Antiparasitic activity of two Brazilian plants: Eugenia mattosii and Marlierea eugeniopsoides

Essential Oils of Aromatic Plant Species from the Atlantic Rainforest Exhibit Extensive Chemical Diversity and Antimicrobial Activity

Microbial resistance, caused by the overuse or inadequate application of antibiotics, is a worldwide crisis, increasing the risk of treatment failure and healthcare costs. Plant essential oils (EOs) consist of hydrophobic metabolites with antimicrobial activity. The antimicrobial potential of the chemical diversity of plants from the Atlantic Rainforest remains scarcely characterized. In the current work, we determined the metabolite profile of the EOs from aromatic plants from nine locations and accessed their antimicrobial and biocidal activity by agar diffusion assays, minimum inhibitory concentration, time-kill and cell-component leakage assays. The pharmacokinetic properties of the EO compounds were investigated by in silico tools. More than a hundred metabolites were identified, mainly consisting of sesqui and monoterpenes. Individual plants and botanical families exhibited extensive chemical variations in their EO composition. Probabilistic models demonstrated that qualitative and quantitative differences contribute to chemical diversity, depending on the botanical family. The EOs exhibited antimicrobial biocidal activity against pathogenic bacteria, fungi and multiple predicted pharmacological targets. Our results demonstrate the antimicrobial potential of EOs from rainforest plants, indicate novel macromolecular targets, and contribute to highlighting the chemical diversity of native species.

Exploring Antiparasitic Molecule Sources from Timber by-Product Industries-Leishmanicidal and Trypanocidal Compounds from Clathrotropis brunnea Amshoff

Through bioguided in vitro assays, the leishmanicidal and trypanocidal effects of an ethanol extract, seven fractions, and two pure substances obtained from Clathrotropis brunnea Amshoff sawdust were established. The effectiveness of the two metabolites was confirmed in a hamster model of cutaneous Leishmaniasis by Leishmania braziliensis and in Balb/c mice infected by Trypanosoma cruzi. In vitro, 3,5-dimethoxystilbene was the most active against L. braziliensis amastigotes, with a median lethal concentration (LC₅₀) of 4.18 μg/ml (17.40 μM) and a selectivity index of 3.55, but showed moderate activity for T. cruzi, with a median effective concentration (EC₅₀) value of 27.7 μg/ml (115.36 μM). Flavanone pinostrobin, meanwhile, showed high activity against L. braziliensis, with an EC₅₀ of 13.61 μg/ml (50.39 μM), as well as for T. cruzi, with an EC₅₀ of 18.2 μg/ml (67.38 μM). The animal model assay of cutaneous Leishmaniasis showed that 50% of the hamsters treated with pinostrobin were definitively cured the cutaneous ulcer, and 40% showed an improvement, with a reduction in the size of the of 84–87%. Moreover, Balb/c mice experimentally infected with T. cruzi and treated for 25 days with pinostrobin experienced a reduction in their parasitemia by 71%. These results demonstrate the high potential of C. brunnea Amshoff against cutaneous Leishmaniasis and American trypanosomiasis and indicate the pharmacological potential of waste from the wood industry, which has tons of potentially useful chemicals for the development of new medicines.

The Pharmacokinetics, Tissue Distribution, Metabolism, and Excretion of Pinostrobin in Rats: Ultra-High-Performance Liquid Chromatography Coupled With Linear Trap Quadrupole Orbitrap Mass Spectrometry Studies

Pinostrobin is a natural flavonoid found in various plants, well known for its wide range of pharmacological activities. However, there are few reports regarding the pharmacokinetics, tissue distribution, metabolism, and excretion of pinostrobin in rats after oral administration as a single compound. Therefore, we established a method using ultra-high-performance liquid chromatography coupled with linear trap quadrupole orbitrap mass spectrometry (UPLC-LTQ orbitrap-MS/MS) to determine pinostrobin and its metabolites in rat plasma, urine, feces, bile, and tissue homogenates. Pharmacokinetic parameters were measured. The large apparent volume of distribution implied that pinostrobin preferentially bound to tissues and preferably remained within the body. Based on previous pharmacological studies of its antiulcer, anti-HP, anti-inflammatory, and antioxidant activities, pinostrobin is mostly distributed in the gastrointestinal tract, indicating its potential as an effective component of traditional Chinese medicines for the treatment of peptic ulcers. Furthermore, 30 flavonoid metabolites were screened using UPLC-LTQ orbitrap-MS/MS. The metabolism pathways (mainly hydroxylation, demethylation, glucuronidation, and sulfation) of pinostrobin in rats have also been proposed. A small amount of pinostrobin in its parent form is excreted through the urine, feces, and bile, indicating that it is mainly metabolized in vivo. In this study, we systemically investigated the pharmacokinetics, tissue distribution, metabolism, and excretion of pinostrobin in rats. Our results provide a significant basis for the clinical development and application of pinostrobin as well as traditional Chinese medicines containing pinostrobin.