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Medicinal plants have been widely used in the treatment of chronic pain. In this study, we describe the antinociceptive effect of the essential oil from Croton conduplicatus (the EO 25, 50, and 100 mg/kg, i.p.), a medicinal plant native to Brazil. Antinociceptive activity was investigated by measuring the nociception induced by acetic acid, formalin, hot plate and carrageenan. A docking study was performed with the major constituents of the EO (E-caryophyllene, caryophyllene oxide, and camphor). The EO reduced nociceptive behavior at all doses tested in the acetic acid-induced nociception test (p < 0.05). The same was observed in both phases (neurogenic and inflammatory) of the formalin test. When the hot-plate test was conducted, the EO (50 mg/kg) extended the latency time after 60 min of treatment. The EO also reduced leukocyte migration at all doses, suggesting that its antinociceptive effect involves both central and peripheral mechanisms. Pretreatment with glibenclamide and atropine reversed the antinociceptive effect of the EO on the formalin test, suggesting the involvement of KATP channels and muscarinic receptors. The docking study revealed a satisfactory interaction profile between the major components of the EO and the different muscarinic receptor subtypes (M2, M3, and M4). These results corroborate the medicinal use of C. conduplicatus in folk medicine.

In this study, the phytochemical profile of extracts from the flowers of Bromelia laciniosa was characterized. The total phenolic and flavonoids contents were determined and the antioxidant and photoprotective activities were evaluated using in vitro assays. Phytochemical analysis demonstrated that the extracts were found to be positive for the presence of anthracene derivatives, anthraquinones, coumarins, flavonoids and tannins, lignans, mono and diterpenes. The ethanol extract (Bl-EtOH) presented the most significant total phenolic content (53.75 § 1.25 mg GAE/g). The dichloromethane extract (Bl-CH 2 Cl 2 ) showed the highest flavonoid content (46.06 § 1.18 mg CE/g). The methanol extract (Bl-MeOH) was the most effective extract in the DPPH (2,2-diphenyl-1-picrylhydrazil) assay (EC 50 141.90 § 3.01 mg/mL). Bl-EtOH and Bl-MeOH showed higher sun protection factor at a concentration of 100 mg/L (3.38 § 0.04 and 3.78 § 0.11, respectively). Therefore, the extracts proved to be interesting for the development of new studies aiming their incorporation into photoprotective cosmetic formulations.

Our findings support the traditional use of this plant as a natural analgesic and suggest that EO is a multi-target natural product, presenting not only antinociceptive effect but also anxiolytic and sedative activities depending on the dose used.

Depressive disorders remain a current public health problem whose prevalence has increased in the past decades. In the constant search for new therapeutic alternatives, βcarboline alkaloids have been identified as good candidates for new antidepressant drugs. In this systematic review, we summarized all pre-clinical investigations involving the use of natural or semisynthetic β-carboline in depression models. A literature search was conducted in August 2018, using PubMed, Scopus and Science Direct databases. All reports were carefully analyzed, and data extraction was conducted through standardized forms. Methodological quality assessment of in vivo studies was also performed. The entire systematic review was performed according to PRISMA statement. From a total of 373 articles, 26 met all inclusion criteria. In vitro and in vivo studies have evaluated a wide variety of β-carbolines through enzymatic and binding assays, and acute or chronic animal models. Most of the in vivo and in vitro studies is concentrated on two molecules: harman and harmine. They have been investigated in several animal models and some mechanisms of action have been proposed for their antidepressant activity. In general, βcarbolines modulate 5-HT and GABA systems, promote neurogenesis, induce neuroendocrine response and restore astrocytic function, being effective when administrated acutely or chronically in different animal models, including chronic mild stress protocols. In short, β-carbolines are multi-target antidepressant compounds and may be useful in the treatment of depressive disorders.

