Effect of Different Extraction Methods on Anthocyanin Content in Hibiscus sabdariffa L. and their Antiplatelet and Vasorelaxant Properties.

Hibiscus sabdariffa L. is a worldwide component for tea and beverages, being a natural source of anthocyanins, which are associated with cardiovascular activities. To investigate this relationship, we explored different methods of aqueous extraction on the anthocyanin content and antioxidant activity of H. sabdariffa L. calyx extract (HSCE). Pharmacological effects via platelet aggregation, calcium mobilization, cyclic nucleotide levels, vasodilator-stimulated phosphoprotein Ser157 and Ser239, and on the vasomotor response of aortic rings isolated from mice are studied herewith. We found that the application of ultrasonic turbolization, 20 min, combined with acidified water was significantly more effective in the extraction process, providing extracts with the highest levels of anthocyanins (8.73 and 9.63 mg/100 g) and higher antioxidant activity (6.66 and 6.78 µM trolox/g of sample). HSCE significantly inhibited (100-1000 µg/mL) arachidonic acid-induced platelet aggregation, reduced calcium mobilization, and increased cAMP and cGMP levels with VASPSer157 and VASPSer239 phosphorylation. Vasorelaxation reduction was confirmed by the aortic rings and endothelium assays treated with nitric oxide synthase inhibitors, soluble guanylyl cyclase (sGC) oxidizing agent, or Ca2+-activated K+ channel inhibitor. The increasing of cGMP levels could be understood considering the sGC stimulation by HSCE compounds in the specific stimulus domain, which allows an understanding of the observed antiplatelet and vasorelaxant properties of H. sabdariffa L. calyx extract.

Rutin present in Alibertia edulis extract acts on human platelet aggregation through inhibition of cyclooxygenase/thromboxane.

Alibertia edulis leaf extract is commonly used in folk medicine, with rutin caffeic and vanillic acids being its major compounds. The Alibertia edulis leaf extract was investigated for its pharmacological effects via platelet aggregation, calcium mobilization, cyclic nucleotides levels, vasodilator-stimulated phosphoprotein Ser157 and Ser239 and protein kinase Cß2 phosphorylation, thromboxane B2, cyclooxygenases 1 and 2, docking and molecular dynamics. Alibertia edulis leaf extract significantly inhibited (100-1000 µg mL-1) platelet aggregation induced by different agonists. Arachidonic acid increased levels of calcium and thromboxane B2, phosphorylation of vasodilator-stimulated phosphoprotein Ser157 and Ser239, and protein kinase Cß, which were significantly reduced by Alibertia edulis leaf extract, rutin, and caffeic acid as well mixtures of rutin/caffeic acid. Cyclooxygenase 1 activity was inhibited for Alibertia edulis leaf extract, rutin and caffeic acid. These inhibitions were firsrtly explored by specific stabilization of rutin and caffeic acid compared to diclofenac at the catalytic site from docking score and free-energy dissociation profiles. Then, simulations detailed the rutin interactions close to the heme group and Tyr385, responsible for catalyzing the conversion of arachidonic acid to its products. Our results reveal the antiplatelet aggregation properties of Alibertia edulis leaf extract, rutin and caffeic acid providing pharmacological information about its origin from cyclooxygenase 1 inhibition and its downstream pathway.

Mirabegron, a ß3-adrenoceptor agonist reduced platelet aggregation through cyclic adenosine monophosphate accumulation.

Mirabegron is a ß3-adrenoceptor agonist and released on the marked for the treatment of overactive bladder. Because mirabegron is the only ß3-adrenoceptor agonist available and substances that increase the levels of cyclic adenosine monophosphate (cAMP) inhibit platelet activity, we tested the hypothesis that mirabegron could have antiplatelet activity. Collagen- and thrombin induced platelet aggregation, thromboxane B2 (TXB2) and cyclic nucleotides quantification and calcium (Ca2+) mobilization were determined in the absence and presence of mirabegron in human washed platelets. Our results revealed that mirabegron (10-300 µM) produced significant inhibitions on platelet aggregation induced by collagen- or thrombin, accompanied by greater intracellular levels of cAMP. The ß3-adrenoceptor antagonist L 748,337 (1 µM) and the adenylate cyclase inhibitor, SQ 22,536 (100 µM) reversed the inhibition induced by mirabegron in thrombin-stimulated platelets. The selective antagonists for ß1-and ß2-adrenoceptors, atenolol and ICI 117,551 (3 µM), respectively did not interfere on the inhibition induced by mirabegron. In Fluo-4 loaded platelets, mirabegron reduced the total and intracellular Ca2+ levels. Pre-incubation with mirabegron almost abolished the levels of TXB2. Mirabegron did not augment the intracellular levels of cyclic guanosine monophosphate. In conclusion, mirabegron inhibited human platelet aggregation through cAMP accumulation, thus suggesting that substances that activate ß3-adrenoceptor could be beneficial as adjuvant antiplatelet therapy.

