Anti-Leishmania effect of icetexanes from Salvia procurrens.

BACKGROUND AND PURPOSE: Leishmaniasis is a globally prevalent vector-borne disease caused by parasites of the genus Leishmania. The available chemotherapeutic drugs present problems related to efficacy, emergence of parasite resistance, toxicity and high cost, justifying the search for new drugs. Several classes of compounds have demonstrated activity against Leishmania, including icetexane-type diterpenes, previously isolated from Salvia and other Lamiaceae genera. Thus, in this study, compounds of Salvia procurrens were investigated for their leishmanicidal and immunomodulatory activities. METHODS: The exudate of S. procurrens was obtained by rapidly dipping the aerial parts in dichloromethane. The compounds were isolated by column and centrifugal planar chromatography over silica gel. The effects on L. amazonensis growth, survival, membrane integrity, reactive oxygen species (ROS) generation, mitochondrial membrane potential and cytotoxicity of the compounds towards human erythrocytes, peripheral blood mononuclear cells and macrophages were evaluated. The effects on intracellular amastigote forms, nitric oxide (NO) and TNF-α production were also investigated. RESULTS: The exudate from the leaves afforded the novel icetexane 7-hydroxyfruticulin A (1) as well as the known demethylisofruticulin A (2), fruticulin A (3) and demethylfruticulin A (4). The compounds (1-4) were tested against promastigotes of L. amazonensis and showed an effective inhibition of the parasite survival (IC50 = 4.08-16.26 µM). In addition, they also induced mitochondrial ROS production, plasma membrane permeability and mitochondrial dysfunction in treated parasites, and presented low cytotoxicity against macrophages. Furthermore, all diterpenes tested reduced the number of parasites inside macrophages, by mechanisms involving TNF-α, NO and ROS. CONCLUSION: The results suggest the potential of 7-hydroxyfruticulin A (1) as well as the known demethylisofruticulin A (2),fruticulin A (3) and demethylfruticulin A (4) as candidates for use in further studies on the design of anti-leishmanial drugs.

Antimicrobial activity of dimeric acylphloroglucinols isolated from southern Brazilian Hypericum species against to resistant bacterial.

The hexanic extracts of Hypericum austrobrasiliense, H. caprifoliatum, H. denudatum, H. pedersenii and H. polyanthemum, and three isolated dimeric acylphloroglucinols (uliginosin B, japonicine A and hyperbrasilol B) were assayed for their antimicrobial activity against some Gram-positive and Gram-negative bacteria (including resistant strains). These extracts were assayed using the disc diffusion test, and the results indicated that the tested species did non exhibit activity on the Gram-negative strains. Subsequently, the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were measured using the broth dilution technique adopted to macrodillution. The most susceptible strains were the MRSA and the S. aureus MLSb. Regarding these pathogens, the better MIC values were obtained with the extracts from H. austrobrasiliense, H. caprifoliatum and H. pedersenii. The acylphloroglucinols uliginosin B and hyperbrasilol B presented the lowest MIC values against Enterococcus faecalis, Staphylococcus aureus, MRSA and S. aureus MLSb resistance.

Phloroglucinol derivatives from Hypericum species induce in vitro proliferation of cells involved in the wound healing process.

The genus Hypericum (Hypericaceae) is a recognized source of therapeutic agents, being some species widely used due to their wound healing properties. In a previous study, south Brazilian species H. caprifoliatum, H. carinatum, H. connatum, H. myrianthum and H. polyanthemum demonstrated potential to induce proliferation of keratinocytes. In the present study, the effect of phloroglucinol derivatives isolated from Hypericum on cell proliferation of human keratinocytes, fibroblasts and stem cells was investigated. The best results, determined by the MTT assay, were achieved with cariphenone B at concentrations of 0.01 and 0.1 µM (122.3% and 114%, respectively) on HaCaT cells. Uliginosin B was able to induce the proliferation of mesenchymal stem cells (129% at 10 µM) and MRC5 fibroblasts (152.5% at 5 µM). These findings confirm the capacity of phloroglucinol derivatives to induce the in vitro cellular proliferation and reinforce the importance of Hypericum species as potential sources of wound healing compounds.

Subtribe Hyptidinae (Lamiaceae): A promising source of bioactive metabolites.

