Metabolomics-Based Profiling via a Chemometric Approach to Investigate the Antidiabetic Property of Different Parts and Origins of Pistacia lentiscus L.

Pistacia lentiscus L. is a medicinal plant that grows spontaneously throughout the Mediterranean basin and is traditionally used to treat diseases, including diabetes. The aim of this work consists of the evaluation of the α-glucosidase inhibitory effect (i.e., antidiabetic activity in vitro) of different extracts from the leaves, stem barks and fruits of P. lentiscus harvested on mountains and the littoral of Tizi-Ouzou in Algeria. Metabolomic profiling combined with a chemometric approach highlighted the variation of the antidiabetic properties of P. lentiscus according to the plant's part and origin. A multiblock OPLS analysis showed that the metabolites most involved in α-glucosidase inhibition activity were mainly found in the stem bark extracts. The highest inhibitory activity was found for the stem bark extracts, with averaged inhibition percentage values of 84.7% and 69.9% for the harvested samples from the littoral and mountain, respectively. On the other hand, the fruit extracts showed a lower effect (13.6%) at both locations. The UHPLC-ESI-HRMS characterization of the metabolites most likely responsible for the α-glucosidase-inhibitory activity allowed the identification of six compounds: epigallocatechin(4a>8)epigallocatechin (two isomers), (epi)gallocatechin-3'-O-galloyl-(epi)gallocatechin (two isomers), 3,5-O-digalloylquinic acid and dihydroxy benzoic acid pentoside.

A Review of Pistacia lentiscus Polyphenols: Chemical Diversity and Pharmacological Activities.

Pistacia lentiscus (lentisk) is a plant species of the Anacardiaceae family. It is a medicinal plant that grows wild in the Mediterranean region. This review aims to update the existing knowledge regarding P. lentiscus polyphenols by consulting references dated from 1996 to 2022. The data are organized and analyzed as follows: (i) to show the chemical diversity of phenolic products from P. lentiscus; (ii) to summarize the variability in phenolic composition and quantity; this could be attributed to plant origin, environmental conditions, phenological stage, and the polarity of the extraction solvents; (iii) to present the pharmacological properties in agreement with the traditional uses of this plant; and (iv) to demonstrate the correlation between the chemical profile and the pharmacological effect. Various compositions were observed, including phenolic acids, flavonoid glycosides, anthocyanins, catechins, and their derivatives. The biological and therapeutic potentials of lentisk extracts have been evaluated in terms of antioxidant, antimicrobial, and anti-inflammatory activities. Most of these activities are related to the phenolic composition of this plant. The content of this review will undoubtedly contribute to the choice of techniques for isolating the different bioactive molecules contained in the P. lentiscus. It is also of significance for the potential development of a micro-industrial sector based on the valorization of lentisk polyphenols.

Profiling of Essential Oils from the Leaves of Pistacia lentiscus Collected in the Algerian Region of Tizi-Ouzou: Evidence of Chemical Variations Associated with Climatic Contrasts between Littoral and Mountain Samples.

Leaves of Pistacia lentiscus were collected from two Algerian sites in the mountains and the littoral of the Tizi-Ouzou region. The harvest was conducted in four consecutive seasons on the same selected set of trees. Essential oils (EOs) were extracted by hydrodistillation; then, they were analyzed by gas chromatography coupled mass spectrometry (GC-MS). Forty-seven constituents could be detected and quantified, including α-pinene (2-13%), ß-caryophyllene (8-25%), ß-myrcene (0.3-19%), bornyl acetate (0.8-7%), δ-cadinene (3-8%), bisabolol (1-9%), ß-pinene (0.9-7%), caryophyllene oxide (4-9%), and α-cadinol (3-11%). Antioxidant (AOx) activities of the EOs were assessed by ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and 2,2'-azino-bis (3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) assays. Significant differences in EO composition and AOx activities appeared dependent on the season and the site. Variations of AOx activities were significant for the FRAP and ABTS tests but not for DPPH. Characterization of the leaf fatty acyl (FA) profiles was performed by GC-MS. Variability appeared according to season and altitude. Polyunsaturated fatty acids levels were high (27-55%) at the coldest date and place. The levels of linolenic acyl in the leaves were significantly correlated with bisabolol levels in the EOs (Spearman's correlation coefficient: 0.818). Such results will be useful for the sustainable local valorization of wild P. lentiscus. These data also open new routes for further studies on terpenoid biosynthesis using correlation networks and fluxomic approaches.

