Antibacterial Activity from Momordica charantia L. Leaves and Flavones Enriched Phase.

Momordica charantia L. (Cucurbitaceae) is a plant known in Brazil as "melão de São Caetano", which has been related to many therapeutic applications in folk medicine. Herein, we describe antibacterial activities and related metabolites for an extract and fractions obtained from the leaves of that species. An ethanolic extract and its three fractions were used to perform in vitro antibacterial assays. In addition, liquid chromatography coupled to mass spectrometry and the molecular networking approach were used for the metabolite annotation process. Overall, 25 compounds were annotated in the ethanolic extract from M. charantia leaves, including flavones, terpenes, organic acids, and inositol pyrophosphate derivatives. The ethanolic extract exhibited low activity against Proteus mirabilis (MIC 312.5 µg·mL-1) and Klebsiella pneumoniae (MIC 625 µg·mL-1). The ethyl acetate phase showed interesting antibacterial activity (MIC 156.2 µg·mL-1) against Klebsiella pneumoniae, and it was well justified by the high content of glycosylated flavones. Therefore, based on the ethyl acetate phase antibacterial result, we suggest that M. charantia leaves could be considered as an alternative antibacterial source against K. pneumoniae and can serve as a pillar for future studies as well as pharmacological application against the bacteria.

Identification of potential inhibitors of Schistosoma mansoni purine nucleoside phosphorylase from neolignan compounds using molecular modelling approaches.

Schistosomiasis is a parasitic disease that is part of the neglected tropical diseases (NTDs), which cause significant levels of morbidity and mortality in millions of people throughout the world. The enzyme purine nucleoside phosphorylase from Schistosoma mansoni (SmPNP) represents a potential target for discovering new agents, and neolignans stand out as an important class of compounds. In this work, molecular modeling studies and biological assays of a set of neolignans were conducted against the PNP enzymes of the parasite and the human homologue (HssPNP). The results of the molecular docking described that the neolignans showed good complementarity by the active site of SmPNP. Molecular dynamics (MD) studies revealed that both complexes (Sm/HssPNP - neolignan compounds) were stable by analyzing the root mean square deviation (RMSD) values, and the binding free energy values suggest that the selected structures can interact and inhibit the catalytic activity of the SmPNP. Finally, the biological assay indicated that the selected neolignans presented a better molecular profile of inhibition compared to the human enzyme, as these ligands did not have the capacity to inhibit enzymatic activity, indicating that these compounds are promising candidates and that they can be used in future research in chemotherapy for schistosomiasis.Communicated by Ramaswamy H. Sarma.

Chemical Composition and In Vitro Antioxidant, Cytotoxic, Antimicrobial, and Larvicidal Activities of the Essential Oil of Mentha piperita L. (Lamiaceae).

The essential oil was obtained by hydrodistillation and the identification and quantification of components were achieved with the use of GC-MS analysis. The antioxidant activity was evaluated by the method of sequestration of DPPH. Essential oils were used for study the cytotoxic front larvae of Artemia salina. In the evaluation of the antimicrobial activity of essential oils, we employed the disk-diffusion method. The potential larvicide in mosquito larvae of the third stage of development of Aedes aegypti to different concentrations of essential oils was evaluated. The major compounds found in the essential oils of M. piperita were linalool (51.8%) and epoxyocimene (19.3%). The percentage of antioxidant activity was 79.9 ± 1.6%. The essential oil showed LC50 = 414.6 µg/mL front of A. saline and is considered highly toxic. It shows sensitivity and halos significant inhibition against E. coli. The essential possessed partial larvicidal efficiency against A. aegypti.

Chemical Composition, an Antioxidant, Cytotoxic and Microbiological Activity of the Essential Oil from the Leaves of Aeollanthus suaveolens Mart. ex Spreng.

Aeollanthus suaveolens species popularly known as catinga de mulata belongs to the Lamiaceae family. In the Amazon region, it is used in folk medicine for the treatment of gastritis, convulsions of epileptic origin, stomach pain and diarrhea in the form of tea and juice. Essential oils have analgesic, anti-inflammatory, and antimicrobial activity. This study evaluated the chemical composition of the A. suaveolens essential oil, and its cytotoxic, antimicrobial and antioxidant activity on Artemia salina Leach. The plant species was collected in Fazendinha district in the city of Macapa-AP. The essential oil obtained from the process was performed by hydrodistillation and identification of components by gas chromatography coupled with mass spectrometer. The antioxidant activity was evaluated by the kidnapping method of 2,2- diphenyl -1-picrilhidrazil radical, while the cytotoxic activity was assessed using saline A. and the microbiological activity was carried out by microdilution method with Escherichia coli, Salmonella sp. and Staphylococcus aureus bacteria. In a chromatographic analysis, the major constituents found in the essential oil of A. suaveolens were (E) -ß-farnesene (37.615%), Linalool (33.375%), α-Santalene (3.255%) and linalyl acetate (3.222%). The results showed that the Escherichia coli and Salmonella sp. bacteria were more susceptible to MIC 50 mg.mL-1 when compared with the Staphylococcus aureus bacterium MIC 100 mg.mL-1. With respect to MBC concentration of 100 mg.mL-1 it was sufficient to inhibit the growth of E. coli. The essential oil did not show antioxidant activity, however, has a high cytotoxic activity against the A. salina, LC50 8.90 µg.mL-1.