Anti-inflammatory, antiproliferative and cytoprotective potential of the Attalea phalerata Mart. ex Spreng. pulp oil.

The anti-inflammatory, antiproliferative and cytoprotective activity of the Attalea phalerata Mart. ex Spreng pulp oil was evaluated by in vitro and in vivo methods. As for the chemical profile, the antioxidant activity was performed by spectrophotometry, and the profile of carotenoids and amino acids by chromatography. Our data demonstrated that A. phalerata oil has high carotenoid content, antioxidant activity and the presence of 5 essential amino acids. In the in vitro models of inflammation, the oil demonstrated the capacity to inhibit COX1 and COX2 enzymes, the production of nitric oxide and also induces macrophages to spreading. In the in vivo models of inflammation, the oil inhibited edema and leukocyte migration in the Wistar rats. In the in vitro model of antiproliferative and cytoprotective activity, the oil was shown inactive against the kidney carcinoma and prostate carcinoma lineage cells and with cytoprotective capacity in murine fibroblast cells, inhibiting the cytotoxic action of doxorubicin. Therefore, it is concluded that A. phalerata pulp oil has anti-inflammatory effects with nutraceutical properties potential due to the rich composition. Moreover, the oil also has cytoprotective activity probably because of its ability to inhibit the action of free radicals.

Campomanesia adamantium Peel Extract in Antidiarrheal Activity: The Ability of Inhibition of Heat-Stable Enterotoxin by Polyphenols.

Campomanesia adamantium (Myrtaceae) is a medicinal plant distributed in Brazilian Cerrado. Different parts of this plant are used in popular medicine for treatment of several diseases like fever, diarrhea, hypercholesterolemia and rheumatism. The aim of this work was to evaluate the inhibition of heat-stable enterotoxin type A (STa) by gallic acid present in the peel of C. adamantium fruit and assays to assess the antidiarrheal activity, anti-inflammatory and cytotoxic properties of peel extract using the T84 cell line model. The possible inhibition exerted by the gallic acid of the peel extract on the STa peptide was inferred by molecular dynamics simulations. The antidiarrheal effects were investigated measuring cGMP accumulation in cells after stimulation by STa toxin and antibacterial activity was assessed. The anti-inflammatory activity was assessed by inhibition of COX-1 and COX-2. MTT and LDH assays were used to evaluate any possible cytotoxic action while the CyQUANT test was used to investigate the effect on cell proliferation. A representation showing how the possible interactions between STa and the gallic acid of the extract might reduce the action of the enterotoxin is presented. C. adamantium peel extract significantly decreased the levels of cGMP in T84 cells. However, no effect on the species of microorganisms was observed. The extract also inhibited COX-1 (IC50 255.70 ± 0.04 ng/mL) and COX-2 (IC50 569.50 ± 0.11 ng/mL) enzymes. Cytotoxicity assay have shown significant changes in cells treated with the extract, which inhibited the cell proliferation until 72 hours of treatment. Direct interactions of phenolic compounds present in the extract with the STa toxin may limit its activity. Curative effect in the diarrhea treatment and its anti-inflammatory action is based on the pharmacological properties, mechanism of action of the C. adamantium peel extract, and no toxic effects of the peel extract presented on this work.

Diuretic and Anti-Inflammatory Activities of the Microencapsulated Acrocomia aculeata (Arecaceae) Oil on Wistar Rats.

Acrocomia aculeata, popularly known as "bocaiuva," is widely acknowledged in culinary and traditional medicines to treat cardiovascular diseases, a combined effect with diuretics that are also used for hypertension. However, there are no scientific data published to support its use as functional food and its ethnopharmacological use. This study intended to determine the composition of fatty acids of the pulp oil and evaluate the diuretic action and anti-inflammatory activity of the in natura and microencapsulated oil orally administrated on rats. The obtained results confirm the prevalence of monounsaturated fatty acids (68.51%), especially oleic acid (65.68%±1.05%), in the oil from the bocaiuva pulp. The in natura A. aculeata oil has diuretic (P<.01) and anti-inflammatory potential, which promoted a marked inhibition on the hind paw edema induced by carrageenan (67%±7% after 2 h) (P<.01). In addition, results show that the oral administration of the bocaiuva oil at 300 (P<.05) and 700 (P<.05) mg/kg doses significantly inhibited the leukocyte migration induced by carrageenan to the pleural cavity in rats. The inhibitions equaled 91%±3% and 81%±16%, respectively. The microencapsulated oil also showed antiedematogenic (P<.01) as well as diuretic activities (P<.01). The microencapsulation by complex coacervation was shown to be a technique that favors the bioavailability and preservation of bioactive components of the bocaiuva oil.