Phenolic Profiling, Antioxidant, and Antibacterial Activities of Selected Medicinal Plants from Tunisia.

Phytochemical screening of aqueous extract from six medicinal wild plants grown in South-eastern of Tunisia: Atriplex halimus, Teucrium polium, Moricandia arvensis, Deverra tortuoa, Haplophyllum tuberculatum and Polygonum equisetiforme were evaluated. Both decoction and ultrasound assisted extraction were used. Antioxidant, antibacterial proprieties, and phenolic profiling, using LC-ESI-MS method, were assessed. Total polyphenols, flavonoids, and condensed tannins contents ranged from 7.47±0.19 to 22.25±0.49 mg GAE/g Dw, 5.47±0.06 to 7.55±0.07 mg RE/g Dw, and 0.33±0.02 to 19.43±0.64 mg TAE/g Dw, respectively. Moreover, the reducing power and DPPH tests showed that P. equisetiforme (EC50 : 12.50±0.50 µg/ml; DPPH⋅+ : 213.49±4.24 mg TEAC/g DW), T. polium (EC50 : 25.00±1.00 µg/ml; DPPH⋅+ : 181.39±9.47 mg TEAC/g DW) as well as H. tuberculatum (EC50 : 56.25±0.25 µg/ml; DPPH⋅+ : 177.83±5.85 mg TEAC/g DW) extracts were the most effective natural antioxidants. For anti-bacterial activity, the ultrasonic extract of H. tuberculatum showed the highest activity against both P. aeruginosa (13.50±0.71 mm) and S. aureus (13.00±0.00 mm) at 10 mg/ml. Furthermore 24 phenolic compounds were identified, with predominance of quinic acid, gallic acid, protocatechuic acid, syringic acid, p-coumaric acid, trans-ferulic acid, catechin (+), trans-cinnamic and silymarin. These results were further consolidated by to heatmap clustering with P. equisetiforme, H. tuberculatum, T. polium as the main antioxidant and antibacterial sources which supports their domestication and industrial use.

Effects of Allium roseum L. extracts on the proliferation and the differentiation of the acute myeloid leukemia cell line U937.

Epidemiologic studies keep up the proposition that Allium vegetables can lower the risk of cancers. Acute myeloid leukemia (AML) cells exhibit high proliferative potency and have a reduced capacity of undergoing apoptosis and maturation. The beneficial effects of Allium seem related to the organosulfur products generated upon processing of these species. For this purpose, the aim of this study was to test Allium roseum fresh (FAE), crude (CAE) and dried (DAE) aqueous extracts for activity against the human acute leukemia cell line (U937). As assessed by flow cytometry, inhibited cell proliferation was in a dose-dependent manner. Firstly, study showed that cell growth was inhibited with 20 mg/mL using FAE and CAE (60% and 73% respectively). Secondly, our experiments clearly indicate that all A. roseum extracts do not induce cell apoptosis. This was confirmed by the soft binding of Annexin V to phosphatidylserine. Finally, the high expression of macrophage's marker CD11 associated with adequate morphological changes proves clearly the differentiation aspect produced by A. roseum extract. Taken together, these data suggest that A. roseum could be a promising candidate for the alternative medicine in the field of cancer therapy.

Biochemical Composition and Biological Activities of Various Population of Brassica tournefortii Growing Wild in Tunisia.

Brassica tournefortii Gouan, commonly known (Aslooz) in Tunisia, is an annual plant, native to the North Africa and Middle East. Brassica species are used as food, their young leaves can be cooked, providing nutrients and health-giving phytochemicals such as phenolic compounds, polyphenols and carotenoids. Phytochemical composition and bioactivity of Brassica tournefortii leaf extracts, collected from four different bioclimatic zones in Tunisia, are investigated in the present study. Results showed that location and climatic variations can alter the phytochemical composition of B. tournefortii. Interestingly, HPLC analysis enabled identifying lutein and beta-carotene at high concentrations, especially in extracts of B. tournefortii collected from Gabes (B2) (344 µg/g of lutein) and B. tournefortii collected from Zarzis (B3) (1364 µg/g of beta-carotene). In particular, the antioxidant activity measured by DPPH assay showed that the extract of the plants collected from the growing region of Zarzis exhibits the highest antioxidant activities (0.99 mg/mL). All the Brassica tournefortii extracts showed a relevant antiproliferative activity, especially toward the Caco-2 cell line. These preliminary data resulted in being useful to correlate growth environmental conditions with different accumulation of metabolites in Brassica species still being poorly studied.

