Thymus algeriensis Boiss. et Reut., a north African endemic plant species: genetic diversity and population structure as assessed by molecular markers, a pioneer step for conservation implications.

BACKGROUND: Thymus algeriensis Boiss. et Reut. is one of the most widespread North African species of the genus Thymus L. The species is subshrub growing primarily in subtropical biome of Morocco, Algeria, Tunisia and Libya. In Tunisia, the plant species is under high pressure of anthropogenic activities including over-collecting. The assessment of genetic diversity and population structure of T. algeriensis is a pioneer step to retrace its evolutionary history and to perform appropriate conservation strategies of the plant species. METHODS AND RESULTS: Seven wild populations growing, widely, in different bioclimatic zones were selected and analysed using two molecular markers systems. Fifteen Simple Sequence Repeats (SSRs) and fifteen Inter-Simple Sequence Repeats (ISSRs) were used to characterize genetically 140 different genotypes. The results showed a high molecular variation within populations and among the studied genotypes. The intra-populations genetic diversity revealed by SSRs was higher (P = 80.95%, Na = 2.143 and He = 0.364) than that based on ISSRs (P = 78.12%, Na = 1.632, He = 0.265 and I = 0.398). As demonstrated by inbreeding coefficients, a significant level of differentiation and a low level of gene flow were detected among studied populations (FST = 0.161 for SSRs and ΦST = 0.197 for ISSRs). Furthermore, the results of ISSRs marker suggest land strips as barriers in population genetic structure. While SSRs marker reflects a relatively structured bioclimatic patterns of studied populations. The Bayesian analysis showed a specific adaptation of populations to local environments. CONCLUSIONS: The used molecular markers (ISSRs and SSRs) seem to be effective in deciphering genetic polymorphism of Tunisian genotypes of T. algeriensis. Therefore, the genetic structure of the studied genotypes could constitute a starting point for further conservation, characterization and breeding programs.

Variation in Phenolic Content, Antioxidant Activity and Alpha-amylase and Acetylcholinesterase Inhibitory Capacities of Different Extracts from Tunisian Satureja barceloi (Willk) L.

The antioxidant activity and the anti-α-amylase and anti-acetylcholinesterase capacities of secondary metabolites from different organs (roots, stems, leaves and flowers) of Tunisian Satureja barceloi were determined. The variation in the distribution of phenolic metabolites among roots, stems, leaves and flowers extracts of S. barceloi with various solvent systems (methanol, ethyl acetate, hexane and distilled water) has not been characterized before. Significant variation of phenolic compounds was observed according to organs rather than to extracting solvents. The analyzed organs show a high level of phenolic compounds although the stems contains the highest total polyphenols (132.53±0.48 mg AGE/g Ex), flavonoids (48.99±0.65 mg RE/g Ex) and flavonols (34.93±0.29 mg QE/g Ex) contents. The phenolic fraction was dominated by sagerinic acid, caffeic acid glucoside and epigallocatechin, detected using HPLC-PDA/ESI-MS. The antioxidant activity of all extracts, evaluated by four in vitro tests, was high and varied significantly according to the type of solvent used and the plant organ. The aqueous extracts of leaves exhibited the greatest inhibitory effect on alpha-amylase while the methanolic extract of leaves and stems revealed the most important acetylcholinesterase inhibitory effect. Hence, S. barceloi extracts could be used as a source of various bioactive molecules in pharmaceutical industry.

Deverra triradiata Hochst. ex Boiss. from the Northern Region of Saudi Arabia: Essential Oil Profiling, Plant Extracts and Biological Activities.