ETHNOPHARMACOLOGICAL RELEVANCE: The subtribe Hyptidinae contains approximately 400 accepted species distributed in 19 genera (Hyptis, Eriope, Condea, Cantinoa, Mesosphaerum, Cyanocephalus, Hypenia, Hyptidendron, Oocephalus, Medusantha, Gymneia, Marsypianthes, Leptohyptis, Martianthus, Asterohyptis, Eplingiella, Physominthe, Eriopidion and Rhaphiodon). This is the Lamiaceae clade with the largest number of species in Brazil and high rates of endemism. Some species have been used in different parts of the world mainly as insecticides/pest repellents, wound healing and pain-relief agents, as well as for the treatment of respiratory and gastrointestinal disorders. AIM OF THE REVIEW: This review aims to discuss the current status concerning the taxonomy, ethnobotanical uses, phytochemistry and biological properties of species which compose the subtribe Hyptidinae. MATERIALS AND METHODS: The available information was collected from scientific databases (ScienceDirect, Pubmed, Web of Science, Scopus, Google Scholar, ChemSpider, SciFinder ACS Publications, Wiley Online Library), as well as other literature sources (e.g. books, theses). RESULTS: The phytochemical investigations of plants of this subtribe have led to the identification of almost 300 chemical constituents of different classes such as diterpenes, triterpenes, lignans, α-pyrones, flavonoids, phenolic acids and monoterpenes and sesquiterpenes, as components of essential oils. Extracts, essential oils and isolated compounds showed a series of biological activities such as insecticide/repellent, antimicrobial and antinociceptive, justifying some of the popular uses of the plants. In addition, a very relevant fact is that several species produce podophyllotoxin and related lignans. CONCLUSION: Several species of Hyptidinae are used in folk medicine for treating many diseases but only a small fraction of the species has been explored and most of the traditional uses have not been validated by current investigations. In addition, the species of the subtribe appear to be very promising as alternative sources of podophyllotoxin-like lignans which are the lead compounds for the semi-synthesis of teniposide and etoposide, important antineoplastic agents. Thus, there is a wide-open door for future studies, both to support the popular uses of the plants and to find new biologically active compounds in this large number of species not yet explored.

Hypericum species: An analysis on the patent technologies.

Hypericum (Hypericaceae) is a genus that comprises approximately 500 species around the world. The industrial relevance of these plants is based on the occurence of specialized metabolites that exhibit a range of pharmaceutical potential. Besides that, several species are relevant due to their ornamental value. Taking to account the vast market worth of products and processes involving Hypericum, the present study aims to provide a comprehensive overview of patents concerning this subject between 2007and 2017. For this purpose, a survey was performed in free databases (Espacenet®, PatentScope® and Google Patents®) using the keyword Hypericum in the patents title or title plus abstract. The documents were then organized by groups (medicinal and non-medicinal approaches), subgroups, type of applicants and countries. Espacenet® was chosen to data analysis, and a total of 174 patents were found. The majority of the applicants are from China and companies appear as the principal owners of patents. Several technologies are not intended for medicinal purposes, being mainly related to the development of new cultivars for ornamental uses. Concerning the medicinal approaches, the chief subject is related to extraction and incorporation into formulations. The main species cited in the documents is H. perforatum and the therapeutic use is for central nervous system diseases. In general, this study covers the patents published in recent years hoping to boost the scientists and companies that invest in Hypericum researches to visualize the state of art, opportunities and challenges for innovation in this area.

Antinociceptive Activity of Phloroglucinol Derivatives Isolated from Southern Brazilian Hypericum Species.

The south Brazilian Hypericum species have revealed the presence of a series of biologically active phloroglucinol derivatives. In this study, a mixture of japonicine A and an isomer with an unreported structure, named japonicine E, was isolated from the roots of H. polyanthemum. Additionally, uliginosin A from H. myrianthum, isouliginosin B from H. polyanthemum, hyperbrasilol B and isohyperbrasilol B from H. caprifoliatum and cariphenone A from H. carinatum were also isolated. The structures were elucidated using 1D- and 2D-NMR experiments and by comparison with previously reported data. The compounds japonicines A/E, uliginosin A, isouliginosin B, hyperbrasilol B and cariphenone A exhibited antinociceptive activity in the mice hot-plate test and did not induce motor impairment in the rotarod apparatus.

Structural diversity and biological activities of phloroglucinol derivatives from Hypericum species.

Plants of the genus Hypericum (Hypericaceae) are used in folk medicine all over the world, H. perforatum being the most well-known species. Standardized extracts of this plant are commercially-available to treat mild to moderate depression cases. The present review summarizes the literature published up to 2016 concerning the phloroglucinol derivatives isolated from Hypericum species, together with their structural features and biological activities. These phytochemical studies led to the isolation of 101 prenylated phloroglucinols, chromanes and chromenes, 35 dimeric acylphloroglucinols, 235 polycyclic polyprenylated acylphloroglucinols, 25 simple benzophenones and 33 phloroglucinol-terpene adducts. These compounds show a diverse range of biological activities, such as antimicrobial, cytotoxic, antinociceptive and antidepressant-like effects.

