Edna Sayuri Suyenaga

Anticancer, antichemotactic and antimicrobial activities of marine sponges collected off the coast of Santa Catarina, southern Brazil

Abstract This study reports the in vitro screening of 10 marine sponges (Porifera) collected from the coastline of Santa Catarina, southern Brazil, in the search for novel pharmaceuticals. Organic and aqueous extracts were tested for anticancer, antibacterial, antifungal and antichemotactic activities. Eight of the ten species tested demonstrated activity in one or more of the bioassays. Organic extracts of Polymastia janeirensis Boury-Esnauls, 1973, Haliclona aff tubifera George and Wilson, 1919, Mycale arcuiris Lerner and Hajdu, 2002 and Raspailia ( syringella ) sp. each demonstrated cytotoxicity at 100 μg/ml in an in vitro screening assay against the HT29 colorectal tumour cell line. Further analysis against three human tumour cell lines (HT29, U373 and NCI-H460) demonstrated IC 50 concentrations ranging from 25 to 50 μg/ml. Aqueous extracts of six species P. janeirensis , M. arcuiris , Raspailia ( syringella ) sp., Guitarra sp., Tedania ignis Duchassaing and Michelotti, 1864 and Pseudaxinella reticulata Ridley and Dendy, 1886 each significantly ( p ≤0.05) retarded the migration of polymorphonuclear (PMN) leukocytes in a chemotactic assay. In antibacterial assays, only H. aff tubifera (four of five bacterial strains) and Axinella corrugata George and Wilson, 1919 (one of five bacterial strains) demonstrated activity. None of the 10 species demonstrated measurable antifungal activity. These extracts are currently undergoing further analysis to identify the active constituents.

Appraisal of the Antichemotactic Activity of Flavonoids on Polymorphonuclear Neutrophils

Flavonoids are polyphenols that are ubiquitous in plants and frequently consumed in the diet. They are suggested to have many beneficial actions on human health, including anti-inflammatory activity. Their properties have been studied in a number of cell types, but little is known about their effects on neutrophil biology. Consequently, we selected 25 flavonoids with different structural features to evaluate their in vitro inhibition of rat polymorphonuclear neutrophil (PMN) chemotaxis, employing a modified Boyden chamber. Migratory activity was measured towards a chemotactic stimulant, formyl-Met-Leu-Phe or lipopolysaccharide. Furthermore, the cytotoxic effect of flavonoids on PMNs was determined by the release of cytosolic lactate dehydrogenase (LDH). Ten flavonoids significantly retarded the migration of PMNs with at least one of the concentrations tested in a range between 0.625 and 100 µM; the best antichemotactic agents were flavone, flavonol, quercetin and rutin. None of the flavanones evaluated presented any significant inhibition of migration in this assay. Our findings indicated that non-hydroxylated flavones possess a better antichemotactic activity when compared to flavones with hydroxy groups. The presence of a sugar moiety in rutin did not produce any increase in this effect, when compared to the respective aglycone analogue. Finally, none of the flavonoids exhibited cell toxicity and for many of these flavonoids this is the first report of the inhibition of PMN chemotaxis.

Beyond organoleptic characteristics: the pharmacological potential of flavonoids and their role in leukocyte migration and in L-selectin and β2-integrin expression during inflammation.

Flavonoids are compounds responsible for several organoleptic characteristics of plant‐derived foods. They are also bioactive compounds with antiinflammatory role. Different mechanisms for this activity have been reported, but their effects on cell migration are not fully understood. In the present study, the role of flavonoids on leukocyte migration in vivo was investigated, using the carrageenan‐induced pleurisy model and intravital microscopy in rats. It was found that quercetin (1), rutin (2), flavone (5), apigenin (6) and flavonol (7) reduced cell migration to the pleural cavity and inhibited rolling, adhesion and transmigration. Additionally, flow cytometry assays showed that the in vitro treatment with all compounds (15–60u2009µm) did not cause cell death and 1 inhibited the cleavage of L‐selectin and the β2‐integrin expression, whereas 2 and 7 only inhibited the β2‐integrin expression. Together, data herein presented clearly show the ability of flavonoids to inhibit in vivo neutrophil influx into inflamed tissue, by acting in different mechanisms of neutrophil migration. Copyright

Chemical composition of essential oils from three southern Brazilian species of Mikania (Asteraceae)

Abstract Samples of essential oils from leaves of Mikania hirsutissima DC, M. involucrata Hook, et Am. and M. laevigata Shultz Bip. ex Baker were analyzed by a combination of capillary gas chromatography and GC/MS. Forty one components have been identified representing 70–95% of the oils content. The oils of M. involucrata and M. laevigata are quite similar and constituted by sesquiterpenes, represented mainly by β-caryophyllene (18.9% and 20.9%), germacrene D (9.9% and 29.8%) and bicyclogermacrene (28.1% and 13.4%). The oil of M. hirsutissima is also characterized by sesquiterpenes, and the major components are ar-curcumene (15.0%) and spathulenol (10.2%), and a small fraction (6.5%) of aliphatic compounds.