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Our findings indicate that CTPr could be a good source of natural inhibitors of the components of snake venom responsible for inducing local inflammation.

BackgroundLippia origanoides Kunth from Northeast Brazil is a plant of pleasant odor used by local people as a food seasoning in substitution the oregano where its carvacrol-rich oil has showed significant antimicrobial activity against human pathogens.MethodsGC and GC-MS analyzed the plant oil composition and its antibacterial activity was evaluated by disk diffusion and microdilution broth methods. The determination of oil antioxidant activity was made by DPPH radical scavenging assay. Oil toxicity was performed on mice.ResultsThe main constituents of the oil were carvacrol (47.2 %), thymol (12.8 %), p-cymene (9.7 %), and p-methoxythymol (7.4 %). The oil was active against the bacteria of Bacillus cereus, B. subtilis, and Salmonella typhimurium, except for Pseudomonas aeruginosa. The antioxidant activity has displayed a high dose–response (r2 = 0.92), with the inhibition of DPPH radical from 15 to 82 %, at concentrations from 5 to 50 μg/mL, and also by the β-carotene bleaching assay, which showed a high inhibition of 85.2 ± 6.8 %, corresponding to about 80 % of the inhibition of Trolox (93.4 ± 0.7 %), used as a standard. The lethal dose (LD50) of the oil was determined in 1673.84 mg mL−1.ConclusionThe results confirmed that the oil of L. origanoides could be utilized for the prevention of food bacterial growth, and as an antioxidative agent for retardation of food oxidation process. The oil has low toxicity, allowing its application in the food industry.Graphical AbstractAerial parts of Lippia origanoides Kunth

ResumoEntre as várias espécies que possuem ampla diversidade para atividades biológicas, estão as da família Myrtaceae, que apresentam alto teor de óleo essencial. Em virtude da carência de estudos com atividade antioxidante do gênero Myrcia (Myrtaceae), o objetivo deste trabalho foi avaliar a capacidade antioxidante do óleo essencial de folhas frescas de Myrcia sylvatica (OEMS) por meio dos métodos de captura de radical livre (DPPH e ABTS) e pela auto-oxidação do FRAP e do sistema β-caroteno/ácido linoleico, comparando a padrões trolox e BHA como referências. A capacidade antioxidante pelo método DPPH apresentou IC50 de 1,94 ± 0,12 mg/mL em 60 minutos de reação. Pelo método ABTS, apresentou atividade antioxidante correspondente a 32,85 ± 0,86 µM de trolox/g de OEMS. Pelo método FRAP apresentou Z de 193,47 ± 2,63 de µM de sulfato ferroso/g de OEMS, em 45 minutos de reação. No teste de β-caroteno/ácido linoleico, o OEMS (4 mg/mL) inibiu 26,1% da oxidação do β-caroteno em 120 min de reação. O óleo essencial de M. sylvatica apresentou baixa atividade antioxidante, sendo pouco eficaz comparativamente às referências, mesmo que testado por mais de um mecanismo. Palavras-chave: Atividade antioxidante. Óleo essencial. DPPH. ABTS. FRAP. β-caroteno/ácido linoleico. Myrcia sylvatica. 118 Revista Fitos. Rio de Janeiro. 2018; 12(2): 117-126 | e-ISSN: 2446-4775 | www.revistafitos.far.fiocruz.br Atividade antioxidante do óleo essencial de Myrcia sylvatica (G. Mey.) DC. por diferentes métodos de análises antioxidantes (ABTS, DPPH, FRAP, β-caroteno/ácido linoleico) AbstractAmong the various species that possess wide diversity for biological activities, are those from the Myrtaceae family, which have high content of essential oil. Due to the lack of studies with Myrcia (Myrtaceae) antioxidant activity, the aim of this work was to evaluate the antioxidant capacity of essential oil from fresh leaves of Myrcia sylvatica (OEMS) by free radical capture methods (DPPH and ABTS) and by autoxidation of the FRAP and the β-carotene/linoleic acid system, comparing trolox and BHA standards as references. The antioxidant capacity by the DPPH method showed IC 50 of 1.94 ± 0.12 mg/mL in 60 minutes of reaction. By the ABTS method, OEMS presented antioxidant activity corresponding to 32.85 ± 0.86 μM trolox/g. By the FRAP method, Z showed 193.47 ± 2.63 μM of ferrous sulfate/g of OEMS in 45 minutes of reaction. In the βcarotene/linoleic acid test, the OEMS (4 mg/mL) inhibited 26.1% of β-carotene oxidation in 120 min of reaction. The essential oil from M. sylvatica presented low antioxidant activity, being less effective compared to the references, even when it was tested by more than one mechanism. IntroduçãoAntioxidantes são substâncias que retardam a velocidade da oxidação, quando ocorre a produção excessiva de radicais de oxigênio durante processos patofisiológicos ou devido a fatores ambientais (1) .Através de um ou mais mecanismos, os antioxidantes têm como função reduzir a oxidação, como por exemplo, por meio da inibição de radicais livres e co...

