Chemical Composition, Antibacterial Activity and In Vitro Anticancer Evaluation of Ochradenus baccatus Methanolic Extract.

Background and Objectives: Ochradenus baccatus belongs to the family Resedaceae. It is widely spread in Saudi Arabia and other countries in Southwest Asia. O. baccatus is extensively used in traditional medicine as an anti-inflammatory and antibacterial agent, in addition to being a vital source of food for certain desert animal species. The aim of the present study was to investigate the chemical composition and antibacterial/anticancer activities of O. baccatus methanolic extracts collected from Hail, Saudi Arabia. Materials and Methods: The O. baccatus extracts were obtained by macerating the crude powder in methanol, followed by filtration and evaporation. Liquid chromatography-mass spectrometry (LC-MS) was used to analyze the methanolic extracts' chemical constituents. Broth microdilution assay for minimum inhibitory concentration (MIC) determination was used to assess antimicrobial activity, while the extracts' anticancer potential was assessed by sulforhodamine B Assay (SRB) assay. Results: The results of the antibacterial assay showed that the methanolic extracts from the roots and branches possessed varying degrees of activity against particular bacterial strains, with the highest activity being exerted by the branches' extract against Escherichia coli and Salmonella typhimurium (St), demonstrating MIC values of 15.6 µg/mL and 20 µg/mL, respectively. Furthermore, the SRB cell viability assay revealed that only the branches' extract inhibited the growth of A549 cancer cells, with an IC50 value of 86.19 µg/mL. The LC-MS analysis of the methanolic extracts from the plant's roots and branches was then conducted, resulting in the identification of 8 and 13 major chemical constituents, respectively. Azelaic acid, ß-amyrin, and phytanic acid are some of the bioactive compounds that were detected in the extracts via LC-MS, and they are thought to be responsible for the observed antibacterial/anticancer activity of O. baccatus methanolic extracts. Conclusions: This study confirmed the antibacterial/anticancer potential of O. baccatus methanolic extracts and analyzed their phytochemical constituents. Further isolation and biological screening are warranted to understand the therapeutic potential of O. baccatus.

Metabolic profiling of Ochradenus baccatus Delile. utilizing UHPLC-HRESIMS in relation to the in vitro biological investigations.

Ochradenus baccatus Delile (Resedaceae) is a desert plant with edible fruits native to the Middle East. Few investigators have reported antibacterial, antiparasitic and anti-cancer activities of the plant. Herein we evaluated the cytotoxic activity of O. baccatus using four cell lines and a zebrafish embryo model. Additionally, liquid chromatography coupled with mass spectroscopy was performed to characterize the extract's main constituents. The highest cytotoxicity was observed against human cervical adenocarcinoma (HeLa), with CC50 of 39.1 µg/mL and a selectivity index (SI) of 7.23 (p < 0.01). Metabolic analysis of the extract resulted in the annotation of 57 metabolites, including fatty acids, flavonoids, glucosinolates, nitrile glycosides, in addition to organic acids. The extract showed an abundance of hydroxylated fatty acids (16 peaks). Further, 3 nitrile glycosides have been identified for the first time in Ochradenus sp., in addition to 2 glucosinolates. These identified phytochemicals may partially explain the cytotoxic activity of the extract. We propose O. baccatus as a possible safe food source for further utilization to partially contribute to the increasing food demand specially in Saharan countries.

Glucosinolates in Wild-Growing Reseda spp. from Croatia.

Glucosinolates (GSLs) are a unique class of thioglucosides that evolved as defense mechanisms in the 16 families of the Brassicales order and present molecular tags which can be placed in a robust phylogenetic framework through investigations into their evolution and diversity. The GSL profiles of three Resedaceae species, Reseda alba, R. lutea, and R. phyteuma, were examined qualitatively and quantitatively with respect to their desulfo-counterparts utilizing UHPLC-DAD-MS/MS. In addition, NMR analysis of isolated 2-hydroxy-2-methylpropyl desulfoGSL (d31) was performed. Three Phe-derived GSLs were found in R. lutea, including glucotropaeolin (11) (0.6-106.69 mol g-1 DW), 2-(α-L-ramnopyranosyloxy)benzyl GSL (109) (8.10-57.89 µmol g-1 DW), glucolepigramin (22) (8.66 µmol g-1 DW in flower), and Trp-derived glucobrassicin (43) (0.76-5.92 µmol g-1 DW). The Phe-derived GSLs 109 (50.79-164.37 µmol g-1 DW), gluconasturtiin (105) (1.97 µmol g-1 DW), and 11 (tr), as well as the Trp-derived GSL glucobrassicin (43) (3.13-11.26 µmol g-1 DW), were all present in R. phyteuma. R. alba also contained Phe-derived 105 (0.10-107.77 µmol g-1 DW), followed by Trp-derived 43 (0.85-3.50 µmol g-1 DW) and neoglucobrassicin (47) (0.23-2.74 µmol g-1 DW). However, regarding the GSLs in R. alba, which originated from Leu biosynthesis, 31 was the major GSL (6.48 to 52.72 µmol g-1 DW) and isobutyl GSL (62) was the minor GSL (0.13 to 1.13 µmol g-1 DW). The discovered Reseda profiles, along with new evidence provided by GSL characterizations, were studied in the context of the current knowledge on GLSs in the Resedaceae family. With the exception of R. alba, the aliphatic GSLs of which were outliers among the Resedaceae species studied, this family typically contains GSLs derived primarily from Trp and Phe biosynthesis, which modifications resulted in GSLs unique to this family, implying presence of the specific genes. responsible for this diversification.

