Chemical defenses of the tropical marine seaweed Canistrocarpus cervicornis against herbivory by sea urchin

This paper reports on the defensive chemical properties of the marine tropical brown seaweed Canistrocarpus cervicornis against herbivory. A natural concentration of dichloromethane crude extract (DCE) obtained from this seaweed significantly inhibited feeding by the sea urchin Lytechinus variegatus. The major metabolite isolated from this active DCE extract was identified as the (4R,7R,14S)-4α,7α-diacetoxy-14-hydroxydolast-1(15),8-diene that strongly inhibited feeding by the same sea urchin. This result suggests that the dolastane diterpenes class may constitute the defensive system of C. cervicornis against herbivory, and probably also of that of other brown seaweeds endowed with a biosynthetic pathway capable of producing compounds of the dolastane-type, a typical skeleton found in Dyctioteae species worldwide. This is the first report showing this compound-type (dolastane diterpenes) as a chemical defense against herbivory in marine seaweeds. This study constitutes an additional report broadening the known spectrum of action and roles of secondary metabolites of the C. cervicornis and Dyctioteae species.Este artigo demonstra a química defensiva anti-herbivoria da macroalga parda marinha Canistrocarpus cervicornis. Em sua concentração natural, o extrato bruto em diclorometano (DCE) inibiu significativamente o consumo alimentar do ouriço-do-mar Lytechinus variegatus. Deste extrato em DCE foi isolado o metabólito majoritário identificado como o diterpeno (4R,7R,14S)-4α,7α-diacetoxi-14-hidroxidolasta-1(15),8-dieno. Esses resultados comprovam que diterpenos da classe dolastano podem compor o sistema defensivo anti-herbivoria de C. cervircornis e, supostamente, o de outras algas pardas capazes de produzi-los, uma vez que são composto típicos encontrados em esqueletos de Dyctiotas em todo o mundo. Este é o primeiro estudo demonstrando a ação anti-herbivoria desta classe de metabolitos (diterpenos dolastanos) em macroalgas marinhas. Tais informações ampliam o conhecimento sobre o papel desses metabolitos especiais em C. cervicornis e de espécies de Dyctiotae

Chemical defenses of the tropical marine seaweed Canistrocarpus cervicornis against herbivory by sea urchin

This paper reports on the defensive chemical properties of the marine tropical brown seaweed Canistrocarpus cervicornis against herbivory. A natural concentration of dichloromethane crude extract (DCE) obtained from this seaweed significantly inhibited feeding by the sea urchin Lytechinus variegatus. The major metabolite isolated from this active DCE extract was identified as the (4R,7R,14S)-4α,7α-diacetoxy-14-hydroxydolast-1(15),8-diene that strongly inhibited feeding by the same sea urchin. This result suggests that the dolastane diterpenes class may constitute the defensive system of C. cervicornis against herbivory, and probably also of that of other brown seaweeds endowed with a biosynthetic pathway capable of producing compounds of the dolastane-type, a typical skeleton found in Dyctioteae species worldwide. This is the first report showing this compound-type (dolastane diterpenes) as a chemical defense against herbivory in marine seaweeds. This study constitutes an additional report broadening the known spectrum of action and roles of secondary metabolites of the C. cervicornis and Dyctioteae species.Este artigo demonstra a química defensiva anti-herbivoria da macroalga parda marinha Canistrocarpus cervicornis. Em sua concentração natural, o extrato bruto em diclorometano (DCE) inibiu significativamente o consumo alimentar do ouriço-do-mar Lytechinus variegatus. Deste extrato em DCE foi isolado o metabólito majoritário identificado como o diterpeno (4R,7R,14S)-4α,7α-diacetoxi-14-hidroxidolasta-1(15),8-dieno. Esses resultados comprovam que diterpenos da classe dolastano podem compor o sistema defensivo anti-herbivoria de C. cervircornis e, supostamente, o de outras algas pardas capazes de produzi-los, uma vez que são composto típicos encontrados em esqueletos de Dyctiotas em todo o mundo. Este é o primeiro estudo demonstrando a ação anti-herbivoria desta classe de metabolitos (diterpenos dolastanos) em macroalgas marinhas. Tais informações ampliam o conhecimento sobre o papel desses metabolitos especiais em C. cervicornis e de espécies de Dyctiotae