MeJA Elicitation of Chicory Hairy Roots Promotes Efficient Increase of 3,5-diCQA Accumulation, a Potent Antioxidant and Antibacterial Molecule.

Cichorium intybus L. (Asteraceae) is an important industrial crop, as well as a medicinal plant which produces some bioactive compounds implicated in various biological effects with potential applications in human health. Particularly, roots produce hydroxycinnamic acids like 5-caffeoyquinic acid and 3,5-dicaffeoylquinic acid (di-CQA). The present investigation relates to the use of methyl jasmonate for enhancing phenolic compounds accumulation and production in hairy root cultures of C. intybus. Elicitated hairy root growth rate increased 13.3 times compared with the initial inoculum in a period of 14 days and di-CQA production represented about 12% of DW. The elicitation has also promoted the production of tricaffeoylquinic acid never described in the chicory roots and identified as 3,4,5-tricaffeoyquinic acid by means of nuclear magnetic resonance. Our study confirmed the strong anti-oxidant effect of di-CQA. Our results also confirmed globally a selectivity of action of di-CQA against Gram-positive bacteria, in particular against some strains of Staphylococcus and Streptococcus. However, a non-negligible antibacterial activity of di-CQA against Pseudomonas aeruginosa was also underlined (MIC = 0.156 mg.mL-1 against some P. aeruginosa strains). The influence of di-CQA has been explored to evaluate its impact on the physiology of P. aeruginosa. Di-CQA showed no effect on the biofilm formation and the production of extracellular pyocyanin. However, it demonstrated an effect on virulence through the production of pyoverdine with a dose-dependent manner by more than 7-fold when treated at a concentration of 128 µg·mL-1, thus suggesting a link between di-CQA and iron sequestration. This study shows that elicitated hairy root cultures of chicory can be developed for the production of di-CQA, a secondary metabolite with high antibacterial potential.

Datura innoxia plants hydroponically-inoculated with Agrobacterium rhizogenes display an enhanced growth and alkaloid metabolism.

BACKGROUND: The production of secondary metabolites through the culture of entire plants is of great interest. Soilless culture, such as hydroponics, enables the control of plant growth and metabolism. Specific environmental conditions must be developed to maximize the productivity of medicinal plants used as efficient natural bioreactors. METHODS: The nutrient solution of newly established hydroponic cultures ofDatura innoxia Mill. were inoculated with Agrobacterium rhizogenes (A.r.) wild strains (TR7, TR107, 11325 or 15834). Growth and the alkaloid contents of roots and aerial parts were analyzed. Axenic cultures were also performed with modified TR7 strains containing the egfp or gus reporter gene. In vitro isolated root cultures enabled the phenological and molecular demonstration of gene transfer. RESULTS: A.r.TR 7 led to a greater improvement in plant secondary metabolism and growth. Positive expression of the reporter genes occurred. Isolation and subculture of some of the roots of these plants showed a hairy root phenotype; molecular tests proved the transfer of bacterial genes into the roots isolated from the plants. CONCLUSIONS: Hyoscyamine and scopolamine productivity is enhanced after A.r. inoculation in the nutrient solution of hydroponic plants. Transformation events occur in the original roots of the plants. This leads to chimeric plants with a part of their roots harboring a hairy root phenotype. Such semi-composite plants could be used for successful specialized metabolite bioproduction in greenhouses.

Investigation of Linum flavum (L.) Hairy Root Cultures for the Production of Anticancer Aryltetralin Lignans.

Linum flavum hairy root lines were established from hypocotyl pieces using Agrobacterium rhizogenes strains LBA 9402 and ATCC 15834. Both strains were effective for transformation but induction of hairy root phenotype was more stable with strain ATCC 15834. Whereas similar accumulation patterns were observed in podophyllotoxin-related compounds (6-methoxy-podophyllotoxin, podophyllotoxin and deoxypodophyllotoxin), significant quantitative variations were noted between root lines. The influence of culture medium and various treatments (hormone, elicitation and precursor feeding) were evaluated. The highest accumulation was obtained in Gamborg B5 medium. Treatment with methyl jasmonate, and feeding using ferulic acid increased the accumulation of aryltetralin lignans. These results point to the use of hairy root culture lines of Linum flavum as potential sources for these valuable metabolites as an alternative, or as a complement to Podophyllum collected from wild stands.

