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Viral diseases transmitted by the female Aedes aegypti L. are considered a major public health problem. The aerial parts of Helicteres velutina K. Schum (Sterculiaceae) have demonstrated potential insecticidal and larvicidal activity against this vector. The objective of this research was to investigate the mechanisms of action involved in the larvicidal activity of this species. The cytotoxicity activity of H. velutina fractions and compounds of crude ethanolic extract of the aerial parts of this species was assessed by using fluorescence microscopy and propidium iodide staining. In addition, the production of nitric oxide (NO) and hemocyte recruitment were checked after different periods of exposure. The fluorescence microscopy revealed an increasing in larvae cell necrosis for the dichloromethane fraction, 7,4'-di-O-methyl-8-O-sulphate flavone and hexane fraction (15.4, 11.0, and 7.0%, respectively). The tiliroside did not show necrotic cells, which showed the same result as that seen in the negative control. The NO concentration in hemolymph after 24 h exposure was significantly greater for the dichloromethane fraction and the 7,4'-di-O-methyl-8-O-sulphate flavone (123.8 and 56.2 µM, respectively) when compared to the hexane fraction and tiliroside (10.8 and 8.3 µM, respectively). The presence of plasmocytes only in the dichloromethane fraction and 7,4'-di-O-methyl-8-O-sulphate flavone treatments suggest that these would be the hemocytes responsible for the highest NO production, acting as a defense agent. Our results showed that the larvicidal activity developed by H. velutina compounds is related to its hemocyte necrotizing activity and alteration in NO production.

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Helicteres velutina K. Schum (Sterculiaceae), a member of Malvaceae sensu lato, is a Brazilian endemic plant that has been used by the indigenous tribe Pankarare as an insect repellent. A previous study has reported the isolation of terpenoids, flavonoids and pheophytins, in addition to the larvicidal activity of crude H. velutina extracts derived from the aerial components (leaves, branches/twigs, and flowers). The present study reports the biomonitoring of the effects of fractions and isolated compounds derived from H. velutina against A. aegypti fourth instar larvae. A crude ethanol extract was submitted to liquid-liquid extraction with hexane, dichloromethane, ethyl acetate and n-butanol to obtain their respective fractions. Larvicidal evaluations of the fractions were performed, and the hexane and dichloromethane fractions exhibited greater activities than the other fractions, with LC50 (50% lethal concentration) values of 3.88 and 5.80 mg/mL, respectively. The phytochemical study of these fractions resulted in the isolation and identification of 17 compounds. The molecules were subjected to a virtual screening protocol, and five molecules presented potential larvicidal activity after analyses of their applicability domains. When molecular docking was analysed, only three of these compounds showed an ability to bind with sterol carrier protein-2 (1PZ4), a protein found in the larval intestine. The compounds tiliroside and 7,4'-di-O-methyl-8-O-sulphate flavone showed in vitro larvicidal activity, with LC50 values of 0.275 mg/mL after 72 h and 0.182 mg/mL after 24 h of exposure, respectively. This is the first study to demonstrate the larvicidal activity of sulphated flavonoids against A. aegypti. Our results showed that the presence of the OSO3H group attached to C-8 of the flavonoid was crucial to the larvicidal activity. This research supports the traditional use of H. velutina as an alternative insecticide for the control of A. aegypti, which is a vector for severe arboviruses, such as dengue and chikungunya.

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Prickly pear peel is an agroindustrial by-product source of dietary fiber and bioactive compounds. Three tonalities of prickly pear cultivars: Cristalina (green), Selección 2-1-62 (yellow-orange) and Roja Lisa (red) were evaluated regarding their bioactive compounds and functional, rheological, and morphological properties. Phytochemical profile assessed by UPLC-ESI-QTOF MSE allowed the identification of 145 compounds: sixty-eight extractable polyphenols, fifteen hydrolysable polyphenols, forty-one betalains, sixteen carotenoids, and five phytosterols. Cristalina showed the highest amount of extractable polyphenols (ferulic and benzoic acid, kaempferol 3-O-glucoside), Cristalina and Selección of hydrolysable polyphenols (gallic acid 3-O-gallate, cinnamic acid, hesperidin, myricetin 3-O-rhamnoside). Betaxanthins, carotenoids, and phytosterols were detected in all cultivars, mainly in Roja Lisa. All cultivars showed acceptable hydration properties, which was related to their porosity. Selección showed the highest elastic (G') and lower viscous (G″) behavior. These results suggest that prickly pear peels can be used as functional ingredients rich in bioactive compounds.

