Cytotoxicity and antibacterial studies of iridoids and phenolic compounds isolated from the latex of Himatanthus sucuuba

The latex of Himatanthus sucuuba (Spruce) Woodson, used popularly in the Amazon for the treatment of tumors, gastritis, inflammations and infections, was evaluated for cytotoxicity and antibacterial activities. The iridoid lactones, plumericin and isoplumericin were isolated from latex by bioassay fractionation and were found to be associated with DNA damage. Gallic acid exhibited the highest antimicrobial activity among the phenolic compounds isolated from the aqueous fraction. The compounds associated to cytotoxicity and antimicrobial activities could be responsible to the effects of this species used in traditional medicine.Key words: Himatanthus sucuuba, iridoids, phenolics, cytotoxicity, antibacterial

Evaluation of Antiplasmodial activity of extracts and constituents from Ampelozizyphus amazonicus

PMID: 26664012 WOS: 000362879000003BACKGROUND: Ampelozizyphus amazonicus Ducke, a plant that is widely used by the population of the Amazonian region to prevent and treat malaria, was investigated in this work, which describes, for the first time, the antiplasmodial activity of its extracts and associates this activity with its isolated constituents. METHODS: Different extracts with solvents of increasing polarity (hexane, chloroform, ethanol, and water) were obtained of the root bark. This procedure resulted in extracts that were characterized for their constituents. The cytotoxicity and activity of the extracts against Plasmodium berghei (schizontocidal activity, liver stage) and Plasmodium falciparum (3D7 and Dd2 strains, erythrocyte stage) were assessed in vitro. RESULTS: Of the four extracts assayed against P. berghei, the chloroform extract showed the greatest activity, with an inhibitory concentration 50% (IC50) value of 30.1 µg/mL, followed by the aqueous extract (IC50 = 39.9 µg/mL). The chloroform extract exhibited the highest antiplasmodial activity in the erythrocyte stage of P. falciparum, with an IC50 value lower than 15 µg/mL. Fractionation of this more active extract led to the isolation and elucidation of pentacyclic triterpenes, lupeol, betulin and betulinic acid, which showed antiplasmodial activities with IC50 values ranging from 5.6 to 80.30 µM. The most active of these, betulinic acid, was further quantified in the extracts by high-performance liquid chromatography-photodiode array detector analyzes. The higher amount was found in the chloroform extract, which was the most active one against P. falciparum. CONCLUSION: The results obtained in this work may partly explain the popular intake of A. amazonicusas an antimalarial remedy in the Amazon region.publishersversionpublishe

Analysis of bond strength between a nylon reinforcement structure and dental resins

Nylon is a polymer that its use to reinforce dental resins has shown positive results such as increased flexural strength. The aim of this study was to evaluate the bond strength between dental resins and a nylon reinforcement. Forty cylindrical nylon

LC‐HRMS for the Identification of β‐Carboline and Canthinone Alkaloids Isolated from Natural Sources

β-carboline and canthinone alkaloids are widely distributed in the Angiosperms. Due to their diverse biological activities, the structures of these alkaloids have been used as important models for the synthesis of novel therapeutic drugs. Combining high-performance liquid chromatography (HPLC) with high-resolution mass spectrometry (HRMS) has provided a valuable tool in the analysis of these alkaloids in, for example, plants, insects, marine creatures, human tissues and body fluids. In this review, we summarized the main β-carboline and canthinone alkaloids studied by liquid chromatography high-resolution mass spectrometry (LC-HRMS) associated with mass analyzers, molecular weight information, mass fragmentation and biological activities, presenting an overview of increasing interest for carboline alkaloids study by LC-HRMS

Alpinia

Species of the genus Alpinia are widely used by the population and have many described biological activities, including activity against insects. In this paper, we describe the bioactivity of the essential oil of two species of Alpinia genus, A. zerumbet and A. vittata, against Rhodnius nasutus, a vector of Chagas disease. The essential oils of these two species were obtained by hydrodistillation and analyzed by GC-MS. The main constituent of A. zerumbet essential oil (OLALPZER) was terpinen-4-ol, which represented 19.7% of the total components identified. In the essential oil of A. vittata (OLALPVIT) the monoterpene β-pinene (35.3%) was the main constituent. The essential oils and their main constituents were topically applied on R. nasutus fifth-instar nymphs. In the first 10 min of application, OLALPVIT and OLALPZER at 125 μg/mL provoked 73.3% and 83.3% of mortality, respectively. Terpinen-4-ol at 25 μg/mL and β-pinene at 44 μg/mL provoked 100% of mortality. The monitoring of resistant insects showed that both essential oils exhibited antifeedant activity. These results suggest the potential use of A. zerumbet and A. vittata essential oils and their major constituents to control R. nasutus population

Natural Products: Insights into Leishmaniasis Inflammatory Response

Leishmaniasis is a vector-borne disease that affects several populations worldwide, against which there are no vaccines available and the chemotherapy is highly toxic. Depending on the species causing the infection, the disease is characterized by commitment of tissues, including the skin, mucous membranes, and internal organs. Despite the relevance of host inflammatory mediators on parasite burden control, Leishmania and host immune cells interaction may generate an exacerbated proinflammatory response that plays an important role in the development of leishmaniasis clinical manifestations. Plant-derived natural products have been recognized as bioactive agents with several properties, including anti-protozoal and anti-inflammatory activities. The present review focuses on the antileishmanial activity of plant-derived natural products that are able to modulate the inflammatory response in vitro and in vivo. The capability of crude extracts and some isolated substances in promoting an anti-inflammatory response during Leishmania infection may be used as part of an effective strategy to fight the disease