Denudatin A, a Dimeric Acylphloroglucinol from Hypericum denudatum Presents an Antinociceptive Effect in Mice.

A new dimeric acylphloroglucinol, denudatin A (1), was isolated from the flowering aerials parts of Hypericum denudatum, along with the known phloroglucinols selancin A (2), hyperbrasilol A (3), uliginosin B (4), and isouliginosin B (5). The structure of 1 was elucidated using 1D, 2D NMR, and MS experiments, and by comparison with previously reported data for Hypericum dimeric acylphloroglucinols. Denudatin A (1) and selancin A (2) were administered orally to mice displaying antinociceptive activity in the hot plate test. The compounds did not induce motor impairment in the rotarod apparatus.

The anti-Trichomonas vaginalis phloroglucinol derivative isoaustrobrasilol B modulates extracellular nucleotide hydrolysis.

Trichomonas vaginalis causes trichomoniasis, a neglected sexually transmitted disease. Due to severe health consequences and treatment failure, new therapeutic alternatives are crucial. Phloroglucinols from southern Brazilian Hypericum species demonstrated anti-T. vaginalis and anti-Leishmania amazonensis activities. The modulation of biochemical pathways involved in the control of inflammatory response by ectonucleotidases, NTPDase, and ecto-5'-nucleotidase represents new targets for combating protozoa. This study investigated the activity of phloroglucinol derivatives of Hypericum species from southern Brazil against T. vaginalis as well as its ability on modulating parasite ectonucleotidases and, consequently, immune parameters through ATP and adenosine effects. Phloroglucinol derivatives screening revealed activity for isoaustrobrasilol B (IC50 38 µm) with no hemolytic activity. Although the most active compound induced cytotoxicity against a mammalian cell lineage, the in vivo model evidenced absence of toxicity. Isoaustrobrasilol B significantly inhibited NTPDase and ecto-5'-nucleotidase activities, and the immune modulation attributed to extracellular nucleotide accumulation was evaluated. The production of ROS and IL-6 by T. vaginalis-stimulated neutrophils was not affected by the treatment. Conversely, IL-8 levels were significantly enhanced. The associative mechanism of trophozoites death and ectonucleotidases modulation by isoaustrobrasilol B may increase the susceptibility of T. vaginalis to host innate immune cell like neutrophils consequently, contributing to parasite clearance.

Characterization of Phloroglucinol-enriched Fractions of Brazilian Hypericum Species and Evaluation of Their Effect on Human Keratinocytes Proliferation.

In this study, a phytochemical and biological investigation on five South Brazilian Hypericum species (Hypericum caprifoliatum, Hypericum carinatum, Hypericum connatum, Hypericum myrianthum, and Hypericum polyanthemum) was carried out. The phloroglucinol-enriched fractions (PEF) of the flowering aerial parts were analyzed by high-performance liquid chromatography for the content of uliginosin A (1), japonicin A (2), uliginosin B (3), hyperbrasilol B (4), and the three benzopyrans, that is, 6-isobutyryl-5,7-dimethoxy-2,2-dimethyl-benzopyran (HP1) (5), 7-hydroxy-6-isobutyryl-5-methoxy-2,2-dimethyl-benzopyran (HP2) (6), and 5-hydroxy-6-isobutyryl-7-methoxy-2,2-dimethyl-benzopyran (HP3) (7). After chemical characterization, the PEF were assayed for cell proliferation on human keratinocyte cell line by MTT. The H. carinatum and H. polyanthemum PEF demonstrated better results with an increase in cell proliferation (138.7% and 120.6%, respectively). The cell counting and Ki-67 assay with H. carinatum PEF confirmed the MTT results. The cell cycle distribution indicates an increase in the cells at S and G2/M phases, which is indicative of proliferation induction. In summary, the results indicate an induction of HaCaT proliferation by the treatment with H. carinatum PEF (at 10 and 15 µg/mL), suggesting a possible use as wound healing agent. Copyright © 2016 John Wiley & Sons, Ltd.

Dimeric acylphloroglucinols from Hypericum austrobrasiliense exhibiting antinociceptive activity in mice.

Three dimeric acylphloroglucinols, austrobrasilol A, austrobrasilol B and isoaustrobrasilol B were isolated from the flowers of Hypericum austrobrasiliense (Hypericaceae, section Trigynobrathys). Their structures were elucidated using mass spectrometry and NMR experiments (1D and 2D), and by comparison with previously reported data for other dimeric acylphloroglucinols isolated from Hypericum and Elaphoglossum genera. The three compounds were orally administered in mice at equimolar doses to uliginosin B (15mg/kg, p.o.) displaying antinociceptive activity in the hot-plate test. The compounds did not induce motor impairment in the rotarod apparatus.