Aroma Profile and Biological Effects of Ochradenus arabicus Essential Oils: A Comparative Study of Stem, Flowers, and Leaves.

The present analysis explores the chemical constituents and determines the in vitro antimicrobial, antidiabetic, and antioxidant significance of the essential oils (EOs) of the stem, leaves, and flowers of Ochradenus arabicus for the first time. The EOs of the flowers presented seventy-four constituents contributing to 81.46% of the total EOs, with the major compounds being 24-norursa-3,12-diene (13.06%), 24-norursa-3,12-dien-11-one (6.61%), and 24-noroleana-3,12-diene (6.25%). The stem EOs with sixty-one compounds contributed 95.95% of the total oil, whose main bioactive compounds were (+)-camphene (21.50%), eremophilene (5.87%), and δ-selinene (5.03%), while a minimum of fifty-one compounds in the leaves' EOs (98.75%) were found, with the main constituents being n-hexadecanoic acid (12.32%), octacosane (8.62%), tetradecanoic acid (8.54%), and prehydro fersenyl acetone (7.27%). The antimicrobial activity of the EOs of O. arabicus stem, leaves, and flowers was assessed against two bacterial strains (Escherichia coli and Streptococcus aureus) and two fungal strains (Penicillium simplicissimum and Rhizoctonia solani) via the disc diffusion assay. However, the EOs extracted from the stem were found effective against one bacterial strain, E. coli, and one fungal strain, R. Solani, among the examined microbes in comparison to the standard and negative control. The tested EOs samples of the O. arabicus stem displayed a maximum potential to cure diabetes with an IC50 = 0.40 ± 0.10 µg/mL, followed by leaves and flowers with an IC50 = 0.71 ± 0.11 µg/mL and IC50 = 10.57 ± 0.18 µg/mL, respectively, as compared to the standard acarbose (IC50 = 377.26 ± 1.20 µg/mL). In addition, the EOs of O. arabicus flowers had the highest antioxidant activity (IC50 = 106.40 ± 0.19 µg/mL) as compared to the standard ascorbic acid (IC50 = 73.20 ± 0.17 µg/mL) using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. In the ABTS assay, the EOs of the same sample (flower) depicted the utmost potential to scavenge the free radicals with an IC50 = 178.0 ± 0.14 µg/mL as compared with the ascorbic acid, having an IC50 of 87.34 ± 0.10 µg/mL the using 2,2-Azino-Bis-3-Ethylbenzothiazoline-6-Sulfonic acid (ABTS) assay. The EOs of all parts of O. arabicus have useful bioactive components due to which they present antidiabetic and antioxidant significance. Furthermore, additional investigations are considered necessary to expose the responsible components of the examined biological capabilities, which would be effective in the production of innovative drugs.

Impact of Phytomediated Zinc Oxide Nanoparticles on Growth and Oxidative Stress Response of In Vitro Raised Shoots of Ochradenus arabicus.

Biogenic nanoparticles have potential roles in the growth and development of plants and animals as they are ecofriendly and free of chemical contaminants. In this study, we assessed the effects of phytomediated zinc oxide nanoparticles (ZnONPs) on shoot growth, biochemical markers, and antioxidant system response in Ochradenus arabicus, which is a medicinal plant. The shoot length and fresh and dry weights were found to be higher in groups with 5 and 10 mg/L ZnONPs than in the control. At high concentrations of ZnONPs (50, 100, and 300 mg/L), biomass was decreased in a concentration-dependent manner. The shoot number was observed to be highest at 50 mg/L among all applied concentrations of ZnONPs. The levels of the stress markers proline and TBARS were found to be higher in shoots treated with 100 and 300 mg/L ZnONPs than in the control as well as NP-treated shoots. The levels of antioxidant enzymes were significantly increased at high concentrations of nanoparticles compared with the control. Thus, synthesized phytomediated ZnONPs from shoots of O. arabicus and their application to the same organ of O. arabicus in vitro were found to be effective as a low concentration of nanoparticles promoted shoot growth, resulting in high biomass accumulation. Thus, using green nanotechnology, such endemic plants could be conserved in vitro and multiple shoots could be produced by reducing the phytohormone concentration for multiple uses, such as the production of potential secondary metabolites.