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Polysaccharides are substances that modify the biological response to several stressors. The present study investigated the antitumor activity of the soluble fraction of polysaccharides (SFP), extracted from cabernet franc red wine, in Walker-256 tumor-bearing rats. The monosaccharide composition had a complex mixture, suggesting the presence of arabinoglactans, mannans, and pectins. Treatment with SFP (30 and 60mg/kg, oral) for 14days significantly reduced the tumor weight and volume compared with controls. Treatment with 60mg/kg SFP reduced blood monocytes and neutrophils, reduced the tumor activity of N-acetylglucosaminidase, myeloperoxidase, and nitric oxide, increased blood lymphocytes, and increased the levels of tumor necrosis factor α (TNF-α) in tumor tissue. Treatment with SFP also induced the expression of the cell necroptosis-related genes Rip1 and Rip3. The antineoplastic effect of SFP appears to be attributable to its action on the immune system by controlling the tumor microenvironment and stimulating TNF-α production, which may trigger the necroptosis pathway.

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This study reports the first phenolics from Wissadula genus (Malvaceae) and the anti-inflammatory activity of 7,4'-di-O-methylisoscutellarein. Using chromatographic methods, five phenolic compounds were isolated from aerial parts of Wissadula periplocifolia (L.) C. Presl. The compounds were identified as 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, trans-cinnamic acid, tamgermanetin and 7,4'-di-O-methylisoscutellarein using spectroscopic methods. The flavone 7,4'-di-O-methylisoscutellarein showed anti-inflammatory activity by inhibiting neutrophils recruitment in a mice model of pleurisy and by decreasing significantly the production of cytokines IL-1ß and TNF-α.

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ETHNOPHARMACOLOGICAL RELEVANCE: Heterotheca ineuloides Cass (Asteraceae), popularly known as árnica mexicana, is widely used in Mexican traditional medicine to treat bruises, dermatological problems, rheumatic pains, and other disorders as cancer. The major constituents in H. inuloides are cadinane type sesquiterpenes, flavonoids and phytosterols. Compounds with a cadinane skeleton have been proved to possess cytotoxic activity against human-tumor cell lines and brine shrimp, and display toxic effects in different animal species. Although this plant has been widely used, there is little available information on the safety and toxicity especially of pure compounds. AIM OF THIS STUDY: Evaluate the potential toxicity of the natural products isolated from H. inuloides and some semisynthetic derivatives. MATERIALS AND METHODS: The toxic aspects of the following natural products isolated from dried flowers of H. inuloides: 7-hydroxy-3,4-dihydrocadalene (1), 7-hydroxycadalene (2), 3,7-dihydroxy-3(4H)-isocadalen-4-one (3), (1R,4R)-1-hydroxy-4H-1,2,3,4- tetrahydrocadalen-15-oic acid (4), D-chiro-inositol (5), quercetin (6), quercetin-3,7,3'-trimethyl ether (7), quercetin-3,7,3',4'-tetramethyl ether (8), eriodictyol-7,4'-dimethyl ether (9), α-spinasterol (10), caryolan-1,9ß-diol (11) and 7-(3,3-dimethylallyloxy)-coumarin (12) as well as the toxic aspects of the semisynthetic compounds 7-acetoxy-3,4-dihydrocadalene (13), 7-benzoxy-3,4-dihydrocadalene (14), 7-acetoxycadalene (15), 7-benzoxycadalene (16), quercetin pentaacetate (17), 7-hydroxycalamenene (18), 3,8-dimethyl-5-(1-methylethyl)-1,2-naphthoquinone (19), and 4-isopropyl-1,6-dimethylbenzo[c]oxepine-7,9-dione (20). Toxic activities of compounds were determined by sulforhodamine B (SRB) assay, Artemia salina assay, RAW264.7 macrophage cells. Additionally, the acute toxicity in mouse of compound 1, the major natural sesquiterpene isolated from the acetone extract, was evaluated. RESULTS: The best cytotoxicity activity was observed for mansonone C (19) on K562 cell line with IC50 1.45 ± 0.14 µM, for 7-hydroxycadalene (2) on HCT-15 cell line with IC50 18.89 ± 1.2 µM, and for quercetin pentaacetate (17) on MCF-7 cell line with IC50 22.57 ± 2.4 µM. Sesquiterpenes mansonone C (19) and 7-hydroxy-3,4-dihydrocadalene (1) caused the strongest deleterious effects against A. salina with IC50 39.4 ± 1.07, and 45.47 ± 1.74 µM, respectively. The number of viable RAW 264.7 cells was reduced with sesquiterpenes 1 and 2 by more than 90%. In addition, the acute study of 1 revealed no lethal effects at 300 mg/kg body weight, however, a reduction in the body weight of mice, morphological changes in the tissues of the liver and kidney and toxic signs were observed at very high doses (2000 mg/kg). CONCLUSION: The results provided evidence for the cytotoxicity of Mexican arnica (H. inuloides) metabolites and may be correlated with one of the popular uses of this plant, in traditional Mexican medicine, as anticancer remedy. Among the active compounds contained in the acetone extract, the cytotoxic activity is mainly ascribable to cadinene type sesquiterpenes. In addition, evidence of acute toxicity suggests that 7-hydroxy-3,4-dihydrocadalene (1) may lead to toxicity at very high doses.

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The phytochemical analysis of aerial parts of Cordia globosa, collected in the Municipality of Picuí, State of Paraíba, Brazil, resulted in the isolation and structural identification of narigenin-4',7-dimethyl ether (0.025 g) and eriodictyol (0.015 g). These compounds are the first flavanones aglycones isolated from the genus Cordia.

