Antiplasmodial and cytotoxic effects of the methanol extract, canthinone alkaloids, squalene- and protolimonoid-type triterpenes from Homalolepis suffruticosa roots.

ETHNOPHARMACOLOGICAL RELEVANCE: Different species of the Simaroubaceae family are used in traditional medicine to treat malaria. Among these is Homalolepis suffruticosa (syn. Simaba suffruticosa and Quassia suffruticosa), which is native to Central Brazil and popularly known as calunga. However, there is a lack of investigation concerning its antimalarial effects. AIM OF THE STUDY: To investigate the antiplasmodial and cytotoxic effects of the isolated metabolites and methanol extract from H. suffruticosa roots as well as to conduct the dereplication of this extract aiming to characterize its metabolic profile by UPLC-DAD-ESI-MS/MS. MATERIALS AND METHODS: Methanol extract of the H. suffruticosa roots and six isolated compounds were evaluated against chloroquine-resistant Plasmodium falciparum W2 strain by the PfLDH method and cytotoxicity in HepG2 cells by the MTT assay. Dereplication of the extract was performed by UPLC-DAD-ESI-MS/MS. RESULTS: The six isolated compounds disclosed high to moderate antiplasmodial activity (IC50 0.0548 ± 0.0083 µg/mL to 26.65 ± 2.40 µg/mL) and cytotoxicity was in the range of CC50 0.62 ± 0.33 µg/mL to 56.43 ± 2.54 µg/mL, while 5-metoxycantin-6-one proved to be the most potent constituent of the six assayed ones. The methanol extract of the roots showed high in vitro antiplasmodial activity (IC50 1.88 ± 0.56 µg/mL), moderate cytotoxicity (CC50 41.93 ± 2.30 µg/mL), and good selectivity index (SI = 22.30). Finally, C20 quassinoids and canthin-6-one alkaloids were putatively identified in the H. suffruticosa methanol extract by LC-MS. CONCLUSIONS: Taken together, the isolated compounds, mainly the 5-metoxycantin-6-one and the methanol extract from H. suffruticosa roots, disclose good antiplasmodial activity, supporting the ethnopharmacological history of the Simaroubaceae species as traditional antimalarial drugs.

In vitro antiplasmodial activity, targeted LC-MS metabolite profiling, and identification of major natural products in the bioactive extracts of Palicourea and Psychotria species from the Amazonia and Atlantic Forest biomes, Brazil.

INTRODUCTION: A great variety of bioactive natural products has been reported for different Palicourea and Psychotria species (Rubiaceae). However, few of them as well as few of species of these botanical genera have been evaluated for antiplasmodial activity. OBJECTIVE: To assess the antiplasmodial activity of 24 extracts from Palicourea and Psychotria genera, along with the targeted LC-MS metabolite profiling, as well as identification of the main metabolites in the bioactive extracts. METHODS: Twenty four ethanol and acid-base extracts from Palicourea and Psychotria genera collected in the Amazonia and Atlantic Forest, Brazil, were evaluated against chloroquine-resistant Plasmodium falciparum W2 strain by PfLDH. The metabolite profiling and putative identification of metabolites from bioactive extracts were determined by LC-DAD-ESI-MS and LC-HRMS, respectively. RESULTS: The ethanol extracts disclosed low antiplasmodial activity (% GI < 50%). High antiplasmodial effect was observed for the acid-base extracts from Psychotria apoda and Psychotria colorata with 100% inhibition of parasite growth inhibition. Fragment ions related to pyrrolidinoindoline alkaloids were observed by LC-DAD-ESI-MS mainly in the most bioactive extracts. The results of the in vitro screening associated with the LC-DAD-ESI-MS and LC-HRMSn data allowed to predict, for the first time, the pyrrolidinoindoline alkaloids as possible antiplasmodial representing, then, new potential natural antimalarial hits. In addition, other metabolite classes such as flavanones, lignans and chalcones were also putatively identified in the bioactive extracts of Psychotria apoda, Psychotria capitata, and Psychotria poeppigiana. CONCLUSION: The present results point to Palicourea and Psychotria species as sources of new antimalarial hits.

