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.

Assessment of the anti-snakebite properties of extracts of Aniba fragrans Ducke (Lauraceae) used in folk medicine as complementary treatment in cases of envenomation by Bothrops atrox

Ethnopharmacological relevance: Extracts of leaves and bark of Aniba fragrans are used as tea (decoction) to treat snakebites in communities in the Brazilian Amazon. The aqueous extract of the leaves of A. fragrans has been proven to be effective against Bothrops venom, but only when pre-incubated with the venom. This study sought to assess the potential of different types of extract of this species to inhibit the biological activities of Bothrops atrox venom (BaV) when used the same way as in folk medicine. The main classes of secondary metabolites and the concentrations of phenolics in the extracts were also determined. Materials and methods: Four types of extract of A. fragrans were prepared: aqueous extract of the leaf (AEL), aqueous extract of the bark (AEB), hydroalcoholic leaf extract (HLE) and extract of the residue from hydro distillation of the leaf (ERHL). The phytochemical profiles of the aqueous extracts were determined using thin layer chromatography (TLC), and the concentrations of phenolics were measured by colorimetric assays. To investigate the potential of the extracts to inhibit the biological activities of BaV, in vitro tests for antiphospholipase and antifibrinolytic activities were performed. In vivo tests for antihemorrhagic and antidefibrinating activities were also carried out, as well as antimicrobial tests for activity against the main bacteria found in the oral cavity of snakes. Interaction between the extracts and the proteins in BaV was assessed by electrophoresis (SDS-PAGE) and Western blot (WB). The cytotoxicity of the extracts was assessed in a strain of MRC-5 human fibroblasts. Results: Terpenoids, flavonoids and condensed and hydrolysable tannins were detected in all the extracts. Metabolites such as coumarins, fatty acids and alkaloids were present in some extracts but not in others, indicating different phytochemical profiles. Phenolics content varied between extracts, and there were more tannins in AEB and HLE. In the in vitro tests, the extracts inhibited the phospholipase and fibrinolytic activities of BaV in the two ratios of venom to extract used. HLE exhibited effective antimicrobial action as it inhibited growth of 11 of the 15 bacteria investigated, including Morganella morganii, the main bacteria described in the oral cavity of snakes. The extracts failed to inhibit the defibrinating activity of BaV, and only the Bothrops antivenom had a significant effect (96.1%) on this activity. Bay-induced hemorrhage was completely inhibited by AEL and AEB when the pre-incubation (venom:extract) protocol was used. When administered orally, as in folk medicine, both AEB and AEL produced significant inhibition of hemorrhagic activity (maximum inhibition 46.5% and 39.2%, respectively). SDS-PAGE and WB of the extracts pre-incubated with BaV showed that the main proteins in the venom had been precipitated by the extracts. None of the four extracts showed cytotoxic effects in the tests carried out with a human fibroblast cell line. Conclusion: In addition to being effective in reducing hemorrhage when administered orally, the extracts displayed a high antimicrobial potential against microorganisms involved in secondary infections at the site of the snakebite. Once the extracts have been tested in accordance with the appropriate regulations, this species could potentially be used to produce a phytomedicine for complementary treatment of the secondary infections due to bacteria that aggravate the local signs and symptoms after snakebite envenomation.

Psittacanthus plagiophyllus Eichl. (Loranthaceae): Perfil fitoquímico, efeito gastroprotetor e toxicidade aguda / Psittacanthus plagiophyllus Eichl. (Loranthaceae): Phytochemical profile, gastroprotective effect and acute toxicity

Psittacanthus plagiophyllus (Loranthaceae) é uma das espécies utilizadas no distrito de Alter do Chão, Santarém - PA, para o tratamento de gastrite. Levando em consideração o uso popular desta espécie, aliado à ausência de estudos farmacológicos e à sua grande disponibilidade nas savanas de Alter do Chão, o objetivo deste trabalho foi investigar o possível efeito gastroprotetor dos extratos aquoso e hidroalcoólico das folhas de P. plagiophyllus contra lesões gástricas induzidas por etanol em ratos, além de sua toxicidade aguda em ratos e de seu perfil fitoquímico por Cromatografia em Camada Delgada. No perfil cromatográfico dos extratos foi identificada a presença de flavonoides, taninos hidrolisáveis e cumarinas. O extrato aquoso de P. plagiophyllus nas doses de 500 e 1000 mg/Kg e o hidroalcoólico na dose de 500 mg/Kg inibiram significativamente a formação de lesões gástricas induzidas por etanol em ratos, quando comparados ao grupo controle, pelo teste de Dunnett (p<0,05). No ensaio de toxicidade aguda não foram observados sinais tóxicos de caráter geral e nem morte dos animais até a dose de 5000 mg/Kg dos extratos, o que indica baixa ou nenhuma toxicidade. Os compostos fenólicos detectados em P. plagiophyllus podem estar relacionados ao efeito gastroprotetor evidenciado.(AU)

Psittacanthus plagiophyllus (Loranthaceae) is one of the many species used in the district of Alter do Chão, Santarém - PA for the treatment of gastritis. Considering the popular use of this species, combined with the absence of pharmacological studies and its wide availability in the savanna of Alter do Chão, the aim of this study was to investigate the possible gastroprotective effect of hydroalcoholic and aqueous extracts of P. plagiophyllus leaves against ethanol-induced gastric lesions in rats, in addition to its acute toxicity in rats and phytochemical profile by Thin Layer Chromatography. The chromatographic profile of the extracts showed the presence of flavonoids, hydrolysable tannins and coumarins. The aqueous extract of P. plagiophyllus at doses of 500 and 1000 mg/Kg and hydroalcoholic at a dose of 500 mg/Kg significantly inhibited the formation of ethanol-induced gastric lesions in rats compared to the control group by the Dunnett's test (p <0.05). In the acute toxicity test were not observed signs of general toxic and no death of the animal to 5000 mg/Kg of the extracts, indicating low or no toxicity. Phenolic compounds found in P. plagiophyllus may be related to evidenced gastroprotective effect.(AU)