Correction: Inhibitory Effects of Hydroethanolic Leaf Extracts of Kalanchoe brasiliensis and Kalanchoe pinnata (Crassulaceae) against Local Effects Induced by Bothrops jararaca Snake Venom.

[This corrects the article DOI: 10.1371/journal.pone.0168658.]

Improving Encapsulation of Hydrophilic Chloroquine Diphosphate into Biodegradable Nanoparticles: A Promising Approach against Herpes Virus Simplex-1 Infection

Chloroquine diphosphate (CQ) is a hydrophilic drug with low entrapment efficiency in hydrophobic nanoparticles (NP). Herpes simplex virus type 1 (HSV-1) is an enveloped double-stranded DNA virus worldwide known as a common human pathogen. This study aims to develop chloroquine-loaded poly(lactic acid) (PLA) nanoparticles (CQ-NP) to improve the chloroquine anti- HSV-1 efficacy. CQ-NP were successfully prepared using a modified emulsification-solvent evaporation method. Physicochemical properties of the NP were monitored using dynamic light scattering, atomic force microscopy, drug loading efficiency, and drug release studies. Spherical nanoparticles were produced with modal diameter of <300 nm, zeta potential of −20 mv and encapsulation efficiency of 64.1%. In vitro assays of CQ-NP performed in Vero E6 cells, using the MTT-assay, revealed different cytotoxicity levels. Blank nanoparticles (B-NP) were biocompatible. Finally, the antiviral activity tested by the plaque reduction assay revealed greater efficacy for CQ-NP compared to CQ at concentrations equal to or lower than 20 µg mL−1 (p < 0.001). On the other hand, the B-NP had no antiviral activity. The CQ-NP has shown feasible properties and great potential to improve the antiviral activity of drugs

Isolation and Identification of the Five Novel Flavonoids from Genipa americana Leaves

Genipa americana is a medicinal plant popularly known as “jenipapo”, which occurs in Brazil and belongs to the Rubiaceae family. It is a species widely distributed in the tropical Central and South America, especially in the Cerrado biome. Their leaves and fruits are used as food and popularly in folk medicine to treat anemias, as an antidiarrheal, and anti-syphilitic. Iridoids are the main secondary metabolites described from G. americana, but few studies have been conducted with their leaves. In this study, the aim was to chemical approach for identify the main compounds present at the extract of G. americana leaves. The powdered leaves were extracted by maceration with EtOH: water (70:30, v/v), following liquid-liquid partition with petroleum ether, chloroform, ethyl acetate and n-butanol. A total of 13 compounds were identified. In addition three flavonoids were isolated from the ethyl acetate fraction: quercetin-3-O-robinoside (GAF 1), kaempferol-3-O-robinoside (GAF 2) and isorhamnetin-3-O-robinoside (GAF 3) and, from n-butanol fraction more two flavonoids were isolated, kaempferol-3-O-robinoside-7-O-rhamnoside (robinin) (GAF 4) and isorhamnetin-3-O-robinoside-7-rhamnoside (GAF 5). Chemical structures of these five flavonoids were elucidated using spectroscopic methods (MS, 1H and 13C-NMR 1D and 2D). These flavonoids glycosides were described for the first time in G. americana

Aspidosperma pyrifolium Has Anti-Inflammatory Properties: An Experimental Study in Mice with Peritonitis Induced by Tityus serrulatus Venom or Carrageenan

Scorpions of the genus Tityus are responsible for the majority of envenomation in Brazil, the Tityus serrulatus species being the most common and dangerous in South America. In this approach, we have investigated the ability of the aqueous extract from the leaves of Aspidosperma pyrifolium in reducing carrageenan-induced inflammation and the inflammation induced by T. serrulatus envenomation in mice. We also evaluated the cytotoxic effects of this extract, using the 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl-2H-tetrazolium (MTT) assay and the results revealed that the extract is safe. Analysis by High Performance Liquid Chromatography coupled with Diode Array Detector (HPLC-DAD) and Liquid Chromatography Coupled with Mass Spectrometry with Diode Array Detection (LC-DAD-MS) showed one major chemical component, the flavonoid rutin and phenolics compounds. For in vivo studies in carrageenan-induced peritonitis model, mice received extracts, dexamethasone, rutin or saline, before administration of carrageenan. For venom-induced inflammation model, animals received T. serrulatus venom and were, simultaneously, treated with extracts, antivenom, rutin or saline. The extract and rutin showed a reduction in the cell migration into the peritoneal cavity, and in the same way the envenomated animals also showed reduction of edema, inflammatory cell infiltration and vasodilation in lungs. This is an original study revealing the potential action of A. pyrifolium against inflammation caused by Tityus serrulatus venom and carrageenan, revealing that this extract and its bioactive molecules, specifically rutin, may present potential anti-inflammatory application

Inhibitory Effects of Hydroethanolic Leaf Extracts of <i>Kalanchoe brasiliensis</i> and <i>Kalanchoe pinnata</i> (Crassulaceae) against Local Effects Induced by <i>Bothrops jararaca</i> Snake Venom