Chemical defenses of the tropical marine seaweed Canistrocarpus cervicornis against herbivory by sea urchin

This paper reports on the defensive chemical properties of the marine tropical brown seaweed Canistrocarpus cervicornis against herbivory. A natural concentration of dichloromethane crude extract (DCE) obtained from this seaweed significantly inhibited feeding by the sea urchin Lytechinus variegatus. The major metabolite isolated from this active DCE extract was identified as the (4R,7R,14S)-4α,7α-diacetoxy-14-hydroxydolast-1(15),8-diene that strongly inhibited feeding by the same sea urchin. This result suggests that the dolastane diterpenes class may constitute the defensive system of C. cervicornis against herbivory, and probably also of that of other brown seaweeds endowed with a biosynthetic pathway capable of producing compounds of the dolastane-type, a typical skeleton found in Dyctioteae species worldwide. This is the first report showing this compound-type (dolastane diterpenes) as a chemical defense against herbivory in marine seaweeds. This study constitutes an additional report broadening the known spectrum of action and roles of secondary metabolites of the C. cervicornis and Dyctioteae species.Este artigo demonstra a química defensiva anti-herbivoria da macroalga parda marinha Canistrocarpus cervicornis. Em sua concentração natural, o extrato bruto em diclorometano (DCE) inibiu significativamente o consumo alimentar do ouriço-do-mar Lytechinus variegatus. Deste extrato em DCE foi isolado o metabólito majoritário identificado como o diterpeno (4R,7R,14S)-4α,7α-diacetoxi-14-hidroxidolasta-1(15),8-dieno. Esses resultados comprovam que diterpenos da classe dolastano podem compor o sistema defensivo anti-herbivoria de C. cervircornis e, supostamente, o de outras algas pardas capazes de produzi-los, uma vez que são composto típicos encontrados em esqueletos de Dyctiotas em todo o mundo. Este é o primeiro estudo demonstrando a ação anti-herbivoria desta classe de metabolitos (diterpenos dolastanos) em macroalgas marinhas. Tais informações ampliam o conhecimento sobre o papel desses metabolitos especiais em C. cervicornis e de espécies de Dyctiotae

Propriedades antioxidantes de folhas e caules de Bauhinia microstachya (Raddi) J.F. Macbr.

This paper describes in vitro antioxidant activities of different extracts (EBHF, EBHC, EBCF, EBCC, EBEF and EBEC) and fractions (FAEF and FAEC) obtained from leaves and stems of Bauhinia microstachya (Fabaceae), using two distinct methodologies: the formation of a phosphomolibdenum complex (a) and the chemical reduction of DPPH free radical (b). When assayed by the phosphomolibdenum complex formation method, EBEF, EBEC, FAEF and FAEC (200 μg.mL-1) showed the highest antioxidant activities with regard to standard ascorbic acid (Vitamin C) (45% ± 1.55, 47% ± 1.10, 49% ± 2.06, 43% ± 3.14, respectively). Similarly, when assayed by the DPPH reduction method, FAEF and FAEC showed that they are highly efficient as antioxidants (EC50 = 2.75 and 2.86 mg.mL-1 respectively) with regard to standard ascorbic acid (EC50 = 36 ± 0.35 mg.mL-1), quercetin (EC50 = 1.60 ± 0.17 mg.mL-1) and rutin (EC50 = 8.13 ± 0.13 mg.mL-1). Phytochemical studies, as well as 1H and 13C NMR analysis of the most active fractions (FAEF and FAEC) established the presence of polyphenols (tannins and flavonoids). The percentage of total flavonoids from the leaves of B. microstachya was shown to be 0.12 g% ± 0.03 (n = 5). These results not only demonstrate the high in vitro antioxidant potential of this plant species, but prompt further chemical, pharmacological and biotechnological research studies with a view to producing new phytotherapics for medical use which are aimed at combating free radicals.Este trabalho descreve as atividades antioxidantes in vitro de diferentes extratos (EBHF, EBHC, EBCF, EBCC, EBEF e EBEC) e frações (FAEF e FAEC) obtidos de folhas e caules de Bauhinia microstachya (Fabaceae), através de duas metodologias distintas: formação do complexo fosfomolibdênico (a) e redução do radical livre DPPH (b). Quando avaliados pelo método da formação do complexo fosfomolibdênico, EBEF, EBEC, FAEF e FAEC (200 μg.mL-1) apresentaram as maiores atividades antioxidantes em relação ao padrão ácido ascórbico (Vitamina C) (45% ± 1,55, 47% ± 1,10, 49% ± 2,06 e 43% ± 3,14, respectivamente). De forma semelhante, quando testadas pelo método da redução do DPPH, FAEF e FAEC, demonstraram-se altamente eficientes como antioxidantes (EC50 = 2,75 e 2,86 mg.mL-1, respectivamente), em relação aos padrões ácido ascórbico (EC50 = 36 ± 0,35 mg.mL-1), quercetina (EC50 = 1,60 ± 0,17 mg.mL-1) e rutina (EC50 = 8,13 ± 0,13 mg.mL-1). Estudos fitoquímicos, bem como análises de RMN 1H e 13C, determinaram, nas frações mais ativas (FAEF e FAEC), a presença de substâncias polifenólicas (taninos e flavonóides). O percentual de flavonóides totais das folhas de B. microstachya foi verificado, sendo de 0,12 g% ± 0,03 (n = 5). Estes resultados, além de demonstrarem o alto potencial antioxidante in vitro desta espécie vegetal, estimulam novos estudos químicos, farmacológicos e biotecnológicos voltados à produção de possíveis fitoterápicos destinados ao combate dos radicais livres