Seasonal changes in rosemary species: A chemotaxonomic assessment of two varieties based on essential oil compounds, antioxidant and antibacterial activities.

Rosemary (Rosmarinus officinalis L.) is a popular herb in cooking, traditional healing, and aromatherapy. This study was conducted to evaluate the effects of meteorological conditions plant growth stage and genetic factors on the yield, quantitative and qualitative composition, on the antioxidant and antimicrobial activities of rosemary essential oil from two Tunisian locations (El Fahs and Matmata) during two successive years. The composition of the essential oils obtained by hydrodistilation from rosemary plants were carried out annually using GC and GC/MS. Results showed the the main constituents were camphor (18.2-28.1%), 1,8-cineole (6.4-18.0%), α-pinene (9.7-13.5%), borneol (4.4-9.5%), and camphene (5.1-8.7%). The principal component and heatmapper analyses showed group segregation of the two studied varities based on major essential oil compounds. Additionally, in vitro antimicrobial and antioxidant activities showed that rosemary essential oils had an important ability in scavenging DPPH, as well as a higher bactericidal effect. The seasonal variation, growth stage and genetic pools seemed to be a factors of significant variation of the composition, antimicrobial and the antioxidant activities of the rosemary essential oils. These finding would be taken to use the chemotaxonomy tools to develop a program for Rosmary protection conservation and identification based on essential oil composition.

The polyphenol/saponin-rich Rhus tripartita extract has an apoptotic effect on THP-1 cells through the PI3K/AKT/mTOR signaling pathway.

BACKGROUND: Hyperactivation of mechanistic target of rapamycin (mTOR) signaling pathway is involved in the regulation of cellular growth, proliferation, and more in general, is a common phenomenon in most types of cancers. Thus, natural substances targeting this pathway can be of great therapeutic potential in supporting the treatment of tumor patients. Rhus tripartita (Ucria) Grande is a plant growing in desertic areas which is traditionally used for the treatment of several diseases in Tunisia. In the present work, the biochemical profile of the main compounds present in the plant leaf extract was determined and the anti-leukemic potential of the plant extracts against acute monocytic leukaemia (AML) THP-1 cells was investigated. METHODS: After HPLC identification of some phenolic compounds present in the plant extract and the quantification of saponin content, the cytotoxic effect of Rhus tripartita extracts on THP-1 cell culture was evaluated using the colorimetric MTT assay for cell viability. THP-1 cells were incubated with medium containing the relative IC50 concentrations of total plant extract, saponin extract and some standard compounds (rutin (R); kaempferol (K); mixture of catechin, epicatechin, and epicatechin-gallate (CEEG); ellagic acid (EA). Finally, qRT-PCR and western blotting analysis were used to evaluate the effect of some flavonoids present in a crude extract of polyphenols and the total extract of saponins on cell survival and apoptosis. RESULTS: Analysis of expression level of some gene (PIK3CA, PTEN, AKT1, mTOR, EIF4E, RPS6KB1, and TSC1) involved in the mTOR pathway and the phosphorylation of S6 and AKT proteins allowed to observe that a total Rhus tripartita extract and some of the compounds found in the extract controls THP-1 cell proliferation and apoptosis via regulation of the PI3K-Akt-mTOR signaling pathway. CONCLUSION: Rhus tripartita-induced inhibition of cell cycle and induction of apoptosis may involve the mTOR pathway. Therefore, Rhus tripartita extract may be a useful candidate as a natural anti-cancer drug to support the treatment of AML.

Allium roseum L. extract inhibits amyloid beta aggregation and toxicity involved in Alzheimer's disease.

