Anti-Leishmanial, Anti-Inflammatory and Antimicrobial Activities of Phenolic Derivatives fromTibouchina paratropica

Tibouchina granulosa Leaves Present Anti-Inflammatory Effect

The ethanol extract (EE) prepared from the leaves of Tibouchina granulosa, and its fraction in ethyl acetate (fEA) were evaluated concerning their capacity to reduce inflammation in different experimental models. fEA was also studied concerning its chemical constituents. EE and fEA were assayed for their anti-inflammatory potential, using formalin-induced licking behavior and carrageenan-induced inflammation into the subcutaneous air pouch (SAP) models. Reduction in polymorphonuclear cells (PMN) activation was performed in freshly isolated PMN. Chromatographic analysis of fEA was performed by HPLC-DAD. Hispiduloside was isolated as the main constituent in fEA, and its quantity was estimated to be 39.3% in fEA. EE (30 mg/kg) significantly reduced the second phase of formalin-induced licking. fEA demonstrated a reduction in leukocyte migration into the SAP. EE and fEA drastically reduced cytokines (TNF-α, IL-1β, and IFN-γ), nitric oxide (NO) production, in vitro PMN migration induced by C5a and IL-8, and TNF-α and IL-1β gene expression. Taken together, our data indicate that either ethanol extract or its fEA fraction from leaves of T. granulosa present an anti-inflammatory effect, contributing to the pharmacological and chemical knowledge of this species and confirming the rationale behind its traditional use.

Virus-like Particles: Fundamentals and Biomedical Applications

Nanotechnology is a fast-evolving field focused on fabricating nanoscale objects for industrial, cosmetic, and therapeutic applications. Virus-like particles (VLPs) are self-assembled nanoparticles whose intrinsic properties, such as heterogeneity, and highly ordered structural organization are exploited to prepare vaccines; imaging agents; construct nanobioreactors; cancer treatment approaches; or deliver drugs, genes, and enzymes. However, depending upon the intrinsic features of the native virus from which they are produced, the therapeutic performance of VLPs can vary. This review compiles the recent scientific literature about the fundamentals of VLPs with biomedical applications. We consulted different databases to present a general scenario about viruses and how VLPs are produced in eukaryotic and prokaryotic cell lines to entrap therapeutic cargo. Moreover, the structural classification, morphology, and methods to functionalize the surface of VLPs are discussed. Finally, different characterization techniques required to examine the size, charge, aggregation, and composition of VLPs are described.

Bio-guided isolation of leishmanicidal and trypanocidal constituents from Pituranthos battandieri aerial parts

Protozoan pathogens that cause neglected tropical diseases are a major public health concern in tropical and developing countries. In the course of our ongoing search for new lead compounds as potential antiprotozoal agents, this study aims to perform a bio-guided fractionation of Pituranthos battandieri, using an in vitro assay against Leishmania amazonensis and Trypanosoma cruzi. Two known polyacetylenes, (-)-panaxydiol (1) and (-)-falcarindiol (2) were identified from the ethanolic extract of the aerial parts of P. battandieri as the main bioactive constituents. Compounds 1 and 2 showed similar potency (IC₅₀ values of 5.76 and 5.68 μM, respectively) against L. amazonensis to miltefosine (IC₅₀ value of 6.48 μM), the reference drug, and low toxicity on macrophage cell lines J774. Moreover, compound 1 exhibited moderate activity (IC₅₀ 23.24 μM) against T. cruzi. In addition, three known furanocoumarins, 8-geranyloxypsoralen (3), 8-geranyloxy-5-methoxypsoralen (4), and phellopterin (5) were isolated. Their structures were elucidated by NMR and MS analysis. Compounds 1 and 2 are described for the first time in the Pituranthos genus, and this is the first report on their antiprotozoal activity. These results highlight this type of polyacetylenes as an interesting scaffold for the development of novel antiparasitic drugs.

Flavonoid Composition of Salacia senegalensis (Lam.) DC. Leaves, Evaluation of Antidermatophytic Effects, and Potential Amelioration of the Associated Inflammatory Response

Predominantly spread in West Tropical Africa, the shrub Salacia senegalensis (Lam.) DC. is known because of its medicinal properties, the leaves being used in the treatment of skin diseases. Prompted by the ethnomedicinal use, a hydroethanolic extract obtained from the leaves of the plant was screened against a panel of microbial strains, the majority of which involved in superficial infections. The extract was found to be active against the dermatophytes Trichophyton rubrum and Epidermophyton floccosum. Notable results were also recorded regarding the attenuation of the inflammatory response, namely the inhibitory effects observed against soybean 5-lipoxygenase (IC₅₀ = 71.14 μg mL^-1), no interference being recorded in the cellular viability of RAW 264.7 macrophages and NO levels. Relevantly, the extract did not lead to detrimental effects against the keratinocyte cell line HaCaT, at concentrations displaying antidermatophytic and anti-inflammatory effects. Flavonoid profiling of S. senegalensis leaves was achieved for the first time, allowing the identification and quantitation of myricitrin, three 3-O-substituted quercetin derivatives, and three other flavonoid derivatives, which may contribute, at least partially, to the observed antidermatophytic and anti-inflammatory effects. In the current study, the plant S. senegalensis is assessed concerning its antidermatophytic and anti-inflammatory properties.

