Antinociceptive and anti-inflammatory activities of an aqueous extract of Chiliotrichum diffusum

The flowers of the Chiliotrichum diffusum (G. Forst.) Kuntze, Asteraceae, have long been used in traditional medicine and rituals. In this study, the anti-inflammatory and antinociceptive activities of a decoction of the flowers were evaluated and a phytochemical analysis was performed by HPLC-DAD. In order to evaluate the antinociceptive activity, the acetic acid-induced abdominal writhing and hot plate tests were used. The anti-inflammatory activity was evaluated using carrageenaninduced rat paw oedema. The decoction induced a significant anti-inflammatory effect (inhibition of 56.0% at 3 h) and produced significant inhibition on nociception in the acetic acid test (ED50 35 mg/kg i.p.; ED50 709 mg/kg p.o.). In the hot plate test, the antinociceptive activity of the extract employed at 500 mg/kg i.p. was significantly suppressed by pretreatment with naloxone (5 mg/kg). HPLC analysis showed the presence of chlorogenic acid, caffeic acid, hyperoside, isoquercitrin, quercitrin, afzelin, quercetin, apigenin and kaempferol. The decoction of C. diffusum proved to have antinociceptive and anti-inflammatory effects that may be related to the presence of the flavones, flavonols and phenolic acids identified. The opiod system seems to be involved in the mechanism of antinociception of the extract.

Antiretroviral activity of fucoidans extracted from the brown seaweed Adenocystis utricularis.

Treatment of human immunodeficiency virus type 1 (HIV-1, causative agent of AIDS) infection represents a major challenge in antiviral therapeutics. Many difficulties are associated with the treatment, including toxicity, resistance and high costs. Taking this into account, research for novel compounds able to overcome these limitations is needed. Sulfated polysaccharides appear to be interesting, given their abundance as components of seaweeds. Herein, a series of fractions obtained from the brown seaweed Adenocystis utricularis was analysed for in vitro anti-HIV-1 activity. These fractions, which have anti-herpes simplex virus activity, were determined previously to belong to the family of fucoidans, sulfated polysaccharides obtained from the cell walls of brown seaweeds. Assays in human PBMC primary cell culture demonstrated that two of the five fractions analysed had potent anti-HIV-1 activity both against WT and drug-resistant HIV-1 strains. For active fractions, it was also shown that the inhibitory effect was not due to an inactivating effect on the viral particle (i.e. no virucidal activity was detected) but rather to a blockade of early events of viral replication. Given these encouraging results, these seaweed-derived fractions appear as good candidates for further studies on their potential for in vivo therapy and/or prophylaxis of HIV-1 infection.