Triplaris gardneriana belongs to the family Polygonaceae, known for producing a number of biologically important molecules. The present study was aimed at identifying and quantify its total flavonoid content and determining the antioxidant and photoprotective potential of the plant's leaves. The flavonoids present in the extract and fractions were analyzed using Liquid chromatography-mass spectrometry (LC-MS). The antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay and autoxidation of β-carotene. The absorbance of the extracts was measured at different concentrations between 260 to 400 nm wavelengths. Calculation of sun protection factor (SPF) was determined using the formula developed by Mansur. The total flavonoid content was determined by the method developed by Dewanto. In the study, the following four flavonols were identified: quercetinhexoside (2a), quercetin-pentoside (2b), quercetin-ramnobioside (2c) and myricetin-hexoside (2d). The crude ethanol extract, ethyl acetate, and methanol fractions showed higher flavonoid content and also exhibited excellent antioxidant and photoprotective activity. The SPF values were best observed for the crude ethanol extract and for the chloroform, ethyl acetate and methanol fractions. The good antioxidant and photoprotective potential can be attributed to the presence of flavonols identified for the first time in this species.

Introduction: Cnidoscolus quercifolius Pohl (Euphorbiaceae) is a Brazilian medicinal plant, popularly known as "favela", "faveleira" and "urtiga-branca". In folk medicine, its leaves and stem barks are used to treat urinary tract infections. In this study, we report the isolation and characterization of a mixture of two lupane-type triterpenes and one bis-nor-diterpene from the hexane extract of the stem barks. Methods: An aliquot of hexane extract was fractioned by means silica gel chromatography column, yielding a mixture of two compounds (1 and 2). Compound 3 was obtained from the chloroform subfraction through preparative thin layer chromatography (TLC). The compounds were identified by comparison of their spectroscopic data to those reported in the literature. The antibacterial activity of these compounds was evaluated by the microdilution method, through determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), using gram-positive (E. faecalis and S. aureus) and gram-negative (E. coli, K. pneumoniae and S. marcescens) strains. Results: The chemical constituents were identified as a mixture of lupeol-3β-O-cinnamate (1) and lupeol-3β-O-dihydrocinnamate (2) and, phyllacanthone (3). Compounds 1/2 and 3 showed a bacteriostatic effect ten and twenty times higher (MIC = 0.5 and 0.25 mg.ml-1 , respectively) than the hexane extract, respectively (MIC = 5.0 mg.ml-1). The molecules also showed a relevant bactericidal effect, mainly compound 3 (MBC = 0.25 mg.ml-1). Conclusion: These results suggest that C. quercifolius may be considered a promising source of new antibacterial agents. In addition, this investigation supports the medicinal use of this plant for the treatment of urinary tract infections.

Neoglaziovia variegata is a Bromeliaceae plant species widely found in Brazil with several pharmacological properties, including photoprotective activity. Although herbal-based active ingredients have been applied in cosmetic products, especially for skin treatment, its application in sunscreen formulations remains unexplored. The aim of this work is to evaluate the photoprotective effect of cosmetic formulations containing hydroalcoholic extract of N. variegata (Nv-HA). Initially, the phenolic and flavonoid total content of Nv-HA were determined. The photoprotective activity of Nv-HA was subsequently assessed using a spectrophotometric method. Nv-HA was incorporated in O/W emulsions in the presence or absence of synthetic filters and their photoprotective efficacy was evaluated by spectrophotometric SPF determination. Finally, the stability study of the formulations was performed through the freezing/defrosting method. Nv-HA showed significant phenolic and flavonoids content (61.66 ± 5.14 mg GAE/g and 90.27 ± 5.03 mg CE/g, resp.). Nv-HA showed SPF values of 5.43 ± 0.07 and 11.73 ± 0.04 for the concentrations of 0.5 and 1.0% (v/v), respectively. It was verified that Nv-HA potentiated the photoprotective effect of formulations containing only synthetic filters. Furthermore, the formulations have remained stable at the end of the preliminary stability study. According to the results, it was concluded that Nv-HA can be used as a chemical filter in cosmetic formulations.