These differences in their flavours can correlated with the vicinity of A. roseum with garlic and A. ampeloprasum with onion. Phytochemical screening of Allium roseum shows the presence of active agents such as saponins, tannins, flavonoids, coumarins, steroids, cardiac glycosides, free quinone and iridoids.

Medicinal and Aromatic Plants of the World - Africa Volume 3

Natural substances of plant origin, have been used by man from the very early times of civilizations. Traditional Medicine (TM), a heritage of Africa, is still servicing approx. 80% of the population of this huge continent comprizing 55 countries, 800 languages and an unmeasurable wealth of plant diversity. The continent with a varied flora of an estimated 68,000 plant species is home to about 35,000 endemic species (Cunningham A, African medicinal plants. Setting priorities at the interface between conservation. UNESCO, Paris, 1993), growing in seven centers of endemism. Africa’s not yet fully explored medicinal plant resources frequently come into the forefront of interest. The recent upsurge is witnessed by the fact that ca. 60% of all recent publications on African medicinal plants, appeared during the last decade. There is a tremendous potential for developing new crops and new products. Research into MAPs seem to offer a nearly unlimited scope for exploration. The ongoing screening for the biological activity of MAPs is also broad and covers several important health related aspects including antimalarial and other antiprotozoal products, anti-proliferative potential, anti-inflammatory and analgesic activities, anti-diabetes activity antioxidant activity and activity on the reproductive cardiovascular and central nervous systems, etc. Despite of this marked recent increase, Africa is lagging behind Europe and Asia in terms of the number of products that have been commercialized and the percentage of flora utilized for international trade. The growing demand on resources, however, has resulted, in some cases, the overexploitation, the occasional local disappearance of favored sources of botanicals and have reduced the diversity of species. By elaborating international and national standards of sustainability, these dangers should be either eased or eradicated. Domestication of wild-crafted species can also contribute to preserve the genetic resources and to reduce the sometimes imminent threats of extinction. The recent initiative to develop national and ultimately an African Herbal Á. Máthé (*) Faculty of Agriculture and Food Science, University of West Hungary, Mosonmagyaróvár, Hungary e-mail: acatius2005@gmail.com M. Neffati • H. Najjaa Arid Zone Research Institute, 4119 Médenine, Tunisia e-mail: neffati.mohamed@ira.rnrt.tn; hanen.najjaa@yahoo.fr

Biological and Chemical Study of Astragalus gombiformis

Extracts of aerial parts and roots of wild Astragalus gombiformis Pomel were tested for their antibacterial, antioxidant, and insecticidal activities and contents of phenolic compounds. Antibacterial activity was tested by the paper disk agar diffusion method and determination of the minimal inhibitor concentration. Among the tested extracts, three extracts (methanol, chloroform, and ethyl acetate) from aerial parts and two extracts (water, methanol) from roots exhibited diameters of inhibition zone equal or above 12 mm (at 150 μg/ disk) and minimal inhibitor concentrations ranging between 233 and 1250 μg/ml. Spectrophotometric and HPLC analyses showed that contents of both total polyphenols and flavonoids, as well as antioxidant activity were higher in the methanolic extract of aerial parts as compared to roots. No insecticidal activity of the extracts of the aerial parts was found against Culex pipiens.

Aromatic and Medicinal Plants of Tunisian Arid and Desert Zone Used in Traditional Medicine, for Drug Discovery and Biotechnological Applications

Tunisian has a high diversity of plants as a result of the variation in topography climate and edaphic conditions of the country. Among these plants several aromatic and medicinal species are traditionally used in folk medicines to treat and/or manage common ailments. Some others species are used in foods as spices and/or in aromatherapy. The present chapter endeavors to highlight the botanical description, geographical distribution, ethno pharmacological uses of 45 species spread over 22 botanical families among those the most used in traditional medicine. Information on the chemical composition and biological activities of these species are also included in this chapter.

Introduction to Medicinal and Aromatic Plants in Africa

Natural substances of plant origin, have been used by man from the very early times of civilizations. Traditional Medicine (TM), a heritage of Africa, is still servicing approx. 80% of the population of this huge continent comprizing 55 countries, 800 languages and an unmeasurable wealth of plant diversity. The continent with a varied flora of an estimated 68,000 plant species is home to about 35,000 endemic species (Cunningham A, African medicinal plants. Setting priorities at the interface between conservation. UNESCO, Paris, 1993), growing in seven centers of endemism. Africa’s not yet fully explored medicinal plant resources frequently come into the forefront of interest. The recent upsurge is witnessed by the fact that ca. 60% of all recent publications on African medicinal plants, appeared during the last decade. There is a tremendous potential for developing new crops and new products. Research into MAPs seem to offer a nearly unlimited scope for exploration. The ongoing screening for the biological activity of MAPs is also broad and covers several important health related aspects including antimalarial and other antiprotozoal products, anti-proliferative potential, anti-inflammatory and analgesic activities, anti-diabetes activity antioxidant activity and activity on the reproductive cardiovascular and central nervous systems, etc. Despite of this marked recent increase, Africa is lagging behind Europe and Asia in terms of the number of products that have been commercialized and the percentage of flora utilized for international trade. The growing demand on resources, however, has resulted, in some cases, the overexploitation, the occasional local disappearance of favored sources of botanicals and have reduced the diversity of species. By elaborating international and national standards of sustainability, these dangers should be either eased or eradicated. Domestication of wild-crafted species can also contribute to preserve the genetic resources and to reduce the sometimes imminent threats of extinction. The recent initiative to develop national and ultimately an African Herbal Pharmacopoeia is likely to mark an important milestone in meeting quality, safety and efficacy standards both in African and international perspectives.

Wild Edible Allium Species from Arid Zones of Tunisia: New Perspectives of Natural Compounds

Allium is the largest and the most important representative genus of the Alliaceae family. For many centuries, several Allium species have been used as vegetables and spices, and as folk medicines for curing various diseases. Besides the well-known garlic and onion, other species are either, widely cultivated for culinary use, such as leek, scallion, shallot and chive, or found as wild endemic species grown spontaneously.