The first complete chloroplast genome sequences in Resedaceae: Genome structure and comparative analysis.

Caylusea hexagyna and Ochradenus baccatus are two species in the Resedaceae family. In this study, we analysed the complete plastid genomes of these two species using high-throughput sequencing technology and compared their genomic data. The length of the plastid genome of C. hexagyna was 154,390 bp while that of O. baccatus was 153,380 bp. The lengths of the inverted repeats (IR) regions were 26,526 bp and 26,558 bp, those of the large single copy (LSC) regions were 83,870 bp and 83,023 bp; and those of the small single copy (SSC) regions were 17,468 bp and 17,241 bp in C. hexagyna and O. baccatus, respectively. Both genomes consisted of 113 genes: 79 protein-coding genes, 30 tRNA genes and 4 rRNA genes. Repeat analysis showed that the plastid genome included all types of repeats, with more frequent occurrences of palindromic sequences. Comparative studies of SSR markers showed that there were 256 markers in C. hexagyna and 255 in O. baccatus; the majority of the SSRs in these plastid genomes were mononucleotide repeats (A/T). All the clusters in the phylogenetic tree had high support. This study reported the first complete plastid genomes of the genera Caylusea and Ochradenus and the first for the Resedaceae family.

Microextraction of Reseda luteola-Dyed Wool and Qualitative Analysis of Its Flavones by UHPLC-UV, NMR and MS.

Detailed knowledge on natural dyes is important for agronomy and quality control as well as the fastness, stability, and analysis of dyed textiles. Weld (Reseda luteola L.), which is a source of flavone-based yellow dye, is the focus of this study. One aim was to reduce the required amount of dyed textile to ≤50 µg for a successful chromatographic analysis. The second aim was to unambiguously confirm the identity of all weld flavones. By carrying out the extraction of 50 µg dyed wool with 25 µL of solvent and analysis by reversed-phase UHPLC at 345 nm, reproducible chromatographic fingerprints could be obtained with good signal to noise ratios. Ten baseline separated peaks with relative areas ≥1% were separated in 6 min. Through repeated polyamide column chromatography and prepHPLC, the compounds corresponding with the fingerprint peaks were purified from dried weld. Each was unequivocally identified, including the position and configuration of attached sugars, by means of 1D and 2D NMR and high-resolution MS. Apigenin-4'-O-glucoside and luteolin-4'-O-glucoside were additionally identified as two trace flavones co-eluting with other flavone glucosides, the former for the first time in weld. The microextraction might be extended to other used dye plants, thus reducing the required amount of precious historical textiles.

Investigation of glucosinolates in the desert plant Ochradenus baccatus (Brassicales: Resedaceae). Unveiling glucoochradenin, a new arabinosylated glucosinolate.

Here we describe the structure elucidation and quantification of six glucosinolates (GSLs) from the roots of the desert plant Ochradenus baccatus, Delile 1813 (family Resedaceae; order Brassicales). The structure elucidation was established on the corresponding enzymatically desulfated derivatives of the native GSLs of the plant. Among these GSLs we describe the previously undescribed 2″-O-(α-L-arabinopyranosyloxy)benzylglucosinolate (1a), for which we propose the name glucoochradenin. The other five glucosinolates (2a-6a) were (2S)-2-hydroxy-2-phenylethylglucosinolate (2a; glucobarbarin), 2″-O-(α-L-rhamnopyranosyloxy)benzylglucosinolate (3a), benzylglucosinolate (4a; glucotropaeolin), indol-3-ylmethylglucosinolate (5a; glucobrassicin) and phenethylglucosinolate (6a; gluconasturtiin), all elucidated as their desulfo-derivatives, 2b-6b respectively). Structures were elucidated by MS and 1D and 2D-NMR techniques, the identity of the arabinose verified by ion chromatography, and the absolute configuration of the sugar units determined by hydrolysis, coupling to cysteine methyl-ester and phenyl isothiocyanate followed by HPLC-MS analysis of the resulted diastereomers. Response factors were generated for desulfo-2″-O-(α-L-arabinopyranosyloxy)benzylglucosinolate and for desulfo-2″-O-(α-L-rhamnopyranosyloxy)benzylglucosinolate and all six GSLs were quantified, indicating that the root of O. baccatus is rich in GSLs (Avg. 61.3 ± 10.0 µmol/g DW and up to 337.2 µmol/g DW).