Chemical defense of Hymeniacidon heliophila (Porifera: halichondrida) against tropical predators

Diversos organismos bênticos possuem defesas químicas que ajudam a diminuir a predação. Embora sua eficácia seja comprovada, muitos de seus efeitos são ainda desconhecidos. Múltiplas funções dos metabolitos secundários foram evidenciadas em algumas esponjas e isso pode representar uma vantagem adaptativa, considerando o alto valor energético gasto pelas espécies para produzí-los. O objetivo desse trabalho foi investigar as propriedades defensivas de extratos da esponja Hymeniacidon heliophila contra predadores tropicais: paguros (Calcinus tibicens), ouriços-do-mar (Lytechinus variegatus) e peixes generalistas. Extratos em n-hexano, acetato de etila e acetona/metanol foram usados nos ensaios e todos foram eficientes na redução do consumo por C. tibicen; extratos em n-hexano reduziram o consumo por L. variegatus; e extratos de média polaridade reduziram o consumo por peixes. A variação na ação ou as funções ecológicas múltiplas dos extratos indicam que diferentes tipos de substâncias podem ser associadas ao sistema defensivo produzido por Hymeniacidon heliophila.Various benthic organisms have chemical defenses which reduce their predators' consumption. Although their efficiency may be noticed in many organisms, many of their effects are not well- known yet. Multiple ecological roles of secondary metabolites are shown in some sponges, which may represent an adaptative advantage considering the high amount of energy used to produce these chemical compounds. The goal of this work was to investigate the defensive property of the extracts from the sponge Hymeniacidon heliophila against the tropical predators: hermit crabs (Calcinus tibicens), sea urchins (Lytechinus variegatus) and generalist fishes. Extracts obtained with n-hexane, ethyl acetate and acetone/methanol were used in assays and all of them were effective in reducing the consumption by C. tibicens; n-hexane extract reduced the consumption by L. variegatus; and medium polarity extracts reduced fish consumption. Either the variation in action or the multiple ecological roles of the extracts indicates that different types of compounds can be associated to the defensive system produced by H. heliophila

Effect of Elatol, Isolated from Red Seaweed Laurencia dendroidea, on Leishmania amazonensis

In the present study, we investigated the antileishmanial activity of sesquiterpene elatol, the major constituent of the Brazilian red seaweed Laurencia dendroidea (Hudson) J.V. Lamouroux, against L. amazonensis. Elatol after 72 h of treatment, showed an IC50 of 4.0 μM and 0.45 μM for promastigote and intracellular amastigote forms of L. amazonensis, respectively. By scanning and transmission electron microscopy, parasites treated with elatol revealed notable changes compared with control cells, including: pronounced swelling of the mitochondrion; appearance of concentric membrane structures inside the organelle; destabilization of the plasma membrane; and formation of membrane structures, apparently an extension of the endoplasmic reticulum, which is suggestive of an autophagic process. A cytotoxicity assay showed that the action of the isolated compound is more specific for protozoa, and it is not toxic to macrophages. Our studies indicated that elatol is a potent antiproliferative agent against promastigote and intracellular amastigote forms, and may have important advantages for the development of new anti-leishamanial chemotherapies

Propriedades antioxidantes de folhas e caules de Bauhinia microstachya (Raddi) J.F. Macbr.