Enhanced Stilbene Production and Excretion in Vitis vinifera cv Pinot Noir Hairy Root Cultures.

Stilbenes are defense molecules produced by grapevine in response to stresses including various elicitors and signal molecules. Together with their prominent role in planta, stilbenes have been the center of much attention in recent decades due to their pharmaceutical properties. With the aim of setting up a cost-effective and high purity production of resveratrol derivatives, hairy root lines were established from Vitis vinifera cv Pinot Noir 40024 to study the organ-specific production of various stilbenes. Biomass increase and stilbene production by roots were monitored during flask experiments. Although there was a constitutive production of stilbenes in roots, an induction of stilbene synthesis by methyl jasmonate (MeJA) after 18 days of growth led to further accumulation of ε-viniferin, δ-viniferin, resveratrol and piceid. The use of 100 µM MeJA after 18 days of culture in the presence of methyl-ß-cyclodextrins (MCDs) improved production levels, which reached 1034µg/g fresh weight (FW) in roots and 165 mg/L in the extracellular medium, corresponding to five-and 570-foldincrease in comparison to control. Whereas a low level of stilbene excretion was measured in controls, addition of MeJA induced excretion of up to 37% of total stilbenes. The use of MCDs increased the excretion phenomenon even more, reaching up to 98%. Our results demonstrate the ability of grapevine hairy roots to produce various stilbenes. This production was significantly improved in response to elicitation by methyl jasmonate and/or MCDs. This supports the interest of using hairy roots as a potentially valuable system for producing resveratrol derivatives.

Kinetics of glucosylated and non-glucosylated aryltetralin lignans in Linum hairy root cultures.

Due to their pronounced cytotoxic activity, a number of aryltetralin lignans (ATLs), such as podophyllotoxin (PTOX), are used as antitumor compounds. The production of such molecules from entire plants or plant cell-tissue-organ cultures is thus of interest to the pharmaceutical industry. Hairy root cultures constitute a good tool not only for phytochemical production but also for investigating plant secondary metabolism. This work reports on the growth and ATL biosynthesis in two hairy root cultures of Linum album Kotschy ex Boiss. and Linum flavum. The kinetics of accumulation of the intermediates of MPTOX biosynthesis and of their glucosylated forms are described over a 21-day period of growth. An accumulation of non-glucosylated forms of the ATLs during the exponential phase of the cultures is followed by an accumulation of the glucosylated forms during the stationary phase. Our results show a strong coordination of the biosynthetic paths derived from deoxypodophyllotoxin via deoxypodophyllotoxin 6-hydroxylase and deoxypodophyllotoxin 7-hydroxylase, and a coordinated glucosylation of podophyllotoxin, methoxypodophyllotoxin, and 5'-demethoxymethoxypodophyllotoxin. Furthermore, our results suggest an important role of ß-peltatin-6-glucoside formation in the control of ATL accumulation in Linum hairy root cultures.

Structural features and bioremediation activity of an exopolysaccharide produced by a strain of Enterobacter ludwigii isolated in the Chernobyl exclusion zone.

The bacterium Enterobacter ludwigii Ez-185-17, member of the family Enterobacteriaceae, was isolated from the root nodules of plants harvested in the nuclear power region of Chernobyl. Under batch culture conditions, the bacteria produce a high-molecular-mass exopolysaccharide (EPS). After purification, the structure of this EPS was determined using a combinatory approach including monosaccharide composition (GC-FID, HPAEC-PAD) and branching structure determination (GC-MS), as well as 1D/2D NMR ((1)H, (13)C) and ESI-MS (HR, MS/MS) studies of oligosaccharides obtained from mild acid hydrolysis. The EPS was found to be a charged hexasaccharide with a repeating unit composed of d-galactose, d-glucose, l-fucose, d-glucuronic acid (2:1:2:1) and substituted with acyl and pyruvyl groups. The metal-binding properties of the exopolysaccharide were then investigated, and the results seem to indicate that the EPS decreased Cd sequestration in flax seeds.

Exopolysaccharide production by nitrogen-fixing bacteria within nodules of Medicago plants exposed to chronic radiation in the Chernobyl exclusion zone.