Bellucia dichotoma Cogn. (Melastomataceae) is one of various plant species used in folk medicine in the west of the state of Pará, Brazil, to treat snake bites. Many studies have been carried out to evaluate the effectiveness of anti-snake bite plants, but few of these use the same preparation methods and doses as those traditionally used by the local populations. This study therefore compared inhibition of the main local effects of B. atrox venom (BaV) by aqueous extract of B. dichotoma (AEBd) administered according to traditional methods and pre-incubated with BaV). The concentrations of phenolic compounds (tannins and flavonoids) in AEBd were determined by colorimetric assays. The effectiveness of AEBd in inhibiting the hemorrhagic and edematogenic activities of BaV was evaluated in mice in four different experimental in vivo protocols: (1) pre-incubation (venom:extract, w/w); (2) pre-treatment (p.o.); (3) post-treatment (p.o.); and (4) AEBd (p.o.) in combination with Bothrops antivenom (BA) (i.v.). To assess in vitro inhibition of BaV phospholipase A₂ activity, the pre-incubation method or incorporation of AEBd or BA in agarose gels were used. The effect of AEBd on BaV was determined by SDS-PAGE, zymography and Western blot. Colorimetric assays revealed higher concentrations of (condensed and hydrolyzable) tannins than flavonoids in AEBd. Hemorrhagic activity was completely inhibited using the pre-incubation protocol. However, with pre-treatment there was no significant inhibition for the concentrations tested, and with the post-treatment only the 725 mg/kg dose of AEBd was able to inhibit 40.5% (p = 0.001) of the hemorrhagic activity of BaV. Phospholipase A₂ activity was only inhibited when AEBd was pre-incubated with BaV. BaV-induced edema was completely inhibited with pre-incubation (p < 0.05) and significantly reduced (p < 0.05) with pre- and post-treatment (p.o.) for the concentrations tested. The reduction in local edema was even greater when AEBd was administered in combination with BA. The SDS-PAGE profiles showed that several of the BaV protein (SDS-PAGE) and enzyme (zymography) bands were not detected when the venom was pre-incubated, and Western blot revealed that this was not caused by the AEBd enzymes observed in the zymogram. The "pseudo inhibition" observed after pre-incubation in this study may be due to the presence of tannins in the extract, which could act as chelating agents, removing metalloproteins and Ca²⁺ ions and thus inhibiting hemorrhagin and PLA₂ activity. However, when administered according to traditional methods, B. dichotoma extract was effective in blocking BaV-induced edematogenic activity and had an additional effect on inhibition of this activity by BA.

ResumoMikania laevigata (Asteraceae) é popularmente usada no tratamento de doenças respiratórias, incluindo asma, bronquite e tosse. No Brasil, extratos de guaco são usados como produtos medicinais autorizados pela Agência Nacional de Vigilância Sanitária (ANVISA). No estudo, avaliou-se a adaptação e influência da variação sazonal do guaco, em um cultivo mantido em Santarém, Estado do Pará, Brasil; além do monitoramento da cumarina, seu principal constituinte ativo. No cultivo do guaco, as variáveis climáticas e o teor de cumarina foram avaliados mensalmente. A cumarina foi analisada por CCD (Cromatografia em Camada Delgada) e quantificada por HPLC (Cromatografia Liquida de Alta Eficiência) com base nos extratos hidroalcoólico e aquoso das folhas desidratadas. Na estação chuvosa (janeiro a julho), o guaco teve um crescimento homogêneo. Na estação de estiagem (agosto a novembro) houve perda das plantas que cresciam a pleno sol. O teor de cumarina foi detectado durante o desenvolvimento da planta, com níveis que variaram de 0,470 ± 0,01% a 0,886 ± 0,063%. O tempo da coleta não influenciou no teor de cumarina nas plantas cultivadas com 50% de sombra, tendo a média de 0,712% no extrato hidroalcoólico e 0,744% no extrato aquoso. Baseado nos resultados, em condições de sombreamento parcial, assegurou-se que o cultivo do guaco no Baixo Rio Amazonas pode ser replicado pelos pequenos agricultores, em seus Arranjos Produtivos Locais (APL) de plantas medicinais. Palavras AbstractMikania laevigata (Asteraceae) is popularly used in the treatment of respiratory diseases, including asthma, bronchitis, and cough. In Brazil, guaco extracts are used as medicinal products authorized by the National Health Surveillance Agency (ANVISA). In the study, it was evaluated the adaptation and the influence of the seasonal variation of guaco, in a cultivation held in Santarém, state of Pará, Brazil, and a monitoring of coumarin, its primary active constituent. In the growing of guaco, the climate variables, and the coumarin content were evaluated monthly. The coumarin was analyzed by TLC (Thin Layer Chromatography) and

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