Antiedema and antinociceptive potential of the essential oil of Pectis elongata Kunt (Asteraceae) from the Brazilian Amazon.

ETHNOPHARMACOLOGICAL RELEVANCE: Pectis elongata, a herbaceous species that is known in northern Brazil as "cominho" or "limãozinho", is traditionally used in the region for the treatment of fevers, colds, hypotension, genitourinary and gastric disorders, and pain. AIM OF THE STUDY: Determine the chemical composition and acute oral toxicity and evaluate whether Pectis elongata essential oil (PeEO) has antiedema and antinociceptive activity. MATERIALS AND METHODS: The chemical composition was determined using gas chromatography coupled to mass spectrometry (GC/MS) and the degree of toxicity determined by the LD50. The antiedema and antinociceptive potential was evaluated via the λ-carrageenan-induced paw edema test and formalin test, respectively. RESULTS: Citral (geranial and neral) was characterized as a major component of the PeEO, representing 89% of the total identified compounds. According to OECD criteria (2002), the EO was considered non-toxic since it presented LD50 values over 2000 mg kg-1. Its antiedema potential was observed at doses of 200 and 400 mg kg-1 (p ≤ 0.05). At a dose of 400 mg kg-1, PeEO also showed antinociceptive potential (p ≤ 0.05), both in the neurogenic phase and in the inflammatory phase. CONCLUSIONS: PeEO, which is rich in citral, did not induce any characteristic signs of acute oral toxicity and was also efficient in reducing carrageenan-induced paw edema, in addition to presenting antinociceptive potential and acting on both central and peripheral pain. It is thus a promising candidate for the development of a new herbal medicine with anti-inflammatory and analgesic action.

Fish consumption habits of pregnant women in Itaituba, Tapajós River basin, Brazil: risks of mercury contamination as assessed by measuring total mercury in highly consumed piscivore fish species and in hair of pregnant women.

The Tapajós River basin in the Amazon region, Brazil is one of the most active gold mining areas in the world. In this study, we evaluated fish consumption habits and mercury exposure in 110 pregnant women in the city of Itaituba by measuring their total hair mercury concentrations. In addition, we investigated seasonal differences in mercury concentrations in two highly consumed piscivorous fish species, tucunaré (Cichla spp.) and pescada (Plagioscion squamosissimus). Total fish mercury concentrations (THg) during the dry season were 0.62±0.07 mg/kg for Cichla spp. and 0.73±0.08 mg/kg for P. squamosissimus. During the rainy season they were 0.39±0.04 and 0.84±0.08 mg/ kg, respectively. Of our participants 44 % declared that they ate Cichla spp. and 67 % P. squamosissimus. Mean mercury concentration in their hair was 1.6±0.2 mg/kg and was above the US Environmental Protection Agency (US EPA) reference dose of 1 mg/kg in 48 % of them. Mean fish THg concentrations were also above the joint Food and Drug Administration and US EPA safety limit of 0.5 mg/kg for P. squamosissimus during both seasons and for Cichla spp. during the dry season only. These results show that pregnant women should avoid consumption of these piscivorous fish species during pregnancy and call for a regular programme to monitor Hg levels in that area.