Nitrogen-fixing bacteria isolated from root nodules of Medicago plants growing in the 10 km zone around the Chernobyl nuclear power plant were screened for the production of new water-soluble acidic exopolysaccharides (EPSs). The different strains belonged to the Enteriobacteriaceae family (Enterobacter ludwigii, Raoultella terrigena, Klebsiella oxytoca), except for one which belonged to the Rhizobiaceae family (Sinorhizobium meliloti). All of the bacteria produced highly viscous EPS with an average molecular weight comprised between 1 x 10(6) and 3 x 10(6) Da. Five different compositions of EPS were characterized by physico-chemical analyses and (1)H NMR spectroscopy: galactose/mannose (2/1), galactose/glucose (1/1), galactose/glucose/mannose (1/2/1), fucose/galactose/glucose (2/1/1) and fucose/galactose/glucose/mannose (2/2/1/1 or 1/1/2/4). Glucuronic acid, a charged monosaccharide, was also recovered in most of the different EPSs.

Oligogalacturonic acid inhibit bone resorption and collagen degradation through its interaction with type I collagen.

In this study, we showed that oligogalacturonic acid (OGA) purified from flax pectin inhibit in vitro osteoclastic bone resorption in a dose-dependent manner. The OGA inhibitory effect was neither linked to an effect on osteoclast apoptosis, nor to an inhibition of cathepsin K activity. By means of an in vitro collagen degradation assay we demonstrated that OGA prevented triple-helical type I collagen cleavage by cathepsin K in a dose and chain length dependent manner. This inhibition was not restricted to cathepsin K, since collagenolytic activity of other lysosomal cysteine proteases, such as cathepsin B and cathepsin L, as well as matrixmetalloproteinases such as MMP-9 were also inhibited. Interestingly, using non-collagen substrates we demonstrated that OGA does not inhibit the proteolytic activity of cathepsin B and L, suggesting that OGA inhibits collagen degradation without affecting the lysosomal cysteine enzyme proteolytic activity. Finally, preliminary study using surface plasmon resonance (SPR) showed that OGA binds to type I collagen but not to albumin, consistent with a specific effect on collagen. These results suggest that the observed inhibition of collagen degradation by OGA may be due to its ability to bind to the collagen molecule. By masking the collagen surface, OGA may render the collagen cleavage site less accessible to enzymes and thus prevent its enzymatic degradation.

Inhibitors of Civ1 kinase belonging to 6-aminoaromatic-2-cyclohexyldiamino purine series as potent anti-fungal compounds.

There is today a blatant need for new antifungal agents, because of the recent increase in life-threatening infections involving an ever-greater number of fungal strains. Fungi make extensive use of kinases in the regulation of essential processes, in particular the cell cycle. Most fungal kinases, however, are shared with higher eukaryotes. Only the kinases which have no human homologs, such as the histidine kinases, can be used as targets for antifungal drugs design. This review describes efforts directed towards the discovery of drugs active against a novel target, the atypical cell cycle kinase, Civ1.

The cell cycle of pathogenic fungi: target for drugs.

Life-threatening fungal infections are becoming more frequent and involve a greater variety of strains, many of which are drug-resistant. Both public research organisations and the pharmaceutical industry are committed to the development of new drugs to satisfy this increasing medical need. The approach described here exemplifies the efforts directed towards the discovery of drugs which are active against novel targets, exemplified by the cell-cycle regulator, Civ1.

Recent advances in cyclin-dependent kinase inhibition. Purine-based derivatives as anti-cancer agents. Roles and perspectives for the future.

Protein kinases (Ser/Thr and Tyr) play a key role in signal transduction pathways. It has been shown that deregulation of the Cdk activity is linked to cell proliferation and cancer. Inhibition of cyclin-dependent kinases (Cdks) is an important target for potential new anti-cancer drugs. Following the discovery of Olomoucine, a wide range of tri-substituted purine derivatives have been synthesized, leading to potent Cdk inhibitors. These purine-derived compounds bind to the ATP pocket of the protein. Of interest for structure-based drug design, the different crystal structures published to date show evidence for three different binding modes for the purine ring, allowing diverse exploration of the ATP binding site. Some examples of synthesis and structure activity relationships are discussed for a set of purine derivatives, tri-substituted on C-2, N-9 and C-6. Finally, in vivo activities are reviewed, as well as the applications in other therapeutic areas.