Glucosinolate profiles and phylogeny in Barbarea compared to other tribe Cardamineae (Brassicaceae) and Reseda (Resedaceae), based on a library of ion trap HPLC-MS/MS data of reference desulfoglucosinolates.

A library of ion trap MS2 spectra and HPLC retention times reported here allowed distinction in plants of at least 70 known glucosinolates (GSLs) and some additional proposed GSLs. We determined GSL profiles of selected members of the tribe Cardamineae (Brassicaceae) as well as Reseda (Resedaceae) used as outgroup in evolutionary studies. We included several accessions of each species and a range of organs, and paid attention to minor peaks and GSLs not detected. In this way, we obtained GSL profiles of Barbarea australis, Barbarea grayi, Planodes virginica selected for its apparent intermediacy between Barbarea and the remaining tribe and family, and Rorippa sylvestris and Nasturtium officinale, for which the presence of acyl derivatives of GSLs was previously untested. We also screened Armoracia rusticana, with a remarkably diverse GSL profile, the emerging model species Cardamine hirsuta, for which we discovered a GSL polymorphism, and Reseda luteola and Reseda odorata. The potential for aliphatic GSL biosynthesis in Barbarea vulgaris was of interest, and we subjected P-type and G-type B. vulgaris to several induction regimes in an attempt to induce aliphatic GSL. However, aliphatic GSLs were not detected in any of the B. vulgaris types. We characterized the investigated chemotypes phylogenetically, based on nuclear rDNA internal transcribed spacer (ITS) sequences, in order to understand their relation to the species B. vulgaris in general, and found them to be representative of the species as it occurs in Europe, as far as documented in available ITS-sequence repositories. In short, we provide GSL profiles of a wide variety of tribe Cardamineae plants and conclude aliphatic GSLs to be absent or below our limit of detection in two major evolutionary lines of B. vulgaris. Concerning analytical chemistry, we conclude that availability of authentic reference compounds or reference materials is critical for reliable GSL analysis and characterize two publicly available reference materials: seeds of P. virginica and N. officinale.

The impact of seed micromorphology in the subgeneric classification of the genus Reseda L. (Resedaceae) in Turkey.

Seed micromorphology of 18 taxa belonging to the genus Reseda (Resedaceae) in Turkey were investigated with scanning electron microscopy (SEM), in order to understand and check its diagnostic significance at subgeneric and sectional level. Seeds of Reseda species were photographed to evaluate different characteristics including appearance of the seed, testa ornamentation and the existence of carunculoid tissue at hilum regions. In addition, cluster analysis and principal component analysis (PCA) were performed to test whether the micromorphological data of the related taxa is compatible with the current classification of the genus. According to seed micromorphology, Reseda taxa in Turkey are divided into four main groups particularly by testa ornamentation as papillose, rugose, rugulose, and smooth. These results are also in agreement with the sectional classification of the genus in morphological and molecular perspective. The tree topology of Unweighted Pair Group Method with Arithmetic Average based on seed features supported the traditional classification. Principle component analysis revealed testa surface ornamentation as the most distinctive character for species identification. PCA also confirms our cluster grouping of the subgeneric and sectional classification of the taxa in Turkey. An identification key for the genus Reseda in Turkey is provided in the light of current data. The seed data is helpful for the identification of the genus Reseda in Turkey at sectional level. However, for an accurate identification at specific level, seed micromorphology is not sufficient alone and must be evaluated together with all diagnostic morphological features.

ANTIMICROBIAL ACTIVITIES OF SOME SAUDI ARABIAN HERBAL PLANTS.

BACKGROUND: Several edible plants are used in Kingdom of Saudi Arabia since early time to control microbial infections. In the present study, twenty-four Saudi Arabian medicinal plants d according to traditionally used were select and investigated for the antimicrobial activities. MATERIALS AND METHODS: This study was designed at evaluating the antimicrobial activities of the methanol extracts of twenty-four species of sixteen plant families used in the traditional medicine by Saudi Arabian people for the treatment of numerous ailments of the microbial and non-microbial origin against four Gram-positive, four Gram-negative bacteria and four fungi and yeast using the agar well diffusion method. RESULTS: Of most of the plants tested were found to be active against two to eight organisms. Five plants were active against eight organisms. The data appeared that extracts of Echium arabicum (SY-176), Rhantarium epapposum (SY-Rumex vesicarus (SY-181), Ziziphus nummularia (SY-188), Caylusea hexagyna (SY-197) and Artemisia monosperma (SY-198) have anti-microbial activity against the most of tested bacteria, fungi and yeast. Whereas (SY-, the extracts of Teucrium oliverianum (SY-175), Zilla spinosa (SY-187), and Rhazya stricta (SY-195) have poor action against the tested bacteria, fungi and yeast. CONCLUSION: The antimicrobial activity of plant extracts against bacteria was more effective than against fungi.