Bioprospection for antiplasmodial activity, and identification of bioactive metabolites of native plants species from the Mata Atlântica biome, Brazil.

A total of 33 extracts of eleven different plants species from Mata Atlântica biome, Brazil, and different fractions of the bioactive extracts were evaluated against chloroquine-resistant Plasmodium falciparum W2 strain by PfLDH method and cytotoxicity to HepG2 cells by the MTT assay, and chemically characterized by LC-DAD-ESI-MS/MS analysis. The results allowed the identification of Alchornea glandulosa, Miconia latecrenata, and Psychotria suterella as the most active plant species. Different flavonoids and tannins in Alchornea glandulosa and Miconia latecrenata besides alkaloids in Psychotria suterella were identified. Bioguided fractionation of A. glandulosa and M. latecrenata leaves extracts led to fractions exhibiting high parasite growth inhibition. Seven known alkaloids were identified in the P. suterella extract, and of these, only 5-carboxystrictosidine had been assayed for antiplasmodial activity what points to this species as the most promising among the eleven one assayed.

Himatanthus bracteatus stem extracts present anti-flavivirus activity while an isolated sesquiterpene glucoside present only anti-Zika virus activity in vitro.

The hexane and ethanol extracts from Himatanthus bracteatus (Apocynaceae) stems were evaluated for antiviral activity against Zika virus, yellow fever virus and dengue virus 2 and for cytotoxicity in Vero cells by MTT assay. The ethanol extract showed good antiviral activity against the three viruses with selective indexes (SI) > 10 and its fractionation led to the isolation of the known plumieride that was active only against Zika virus (SI of 15.97).

Antibacterial screening of plants from the Brazilian Atlantic Forest led to the identification of active compounds in Miconia latecrenata (DC.) Naudin.

Antibiotic resistance is a serious global threat to public health. This has promoted the research for new drug targets, and the use of other approaches, such as antimicrobial combined therapy. The present study evaluated the antibacterial activity of 88 extracts from Brazilian Atlantic Forest trees. The organic extract from leaves of Miconia latecrenata (EMl) was the most promising for inhibiting the growth of Staphylococcus aureus (0.3 mg/mL) and Pseudomonas aeruginosa (2.5 mg/mL). After the bioguided fractionation of EMl and metabolite profiling performed by UPLC-DAD-MS/MS, the ethyl acetate (AFMl) and aqueous (WFMl) fractions showed a mixture of phenolic compounds derived from ellagic acid and quercetin. The MIC value of AFMl was two-times lower than EMl for P. aeruginosa, suggesting that these phenolic compounds can perform bioactivity. Furthermore, EMI and AFMl showed synergism with ampicillin and tetracycline for S. aureus and P. aeruginosa, respectively. These findings suggest that extract and fractions of the Miconia latecrenata leaves can be used as therapeutic antibacterial agents.

Assessment of the phenolic content, mutagenicity and genotoxicity of ethanolic extracts of stem bark and leaves from Strychnos pseudoquina A. St.-hil.

Strychnos pseudoquina is a plant species whose stem bark is used as bitter tonic beverage. The phytochemical analysis, as well as quantification of phenolic constituents and antioxidant activity of ethanolic extracts from S. pseudoquina stem bark, and leaves were conducted. The extracts were tested for mutagenicity (Ames test) and DNA-damaging activity (Plasmid Cleavage test). Leaves recorded the largest amount of flavonoids. The performed high-performance liquid chromatography (HPLC) showed flavonoids such as isorhamnetin and strychnobiflavone (phytochemical markers of the investigated species) in stem barks, but not in leaves. The proanthocyanidin content and antioxidant activity were significantly higher in stem barks than in leaves. Stem bark and leaf extracts presented mutagenic activity against TA98 and TA100 strains with, and without, metabolic activation (S9). The Plasmid Cleavage test did not indicate DNA-damaging activity. Our results suggest that extracts deriving from S. pseudoquina should be used with extreme caution, mainly the stem bark extract, which is widely used in folk medicine.