Allium roseum is an important medicinal and aromatic plant, specific to the North African flora and a rich source of important nutrients and bioactive molecules including flavonoids and organosulfur compounds whose biological activities and pharmacological properties are well known. In the present study, the inhibition of amyloid beta protein toxicity by the ethanolic extract of this plant is investigated for the first time. Preliminary biochemical analyses identified kæmpferol and luteolin-7-o-glucoside as the more abundant phenolic compounds. The effects of A. roseum extract (ARE) on aggregation and aggregate cytotoxicity of amyloid beta-42 (Aß42), whose brain aggregates are a hallmark of Alzheimer's disease, were investigated by biophysical (ThT assay, Dynamic light scattering and transmission electron microscopy) and cellular assays (cytotoxicity, aggregate immunolocalization, ROS measurement and intracellular Ca2+ imaging). The biophysical data suggest that ARE affects the structure of the Aß42 peptide, inhibits its polymerization, and interferes with the path of fibrillogenesis. The data with cultured cells shows that ARE reduces Aß42 aggregate toxicity by inhibiting aggregate binding to the cell membrane and by decreasing both oxidative stress and intracellular Ca2+. Accordingly, ARE could act as a neuroprotective factor against Aß aggregate toxicity in Alzheimer's disease.

Jujube (Zizyphus lotus L.): Benefits and its effects on functional and sensory properties of sponge cake.

Jujube (Ziziphus lotus L.) fruit has multiple functional properties and represents an interesting source of bioactive compounds. The purpose of this study was to improve the functionality and the sensory properties of sponge cake enriched with Z. lotus fruit. The polyphenols and flavonoids levels in the sponge cake and its antioxidant potential increased with the addition of 0-10 g of jujube powder/100 g of wheat flour. The crumb color parameters, L* and b*, decreased with the addition of jujube powder, whereas the a* value increased. In the texture analysis, addition of jujube powder resulted in an increase of the hardness and chewiness, but the springiness was reduced. The sensory evaluation showed that supplementation of jujube powder did not manifest any undesirable organoleptic response and showed satisfactory consumer acceptability. Overall, the addition at 5% jujube powder showed the finest sensory properties of the sponge cake.

Stimulation of insulin secretion by acetylenic fatty acids in insulinoma MIN6 cells through FFAR1.

We examined whether the acetylenic fatty acids 6-octadecynoic acid (6-ODA) and 9-octadecynoic acid (9-ODA) perform as ligands for free fatty acid receptors of medium- and long-chain fatty acids FFAR1 and FFAR4, previously called GPR40 and GPR120, respectively. Phosphorylation of extracellular signal-regulated kinase (ERK)-1/2 was increased through FFAR1 but not through FFAR4 expressed in HEK 293 cells, suggesting that 6-ODA and 9-ODA function as an FFAR1 ligand, but not as an FFAR4 ligand. Activation of ERK in FFAR1-expressing HEK293 cells by 6-ODA and 9-ODA peaked at 10 min after stimulation followed by a slow decrease, similar to ERK activation by rosiglitazone, which peaked at 10 min after stimulation and lasted longer. Glucose-dependent production of insulin from MIN6 insulinoma cells was induced by 6-ODA and 9-ODA in an FFAR1-dependent manner. In this process, 6-ODA and 9-ODA stimulated the production of insulin not in the first phase that occurred within 10 min after stimulation but in the second phase. F-actin-remodeling that reflects insulin granule recruiting to the plasma membrane in the second phase of insulin secretion by 6-ODA and 9-ODA suggested that they have an FFAR1-dependent function in insulin secretion from MIN6 cells.

Biochemical profile and in vitro biological activities of extracts from seven folk medicinal plants growing wild in southern Tunisia.