Seed dormancy of Ochradenus baccatus (Resedaceae), a shrubby species from Arabian desert regions / Dormición de semillas de Ochradenus baccatus (Resedaceae), una especie arbustiva de las regiones desérticas arábicas

Abstract:Ochradenus baccatus is a perennial glycophyte growing in Middle East and it is one of the most important food sources for many animal species in desert regions. The aim of our study was to investigate the effects of seed storage, light, temperature and gibberellic acid (GA3) on germination of O. baccatus seeds. We also investigated the germination characteristics of O. baccatus seeds under different saline concentration and their capability to recover germination once they were transferred to distilled water. Seeds were stored at room temperature (20 ± 2 ºC) and at -18 ºC. Germination tests were conducted at alternating temperatures of 15/25, 20/30 and 25/35 ºC in either continuous darkness or photoperiod of 12-h dark/12-h light. To study the effect of GA3 on germination of O. baccatus seeds, freshly-collected seeds and stored seeds were soaked for 24 h in a GA3 water solution (1 g/L) before sowing. To assess the salinity tolerance during germination, seeds were germinated under different salinity levels (100, 200 and 400 mM NaCl). Stored seeds at room temperature and -18 ºC germinate equally well at different temperature regimes and light conditions. However, freshly matured seeds were not able to germinate even when they were treated with GA3. On the contrary, stored seeds at room temperature and -18 ºC treated with GA3 increase the final germination percentages. These results indicated that O. baccatus seeds have physiological dormancy and they need to be stored in order to break their dormancy. In the present study, one year of storage did not show a significant variation in germination between the two storage conditions assayed. Therefore, further research is needed to know about the maximum storage period for O. baccatus seeds under different storage conditions. Very few O. baccatus seeds (less than 5 %) germinated at the tested lowest concentration of NaCl. However, ungerminated seeds were able to germinate when salinity stress was alleviated. In conclusion, O. baccatus seeds have physiological dormancy, and seed storage (at room temperature and at -18 ºC) for one year is effective for breaking this dormancy. In addition, O. baccatus seeds present ability to remain viable in saline conditions and they will be able to germinate once the salinity level decrease. Rev. Biol. Trop. 64 (3): 965-974. Epub 2016 September 01.

ResumenOchradenus baccatus es un glicófito perenne que crece en oriente Medio y es una de las fuentes de alimentación más importantes para muchas especies animales de regiones desérticas. El objetivo de nuestro estudio fue investigar los efectos del almacenamiento de semillas, luz, temperatura y ácido giberélico (GA3) en la germinación de semillas de O. baccatus. También se ha investigado la germinación de semillas de O. baccatus bajo diferentes concentraciones salinas y su capacidad para recuperar la germinación una vez que fueron transferidas a agua destilada. Las semillas se conservaron a temperatura ambiente (20 ± 2 ºC) y a -18 ºC. Los ensayos de germinación se realizaron a temperaturas alternas de 15/25, 20/30 y 25/35 ºC bajo oscuridad continua o fotoperiodo de 12-h oscuridad/12-h luz. Para estudiar el efecto del GA3 en la germinación de semillas de O. baccatus, semillas recién recolectadas y semillas almacenadas se sumergieron durante 24 h en una solución acuosa de GA3 (1 g/L) antes de la siembra. Para evaluar la tolerancia a la salinidad durante la germinación, la semillas fueron germinadas bajo diferentes niveles de salinidad (100, 200 y 400 mM ClNa). Las semillas conservadas a temperatura ambiente y a -18 ºC germinaron igualmente bien en los diferentes regímenes de temperatura y condiciones de iluminación. Sin embargo, las semillas recién maduradas fueron incapaces de germinar incluso cuando se trataron con GA3. Por el contrario, las semillas almacenadas tratadas con GA3 incrementaron los porcentajes finales de germinación. Estos resultados indican que las semillas de O. baccatus tienen dormición fisiológica y necesitan ser almacenadas para romperla. En este estudio, un año de conservación no supuso una variación significativa en la germinación entre las dos condiciones de conservación ensayadas. Por lo tanto, se precisan investigaciones adicionales para conocer cuáles son los periodos máximos de almacenamiento de semillas de O. baccatus bajo diferentes condiciones de conservación. Muy pocas semillas de O. baccatus (menos del 5 %) germinaron a la concentración más baja de ClNa. Sin embargo, las semillas no germinadas fueron capaces de germinar cuando el estrés salino fue aliviado. En conclusión, las semillas de O. baccatus tienen dormición fisiológica y el almacenamiento de las mismas (a temperatura ambiente y a -18 ºC) durante un año es eficaz para romper dicha dormición. Además, las semillas de O. baccatus presentan capacidad para permanecer viables en condiciones salinas y serán capaces de germinar una vez que el nivel de salinidad disminuya.

