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Dengue virus (DENV) is the most prevalent mosquito-borne viral pathogen and made the disease a major health concern worldwide. However, specific antiviral drugs against this arbovirose or vaccines are not yet available for treatment or prevention. Thus, here we aimed to study the antiviral activity of hydroethanolic extract, fraction ethyl acetate and subfractions of the leaves of Bauhinia holophylla (Fabaceae:Cercideae), a native plant of the Brazilian Cerrado, against DENV-2 by methylthiazolyldiphenyl-tetrazolium bromide (MTT) method in mammalian cells culture. As results, the hydroethanolic extract showed the most potent effect, with an inhibitory concentration (IC50) of 3.2 µg mL-1 and selectivity index (SI) of 27.6, approximately 16-times higher anti-DENV-2 activity than of the ribavirin (IC50 52.8 µg mL-1). Our results showed in this study appointed that B. holophylla has a promising anti-dengue activity, which was associated mainly with the presence of flavonoids.

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RESUMO

The species Annona nutans (R. E. Fries) is a plant found in Bolivia, Paraguay, Argentina and the Brazilian cerrado. Considering the anti-inflammatory and antinociceptive activities of the hydrometanolic fraction (FHMeOH) of A. nutans leaves previously reported, the present study aimed to evaluate in vivo anti-inflammatory and antinociceptive activities of a subfraction obtained from FHMeOH, the butanolic fraction (FBuOHf). Intraperitoneal (i.p.) treatment with FBuOHf (50 and 100 mg · kg-1) inhibited paw edema induced by carrageenan. Moreover, FBuOHf (100 mg · kg-1, i.p.) also suppressed polymorphonuclear (PMN) leukocyte migration in the footpad. Regarding the antinociceptive activity, FBuOHf (50, 100, and 200 mg · kg-1, i.p.) inhibited acetic acid-induced abdominal writhing. In the formalin test, this fraction (200 mg · kg-1, i.p.) reduced licking time only in the inflammatory phase. The FBuOHf contents flavonoids and cinnamic acid derivatives, such as quercetin-3-O-galactoside, quercetin-3-O-glucoside, isorhamnetin-3-O-galactoside, quercetin-3-O-ß-D-apio-furanosyl-(1→2)-galactopyranoside and chlorogenic acid, identified and quantified by LC-MS. The FBuOHf possesses anti-inflammatory and peripheral antinociceptive activities.

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RESUMO

The recent outbreaks of mosquito-borne diseases highlighted the pivotal importance of mosquito vector control in tropical areas worldwide. Several strategies have been developed to control vector populations and disease transmission in endemic areas. The steps to obtain natural active compounds involve the pre-selection in a biological model and subsequently evaluation on specific models. The present study reports the evaluation of 35 extracts, fractions, and essential oils obtained from five species from the Annonaceae family on Artemia salina and Culex quinquefasciatus. The A. salina results were used as a pre-screening for larvicidal test about mosquitoes. A correlation of biological activity in both bioassays was observed for the hydroethanolic extracts and their respective hexane and chloroform fractions of the leaves of Annona species, except A. nutans. The same correlation was also observed for all tested essential oils and petroleum ether extracts from Duguetia species. It was possible to limit an interval of lethality about A. salina, which has a corresponding range to the larvicidal test against the mosquito. The main components present in D. lanceolata essential oil or enriched fraction were α-selinene, aristolochene, (E)-caryophyllene, and (E)-calamenene. For D. furfuracea, the main components present of the underground parts were (E)-asarone, 2,4,5-trimethoxystyrene, spathulenol, and bicyclogermacrene for aerial parts. The A. salina test could be used as a model for the pre-screening of larvicidal activity.

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RESUMO

Annona nutans (Annonaceae) is a plant species found in Bolivia, Paraguay, Argentina, and the Brazilian Cerrado, specifically in the states of Mato Grosso and Mato Grosso do Sul (Brazil). Its common names are Araticû-Mi and Araticû-Ñu. The research contributions regarding the chemical composition and biological activities of extracts from A. nutans are rare, with only four articles being found in the literature. Therefore, the present study evaluated the anti-inflammatory and antinociceptive activities of the hydromethanolic fraction (FHMeOH) using carrageenan-induced paw edema and hot-plate tests. In addition, the antioxidant activity was evaluated by DPPH radical scavenging, total phenolic, flavonoid and tannin content assays and quantification of the major metabolites by LC-MS were performed. Oral treatment with the FHMeOH (at a dose of 300 mg.kg-1) significantly reduced paw edema 2 h and 4 h after the inflammatory stimulus. The intraperitoneal (i.p.) treatment with the FHMeOH (50 and 100 mg.kg-1) proved to be most effective, and the inhibition of acute inflammation was still visible 6 h after carrageenan injection. At doses of 50 and 100 mg.kg-1 (i.p.), FHMeOH exhibits central antinociceptive effects by increasing the latency of the reaction in the hot-plate model. The FHMeOH showed antioxidant potential, and the metabolites quercetin-3-O-galactoside, quercetin-3-O-glucoside, isorhamnetin-3-O-galactoside, quercetin-3-O-ß-D-apiofuranosyl-(1→2)-galactopyranoside, and chlorogenic acid were identified and quantified by LC-MS. Our results indicate, for the first time, that FHMeOH has anti-inflammatory, antinociceptive and antioxidant potential, and it is a promising source of studies for new herbal medicines

Annona nutans (Annonaceae) é uma espécie de planta encontrada na Bolívia, Paraguai, Argentina e no Cerrado brasileiro, especificamente nos estados de Mato Grosso e Mato Grosso do Sul (Brasil). Seus nomes mais comuns são aratico e Araticû-Mi e Araticû-Ñu. As contribuições da pesquisa em relação à composição química e atividades biológicas dos extratos de A. nutans são raras, com apenas quatro artigos encontrados na literatura. Portanto, o presente estudo avaliou as atividades anti-inflamatória e antinociceptiva da fração hidrometanólica (FHMeOH) utilizando edema de pata induzido por carragenina e testes de placaquente. Além disso, a atividade antioxidante foi avaliada por meio de sequestro de radical DPPH, e foram realizados ensaios de quantificação de fenóis, flavonoides e taninos totais e quantificação dos principais metabólitos por CL-EM. O tratamento oral com a FHMeOH (na dose de 300 mg.kg-1) reduziu significativamente o edema da pata 2 e 4 h após o estímulo inflamatório. Por outro lado, o tratamento intraperitoneal (i.p.) com FHMeOH (50 e 100 mg.kg-1) provou ser mais eficaz e a inibição da inflamação aguda foi ainda visível 6 horas após a injeção de carragenina. Nas doses de 50 e 100 mg.kg-1 (i.p.), FHMeOH exibiu efeitos antinociceptivos centrais aumentando a latência da reação no modelo de placa quente. FHMeOH apresentou potencial antioxidante e os metabólitos quercetina-3-O-galactosídeo, quercetina-3-O-glicosídeo, isoramnetina-3-O-galactosídeo, quercetina- 3-O-ß-D-apiofuranosil-(1 → 2)-galactopiranosídeo e ácido clorogênico foram identificados e quantificados por CL-EM. Nossos resultados indicam, pela primeira vez, que o FHMeOH possui efeitos anti-inflamatórios, antinociceptivos e antioxidantes, sendo uma fonte promissora de estudos para novos medicamentos fitoterápicos.

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