Devrra triradiata Hochst. ex Boiss is an occasional plant species in the Northern region of Saudi Arabia. The shrub is favored on sandy desert wadis, gypsaceous substrate, and sandy gravel desert. In folk medicine, the plant is used for many purposes; to relieve stomach pains, against intestinal parasites, and for the regulation of menstruation. The present study describes the chemical composition of the essential oils (EOs) of different plant parts of D. triradiata. In vivo and in vitro biological activities of plant extracts and essential oils were also studied. Phenylpropanoids, elemicin (flowers: 100%), dillapiole (Stems: 82.33%; and seeds: 82.61%), and apiol (roots: 72.16%) were identified as the major compounds. The highest antioxidant activity was recorded for the EOs of roots and stems (IC50 = 0.282 µg/mL and 0.706 µg/mL, respectively). For plant extracts, ethyl acetate showed the highest antioxidant activities (IC50 = 2.47 and 3.18 µg/mL). EOs showed high antifungal activity against yeasts with low azole susceptibilities (i.e., Malassezia spp. and Candida krusei). The MIC values of EOs ranged between 3.4 mg/mL and 56.4 mg/mL. The obtained results also showed phytotoxic potential of plant extracts both on the germination features of Triticum aestivum seeds and the vegetative growth of seedlings.

Molecular signature of phylogenetic relationships and demographic history of Tunisian Mactra stultorum: Evidence from mitochondrial and nuclear DNA data.

The genetic structure of Mactra stultorum is inferred from partial sequence of a mitochondrial cox1gene and of the internal transcribed spacer region ITS1. The samples with two colors of shell (white and brown) were collected from three sites belonging to the Tunisian coasts: Kalaât El Andalous (KA) and Soliman (SM) and Gabes (GM)). The phylogenetic trees obtained from the 2 markers are similar and subdivided samples into 3 distinct clades; clade (1) regrouped GM, clade (2) regrouped KS (KS contains samples from SM and KAa) and clade (3) is formed by KAb. Using the external sequences from genbank, it can be suggested that M. stultorum from the three clades KS, GM and KAb are three subspecies. The two sympatric M. stultorum from KA (KAa and KAb) appear to be genetically isolated showing a high genetic distance and no common haplotypes where the shell color serves for segregating marker. A total of 29 and 18 haplotypes were detected in the examined cox1 and ITS1 regions, respectively. Our study revealed higher levels of genetic diversity for ITS1 compared to cox1. For both markers, significant clinal changes in haplotypes frequencies between the north and the south populations supported by the absence of common haplotypes were observed. The demographic history of M. stultorum populations has been assessed using neutral tests and mismatch distribution for cox1 marker. A unimodal curve of the Mismatch's distribution and negative significant neutral tests suggested a recent sudden demographic expansion for GM.

Allium sativum mitigates oxidative damages induced by Microcystin-LR in heart and liver tissues of mice.

Microcystins (MCs) are hepatotoxic cyanotoxins implicated in several incidents of human and animal toxicity. Microcystin-(Lysine, Arginine) or MC-LR is the most toxic and encountered variant of MCs where oxidative stress plays a key role in its toxicity. This study investigated the oxidative damages induced in the liver and heart of Balb/C mice by an intraperitoneal injected acute dose of MC-LR. Thereafter, the potential protective effect of garlic (Allium sativum) extract supplementation against such damages was assessed through the evaluation of oxidative stress and cytotoxicity markers. Lipid peroxidation (LPO), carbonyl content (CC), glutathione content (GSH), alkaline phosphatase activity (ALP), lactate dehydrogenase (LDH) and sorbitol dehydrogenase (SDH) activities were measured. Results showed important oxidative damages in hepatic and cardiac cells of mice injected with the toxin. However, these damages have been significantly reduced in mice supplemented with garlic extract. Thus, this study demonstrated for the first time the effective use of garlic as an antioxidant agent against oxidative damages induced by MC-LR. As well, this study supports the use of garlic as a potential remedy against pathologies related to toxic agents.

Ethnopharmacological study of natural products used for traditional cancer therapy in Algeria.