Seed dormancy of Ochradenus baccatus (Resedaceae), a shrubby species from Arabian desert regions.

Ochradenus baccatus is a perennial glycophyte growing in Middle East and it is one of the most important food sources for many animal species in desert regions. The aim of our study was to investigate the effects of seed storage, light, temperature and gibberellic acid (GA3) on germination of O. baccatus seeds. We also investigated the germination characteristics of O. baccatus seeds under different saline concentration and their capability to recover germination once they were transferred to distilled water. Seeds were stored at room temperature (20 ± 2 ºC) and at -18 ºC. Germination tests were conducted at alternating temperatures of 15/25, 20/30 and 25/35 ºC in either continuous darkness or photoperiod of 12-h dark/12-h light. To study the effect of GA3 on germination of O. baccatus seeds, freshly-collected seeds and stored seeds were soaked for 24 h in a GA3 water solution (1 g/L) before sowing. To assess the salinity tolerance during germination, seeds were germinated under different salinity levels (100, 200 and 400 mM NaCl). Stored seeds at room temperature and -18 ºC germinate equally well at different temperature regimes and light conditions. However, freshly matured seeds were not able to germinate even when they were treated with GA3. On the contrary, stored seeds at room temperature and -18 ºC treated with GA3 increase the final germination percentages. These results indicated that O. baccatus seeds have physiological dormancy and they need to be stored in order to break their dormancy. In the present study, one year of storage did not show a significant variation in germination between the two storage conditions assayed. Therefore, further research is needed to know about the maximum storage period for O. baccatus seeds under different storage conditions. Very few O. baccatus seeds (less than 5 %) germinated at the tested lowest concentration of NaCl. However, ungerminated seeds were able to germinate when salinity stress was alleviated. In conclusion, O. baccatus seeds have physiological dormancy, and seed storage (at room temperature and at -18 ºC) for one year is effective for breaking this dormancy. In addition, O. baccatus seeds present ability to remain viable in saline conditions and they will be able to germinate once the salinity level decrease.

Palaearctic Hoplitis bees of the subgenus Platosmia (Megachilidae, Osmiini): biology, taxonomy and key to species.

Platosmia, a subgenus of the osmiine bee genus Hoplitis (Megachilidae), contains ten species, which are confined to desertic and semidesertic areas of the Palaearctic region. Analysis of female pollen loads and field observations indicate that several H. (Platosmia) species are strictly oligolectic on Reseda (Resedaceae) and possibly Hedysareae (Fabaceae), while others are mesolectic on both Reseda and Fabaceae. The few data available so far suggest that preexisting cavities in stones and rocks serve as nesting sites of H. (Platosmia). The taxonomic revision of H. (Platosmia) revealed the existence of an undescribed species from the Arabian peninsula, H. arabiae spec. nov.. Hoplitis incognita Zanden, 1996 and H. quarzazati (Zanden, 1998) are newly synonymized with H. maghrebensis (Zanden, 1992) and H. platalea (Warncke, 1990), respectively. Identification keys for all H. (Platosmia) species are given including the hitherto unknown male or female sex of three species.

In vitro antibacterial activities of compounds isolated from roots of Caylusea abyssinica.

BACKGROUND: Caylusea absyssinica, a plant used as vegetable and for medicinal purposes was selected for in vitro antibacterial evaluation in this study. The main aim of this study was to isolate compounds from the plant roots and evaluate their antibacterial activities on clinical bacterial test strains. METHODS: Compounds from roots of Caylusea absyssinica (fresen) were identified based on observed spectral (1H-NMR, 13C-NMR and IR) data and physical properties (melting point) as well as reported literature. Disk diffusion method was employed to evaluate the antibacterial activities of the isolated compounds on four test bacterial strains namely, Staphylococcus aureus (ATCC25903), Escherichia coli (ATCC25722), Pseudomonas aeruginosa (DSMZ1117) and Salmonella thyphimurium (ATCC13311). RESULTS: Two compounds, CA1 and CA2 were isolated from the methanol crude extract of the roots of Caylusea absyssinica (fresen). The compounds were identified as ß-sitosterol and stigmasterol, respectively. Evaluation of antibacterial activities revealed that the compounds are active against all the bacterial strains in the experiment, showing inhibition zones ranging from 12 mm-15 mm by CA1 and 11 mm-18 mm by CA2 against the different test strains. However, the compounds were less active than the reference drug (Gentamycine), which showed minimum inhibition zone of 21 mm (Pseudomonas aeruginosa) and maximum of 28 mm (Escherichia coli) inhibition zone. DISCUSSION AND CONCLUSION: The isolation of the compounds is the first report from roots of Caylusea abyssinica and could be potential candidates for future antibacterial drug development programs.

