Pharmacological validation of Solanum mammosum L. as an anti-infective agent: Role of solamargine.

ETHNOPHARMACOLOGICAL RELEVANCE: Fungal and bacterial infections remain a major problem worldwide, requiring the development of effective therapeutic strategies. Solanum mammosum L. (Solanaceae) ("teta de vaca") is used in traditional medicine in Peru to treat fungal infections and respiratory disorders via topical application. However, the mechanism of action remains unknown, particularly in light of its chemical composition. MATERIALS AND METHODS: The antifungal activity of TDV was determined against Trichophyton mentagrophytes and Candida albicans using bioautography-TLC-HRMS to rapidly identify the active compounds. Then, the minimum inhibitory concentration (MIC) of the fruit crude extract and the active compound was determined to precisely evaluate the antifungal activity. Additionally, the effects of the most active compound on the formation of Pseudomonas aeruginosa biofilms and pyocyanin production were evaluated. Finally, a LC-HRMS profile and a molecular network of TDV extract were created to characterize the metabolites in the fruits' ethanolic extract. RESULTS: Bioautography-TLC-HRMS followed by isolation and confirmation of the structure of the active compound by 1D and 2D NMR allowed the identification solamargine as the main compound responsible for the anti-Trichophyton mentagrophytes (MIC = 64 µg mL-1) and anti-Candida albicans (MIC = 64 µg mL-1) activities. In addition, solamargine led to a significant reduction of about 20% of the Pseudomonas aeruginosa biofilm formation. This effect was observed at a very low concentration (1.6 µg mL-1) and remained fairly consistent regardless of the concentration. In addition, solamargine reduced pyocyanin production by about 20% at concentrations of 12.5 and 50 µg mL-1. Furthermore, the LC-HRMS profiling of TDV allowed us to annotate seven known compounds that were analyzed through a molecular network. CONCLUSIONS: Solamargine has been shown to be the most active compound against T. mentoagrophytes and C. albicans in vitro. In addition, our data show that this compound affects significantly P. aeruginosa pyocyanin production and biofilm formation in our conditions. Altogether, these results might explain the traditional use of S. mammosum fruits to treat a variety of fungal infections and respiratory disorders.

Profiling of Hura crepitans L. latex by ultra-high-performance liquid chromatography/atmospheric pressure chemical ionisation linear ion trap Orbitrap mass spectrometry.

INTRODUCTION: The phytochemistry of the latex of Hura crepitans L. (Euphorbiaceae), a widespread tree in the Amazonian forest having many uses, is little known. Only huratoxin, a daphnane diterpene orthoester, has been described despite the high pharmacological potential of this kind of compounds. Glucosphingolipids (cerebrosides) are also known to be distributed in Euphorbiaceae latexes. OBJECTIVE: To tentatively identify daphnanes diterpenes and cerebrosides in the latex of H. crepitans. METHODS: An ethanolic extract of the lyophilised latex of H. crepitans was analysed by ultra-high-performance liquid chromatography (UHPLC) coupled with positive and negative atmospheric pressure chemical ionisation high-resolution mass spectrometry (APCI-HRMS) method using a quadrupole/linear ion trap/Orbitrap (LTQ-Orbitrap). Tandem mass spectrometry (MS/MS) spectra were recorded by two different fragmentation modes: collision induced dissociation (CID) and higher-energy collisional dissociation (HCD). RESULTS: The analysis of CID- and HCD-MS/MS spectra allowed to propose fragmentation patterns for daphnane esters and cerebrosides and highlight diagnostic ions in positive and negative ion modes. A total of 34 compounds including 24 daphnane esters and 10 cerebrosides have been tentatively annotated. Among them, 17 daphnane diterpenes bearing one or two acyl chains are new compounds and the cerebrosides are described in the genus Hura for the first time. CONCLUSION: This study revealed the chemical constituents of the latex of H. crepitans and particularly its richness and chemical diversity in daphnane diterpenes, more frequently encountered in the species of Thymelaeaceae.

Antiprotozoal activity of medicinal plants used by Iquitos-Nauta road communities in Loreto (Peru).

ETHNOPHARMACOLOGICAL RELEVANCE: In the Peruvian Amazon, the use of medicinal plants is a common practice. However, there is few documented information about the practical aspects of their use and few scientific validation. The starting point for this work was a set of interviews of people living in rural communities from the Peruvian Amazon about their uses of plants. Protozoan diseases are a public health issue in the Amazonian communities, who partly cope with it by using traditional remedies. Validation of these traditional practices contributes to public health care efficiency and may help identify new antiprotozoal compounds. AIMS OF STUDY: to inventory and validate the use of medicinal plants by rural people of Loreto region. MATERIALS AND METHODS: Rural mestizos were interviewed about traditional medication of parasite infections with medicinal plants. Ethnopharmacological surveys were undertaken in two villages along Iquitos-Nauta road (Loreto region, Peru), namely 13 de Febrero and El Dorado communities. Forty-six plants were collected according to their traditional use for the treatment of parasitic diseases, 50 ethanolic extracts (different parts for some of the plants) were tested in vitro on Plasmodium falciparum (3D7 sensitive strain and W2 chloroquine resistant strain), Leishmania donovani LV9 strain and Trypanosoma brucei gambiense. Cytotoxic assessment (HUVEC cells) of the active extracts was performed. Two of the most active plants were submitted to preliminary bioguided fractionation to ascertain and explore their activities. RESULTS: From the initial plants list, 10 were found to be active on P. falciparum, 15 on L. donovani and 2 on the three parasites. The ethanolic extract from Costus curvibracteatus (Costaceae) leaves and Grias neuberthii (Lecythidaceae) bark showed strong in vitro activity on P. falciparum (sensitive and resistant strain) and L. donovani and moderate activity on T. brucei gambiense. CONCLUSIONS: The Amazonian forest communities in Peru represents a source of knowledge on the use of medicinal plants. In this work, several extracts with antiprotozoal activity were identified. This work contributes to validate some traditional uses and opens subsequent investigations on active compounds isolation and identification.