Traditional and complementary medicine constitutes an important, and often underestimated, source of healthcare for multiple diseases including cancer. However, little is known about the ethnomedical knowledge and practices in Northern Africa. The main objective of this study is to identify and analyze the variety of natural products used in Algerian ethnopharmacology for cancer therapy. For this purpose, semi-structured interviews with 225 traditional healers, herbalists and practitioners were realized in twelve locations in Algeria throughout field studies performed from June 2015 to July 2019. Interviews covered popular and vernacular names of the natural product, mode of use and administration, dose, period of treatment, toxicity and side effects among other data. The obtained results reveal the use of 113 medicinal plants (belonging to 53 families and 104 genera), 10 animal species and various products and by-products from different origins such as honey, olive oil, thorns, urine, milk, animal fat and the alkaline water of Zamzam. Basing on the frequency of citation (FC), use reports (UR) and use value (UV), the most used natural products for cancer treatment are honey (FC = 181, UR = 194, UV = 0.65), Nigella sativa L. (FC = 131, UR = 152, UV = 0.54), Aristolochia longa L. (FC = 118, UR = 144, UV = 0.51), Berberis vulgaris L. (FC = 111, UR = 142, UV = 0.51), Curcuma longa L. (FC = 107, UR = 121, UV = 0.43), Trigonella foenum-graecum L. (FC = 102; UR = 119, UV = 0.43), Citrus limon (L.) Obseck (FC = 97, UR = 120, UV = 0.43), Artemisia herba-alba Asso (FC = 92, UR = 115, UV = 0.41) and the holy water 'Zamzam' (FC = 110, UR = 110, UV = 0.43) respectively. Mixtures of two or more ingredients were frequently used. The use of Pelophylax saharicus skin' was reported for the first time for the treatment of visible tumors and skin cancer. This is the first study documenting the traditional uses of various natural products for cancer treatment in Algeria. Our findings are relevant to document the traditional uses of numerous natural products and to provide background basis to search for novel compounds for cancer therapy.

Differentiation of Phenolic Composition Among Tunisian Thymus algeriensis Boiss. et Reut. (Lamiaceae) Populations: Correlation to Bioactive Activities.

: Twelve Tunisian Thymus algeriensis populations growing wild in different bioclimatic zones, extending from the subhumid to the upper-arid bioclimates, were compared regarding their phenolic composition and their ability to serve as antioxidant, anti-acetylcholinesterase, and antibacterial agents. A significant variation of phenol profile was observed between the analyzed populations, as assessed by ultra-high-performance liquid chromatography coupled with a diode array detector and an electrospray mass spectrometer (UHPLC-DAD-ESI/MSn) technique. Rosmarinic acid was the main phenolic compound in most populations (383.8-1157.8 µg/mL extract), but still, those from the upper-arid bioclimatic zone were distinguished by the presence of carvacrol (1374.7 and 2221.6 µg/mL extract), which was absent in the remaining ones. T. algeriensis methanolic extracts were found to possess a substantial antioxidant and anti-acetylcholinesterase activities, with significant variation observed between populations, which were correlated to their phenolic contents. The antibacterial activity of the extracts tested against seven bacteria was revealed only by populations collected from upper-arid bioclimate and mainly associated with the presence of carvacrol. Extracts revealed a bacteriostatic effect against all bacteria (MIC = 1.4 mg/mL). Yet, the bactericidal activity (MBC = 1.4mg/mL) was restricted to the gram-negative bacteria Escherchia coli.

Polyphenolic Profiling, Quantitative Assessment and Biological Activities of Tunisian Native Mentha rotundifolia (L.) Huds.

Phenolic profiling of ten plant samples of Mentha rotundifolia (L.) Huds. collected from different bioclimatic areas of Tunisia, was for the first time carried out by using a fast ultra-high-performance liquid chromatography (UHPLC)-high resolution tandem mass spectrometry (HRMS/MS) method on a Q Exactive platform equipped with an electrospray ionization (ESI) source. An intraspecific, interpopulation variability was evidenced and a total of 17 polyphenolic metabolites were identified and quantified by using the UHPLC-HRESIMS/MS method, here validated for specificity, linearity, limit of detection, limit of quantitation, accuracy and precision. The quantitative method resulted sensitive at the nM level and reliable for rapid polyphenol quantification in vegetal matrices. The metabolomic study allowed us to identify a new compound, named salvianolic acid W, which was isolated and characterized mainly by NMR and MS analysis. A statistical correlation of the phenolic composition with antioxidant and anti-acetylcholinesterase activities was provided.