Taste and physiological responses to glucosinolates: seed predator versus seed disperser.

In contrast to most other plant tissues, fleshy fruits are meant to be eaten in order to facilitate seed dispersal. Although fleshy fruits attract consumers, they may also contain toxic secondary metabolites. However, studies that link the effect of fruit toxins with seed dispersal and predation are scarce. Glucosinolates (GLSs) are a family of bitter-tasting compounds. The fleshy fruit pulp of Ochradenus baccatus was previously found to harbor high concentrations of GLSs, whereas the myrosinase enzyme, which breaks down GLSs to produce foul tasting chemicals, was found only in the seeds. Here we show the differential behavioral and physiological responses of three rodent species to high dose (80%) Ochradenus' fruits diets. Acomys russatus, a predator of Ochradenus' seeds, was the least sensitive to the taste of the fruit and the only rodent to exhibit taste-related physiological adaptations to deal with the fruits' toxins. In contrast, Acomys cahirinus, an Ochradenus seed disperser, was more sensitive to a diet containing the hydrolyzed products of the GLSs. A third rodent (Mus musculus) was deterred from Ochradenus fruits consumption by the GLSs and their hydrolyzed products. We were able to alter M. musculus avoidance of whole fruit consumption by soaking Ochradenus fruits in a water solution containing 1% adenosine monophosphate, which blocks the bitter taste receptor in mice. The observed differential responses of these three rodent species may be due to evolutionary pressures that have enhanced or reduced their sensitivity to the taste of GLSs.

Cytotoxic effect of Reseda lutea L.: A case of forgotten remedy.

ETHNOPHARMACOLOGICAL RELEVANCE: Reseda lutea L. (Resedaceae) or Wild Mignonette is a widely distributed plant species. Pliny the Elder (AD 23-AD 79), a Roman scholar and naturalist, reported the use of R. lutea for reducing tumors in his Historia naturalis. Accounts of the beneficial effects of R. lutea in tumor treatment could also be found in the works of later authors, such as Étienne François Geoffroy (1672-1731) and Samuel Frederick Gray (1766-1828). However, to date no in vivo or in vitro evidence exists in support of the alleged tumor healing properties of R. lutea. MATERIALS AND METHODS: The composition of autolysates obtained from different organs (root, flower and fruit) of R. lutea was investigated by GC and GC-MS analyses and IR, 1D and 2D NMR spectroscopy. These analyses led to the discovery of a new compound isolated in pure form from the flower autolysate. Autolysates and their major constituents were submitted to MTT-dye reduction cytotoxic assay on human A375 (melanoma) and MRC5 (fibroblast) cell lines. Mechanism of the cytotoxic effects was studied by cell cycle analysis and Annexin V assay. RESULTS: Benzyl isothiocyanate and 2-(α-l-rhamnopyranosyloxy)benzyl isothiocyanate were identified as the major constituents of the root and flower autolysates, respectively (the later represents a new natural product). These compounds showed significant antiproliferative effects against both cell lines, which could also explain the observed high cytotoxic activity of the tested autolysates. Cell cycle analysis revealed apoptosis as the probable mechanism of cell death. CONCLUSIONS: Tumor healing properties attributed to R. lutea in the pre-modern texts were substantiated by the herein obtained results. Two isothiocyanates were found to be the major carriers of the observed activity. Although there was a relatively low differential effect of the plant metabolites on transformed and non-transformed cell lines, one can argue that the noted strong cytotoxicity provides first evidence that could explain the long forgotten use of this particular species.

The photoprotective and antioxidative properties of luteolin are synergistically augmented by tocopherol and ubiquinone.

Ultraviolet radiation induces DNA damage and oxidative stress which can result in skin inflammation, photoaging, and photocarcinogenesis. The flavonoid luteolin that is present in high amounts in the dyers weld, Reseda luteola, is one of the most potent antioxidative plant metabolites and also has ultraviolet-absorbing properties.The aim of this study was to determine whether tocopherol and ubiquinone add synergistic antioxidative values to luteolin. None of the substances showed cytotoxic effects in concentrations from 0.25 to 4 µg/mL. The photoprotective and antioxidant effect of equivalent concentrations of luteolin, tocopherol, and ubiquinone and their combination in a ratio of 4 : 4 : 1 were studied in solar simulator irradiated human skin fibroblasts. Luteolin had a half-maximal radical scavenging concentration of 2 µg/mL, whereas tocopherol and ubiquinone were only effective at higher concentrations. None of the substances showed a phototoxic effect, and only luteolin had a moderate photoprotective effect at 2 µg/mL. The combination of luteolin, tocopherol, and ubiquinone exerted a synergistic radical scavenging effect already at a concentration of 0.25 µg/mL and a complete photoprotection at 2 µg/mL.In summary, our findings suggest that the potent antioxidant and photoprotective effect of flavonoids like luteolin may be further increased by the addition of low concentrations of other antioxidants such as tocopherol and ubiquinone.

