No abstract

No abstract

a b s t r a c tThis work reports the nutritional potential and the antiradical activity of the cladodes of the Brazilian Opuntia monacantha Haw. (Cactaceae), as well the isolation of kaempferol and isorhamnetin through activity-guided fractionation from its active MeOH extract. TLC, HPLC-DAD and NMR techniques were used to detect and identify the compounds. The water (91.1%), ash, protein, fibre and lipid contents (15.0, 5.4, 18.5 and 1.4 g/100 g, respectively) were shown to be quite similar to the mean values of other Opuntia spp., some widely used as food and forage. The antioxidant activity of their MeOH extract and of its n-hexane, EtOAc and n-BuOH fractions was assessed by measuring the ability of the fractions to scavenge DPPH radical, showing an activity enhancement for the fractions in comparison to the crude MeOH extract. The well-known free-radical scavenging activity of the isolated flavonoids reinforces the contribution of these compounds to the presented activity of the O. monacantha cladodes.

Uncaria tomentosa (Willd.) DC (Rubiaceae) is a large woody vine that is native to the Amazon and Central American rainforests and is used widely in traditional medicine for its immunomodulatory and antiinflammatory activities. The present work used in vivo immunotoxic and in vitro immunomodulatory experiments to investigate the effects of a pentacyclic oxindole alkaloid extract from U. tomentosa bark on lymphocyte phenotype, Th1/Th2 cytokine production, cellular proliferation and cytotoxicity. For the in vivo immunotoxicity testing, BALB/c male mice were treated once a day with 125, 500 or 1250 mg/kg of U. tomentosa extract for 28 days. For the in vitro protocol, lymphocytes were cultured with 10-500 μg/mg of the extract for 48 h. The extract increased the cellularity of splenic white pulp and the thymic medulla and increased the number of T helper lymphocytes and B lymphocytes. Also, a large stimulatory effect on lymphocyte viability was observed. However, mitogen-induced T lymphocyte proliferation was significantly inhibited at higher concentrations of U. tomentosa extract. Furthermore, an immunological polarization toward a Th2 cytokine profile was observed. These results suggest that the U. tomentosa aqueous-ethanol extract was not immunotoxic to mice and was able to modulate distinct patterns of the immune system in a dose-dependent manner.

Uncaria guianensis (Aublet) J. F. Gmelin is an herbal medicine from tropical areas of South and Central America. We investigated the anti-inflammatory and anti-allergic properties of an ethanolic extract of U. guianensis leaves, containing alkaloids, flavonoids and phenol carboxylic acids, as revealed by thin layer chromatography (TLC). Oral pre-treatment with U. guianensis inhibited zymosan-induced paw oedema (500 mg/paw) and pleural exudation (100 mg/kg) within 4 h (25-200 mg/kg). U. guianensis (100 mg/kg) inhibited total leukocyte and neutrophil numbers in the pleural cavity 4 h after zymosan stimulation. Pre-treatment with U. guianensis (100 mg/kg, p.o.) inhibited total leukocyte, neutrophil and eosinophil recruitment into the pleural cavity 24 h after LPS (250 ng/cavity, i.t.). Pre-treatment with U. guianensis inhibited paw oedema (25-200 mg/kg) induced by ovalbumin (OVA) within 1 h, and neutrophil and eosinophil recruitment into the mice pleural cavity 24 h after OVA (100 mg/kg). In vitro data revealed that U. guianensis impaired LPS-induced nitric oxide and CXCL8 generation by murine peritoneal macrophages, as well as OVA-induced interleukin-5 synthesis by previously sensitized spleen cells. These results demonstrate that U. guianensis leaves provide effective anti-inflammatory and anti-allergic activities.