Euphorbia honey and garlic: Biological activity and burn wound recovery.

Currently, chronic wounds and microbial resistance to antibiotics have led to search new healing agents. Combinations of natural products are widely practiced in traditional medicine and exhibited synergistic activity with increased efficacy in treating several pathologies. This study assays the antioxidant, synergistic antimicrobial and burn wound healing activities of Euphorbia honey and Allium sativum (garlic). The minimal inhibitory concentration (MIC) of each natural product was determined against microorganisms commonly found in wound infections. The synergistic antimicrobial effect was assessed by mixing different concentrations of honey and garlic extract below their relative MICs. Subsequently, the antioxidant activity, total phenolic (TPC) and flavonoid (TFC) contents of both natural products and a selected mixture of them were evaluated. Efficacy of that mixture was also evaluated as topical application on male and female Wistar rats skin burn wound, compared to Euphorbia honey and two conventional treatments. Results showed that the mixture honey-A. sativum has synergistic antimicrobial effect against all tested strains. Besides, A. sativum presented higher antioxidant activity along with higher TPC and TFC compared to honey and their mixture. However, the mixture showed higher wound healing activity reflected by shorter epithelialization and wound contraction time, as well as, better histological recovery of the treated tissues. Our results also showed that burn wound healing is not affected by gender. Our findings support the idea of combining natural products as an effective therapy.

Genetic relationships among subspecies of Capparis spinosa L. from Tunisia by using ISSR markers.

In Tunisia, Capparis spinosa L. is widely distributed in different geographic areas. Although it has been extensively studied morphologically, the phylogenetic relationships by using molecular markers among Capparis taxa are still unclear. The Inter-Simple Sequence Repeats (ISSR) molecular markers were used to assess the genetic relationship of this species cultivated in the North and the South of Tunisia. Fifteen ISSR primers were analyzed to characterize the genetic profiles of 67 different genotypes. The ISSR markers produced 108 bands ranging from 4 (ISSR8) to 11 (IAM12 and ISSR16) with an average of 7.2. The observed heterozygosity ranged from 0.43 to 0.95 for ISSR7 and IAM12, respectively. The Polymorphic Information Content (PIC) ranged from 0.48 at the UBC808 to 0.85 at IAM12 and eight loci could be classified as useful for genetic mapping (PIC > 0.7). The genetic diversity within a population was high and varied according to the subspecies and bioclimatic zones. Both UPGMA (Unweighted Pair Group Method with Arithmetic mean) and PCoA (Principal Coordinate Analysis) analyses showed that populations from each subspecies grouped together. However, the structure analysis generated more groups than the PCoA plot and UPGMA, which revealed the mixed allelic of the species Capparis spinosa in Tunisia.

Phytochemical profile and biological activities of Deverra tortuosa (Desf.)DC.: a desert aromatic shrub widespread in Northern Region of Saudi Arabia.

The present study describes the chemical composition of the essential oil of different plant parts of Devrra tortuosa; in vivo and in vitro biological activities of plant extract and essential oils. Apiol was found to be the major component of the oil (between 65.73% and 74.41%). The best antioxidant activities were observed for the oil of flowers (IC50 = 175 µg/ml). The samples of stems and roots exhibit lower antioxidant activity (IC50 = 201 µg/ml and 182 µg/ml, respectively). The values of IC50 showed that the extracts of methanol exhibit the highest antioxidants activities (IC50 = 64.8 102 µg/ml). EOs showed excellent antifungal activity against yeasts with low azole susceptibilities (i.e. Malassezia spp. and Candida krusei). The MIC values of oils varied between 2.85 mg/mL and 27 mg/mL. The obtained results also showed that the plant extracts inhibited the germination and the shoot and root growth of Triticum æstivum seedlings.

Relationship between chemotypic and genetic diversity of natural populations of Artemisia herba-alba Asso growing wild in Tunisia.