Phytochemistry and antiplasmodial activity of Xylopia sericea leaves.

Aiming to investigate the antiplasmodial activity and the phytochemical composition of Xylopia sericea leaves, the essential oil and dichloromethane extract were analyzed by gas and liquid chromatography, respectively, both of them coupled to mass spectrometry, and were evaluated against the chloroquine-resistant Plasmodium falciparum strain (W2) and for cytotoxicity to HepG2 cells. Low growth inhibition of P. falciparum as well as low cytotoxicity to HepG2 cells were observed for the essential oil. The leaves dichloromethane extract showed moderate growth inhibition of P. falciparum and low cytotoxicity to HepG2 cells. Bioguided chromatographic fractionation of this extract led to fractions with increased antiplasmodial activity from which liriodenine (IC50 6.1 ± 0.1 µg/mL, CC50 > 1000.0 µg/mL, SI > 164), an aporphine alkaloid, and an acetogenin-rich fraction containing mainly isomers of annomontacin and 4-deoxy-annomontacin (IC50 22.7 ± 1.9 µg/mL, CC50 336.1 ± 15.5 µg/mL, SI = 15) might be highlighted for their antiplasmodial activity.

Antioxidant study indicative of antibacterial and antimutagenic activities of an ellagitannin-rich aqueous extract from the leaves of Miconia latecrenata.

Ethnopharmacological relevance; Several plant species of Miconia genus are commonly used in Brazilian folk medicine as anti-inflammatory agents and for the treatment of infectious diseases. Infusions and extracts of Miconia species are also reported as analgesic, antimicrobial, antimalarial, antioxidant, anti-inflammatory, antinociceptive, antimutagenic, and antitumoral. Aim of the study; To determine the phytochemical composition of an aqueous extract of Miconia latecrenata leaves and to evaluate its antioxidant, antibacterial, antimutagenic and antigenotoxic activities. Materials and Methods; The following methods were used for the different effects: I) antioxidant - ß-carotene/linoleic acid, lipid peroxidation, and DPPH• radical scavenging; II) antibacterial - agar well diffusion and MIC methods); III) antimutagenic assays - Ames Test; and IV) antigenotoxic - Plasmid cleavage test. The phytochemical analysis and phenolic quantification were carried out by UPLC-DAD-ESI-MS/MS and colorimetry, respectively. In addition, statistical correlation analysis was performed aiming to evaluate the Pearson correlation between phenolic compounds and biological assays. Results; A high content of tannins was observed and the ellagitannin isomers of 1,2,3,5-tris-galloyl-4,6-HHDP-glucose were identified as the main constituents of the leaves aqueous extract. High antioxidant effect, in different tests, high antibacterial activity to gram-positive and negative strains, as well as high antimutagenic activity were observed. Statistical analysis showed a high Pearson correlation for the tannin content in relation to the results of the antioxidant and antibacterial tests. In general, the antioxidant action of the aqueous extract showed low correlation with the antimutagenic activity. Conclusions; The present results confirmed the expectations regarding the pharmacological profile of M. latecrenata supporting its therapeutic potential in relation to ROS/RNS related disorders. Furthermore, the phenolic compounds of M. latecrenata can act, in turn, minimizing or inhibiting the biological macromolecules damage, especially DNA.

Antiplasmodial activity and cytotoxicity, isolation of active alkaloids, and dereplication of Xylopia sericea leaves ethanol extract by UPLC-DAD-ESI-MS/MS.

