Search

The ethnomedicinal plant Curatella americana L. (Dilleniaceae) is a common shrub in the Brazilian Cerrado, whose ethanolic extract showed significant in vitro anti-Zika virus activity by the MTT colorimetric method. Currently, there is no drug in clinical use specifically for the treatment of this virus; therefore, in this work, the antiviral and cytotoxic properties of the ethanolic extract, fractions, and compounds were evaluated. The ethanolic extract of the leaves showed no cytotoxicity for the human MRC-5 cell and was moderately cytotoxic for the Vero cell (CC 50 161.5 ± 2.01 µg/mL). This extract inhibited the Zika virus multiplication cycle with an EC 50 of 85.2 ± 1.65 µg/mL. This extract was fractionated using the liquid-liquid partition technique, and the ethyl acetate fraction showed significant activity against the Zika virus with an EC 50 of 40.7 ± 2.33 µg/mL. From the ethyl acetate fraction, the flavonoids quercetin-3- O -hexosylgallate ( 1 ), quercetin-3- O -glucoside ( 2 ), and quercetin ( 5 ) were isolated, and in addition to these compounds, a mixture of quercetin-3- O -rhamnoside ( 3 ) and quercetin-3- O -arabinoside ( 4 ) was also obtained. The isolated compounds quercetin and quercetin-3-O-hexosylgallate inhibited the viral cytopathic effect at an EC 50 of 18.6 ± 2.8 and 152.8 ± 2.0, respectively. Additionally, analyses by liquid chromatography coupled to a mass spectrometer allowed the identification of another 24 minor phenolic constituents present in the ethanolic extract and in the ethyl acetate fraction of this species.

Plant extracts are complex mixtures that are difficult to characterize, and mass spectrometry is one of the main techniques currently used in dereplication processes. Fridericia chica is a species with medicinal uses in Latin American countries, used in the treatment of inflammatory and infectious diseases. Extracts of this plant species are characterized by the presence of anthocyanidins. In this study, using high-resolution mass spectrometry coupled with liquid chromatography, it was possible to determine the molecular formula of thirty-nine flavonoids. Fragmentation analysis, ultraviolet spectrum and nuclear magnetic resonance data allowed the partial characterization of the structures of these compounds. The spectral dataset allowed the identification of a series of flavones in addition to the desoxyanthocyanidins common in extracts of the species. The occurrence of some of the proposed structures is uncommon in extracts of species of the Bignoniaceae family, and they are reported for the first time in the extract of this species. Quantitative analyses of total flavonoids confirmed the high content of these constituents in the species, with 4.09 ± 0.34 mg/g of dry plant material. The extract under study showed low in vitro cytotoxicity with CC 50 ≥ 296.7 ± 1.4 µg/mL for Vero, LLC-MK2 and MRC-5 cell lines. In antiviral activity assays, inhibition of the cytopathic effects of Dengue, Zika and Mayaro viruses was observed, with EC 50 values ranging between 30.1 and 40.9 µg/mL. The best result was observed against the Mayaro virus, with an EC 50 of 30.1 µg/mL.

Passiflora alata or passion fruit is a native flowering plant from Amazon, geographically spread from Peru to Brazil. The plant has long been used in folks medicine for its pharmacological properties and is included in the Brazilian Pharmacopoeia since 1929. The aim of this study was to evaluate the potential cytotoxic and antitumor activities of Passiflora alata leaf extract (P a LE) in S180-tumor bearing mice. The percentage of cell proliferation inhibition (% CPI) and IC 50 in relation to 4 tumor cell lines were determined in PC3, K-562, HepG2 and S180 cell lines using the MTT assay. P a LE showed a CPI > 75% and greater potency (IC 50 < 30 µg/mL) against PC3 and S180 cell lines. Pa LE showed antitumor activity in treatments intraperitoneally (36.75% and 44.99% at doses of 100 and 150 mg/kg/day, respectively). Toxicological changes were shown in the reduced body mass associated with reduced food consumption, increased spleen mass associated with histopathological increase in the white pulp of the spleen and increased number of total leukocytes with changes in the percentage relationship between lymphocytes and neutrophils. Our outcomes corroborate the conclusion that Pa LE has antitumor activity in vitro and in vivo with low toxicity.

Fruit plants have been widely used by the population as a source of food, income and in the treatment of various diseases due to their nutritional and pharmacological properties. The aim of this study was to review information from the most current research about the phytochemical composition, biological and toxicological properties of four fruit species widely used by the world population in order to support the safe medicinal use of these species and encourage further studies on their therapeutic properties. The reviewed species are: Talisia esculenta, Brosimum gaudichaudii, Genipa americana, and Bromelia antiacantha . The review presents the botanical description of these species, their geographical distribution, forms of use in popular medicine, phytochemical studies and molecules isolated from different plant organs. The description of the pharmacological mechanism of action of secondary metabolites isolated from these species was detailed and toxicity studies related to them were reviewed. The present study demonstrates the significant concentration of phenolic compounds in these species and their anti-inflammatory, anti-tumor, photosensitizing properties, among others. Such species provide important molecules with pharmacological activity that serve as raw materials for the development of new drugs, making further studies necessary to elucidate mechanisms of action not yet understood and prove the safety for use in humans.

The aim of the present work was to carry out a bioguided isolation of antiviral chemical constituents from an ethanol extract of leaves from Arrabidaea pulchra (Cham.) Sandwith (EEAPL) that had shown in vitro activity in a previous screening using DNA and RNA viruses. The activity of EEPAL was evaluated against the DNA viruses Human herpesvirus 1 (HSV-1) and Vaccinia virus Western Reserve (VACV-WR) as well as against the RNA viruses Murine encephalomyocarditis virus (EMCV), and Dengue virus 2 (DENV-2) by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay. Cytotoxicity was determined in LLCMK2 and Vero cells and the Selectivity Indexes (SI) were calculated. The most potent effect was observed against DENV-2 (EC50 46.8 ± 1.6 µg mL(-1); SI 2.7). For HSV-1 and VACV-WR EC50 values > 200 µg mL(-1) were determined, while no inhibition of the cytopathic effect was observed with EMCV. Bioguided fractionation of EEAPL by partition between immiscible solvents followed by chromatography over a Sephadex LH20 column afforded two arylpropanoid glycosides, verbascoside (AP 1) and caffeoylcalleryanin (AP 2), along with a terpenoid, ursolic acid (AP 3). AP 1 and AP 3 exhibited similar anti-DENV-2 profiles, with SI values of 3.8 and 3.1, respectively, while AP 2 was the most effective anti-DENV-2 constituent, with a SI of 20.0. Our results show that A. pulchra leaves ethanol extract (EEAPL) affords compounds with antiviral activity, mainly against DENV-2.