This paper describes in vitro antioxidant activities of different extracts (EBHF, EBHC, EBCF, EBCC, EBEF and EBEC) and fractions (FAEF and FAEC) obtained from leaves and stems of Bauhinia microstachya (Fabaceae), using two distinct methodologies: the formation of a phosphomolibdenum complex (a) and the chemical reduction of DPPH free radical (b). When assayed by the phosphomolibdenum complex formation method, EBEF, EBEC, FAEF and FAEC (200 μg.mL-1) showed the highest antioxidant activities with regard to standard ascorbic acid (Vitamin C) (45% ± 1.55, 47% ± 1.10, 49% ± 2.06, 43% ± 3.14, respectively). Similarly, when assayed by the DPPH reduction method, FAEF and FAEC showed that they are highly efficient as antioxidants (EC50 = 2.75 and 2.86 mg.mL-1 respectively) with regard to standard ascorbic acid (EC50 = 36 ± 0.35 mg.mL-1), quercetin (EC50 = 1.60 ± 0.17 mg.mL-1) and rutin (EC50 = 8.13 ± 0.13 mg.mL-1). Phytochemical studies, as well as 1H and 13C NMR analysis of the most active fractions (FAEF and FAEC) established the presence of polyphenols (tannins and flavonoids). The percentage of total flavonoids from the leaves of B. microstachya was shown to be 0.12 g% ± 0.03 (n = 5). These results not only demonstrate the high in vitro antioxidant potential of this plant species, but prompt further chemical, pharmacological and biotechnological research studies with a view to producing new phytotherapics for medical use which are aimed at combating free radicals.Este trabalho descreve as atividades antioxidantes in vitro de diferentes extratos (EBHF, EBHC, EBCF, EBCC, EBEF e EBEC) e frações (FAEF e FAEC) obtidos de folhas e caules de Bauhinia microstachya (Fabaceae), através de duas metodologias distintas: formação do complexo fosfomolibdênico (a) e redução do radical livre DPPH (b). Quando avaliados pelo método da formação do complexo fosfomolibdênico, EBEF, EBEC, FAEF e FAEC (200 μg.mL-1) apresentaram as maiores atividades antioxidantes em relação ao padrão ácido ascórbico (Vitamina C) (45% ± 1,55, 47% ± 1,10, 49% ± 2,06 e 43% ± 3,14, respectivamente). De forma semelhante, quando testadas pelo método da redução do DPPH, FAEF e FAEC, demonstraram-se altamente eficientes como antioxidantes (EC50 = 2,75 e 2,86 mg.mL-1, respectivamente), em relação aos padrões ácido ascórbico (EC50 = 36 ± 0,35 mg.mL-1), quercetina (EC50 = 1,60 ± 0,17 mg.mL-1) e rutina (EC50 = 8,13 ± 0,13 mg.mL-1). Estudos fitoquímicos, bem como análises de RMN 1H e 13C, determinaram, nas frações mais ativas (FAEF e FAEC), a presença de substâncias polifenólicas (taninos e flavonóides). O percentual de flavonóides totais das folhas de B. microstachya foi verificado, sendo de 0,12 g% ± 0,03 (n = 5). Estes resultados, além de demonstrarem o alto potencial antioxidante in vitro desta espécie vegetal, estimulam novos estudos químicos, farmacológicos e biotecnológicos voltados à produção de possíveis fitoterápicos destinados ao combate dos radicais livres

Time of addition studies with seaweed extracts A1, A3, A8 and A12.

<p>(<b>A</b>) Huh 7.5 cells were infected with DENV-4 with an MOI of 0.1 following each treatment (before the infection, −1.5 h; during the infection, 0 h; and after the infection, +1.5 h) at the MNTD, the cells were submitted to the ELISA assay (<b>B</b>) and the supernatant for the foci-forming assay. The dashed line represents the detection limit of the foci-forming assay.</p