OBJECTIVES: To assess the antiplasmodial activity of the ethanol extract of Xylopia sericea leaves, Annonaceae, often associated with antimalarial use and to perform a bioguided isolation of active compounds. METHODS: Dereplication of ethanol extract by the UPLC-DAD-ESI-MS/MS technique allowed the identification of the major constituents, isolation and identification of alkaloids. The antiplasmodial and cytotoxic activity of the extract, fractions and isolated compounds was evaluated against the chloroquine-resistant W2 strain Plasmodium falciparum and HepG2 cells, respectively. KEY FINDINGS: Ethanol extract showed high reduction of parasitemia as well as moderate cytotoxicity (86.5 ± 3.0% growth inhibition at 50 µg/ml and CC50 72.1 ± 5.1 µg/ml, respectively). A total of eight flavonoids were identified, and two aporphine alkaloids, anonaine and O-methylmoschatoline, were isolated. Anonaine disclosed significant antiplasmodial effect and moderate cytotoxicity (IC50 23.2 ± 2.7 µg/ml, CC50 38.3 ± 2.3 µg/ml, SI 1.6) while O-methylmoschatoline was not active against P. falciparum and showed a low cytotoxicity (33.5 ± 1.9% growth inhibition at 50 µg/ml, CC50 274.4 ± 0.5 µg/ml). CONCLUSIONS: Characterization of Xylopia sericea leaves ethanol extract by UPLC-DAD-ESI-MS/MS as well as its antiplasmodial activity and the occurrence of anonaine and O-methylmoschatoline in this Xylopia species are reported by the first time.

Phytochemical characterization and antioxidant, antibacterial and antimutagenic activities of aqueous extract from leaves of Alchornea glandulosa.

Plant extracts exist as a complex matrix which serves as a source of numerous bioactive metabolites. The ultra performance liquid chromatography with diode-array detection-coupled electrospray ionization-mass spectrometry/mass spectrometry technique was used to characterize the aqueous extract from leaves of Alchornea glandulosa (EAG), a species popularly used to treat gastrointestinal problems as an antiulcer agent. Quantification of phenolic derivatives was determined using Folin-Ciocalteu and aluminum trichloride (AlCl3) methods. In addition, antioxidant (2,2-diphenyl-1-picrylhydrazyl [DPPH•] radical scavenging, ß-carotene-linoleic acid, and lipid peroxidation), antibacterial (agar well diffusion method and minimum inhibitory concentration), antimutagenic (Ames test), and antigenotoxic (plasmid cleavage) assays were also performed on this plant extract. The ellagitannin tris-galloyl-hexahydroxydiphenic acid-glucose was identified as the predominant compound along with tannins as majority metabolites. EAG showed high antioxidant activity accompanied by moderate antibacterial activity against Staphylococcus aureus. The highest antimutagenic activity was observed for TA97 strain without metabolic activation (S9) and with metabolic activation, TA100 and TA102 were completely inhibited. In addition, EAG exhibited potential signs of antigenotoxic action. The high antioxidant and antimutagenic activity observed for EAG suggests important therapeutic uses that still need to be verified in future studies.

Identification of phenolic compounds and biologically related activities from Ocotea odorifera aqueous extract leaves.

Ocotea odorifera (Vell.) Rohwer is popularly used as food and flavoring. The aim of this study was to determine the chemical composition of the aqueous extract from O. odorifera leaves and evaluate the correlation of their phytochemical composition and biological activities. The antioxidant effect was determined by DPPH radical scavenging, ß-carotene-linoleic acid and lipid peroxidation assays; the antibacterial activity was evaluated by the hole plate and MIC techniques and the antimutagenic activity was evaluated by the Ames test. Identification of phytochemicals was performed by LC-ESI/MS and the correlation between the phytochemical composition of the extract and the evaluated activities. The results allowed the identification of 13 phenolic compounds in the extract that exhibited high antioxidant activity and moderate antibacterial and antimutagenic action. Statistical analyses showed correlation of the total phenolic content with biologically related activities. The phytochemical analyses, together with the biological results, support the popular use of O. odorifera.

