Biological properties of Cakile maritima Scop. (Brassicaceae) extracts.

OBJECTIVE: Cakile maritima scop. (CKM) is a herbaceous plant (Brassicaceae) growing also in high salinity environment. It is an annual plant growing in clumps or mounds in the sand on beaches and bluffs. MATERIALS AND METHODS: Stems, seeds, leaves and flowers of CKM were used to obtain 70% of ethanol extracts. The phenolic content of the different extracts was evaluated by the Folin-Ciocalteu method. The separation of phytochemical compounds was based on ultra-performance liquid chromatography coupled to mass spectrometry. Radical scavenging activity was determined by 1,1-diphenyl-2-picrylhydrazyl assay. The qualitative assay for the inhibition of α-glucosidase was quantified spectrophotometrically and the anti-inflammatory activity was determined in the U937 cell line by using gene expression of pro-inflammatory cytokines. Cell viability assay was done in U937, MM1S, and U266 cells by using the 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay. The antimicrobial activity was investigated by MIC determination, "double-triple combinations assay", and growth inhibition curves analysis, using the extracts individually or in various combination. Statistical analysis was performed by the Student's t-test and ANOVA. RESULTS: All parts of the plant exhibited a high antioxidant capacity as measured by DPPH assay. Furthermore, all extracts reduced (about 10 folds) the expression of inflammatory cytokines in macrophage following LPS treatment. As regards the antibacterial activity, only the seeds extract was able to inhibit both Gram-negative and Gram-positive bacteria when tested alone, whereas dual combinations of different extracts (leaves, flowers, stems and seeds) caused bacterial inhibition exhibiting a synergic action. Finally, we showed that the extracts did not exhibit cytotoxic effects in normal cells and that, surprisingly, it exhibited an anti-proliferative effect (inhibition ≈80%) in multiple myeloma U266 cells. CONCLUSIONS: Our study suggests that CKM possesses antioxidant, anti-inflammatory, antibacterial, anti-proliferative activities and such pleiotropic effects may be exploited under various pathological conditions.

Seed dormancy and control of germination in Sisymbrella dentata (L.) O.E. Schulz (Brassicaceae).

Seed germination responsiveness to environmental cues is crucial for plant species living in changeable habitats and can vary among populations within the same species as a result of adaptation or modulation to local climates. Here, we investigate the germination response to environmental cues of Sisymbrella dentata (L.) O.E. Schulz, an annual endemic to Sicily living in Mediterranean Temporary Ponds (MTP), a vulnerable ecosystem. Germination of the only two known populations, Gurrida and Pantano, was assessed over a broad range of conditions to understand the role of temperatures, nitrate, hormones (abscisic acid - ABA and gibberellins - GA) and after-ripening in dormancy release in this species. Seed germination responsiveness varied between the two populations, with seeds from Gurrida germinating under a narrower range of conditions. Overall, this process in S. dentata consisted of testa and endosperm rupture as two sequential events, influenced by ABA and GA biosynthesis. Nitrate addition caused an earlier testa rupture, after-ripening broadened the thermal conditions that allow germination, and alternating temperatures significantly promoted germination of non-after-ripened seeds. Primary dormancy in S. dentata seeds likely allows this plant to form a persistent seed bank that is responsive to specific environmental cues characteristic of MTP habitats.