Recently, much attention has been paid to the extracts obtained from plant species in order to analyse their biological activities. Due to the climate diversity in Tunisia, the traditional pharmacopoeia consists of a wide arsenal of medicinal plant species since long used in folk medicine, in foods as spices, and in aromatherapy. Although many of these species are nearly facing extinction, only a small proportion of them have been scientifically studied. Therefore, this study explores the biochemical properties of seven spontaneous plants, which were harvested in the arid Tunisian desert: Marrubium vulgare (L.), Rhus tripartita (Ucria) D.C., Thymelaea hirsute (L.) Endl., Plantago ovata (Forsk.), Herniaria fontanesii (J. Gay.), Ziziphus lotus (L.) and Hyoscyamus albus (L.). Extracts from these plants were found to contain different types of secondary metabolites (polyphenols, flavonoids, condensed tannins, crude saponins, carotenoids and alkaloids) that are involved in important biological activities. The biological activity of the extracts obtained from each Tunisian plant was assessed: first of all, leukaemia and colon cancer cell lines (K-562 and CaCo-2 respectively) were treated with different concentrations of extracts, and then the anti-proliferative activity was observed. The results showed, in particular, how the plant extract from Rhus tripartita significantly inhibits cell proliferation, especially on the K-562 tumour cell line. Subsequently, the anti-inflammatory activity was also assessed, and the results showed that Herniaria fontanesii and Marrubium vulgare possess the highest activity in the group of analysed plants. Finally, the greatest acetylcholinesterase inhibitory effect was exhibited by the extract obtained from Rhus tripartita. In conclusion, all the Tunisian plants we analysed were shown to contain a remarkable amount of different bio-active compounds, thus confirming their involvement in several biological activities. Rhus tripartita and Ziziphus lotus were shown to be particularly effective in anti-proliferative activity, while Herniaria fontanesii were shown to have the best anti-inflammatory activity.

Bioactive flavones isolated from Tunisian Artemisia campestris L. Leaves.

Four flavones were isolated from dried leaves of Artemisia campestris L. 2',4',5,7-tetrahydroxy-5',6-dimethoxyflavone, eupatilin and dimethoxycentaureidin were reported for the first time in this species whereas cirsiliol was previously identified but it was isolated for the first time. Their structures were elucidated by spectroscopic methods, including 1D and 2D NMR experiments and mass spectrometry analysis. In addition, all isolated flavones were evaluated for their antioxidant, anti-inflammatory, anti-superoxide dismutase, anti-xanthine oxidase and cytotoxic activities. The results showed that all isolated compounds exhibited potent anti-xanthine oxidase activity with IC50 ranging from 3.3 to 6.8 µM, which was higher than that of the control compound allopurinol (8.2 ± 0.6 µM). In addition, cirsiliol was found to be the most cytotoxic against OVCAR-3, IGROV-1and HCT-116 cell lines at 15µM, with inhibition percentage values of 53.7, 48.8 and 40.9%, respectively. All compounds also showed weak to moderate anti-inflammatory and anti-superoxide dismutase activities.

Anti-stress and neuronal cell differentiation induction effects of Rosmarinus officinalis L. essential oil.

BACKGROUND: Mood disorder accounts for 13 % of global disease burden. And while therapeutic agents are available, usually orally administered, most have unwanted side effects, and thus making the inhalation of essential oils (EOs) an attractive alternative therapy. Rosmarinus officinalis EO (ROEO), Mediterranean ROEO reported to improve cognition, mood, and memory, the effect on stress of which has not yet been determined. Here, the anti-stress effect of ROEO on stress was evaluated in vivo and in vitro. METHODS: Six-week-old male ICR mice were made to inhale ROEO and subjected to tail suspension test (TST). To determine the neuronal differentiation effect of ROEO in vitro, induction of ROEO-treated PC12 cells differentiation was observed. Intracellular acetylcholine and choline, as well as the Gap43 gene expression levels were also determined. RESULTS: Inhalation of ROEO significantly decreased the immobility time of ICR mice and serum corticosterone level, accompanied by increased brain dopamine level. Determination of the underlying mechanism in vitro revealed a PC12 differentiation-induction effect through the modulation of intracellular acetylcholine, choline, and Gap43 gene expression levels. ROEO activates the stress response system through the NGF pathway and the hypothalamus-pituitary-adrenal axis, promoting dopamine production and secretion. The effect of ROEO may be attributed to its bioactive components, specifically to α-pinene, one of its major compounds that has anxiolytic property. CONCLUSIONS: The results of this study suggest that ROEO inhalation has therapeutic potential against stress-related psychiatric disorders.

