Influence of Styrax camporum and of Chemical Markers (Egonol and Homoegonol) on DNA Damage Induced by Mutagens with Different Mechanisms of Action.

This study evaluated the influence of Styrax camporum stems hydroalcoholic extract (SCHE) and of chemical markers of the genus, egonol (EG) and homoegonol (HE), on DNA damage induced in V79 cells by mutagens with different mechanisms of action. These natural products were combined with different mutagens [methyl methanesulfonate (MMS), hydrogen peroxide (H2O2), (S)-(+)-camptothecin (CPT), and etoposide (VP-16)] to evaluate the modulatory effect on DNA damage. The results showed that SCHE was genotoxic at the highest concentration tested (60 µg/mL). Treatment with EG or HE alone induced no genotoxic effect, while genotoxic activity was observed when the two compounds were combined. The SCHE extract was able to reduce the frequency of micronuclei induced by H2O2 and VP-16. Similar results were observed when the cell cultures were treated with EG and/or HE plus VP-16. In contrast, the highest concentration (40 µg/mL) SCHE potentiated DNA damage induced by VP-16. Neolignan EG alone or combined with HE also potentiated H2O2-induced genotoxicity. However, these natural products did not influence the frequency of DNA damage induced by MMS or CPT. Therefore, the influence of SCHE and of chemical markers (EG and HE) of the genus on the induction of DNA damage depends on the concentration tested and on the mutagen used.

Study of the cytotoxic activity of Styrax camporum extract and its chemical markers, egonol and homoegonol.

The benzofuran lignans egonol and homoegonol are found in all species of the genus Styrax. Since natural products are important sources of new anticancer drugs, this study evaluated the cytotoxic activity of a hydroalcoholic extract of the stems of S. camporum (SCHE) and their chemical markers, egonol (EG) and homoegonol (HE), against different tumor cell lines (B16F10, MCF-7, HeLa, HepG2, and MO59J). A normal human cell line (GM07492A) was included. Cytotoxic activity was evaluated at different treatment times (24, 48 and 72 h) using the XTT assay. More effective results were observed after 72 h of treatment. The lowest IC50 values were found for the HepG2 cell line, ranging from 11.2 to 55.0 µg/mL. The combination of EG and HE exerted higher cytotoxic activity than SCHE or treatment with either lignan alone, with the lowest IC50 (13.31 µg/mL) being observed for the MCF-7 line. Furthermore, treatment with these lignans was significantly more cytotoxic for some tumor cell lines compared to the normal cell line, GM07492A, indicating selectivity. These results suggest that these lignans may be used to treat cancer without affecting normal cells.

Quinone and hydroquinone metabolites from the ascidians of the genus Aplidium.

Ascidians of the genus Aplidium are recognized as an important source of chemical diversity and bioactive natural products. Among the compounds produced by this genus are non-nitrogenous metabolites, mainly prenylated quinones and hydroquinones. This review discusses the isolation, structural elucidation, and biological activities of quinones, hydroquinones, rossinones, longithorones, longithorols, floresolides, scabellones, conicaquinones, aplidinones, thiaplidiaquinones, and conithiaquinones. A compilation of the 13C-NMR spectral data of these compounds is also presented.

Antibacterial evaluation of Styrax pohlii and isolated compounds

The antibacterial activity of the compounds egonol (1) and homoegonol (2), of the crude ethanolic extract of Styrax pohlii (Styracaceae) aerial parts (EE), and of its n-hexane (HF), EtOAc (EF), n-BuOH (BF), and hydromethanolic (HMF) fractions was evaluated against the following microorganisms: Streptococcus pneumoniae (ATCC 6305), S. pyogenes (ATCC 19615), Haemophilus influenzae (ATCC 10211), Pseudomonas aeruginosa (ATCC 27853), and Klebsiella pneumoniae (ATCC 10031). The broth microdilution method was used for determination of the minimum inhibitory concentration (MIC) during preliminary evaluation of antibacterial activity. The EE yielded MIC values of 400 µg/mL for S. pneumoniae and P. aeruginosa and 300 µg/mL for H. influenzae. The HF and EF fractions exhibited enhanced antibacterial activity, with MIC values of 200 µg/mL against S. pneumoniae, but only EF displayed activity against H. influenzae (MIC 200 µg/mL). The best MIC value with compounds 1 and 2 (400 µg/mL) was obtained for (1) against S. pneumoniae and P. aeruginosa. Therefore, 1 exhibited weak antibacterial activity against these standard strains.

As atividades antimicrobianas das substâncias egonol (1) e homoegonol (2), do extrato etanólico das partes aéreas de Styrax pohlii (Styracaceae) (EE), bem como das frações n-hexano (HF), AcOEt (EF), n-BuOH (BF) e hidrometanólica (HMF) foram avaliadas frente aos seguintes microorganismos: Streptococcus pneumoniae (ATCC 6305), S. pyogenes (ATCC 19615), Haemophilus influenzae (ATCC 10211), Pseudomonas aeruginosa (ATCC 27853) e Klebsiella pneumoniae (ATCC 10031). O método de microdiluição em caldo foi utilizado para a determinação da concentração inibitória mínima (CIM) na avaliação preliminar da atividade antimicrobiana. EE mostrou valores de CIM de 400 µg/mL para S. pneumoniae e P. aeruginosa, e 300 µg/mL para H. influenzae. As frações HF e EF apresentaram melhora na atividade antimicrobiana, com valores de CIM de 200 µg/mL frente S. pneumoniae, mas apenas EF apresentou ação contra H. influenzae (200 µg/mL). Em relação às substâncias 1 e 2, o melhor valor de CIM (400 µg/mL) foi obtido por 1 frente a S. pneumoniae e P. aeruginosa, que exibiu fraca atividade antimicrobiana contra estas cepas padrões.

Schistosomicidal evaluation of flavonoids from two species of Styrax against Schistosoma mansoni adult worms.

CONTEXT: Schistosomiasis is a major health problem worldwide. Thus, the search for new schistosomicidal agents from natural sources can provide prototypes for drug discovery. OBJECTIVE: The present study investigated the chemical composition of the EtOAc fractions of Styrax pohlii Pohl (Styracaceae) (EF-SP) aerial parts and S. camporum A. DC. leaves (EF-SC), as well as schistosomicidal activities against Schistosoma mansoni adult worms, which have not yet been studied. MATERIALS AND METHODS: The crude ethanol extracts of S. camporum leaves and S. pohlii aerial parts (EE-SC and EE-SP) were partitioned with n-hexane, EtOAc, and n-BuOH. The EtOAc fractions were purified by preparative HPLC. The crude extracts, EtOAc fractions and pure compounds were tested against S. mansoni adult worms in vitro. RESULTS: The purification procedure resulted in the isolation of kaempferol-3-O-(2'',4''-di-O-(E)-p-coumaroyl)-ß-d-glucopyranoside (1), kaempferol-3-O-(2'',6''-di-O-(E)-p-coumaroyl)-ß-d-glucopyranoside (2), quercetin (3), and kaempferol (4). The bioassay results indicated that EE-SC, EF-SC, EF-SP, and compounds 2 and 4 are able to separate coupled S. mansoni adult worms. Additionally, EE-SC, EF-SP, and compound 4 killed the adult schistosomes in vitro at 100 µg/mL and 100 µM. DISCUSSION AND CONCLUSION: This is the first time that the presence of compounds 1-2 in S. pohlii and 3-4 in S. camporum has been reported. Additionally, biological results indicated that S. pohlii and S. camporum have great potential as a source of active compounds.