Avaliação do potencial genotóxico de extratos etanólicos de cascas e folhas de Bathysa cuspidata (A. St-Hil) Hook / Evaluation of the genotoxic potential of ethanolic extracts of stem bark and leaves of Bathysa cuspidata (A. St-Hil) Hook

Bathysa cuspidata (A.St.-Hil.) Hook. is a native tree of the Brazilian Atlantic Forest biome, widely used in Brazilian herbal medicine. Despite its widespread use, there is no report as yet regarding the toxicology of this plant. In this study, the mutagenic and genotoxic effects of ethanolic extracts of B. cuspidata stem bark (SBC) and leaves (LBC) were assessed. The mutagenicity of the extracts was estimated by performing the Ames test on strains TA98 and TA100 of Salmonella typhimurium, in the absence and presence of metabolic activation. The direct action of the extracts on DNA was assessed through plasmid treatment. Phytochemical screening was conducted to compare the secondary metabolite composition of the extracts. No mutagenic activity was found in LBC when tested on strain TA98 or TA100, without or with metabolic activation. However, SBC did show mutagenic activity. Plasmid tests did not indicate genotoxic action for either SBC or LBC. Differences in the composition of secondary metabolites present in the bark and leaves, detected by phytochemical analysis, appear to be a deciding factor in differences in mutagenicity between SBC and LBC. The findings in this study suggest caution in the use of B. cuspidata bark.

Bathysa cuspidata (A.St.-Hil.) Hook. é uma árvore nativa do bioma Mata Atlântica largamente utilizada na medicina popular brasileira. Apesar do amplo uso, ainda não existe relato sobre a toxicologia dos compostos obtidos dessa espécie vegetal. O presente estudo avaliou efeitos mutagênicos e genotóxicos de extratos etanólicos de B. cuspidata obtidos das cascas do caule (SBC) e das folhas (LBC). A mutagenicidade dos extratos foi avaliada utilizando o teste de Ames nas linhagens TA98 e TA100 de Salmonella typhimurium, na ausência e presença de ativação metabólica. Os efeitos dos extratos diretamente sobre o DNA foram avaliados por clivagem plasmidial. Análises fitoquímicas foram realizadas para comparar a composição de metabólitos secundários dos extratos. Não foi encontrada atividade mutagênica para LBC quando avaliados utilizando as cepas TA98 e TA100, sem ou com ativação metabólica. No entanto, SBC apresentou atividade mutagênica. Clivagem plasmidial não indicou ação genotóxica tanto para SBC quanto para LBC. Diferenças na composição dos metabólitos secundários presentes nos cascas e folhas, detectadas pelas análises fitoquímicas, devem ser determinantes para a variação do efeito mutagênico entre SBC e LBC. Os resultados sugerem cautela no emprego de cascas de B. cuspidata.

The mutagenic, DNA-damaging and antioxidative properties of bark and leaf extracts from Coutarea hexandra (Jacq.) K. Schum.

Coutarea hexandra is a species commonly known in Brazil as quina, and its bark is used in folk medicine. In this study, we assess the mutagenic and DNA-damaging effects of ethanol extracts from C. hexandra stem bark (SCH) and leaves (LCH) by employing the Ames test on the TA98 and TA100 strains of Salmonella typhimurium in addition to a plasmid treatment test. Furthermore, we performed a phytochemical analysis by TLC and HPLC, a quantification of the phenolic constituents and an assessment of the antioxidative activity. SCH and LCH showed mutagenic action in the Ames test for TA98 strains after metabolic activation. LCH also showed mutagenicity for the TA100 strain after metabolic activation. The findings from the plasmid treatment test did not indicate any DNA-damaging activity for either of the extracts with the tested dosages. SCH showed greater flavonoid content and greater antioxidative potential in relation to LCH. This study suggests that caution is advisable in the use of this plant. However, in vivo studies should be conducted to confirm these data.