Upregulation of Mitf by Phenolic Compounds-Rich Cymbopogon schoenanthus Treatment Promotes Melanogenesis in B16 Melanoma Cells and Human Epidermal Melanocytes.

Melanin provides inherent protection against skin cancer by absorbing broad-spectrum radiant energy of UV radiation. Cutaneous malignant melanoma incidence has recently been observed to increase and the frequency is closely associated with the skin color, highlighting the importance of skin pigmentation. Here, we showed how melanin biosynthesis is enhanced by treatment with phenolic compounds-rich Cymbopogon schoenanthus (CYM) in B16 murine melanoma cells and human epidermal melanocytes (HEM). CYM increased the melanin content of the cells by upregulating the expression of tyrosinase (TYR), tyrosinase-related protein 1 (TRP1), and dopachrome tautomerase (DCT) at the protein and mRNA levels, comparable to the effect of α-melanocyte-stimulating hormone (MSH), in both B16 cells and HEM. Moreover, global gene expression analysis showed that at least 44 pigmentation-associated genes were modulated, including the microphthalmia-associated transcription factor (Mitf) and its transcriptional regulators (Sox10, Pax3, and Lef1). Upregulation of copper transport-associated gene Atp7b indicates that CYM also promotes tyrosinase activity. CYM upregulated Mitf and possibly activates tyrosinase enzyme, providing evidence for its possible use to promote melanogenesis and as a therapeutic agent against hypopigmentation disorders.

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.

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.

Thin layer convective air drying of wild edible plant (Allium roseum) leaves: experimental kinetics, modeling and quality.

The present study deals with the valorization of an edible spontaneous plant of the Tunisian arid areas: Allium roseum. This plant is traditionally used for therapeutic and culinary uses. Thin-layer drying behavior of Allium roseum leaves was investigated at 40, 50 and 60 °C drying air temperatures and 1 and l.5 m/s air velocity, in a convective dryer. The increase in air temperature significantly affected the moisture loss and reduced the drying time while air velocity was an insignificant factor during drying of Allium roseum leaves. Five models selected from the literature were found to satisfactorily describe drying kinetics of Allium roseum leaves for all tested drying conditions. Drying data were analyzed to obtain moisture diffusivity values. During the falling rate-drying period, moisture transfer from Allium roseum leaves was described by applying the Fick's diffusion model. Moisture diffusivity varied from 2.55 × 10(-12) to 8.83 × 10(-12) m(2)/s and increased with air temperature. Activation energy during convective drying was calculated using an exponential expression based on Arrhenius equation and ranged between 46.80 and 52.68 kJ/mol. All sulfur compounds detected in the fresh leaves were detected in the dried leaves. Convective air drying preserved the sulfur compounds potential formation.

Population structure and genetic diversity of a medicinal plant species Retama raetam in southern Tunisia.

Retama raetam is a stem-assimilating, C3, evergreen, medicinal plant species, desert legume common to arid ecosystems around the Mediterranean basin. This study addresses the genetic diversity and relationship among and within three populations collected from different habitats in southern Tunisia by Random Amplified Polymorphic DNA (RAPD). Estimates of the percentage of polymorphic bands, Shannon's diversity information index and Nei's gene diversity index were determined. Results showed that population from the Island Djerba has the lowest Nei's gene diversity; this also was for Shannon diversity index. An analysis of molecular variance indicated that the majority of variation existed within populations (68%) and that there was significant differentiation among populations (phiPT = 0.316, p < 0.001). Genetic distance (phiPT based values) between pairwise populations ranged from 0.098 to 0.505 and the differentiation between pair-wise populations was significant when individual pairs of populations were compared. Based on the coefficient of gene differentiation (Gst), gene flow (Nm) was estimated and was found to vary from 0.490 to 4.609 between pair-wise populations and 1.42 among populations. The results of UPGMA cluster analysis and PCoA analysis indicated that most variation occurred within populations and that genetic differentiation had happened between populations. These findings are important for a better understanding of the adaptive strategy of R. raetam in southern Tunisia and will be useful for conservation managers to work out an effective strategy to protect this important species.