DDT concentration in fish from the Tapajós River in the Amazon region, Brazil.

DDT and metabolites were measured in six species of fish collected from the Tapajós River in the village of Barreiras, near the town of Itaituba in the Brazilian Amazon region. The selected fish were the most consumed and economically important to the local people. DDT was used frequently in this region for malaria control. Fish samples were analyzed after extraction by microwave-assisted extraction in hexane/acetone (8:2, v/v) by gas chromatography with electron capture detector. Residues of op'-DDT and pp'-DDT and metabolites were detected, including pp'-DDE, pp'-DDD, op'-DDT, and op'-DDE, in 98% of the samples, with a greater abundance of pp'-DDT. Total DDT levels were 7.1-249.5 ng g(-1) wet weight (w.w). The DDE/DDT ratio was low, indicating recent exposure to DDT. The study area that may be related to generated waste used in public health campaigns to combat mosquitos (Anopheles spp.), still present in the Amazon environment, that transmit malaria. DDT levels and metabolites found in fish species do not present risks to human health because they are below acceptable limits for consumption.

Acaricide activity of different extracts from Piper tuberculatum fruits against Rhipicephalus microplus.

Rhipicephalus microplus is the main tick that affects cattle. Plant bioactive molecules can be used to control this ectoparasite. The aim of this study was to evaluate the in vitro efficacy of Piper tuberculatum fruit extracts obtained with different solvents on R. microplus larvae and engorged females. Hexane, ethyl ether, ethanolic, and methanolic extracts of P. tuberculatum fruits were evaluated. After extraction, all of the extracts were dried. Adult immersion tests and larval packet tests were performed with five different concentrations of each of the extracts. The hexane extracts of P. tuberculatum showed the highest larvicidal activity against R. microplus (lethal concentration (LC50 = 0.04 mg/mL), followed by the ethyl ether (LC50 = 0.08 mg/mL), ethanolic (LC50 = 2.73 mg/mL), and methanolic (LC50 = 4.49 mg/mL) extracts. The P. tuberculatum fruit extracts were also effective against R. microplus-engorged females. Ethyl acetate extracts showed the highest efficiency (LC50 = 18.4 mg/mL), followed by the methanolic (LC50 = 105.6 mg/mL), ethanolic (LC50 = 140.0 mg/mL), and hexane (LC50 = 297.4 mg/mL) extracts. All of the extracts showed similar chromatographic profiles containing 24% piperine. The P. tuberculatum fruit extracts contain bioactive compounds with great potential to improve the standard formulations of acaricides for the control of R. microplus.

A dehydrorotenoid produced by callus tissue culture and wild plant roots of Boerhaavia coccinea

Calli cultures were established from leaves and stem of B. coccinea plantlet produced in vitro and analysed for isoflavonoid content. The quantification of 6,9,11-trihydroxy-6a,12a-dehydrorotenoid isolated from the roots of Boerhaavia coccinea P. Miller collected from its natural environment, and the same metabolite produced in callus tissue culture of the same plant are described in this paper. The rotinary quantitative HPLC analysis indicated that callus culture produced the same isoflavonoid compound found in the roots of intact wild growing plant. The amount of the secondary metabolite produced in vitro was 955.35 µg/g of dry cell weight, 2.5 times more than the highest amount concentration produced by the wild growing plant in its natural environment.

Cultura de calos foram estabelecidos de folhas e galhos finos de plântula de B. coccinea produzida in vitro e analisada para isoflavonóide. A quantificação do 6,9,11-triidroxi-6a,12a-desidro-rotenóide isolado das raízes de B. coccinea P Miller, coletada em seu habitat natural, e do mesmo rotenóide produzido na cultura de células estão descritos neste artigo. A análise rotineira em CLAE mostrou que a cultura de calos produziu o mesmo isoflavonóide encontrado nas raízes da planta do campo. A quantidade do metabólito secundário produzido in vitro foi de 955.35 µg/g de massa seca de callus, atingindo uma concentração de 2,5 vezes maior do que a quantidade do metabólito produzido pela planta em seu meio ambiente natural.