A total of 80 individuals collected from eight populations growing wild in different geographic zones were considered to assess the intraspecific variability of essential oil composition, genetic diversity and population structure of Artemisia herba-alba. The essential oil composition varied significantly between populations. Essential oil profiles were classified into four chemotypes (trans-sabinyl acetate, α-thujone/trans-sabinyl acetate, camphor and α-thujone/camphor/ß-thujone). Despite significant correlation between the amount of some essential oil compounds and a set of climatic data, the global chemical divergence among populations was not related to their bioclimatic and geographic appurtenances. A high level of genetic diversity within populations was revealed either with RAPD and ISSR markers (Na = 1.67, PPL = 66.5%, H = 0.26, I = 0.38 and Na = 1.7, PPL = 69.8%, H = 0.26, I = 0.38, respectively). The level of genetic diversity varied across populations and chemotypes. Populations from the α-thujone/trans-sabinyl acetate chemotype exhibited the highest genetic diversity as revealed by the RAPD markers. However, populations from α-thujone/camphor/ß-thujone chemotype showed the important genetic variation determined by ISSR markers. A significant genetic differentiation among populations and among chemotypes was detected. The combined analysis showed a significant correlation (r = 0.484, p = .032) between the chemical and molecular markers. The PCA, performed on percentages of major oil compounds and the frequencies of polymorphic RAPD and ISSR bands, divided populations according to their chemotypic classification. Taking into consideration the current situation of A. herba-alba populations and their endangered habitats, these results are of value in order to ensure the in-situ and ex-situ conservation of this medicinal species.

Essential Oil Variability in Natural Populations of Artemisia campestris (L.) and Artemisia herba-alba (Asso) and Incidence on Antiacetylcholinesterase and Antioxidant Activities.

The intraspecific variability of Artemisia herba-alba and A. campestris essential oils and the evaluation of their antioxidant and antiacetylcholinesterase activities were determined. Artemisia herba-alba essential oil was found rich in camphor (19.61%), α-thujone (19.40%), ß-thujone (9.44%), chrysanthenone (9.26%), and trans-sabinyl acetate (8.43%). The major compounds of A. campestris essential oil were germacrene D (16.38%), ß-pinene (16.33%), and limonene (9.17%). Significant variation in the essential oil composition was observed among populations of each species. The divergence between populations was attributed to the variation of some climatic factors such as altitude, annual rainfall, winter cold stress, summer precipitation, summer drought stress, evapotranspiration, and humidity. Artemisia herba-alba and A. campestris essential oils exhibited promising antioxidant and antiacetylcholinesterase activities. The level of activity varied significantly according to the species and the essential oil. The highest scavenging activity (IC50 = 0.14 mg/ml) and the uppermost capacity to prevent ß-carotene bleaching (IC50 = 0.10 mg/ml) characterized A. campestris from population 6. A. campestris population 3 possessed the uppermost ability to reduce ferric ions (450.7 µmol Fe2+ /g EO). The population 2 of A. campestris showed the strongest antiacetylcholinesterase activity (IC50 = 0.02 mg/ml). The variation of these activities between the essential oils was explained by their composition differences.

Essential Oils of Myrtaceae Species Growing Wild in Tunisia: Chemical Variability and Antifungal Activity Against Biscogniauxia mediterranea, the Causative Agent of Charcoal Canker.