A análise fitoquímica das partes aéreas de Cordia globosa, coletadas no município de Picuí, PB, Brasil, resultou no isolamento e identificação estrutural da 7,4'-dimetilnarigenina (0,025 g) e eriodictiol (0,015 g). Estas duas flavanonas são as primeiras agliconas, desta classe, isoladas no gênero Cordia.

RESUMO

Os flavonóides 5,3’,4’-triidroxi-7-metoxiflavona, 5,3’-diidroxi-7-4’-dimetoxiflavona, 5,4’-diidroxi-7-metoxiflavona e uma mistura de esteróides (β-sitosterol e estigmasterol) foram isoladas das partes aιreas de Piper carniconnectivumC.DC, Piperaceae. As estruturas desses compostos foram estabelecidas por análises espectroscópicas de UV, IV e RMN de ¹H e 13C, incluindo técnicas uni e bidimensionais.

The flavonoids 5,3’,4’-trihydroxy-7-methoxyflavone, 5,3’-dihydroxy-7-4’-dimethoxyflavone, 5,4’-dihydroxy-7-methoxyflavone and steroids mixture (β-sitosterol and stigmasterol) were isolated from the dried aerials parts of Piper carniconnectivumC.DC. Their structures were established by spectroscopic analyses (UV, IV and ¹H, 13C NMR, including 1D and 2D NMR).

RESUMO

A total of twenty different extracts from six Brazilian Bromeliaceae species was screened for antioxidant activity by assessment of their capacity to scavenge the DPPH radical. In a general way, the polar rhizome extracts from Bromeliaceae representatives showed better antioxidant results than the extracts from leaves and fruits of the same species. The best results were found for the rhizome extracts of Vriesea procera (Mart. ex Schult.f.) Wittm. and Neoregelia cruenta (Graham) L.B. Sm. Crude methanol extract of Ananas bracteatus (Lindl.) Schult. & Schult. f. leaf had a significant antiradical activity among the leaves extracts assessed its purification afforded four metabolites: 2-O-feruloyl glyceride, 2-O-p-coumaroyl glyceride, 5,7,4'-trihydroxy-3,3',5'-trimethoxyflavone and 3-O-β-D-glucopyranosyl sitosterol.

Um total de vinte extratos de seis espécies de Bromeliaceae brasileiras foram avaliadas quanto a atividade antioxidante, usando-se o método colorimétrico de redução do radical DPPH. De maneira geral, os extratos polares dos rizomas das espécies de Bromeliaceae testadas revelaram melhor perfil antioxidante do que os extratos das folhas e dos frutos das mesmas espécies. Os melhores resultados foram encontrados para os rizomas de Vriesea procera (Mart. ex Schult.f.) Wittm. e Neoregelia cruenta (Graham) L.B. Sm. O extrato bruto metanólico das folhas de Ananas bracteatus (Lindl.) Schult. & Schult. f. apresentou uma atividade significativa, em relação aos extratos de folhas testados, e o processo de purificação desse extrato resultou na identificação de quatro metabólitos: ferulato de 2-glicerila, p-cumarato de 2-glicerila, 5,7,4'-triidroxi-3,3',5'-trimetoxiflavona e 3-O-β-D-glicopiranosil sitosterol.

RESUMO

From the wood benzene and chloroform extracts of Swartzia brachyrachis Harms var.brachyrachis were isolated, by chromatografph methods, an undocumented isoflavone (7,4'-dihydroxy-5,3',5'trimethoxy-6-methylisoflavone) named brachyrachisine and a glucoside (3-O--D-glucopyranosylsitosterol). The structures were elucidated by spectroscopic analysis.

Dos extratos benzênico e clorofórmico da madeira de Swartzia brachyrachisHarms var. brachyrachis foram isolados, por métodos cromatográficos, uma isoflavona inédita (7,4'diidroxi -5,3'5'-trimetoxi-6-metilisoflavona), denominada brachyrachisina, c um glicosídio (3-O--D-glicopiranosilsitosterol). As estruturas foram elucidadas através de análises espectroscópicas.

RESUMO

From the wood benzene and chloroform extracts of Swartzia brachyrachis Harms var.brachyrachis were isolated, by chromatografph methods, an undocumented isoflavone (7,4'-dihydroxy-5,3',5'trimethoxy-6-methylisoflavone) named brachyrachisine and a glucoside (3-O--D-glucopyranosylsitosterol). The structures were elucidated by spectroscopic analysis.

Dos extratos benzênico e clorofórmico da madeira de Swartzia brachyrachisHarms var. brachyrachis foram isolados, por métodos cromatográficos, uma isoflavona inédita (7,4'diidroxi -5,3'5'-trimetoxi-6-metilisoflavona), denominada brachyrachisina, c um glicosídio (3-O--D-glicopiranosilsitosterol). As estruturas foram elucidadas através de análises espectroscópicas.