Acylated Flavonoid Glycosides are the Main Pigments that Determine the Flower Colour of the Brazilian Native Tree Tibouchina pulchra (Cham.) Cogn

Tibouchina pulchra (Cham.) Cogn. is a plant native to Brazil whose genus and family (Melastomataceae) are poorly studied with regards to its metabolite profile. Phenolic pigments of pink flowers were studied by ultra-performance liquid chromatography with a photodiode array detector and electrospray ionization quadrupole time-of-flight mass spectrometry. Therein, twenty-three flavonoids were identified with eight flavonols isolated by preparative high-performance liquid chromatography and analysed by one- and two-dimensional nuclear magnetic resonance. Kaempferol derivatives were the main flavonols, encompassing almost half of the detected compounds with different substitution patterns, such as glucoside, pentosides, galloyl-glucoside, p-coumaroyl-glucoside, and glucuronide. Concerning the anthocyanins, petunidin p-coumaroyl-hexoside acetylpentoside and malvidin p-coumaroyl-hexoside acetylpentoside were identified and agreed with previous reports on acylated anthocyanins from Melastomataceae. A new kaempferol glucoside was identified as kaempferol-(2''-O-methyl)-4'-O-α-d-glucopyranoside. Moreover, twelve compounds were described for the first time in the genus with five being new to the family, contributing to the chemical characterisation of these taxa.

Licochalcone A Suppresses Specificity Protein 1 as a Novel Target in Human Breast Cancer Cells

Licochalcone A (LCA), isolated from the root of Glycyrrhiza inflata, are known to have medicinal effect such as anti-oxidant, anti-bacterial, anti-viral, and anti-cancer. Though, as a pharmacological mechanism regulator, anti-cancer studies on LCA were not investigated in human breast cancer. We investigated the anti-proliferative and apoptotic effect of LCA in human breast cancer cells MCF-7 and MDA-MB-231 through MTS assay, PI staining, Annexin-V/7-AAD assay, mitochondrial membrane potential assay, multi-caspase assay, RT-PCR, Western blot analysis, and anchorage-independent cell transformation assay. Our results showed the little difference between two cells, as MCF-7 cell is both estrogen/progesterone receptor positive, there were only effect on Sp1 protein level, but not in mRNA level. Adversely, estrogen/progesterone/human epidermal growth factor receptor 2 triple negative, MDA-MB-231 showed decreased Sp1 mRNA, and protein levels. To confirm the participation of Sp1 in breast cancer cell viability, siRNA techniques were introduced. Both cells showed dysfunction of mitochondrial membrane potential and mitochondrial ROS production, which reflects it passed intracellular mitochondrial apoptosis pathway. Additionally, LCA showed the anti-proliferative and apoptotic effect in breast cancer cells through regulating Sp1 and apoptosis-related proteins in a dose- and a time-dependent manner. Consequently, LCA might be a potential anti-breast cancer drug substitute. J. Cell. Biochem. 118: 4652-4663, 2017. © 2017 Wiley Periodicals, Inc.

Characterization of anti-inflammatory effect and possible mechanism of action of Tibouchina granulosa

OBJECTIVES

Tibouchina granulosa, popularly known as 'quaresmeira', belong to a genus widely used in the traditional medicine as infusions from their leaves. Other species of Tibouchina are used as antibacterial, antioxidant or antileishmanial. In this work, our objectives were to investigate the biological effects of T. granulosa in models of acute inflammation.

METHODS

Chemical analysis showed the presence of proanthocyanidins and flavonoids. Infusions from leaves of T. granulosa (1, 3, 10, 30 or 100 mg/kg) were orally administered to mice, and the anti-inflammatory effects were evaluated by the formalin-induced licking response, inhibition of carrageenan-induced cell migration into subcutaneous air pouch (SAP) and inhibition of inflammatory mediator production in inflammatory exudate collected from SAP.

KEY FINDINGS

Our data indicate that tested doses of T. granulosa infusion reduced cell migration, protein extravasated to SAP and cytokine production (i.e. TNF-α and IL-10). All doses also inhibited the first and second phase of formalin-induced licking response.

CONCLUSIONS

Taken together, our results indicate that leaves of T. granulosa present anti-inflammatory effect and can be useful in the preparation of new phytomedicines.