The chemical composition of five Eucalyptus species and five Myrtus communis L. populations was investigated using GC/MS and GC-FID. For Eucalyptus essential oils, 32 compounds, representing 88.56 - 96.83% of the total oil according to species, were identified. The main compounds were 1,8-cineole, α-pinene, p-cymene, γ-gurjunene, α-aromadendrene, and ß-phellandrene. For Myrtle essential oils, 26 compounds, representing 93.13 - 98.91% of the total oil were identified. α-Pinene, 1,8-cineole, linalool, and myrtenyl acetate were found to be the major compounds. Principal component analysis (PCA) showed chemical differentiation between Eucalyptus species and between Myrtle populations. Biscogniauxia mediterranea, the causative agent of charcoal canker, was identified according to its morphological and molecular characteristics. Essential oils of the investigated Eucalyptus species and Myrtle populations were tested for their antifungal capacity against this fungus. The antifungal activity varied according to the essential oil composition. Biscogniauxia mediterranea exhibited powerful resistance to some essential oils including them of Eucalyptus lehmannii and Eucalyptus sideroxylon but it was very sensitive to Eucalyptus camaldulensis oil (IC50  = 3.83 mg/ml) and M. communis oil from Zaghouan (IC50  = 1 mg/ml). This sensitivity was found to be correlated to some essential oil compounds such as p-cymene, carvacrol, cuminaldehyde, and linalool.

Bioactive compounds from Hypericum humifusum and Hypericum perfoliatum: inhibition potential of polyphenols with acetylcholinesterase and key enzymes linked to type-2 diabetes.

CONTEXT: Natural products are reported to have a wide spectrum of pharmacological properties such as antimicrobial, anti-inflammatory and anti-cholinesterase. The genus Hypericum (Hypericaceae) is a source of a variety of molecules with different biological activities, notably hypericin and various phenolics. OBJECTIVES: The goals of the present work were the determination of total phenolic and flavonoid content, hypericin and hyperforin concentration as well as the evaluation of biological of Hypericum humifusum L. (Hhu) and Hypericum perfoliatum L. (Hper). MATERIALS AND METHODS: The various extracts of aerial parts were powdered, and then extracted with methanol. Antibacterial activity was performed according to minimum inhibitory concentration (MIC) and minimum bactericidal (MBC) methods against four Gram-positive bacteria, four Gram-negative bacteria and yeast. RESULTS: The results revealed that H. humifusum, bear the highest total phenolic and flavonoid content (48-113 mg GAE/g and 8-41 mg RE/g, respectively) as well as hypericin (60-90 mg/g) and hyperforin (8-30 mg/g) concentration. Both species showed significant antioxidant activity as revealed by DPPH, FRAP, ABTS, and metal chelating assays. H. humifusum exhibited a strong acetylcholinesterase (3.86-4.57 mg GALAEs/g), α-glucosidase (0.73-2.55 mmol ACEs/g) and α-amylase (3-8 mmol ACEs/g) inhibitory activity. The extract of H. humifusum exhibited strong antibacterial activity mainly against Staphylococcus epidermidis, Staphylococus aureus, and Enterococcus faecium (MIC values ranging from 200 to 250 µg/mL). The highest antifungal activity was showed for H. perfoliatum extract (MIC value = 250 µg/mL). CONCLUSION: The data suggest that H. humifusum could be used as valuable new natural agents with functional properties for pharmacology industries.

Asteraceae Artemisia campestris and Artemisia herba-alba Essential Oils Trigger Apoptosis and Cell Cycle Arrest in Leishmania infantum Promastigotes.

We report the chemical composition and anti-Leishmania and antioxidant activity of Artemisia campestris L. and Artemisia herba-alba Asso. essential oils (EOs). Our results showed that these extracts exhibit different antioxidant activities according to the used assay. The radical scavenging effects determined by DPPH assay were of IC50 = 3.3 mg/mL and IC50 = 9.1 mg/mL for Artemisia campestris and Artemisia herba-alba essential oils, respectively. However, antioxidant effects of both essential oils, determined by ferric-reducing antioxidant power (FRAP) assay, were in the same range (2.3 and 2.97 mg eq EDTA/g EO, resp.), while the Artemisia herba-alba essential oil showed highest chelating activity of Fe2+ ions (27.48 mM Fe2+). Interestingly, we showed that both EOs possess dose-dependent activity against Leishmania infantum promastigotes with IC50 values of 68 µg/mL and 44 µg/mL for A. herba-alba and A. campestris, respectively. We reported, for the first time, that antileishmanial activity of both EOs was mediated by cell apoptosis induction and cell cycle arrest at the sub-G0/G1 phase. All our results showed that EOs from A. herba-alba and A. campestris plants are promising candidates as anti-Leishmania medicinal products.