Physiological and behavioural effects of fruit toxins on seed-predating versus seed-dispersing congeneric rodents.

Fleshy, ripe fruits attract seed dispersers but also seed predators. Although many fruit consumers (legitimate seed dispersers as well as seed predators) are clearly exposed to plant secondary compounds (PSCs), their impact on the consumers' physiology and foraging behaviour has been largely overlooked. Here, we document the divergent behavioural and physiological responses to fruit consumption of three congeneric rodent species in the Middle East, representing both seed dispersers and seed predators. The fruit pulp of the desert plant Ochradenus baccatus contains high concentrations of glucosinolates (GLSs). These GLSs are hydrolyzed into active toxic compounds upon contact with the myrosinase enzyme released from seeds crushed during fruit consumption. Acomys russatus and A. cahirinus share a desert habitat. Acomys russatus acts as an O. baccatus seed predator, and A. cahirinus circumvents the activation of the GLSs by orally expelling vital seeds. We found that between the three species examined, A. russatus was physiologically most tolerant to whole fruit consumption and even A. minous, which is evolutionarily naïve to O. baccatus, exhibits greater tolerance to whole fruit consumption than A. cahirinus. However, like A. cahirinus, A. minous may also behaviourally avoid the activation of the GLSs by making a hole in the pulp and consuming only the seeds. Our findings demonstrate that seed predators have a higher physiological tolerance than seed dispersers when consuming fruits containing toxic PSCs. The findings also demonstrate the extreme ecological/evolutionary lability of this plant-animal symbiosis to shift from predation to mutualism and vice versa.

Evaluation of the effects of 80% methanolic leaf extract of Caylusea abyssinica (fresen.) fisch. & Mey. on glucose handling in normal, glucose loaded and diabetic rodents.

BACKGROUND: The leaves of Caylusea abyssinica (fresen.) Fisch. & Mey. (Resedaceae), a plant widely distributed in East African countries, have been used for management of diabetes mellitus in Ethiopian folklore medicine. However, its use has not been scientifically validated. The present study was undertaken to investigate antidiabetic effects of the hydroalcoholic leaf extract of C. abyssinica extract in rodents. MATERIALS AND METHOD: Male Animals were randomly divided into five groups for each diabetic, normoglycemic and oral glucose tolerance test (OGTT) studies. Group 1 served as controls and administered 2% Tween-80 in distilled water, (TW80); Group 2 received 5 mg/kg glibenclamide (GL5); Groups 3, 4 and 5 were given 100 (CA100), 200 (CA200) and 300 (CA300) mg/kg, respectively, of the hydroalcoholic extract of C. abyssinica. Blood samples were then collected at different time points to determine blood glucose levels (BGL). Data were analyzed using one way ANOVA followed by Dunnet's post hoc test and p < 0.05was considered as statistically significant. RESULTS: In normal mice, CA200 and GL5 induced hypoglycemia starting from the 2nd h but the hypoglycemic effect of CA300 was delayed and appeared at the 4th h (p < 0.05 in all cases). In diabetic mice, BGL was significantly reduced by CA100 (p < 0.05) and CA300 (p < 0.01) starting from the 3rd h, whereas CA200 (p < 0.001) and GL5 (p < 0.05) attained this effect as early as the 2nd h. In OGTT, TW80 (p < 0.01) and CA100 (p < 0.01) brought down BGL significantly at 120 min, while CA200 (p < 0.001) and GL5 (p < 0.001) achieved this effect at 60 min indicating the oral glucose load improving activity of the extract. By contrast, CA300 was observed to have no effect on OGTT. Acute toxicity study revealed the safety of the extract even at a dose of 2000 mg/kg. Preliminary phytochemical study demonstrated the presence of various secondary metabolites, including, among others, saponins, flavonoids and alkaloids. CONCLUSION: The results indicate that C. abyssinica is endowed with antidiabetic and oral glucose tolerance improving actions, particularly at the dose of 200 mg/kg in experimental animals. These activities of the plant extract may be related to the presence of secondary metabolites implicated in antidiabetic activities of plant extracts via different hepatic and extra-hepatic mechanisms. These results thus support the traditional use of the leaf extract for the management of diabetes mellitus.