<div><p>The species <i>Kalanchoe brasiliensis</i> and <i>Kalanchoe pinnata</i>, both known popularly as “Saião,” are used interchangeably in traditional medicine for their antiophidic properties. Studies evaluating the anti-venom activity of these species are scarce. This study aims to characterize the chemical constituents and evaluate the inhibitory effects of hydroethanolic leaf extracts of <i>K</i>. <i>brasiliensis</i> and <i>K</i>. <i>pinnata</i> against local effects induced by <i>Bothrops jararaca</i> snake venom. Thin Layer Chromatography (TLC) and High Performance Liquid Chromatography coupled with Diode Array Detection and Electrospray Mass Spectrometry (HPLC-DAD-MS/MS) were performed for characterization of chemical markers of the extracts from these species. For antiophidic activity evaluation, <i>B</i>. <i>jararaca</i> venom-induced paw edema and skin hemorrhage in mice were evaluated. In both models, hydroethanolic extracts (125–500 mg/kg) were administered intraperitoneally in different protocols. Inhibition of phospholipase enzymatic activity of <i>B</i>. <i>jararaca</i> was evaluated. The HPLC-DAD-MS/MS chromatographic profile of extracts showed some particularities in the chemical profile of the two species. <i>K</i>. <i>brasileinsis</i> exhibited major peaks that have UV spectra similar to flavonoid glycosides derived from patuletin and eupafolin, while <i>K</i>. <i>pinnata</i> showed UV spectra similar to flavonoids glycosides derived from quercetin and kaempferol. Both extracts significantly reduced the hemorrhagic activity of <i>B</i>. <i>jararaca</i> venom in pre-treatment protocol, reaching about 40% of inhibition, while only <i>K</i>. <i>pinnata</i> was active in post-treatment protocol (about 30% of inhibition). In the antiedematogenic activity, only <i>K</i>. <i>pinnata</i> was active, inhibiting about 66% and 30% in pre and post-treatment protocols, respectively. Both extracts inhibited phospholipase activity; however, <i>K</i>. <i>pinnata</i> was more active. In conclusion, the results indicate the potential antiophidic activity of <i>Kalanchoe</i> species against local effects induced by <i>B</i>. <i>jararaca</i> snake venom, suggesting their potential use as a new source of bioactive molecules against bothropic venom.</p></div

Inhibition of the edematogenic activity of <i>B</i>. <i>jararaca</i> venom (BjV) by extracts of <i>K</i>. <i>brasiliensis</i> (Kb) (A) and <i>K</i>. <i>pinnata</i> (Kp) (B) in post-treatment protocol.

<p>BjV was injected i.pl. in the right hind paw of mice 5 min before treatment with extract (500 mg/kg, i.p.). Paw thickness was measured during 120 min after venom injection. Edema was expressed as the increase in paw thickness calculated, by the percentage difference between the paw thickness after (at respective time) and before (basal values) venom injection. The points represent the mean ± SEM (n = 5). *p<0.05 and **p<0.01 compared to the group receiving venom alone along with the i.p. injection of 5% castor oil in PBS (Two-way ANOVA followed by the Bonferroni test).</p

Phytochemical Analysis by HPLC–HRESI-MS and Anti-Inflammatory Activity of Tabernaemontana catharinensis

Tabernaemontana catharinensis (Apocynaceae) has been popularly used by folk medicine because of its anti-inflammatory, analgesic, and antiophidic properties. This study aims to analyze the flavonoids composition of the hydroethanolic extract and of the ethyl acetate (EtOAc) and butanol (BuOH) fractions of T. catharinensis leaves, as well as to evaluate their anti-inflammatory activity using in vivo models. The phytochemical profile, determined by High-Performance Liquid Chromatography–High-Resolution Electrospray Ionization-Mass Spectrometry (HPLC–HRESI-MS), showed the presence of flavonoids mainly having an isorhamnetin nucleus. The anti-inflammatory activity was evaluated in carrageenan-induced paw edema (pre- and post-treatment) with oral administration of a T. catharinensis hydroethanolic extract (50, 100, and 150 mg/kg) and of organic fractions (50 mg/kg). The extract and fractions showed antiedematogenic activity by decreasing myeloperoxidase (MPO) production. In the zymosan-air-pouch model, the extract and fractions inhibited leukocyte migration and significantly decreased the levels of various proteins, such as MPO, interleukin (IL)-1β, and tumor necrosis factor (TNF)-α. The cytotoxicity was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, which revealed no cytotoxicity of the extract and the fractions. These results suggest that the hydroethanolic extract and organic fractions of T. catharinensis leaves have sufficient anti-inflammatory activity to support the popular use of this plant in the treatment of inflammatory disorders

Inhibition of the edematogenic activity of <i>B</i>. <i>jararaca</i> venom (BjV) by extracts of <i>K</i>. <i>Brasiliensis</i> (Kb) (A) and <i>K</i>. <i>pinnata</i> (Kp) (B) in pre-treatment protocol.

<p>BjV was injected i.pl. in the right hind paw of mice pre-treated i.p. with different extracts. Paw thickness was measured during 120 min after venom injection. Edema was expressed as the increase in paw thickness calculated as the percentage difference between the paw thickness after (at respective time) and before (basal values) venom injection. The points represent the mean ± SEM (n = 5). *p<0.05, **p<0.01 and ***p<0.001 compared to the group receiving venom alone along with the i.p. injection of 5% castor oil in PBS (Two-way ANOVA followed by the Bonferroni test).</p