Ecological systems as computer networks: Long distance sea dispersal as a communication medium between island plant populations.

Ecological systems are known to exchange genetic material through animal species migration and seed dispersal for plants. Isolated plant populations have developed long distance dispersal as a means of propagation which rely on meteorological such as anemochory and hydrochory for coast, island and river bank dwelling species. Long distance dispersal by water, in particular, in the case of water current bound islands, calls for the analogy with computer networks, where each island and nearby mainland site plays the role of a network node, the water currents play the role of a transmission channel, and water borne seeds as data packets. In this paper we explore this analogy to model long distance dispersal of seeds among island and mainland populations, when traversed with water currents, in order to model and predict their future genetic diversity. The case of Pancratium maritimum L. populations in Tunisia is used as a proof of concept, where their genetic diversity is extrapolated.

Bioactive compounds contents, antioxidant and antimicrobial activities during ripening of Prunus persica L. varieties from the North West of Tunisia.

Bioactive molecules from fruits of four varieties of Prunus persica at different stages of ripening (green, small orange, red) were studied. For example, contents on polyphenols (20.36mg GAE/g FW) and flavonoids (0.764mg RE/g FW) were high and varied according variety. The antioxidant activity, using four different tests (DPPH radical scavenging activity, reducing power, ß carotene bleaching system and TBARS assay) showed that the variety Chatos exhibited the highest antioxidant activity comparing with others varieties. The antibacterial activity of Prunus persica varieties studied seems to be more sensitive against Staphylococcus aureus and Listeria monocytogenes. The capacity of peach DMSO extracts to inhibit Candida albicans growth was more pronounced, especially, in the presence of Chatos DMSO extract. Enzymes inhibition gives results which correlate with polyphenols, flavonoids and condensed tannins contents, and so, confirm the fascinating bioactivity of this fruit.

Genetic diversity and phylogenetic analysis of two Tunisian bivalves (Mactridae) Mactra corallina (Linnaeus, 1758) and Eastonia rugosa (Helbling, 1799) based on COI gene sequences.

A partial sequence of mitochondrial cytochrome c oxidase subunit I (COI) was used as a genetic marker for a genetic diversity and phylogenetic analysis (DNA barcoding) of two Mactridae species, Mactra corallina and Eastonia rugosa, collected from the Tunisian coast. These Mactridae species could be distinguished by DNA barcoding techniques and they will be considered as monophyletic clades with the Neighbor-Joining (NJ) tree. The genetic structure detected that E. rugosa presents three haplotypes with a high frequency of HER1 (0.89). However, M. corralina shared 14 haplotypes. The haplotypic diversity (H) was equal to 0.205 and 0.954, respectively, for E. rugosa and M. corallina. While the nucleotide diversity (π) was higher for M. corallina (π=0.0818), the mismatch distribution showed a unimodal curve for E. rugosa (a recent sudden demographic expansion) and a multimodal distribution for M. corallina (size stability).

Modeling hydrochory effects on the Tunisian island populations of Pancratium maritimum L. using colored Petri nets.

Hydrochory, the seed dispersal by water, is a strategy used by many aquatic and some terrestrial plants to move into areas appropriate for establishment. In this paper we model the hydrochory effects on the Tunisian island populations of Pancratium maritimum L. using colored Petri nets. Nineteen Tunisian coastal sites were considered including fourteen mainland and five island sites. The model was simulated for 400 thousand Atlantic Tunisian Current cycles (years). Snapshots of the island population's genetic makeup were taken for 50, 200 and 400 thousand years. The evolution of the obtained dendrograms showed a clear divide between the northern and southern island populations according to their estimated genetic make-up for the considered simulation durations. Hydrochory is not only with important ecological consequences, such as maintaining the populations of P. maritimum but also it may move species into areas appropriate for establishment. In this context, in situ and ex situ conservation measures of P. maritimum populations should be adopted very fast.