Biological activities of triterpenoids from Poraqueiba sericea stems.

Eleven compounds were isolated from Poraqueiba sericea stems and identified as niga-ichigoside-F1 (1), trachelosperoside B1 (2), 4-epi-niga-ichigoside (7), 19α-hydroxyasiatic acid (3), myrianthic acid (4), hyptatic acid (5), trachelosperogenin B (6), arjunolic acid (8), and trachelosperogenin E (9), secologanoside (10) and secoxyloganin (11). Compounds 1-11 were tested for their antileishmanial activities against Leishmania infantum promastigotes, 1-6 and 8-11 were tested for their cytotoxic activities on fibroblasts, 1-3, 5-6, 8-11 were evaluated for their anti-elastase and anti-acetylcholinesterase assays activities by a spectrophotometric method and 1-2, 5 and 7-10 were tested using bioautography for their ß-glucosidase. No antileishmanial activity was detected; compounds 1, 2 and 11 showed a moderate cytotoxic activity with IC50 17.7, 20.5 and 10.9 µg/mL, respectively; compounds 2, 8, 9 and 10 gave a percentage of inhibition ranging from 13 to 16% (at 50 µg/mL) and compounds 1 and 2 showed an inhibition zone on ß-glucosidase and anti-acetylcholinesterase assays.

Leishmanicidal compounds and potent PPARγ activators from Renealmia thyrsoidea (Ruiz & Pav.) Poepp. & Endl.

ETHNOPHARMACOLOGICAL RELEVANCE: Leaves and rhizomes of Renealmia thyrsoidea (Ruiz & Pav.) Poepp. & Endl. traditionally used in the Yanesha pharmacopoeia to treat skin infections such as leishmaniasis ulcers, or to reduce fever were chemically investigated to identify leishmanicidal compounds, as well as PPARγ activators. METHODS: Compounds were isolated through a bioassay-guided fractionation and their structures were determined via detailed spectral analysis. The viability of Leishmania amazonensis axenic amastigotes was assessed by the reduction of tetrazolium salt (MTT), the cytotoxicity on macrophage was evaluated using trypan blue dye exclusion method, while the percentage of infected macrophages was determined microscopically in the intracellular macrophage-infected assay. The CD36, mannose receptor (MR) and dectin-1 mRNA expression on human monocytes-derived macrophages was evaluated by quantitative real-time PCR. RESULTS: Six sesquiterpenes (1-6), one dihydrobenzofuranone (7) and four flavonoids (8-11) were isolated from the leaves. Alongside, two flavonoids (12-13) and five diarylheptanoids (14-18) were identified in the rhizomes. Leishmanicidal activity against Leishmania amazonensis axenic amastigotes was evaluated for all compounds. Compounds 6, 7, and 11, isolated from the leaves, showed to be the most active derivatives. Diarylheptanoids 14-18 were also screened for their ability to activate PPARγ nuclear receptor in macrophages. Compounds 17 and 18 bearing a Michael acceptor moiety strongly increased the expression of PPARγ target genes such as CD36, Dectin-1 and mannose receptor (MR), thus revealing interesting immunomodulatory properties. CONCLUSIONS: Phytochemical investigation of Renealmia thyrsoidea has led to the isolation of leishmanicidal compounds from the leaves and potent PPARγ activators from the rhizomes. These results are in agreement with the traditional uses of the different parts of Renealmia thyrsoidea.

Dihydrochalcones and benzoic acid derivatives from Piper dennisii.

Two new dihydrochalcones (1, 2), as well as eight known compounds, piperaduncin C (3), 2',6'-dihydroxy-4'-methoxydihydrochalcone (4), 4,2',6'-trihydroxy-4'-methoxydihydrochalcone (5), 4-hydroxy-3,5-bis(3-methyl-2-butenyl)-benzoic acid (6), 3,5-bis(3-methyl-2-butenyl)-4-methoxybenzoic acid (7), 4-hydroxy-3-(3-methyl-2-butenoyl)-5-(3-methyl-2-butenyl)-benzoic acid (8), 2,2-dimethyl-8-(3-methyl-2-butenyl)-2H-1-chromene-6-carboxylic acid (9), and 3-(3',7'-dimethyl-2',6'-octadienyl)-4-methoxybenzoic acid (10) were isolated from the leaves of Piper dennisii Trelease (Piperaceae), using a bioassay-guided fractionation to determine their antileishmanial potential. Among them, compound 10 exhibited the best antileishmanial activity (IC50 = 20.8 µM) against axenic amastigote forms of Leishmania amazonensis, with low cytotoxicity on murine macrophages. In the intracellular macrophage-infected model, compound 10 proved to be more active (IC50 = 4.2 µM). The chemical structures of compounds 1-10 were established based on the analysis of the spectroscopic data.