Antistress Effects of the Ethanolic Extract from Cymbopogon schoenanthus Growing Wild in Tunisia.

This study aimed to investigate the antistress properties of the ethanol extract of Cymbopogon schoenanthus (CSEE), growing wild in the southern part of Tunisia. The effect of extracts on H2O2-induced cytotoxicity and stress in human neuroblastoma SH-SY5Y cells. Its effect on stress-induced in ICR mice was exposed to force swim and tail suspension, in concordance with heat shock protein expression (HSP27 and HSP90), corticosterone, and catecholamine neurotransmitters level. Our results demonstrated that pretreatment of SH-SY5Y cells with CSEE at 1/2000, 1/1000, and 1/500 v/v dilutions significantly inversed H2O2-induced neurotoxicity. Moreover, CSEE treatments significantly reversed heat shock protein expression in heat-stressed HSP47-transformed cells (42°C, for 90 min) and mRNA expression of HSP27 and HSP90 in H2O2-treated SH-SY5Y. Daily oral administration of 100 mg/kg and 200 mg/kg CSEE was conducted to ICR mice for 2 weeks. It was resulted in a significant decrease of immobility time in forced swimming and tail suspension tests. The effect of CSEE on animal behavior was concordant with a significant regulation of blood serum corticosterone and cerebral cortex levels of catecholamine (dopamine, adrenaline, and noradrenaline). Therefore, this study was attempted to demonstrate the preventive potential of CSEE against stress disorders at in vitro and in vivo levels.

Identification of 6-octadecynoic acid from a methanol extract of Marrubium vulgare L. as a peroxisome proliferator-activated receptor γ agonist.

6-Octadecynoic acid (6-ODA), a fatty acid with a triple bond, was identified in the methanol extract of Marrubium vulgare L. as an agonist of peroxisome proliferator-activated receptor γ (PPARγ). Fibrogenesis caused by hepatic stellate cells is inhibited by PPARγ whose ligands are clinically used for the treatment of diabetes. Plant extracts of Marrubium vulgare L., were screened for activity to inhibit fibrosis in the hepatic stellate cell line HSC-T6 using Oil Red-O staining, which detects lipids that typically accumulate in quiescent hepatic stellate cells. A methanol extract with activity to stimulate accumulation of lipids was obtained. This extract was found to have PPARγ agonist activity using a luciferase reporter assay. After purification using several chromatographic methods, 6-ODA, a fatty acid with a triple bond, was identified as a candidate of PPARγ agonist. Synthesized 6-ODA and its derivative 9-octadecynoic acid (9-ODA), which both have a triple bond but in different positions, activated PPARγ in a luciferase reporter assay and increased lipid accumulation in 3T3-L1 adipocytes in a PPARγ-dependent manner. There is little information about the biological activity of fatty acids with a triple bond, and to our knowledge, this is the first report that 6-ODA and 9-ODA function as PPARγ agonists.

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.

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 microg/ disk) and minimal inhibitor concentrations ranging between 233 and 1250 microg/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.

Growth, root colonization and nutrient status of Helianthemum sessiliflorum Desf. inoculated with a desert truffle Terfezia boudieri Chatin.

This study aims to investigate the effects of inoculation using Terfezia boudieri Chatin ascospores (ectomycorrhizal fungus) on growth, root colonization and nutrient status of Helianthemum sessiliflorum Desf. seedlings grown in pots on two-soil types (gypseous and sandy loam). Mycorrhizal seedlings had significantly increased their height and leaf number compared to non-mycorrhizal ones. Regardless of mycorrhizal inoculation treatments, the plants growing on gypseous soil showed higher growth as compared to sandy loam one. It appears that inoculation with T. boudieri changed root morphology, increasing branching of first-order lateral roots of H. sessiliflorum seedlings. The highest root mycorrhizal colonization was recorded in inoculated seedlings on sandy loam soil (89%) when compared to gypseous one (52%). N, P and K concentrations in mycorrhizal seedlings were significantly improved by fungal inoculation. It can be concluded that inoculation of H. sessiliflorum with T. boudieri increased growth attributes and improved plant nutritional status.