Ana Silvia Suassuna Carneiro Lúcio

Coatings comprising chitosan and Mentha piperita L. or Mentha × villosa Huds essential oils to prevent common postharvest mold infections and maintain the quality of cherry tomato fruit

In this study, we evaluated the efficacy of coatings comprising shrimp chitosan (CHI) and Mentha piperita L. (MPEO) or Mentha × villosa Huds (MVEO) essential oils to control mold infections caused by Aspergillus niger, Botrytis cinerea, Penicillium expansum and Rhizopus stolonifer in cherry tomato fruits (Solanum lycopersicum L.) during storage at room temperature (25°C for 12 days) and low temperature (12°C for 24 days). The effects of the coatings on the physicochemical and sensory characteristics of cherry tomato fruits during storage were also assessed. The minimum inhibitory concentration (MIC) of CHI against all test fungi was 8 mg/mL, whereas the MIC for both MPEO and MVEO was 5 μL/mL. Combinations of CHI at 4 mg/mL and MPEO or MVEO at 2.5 or 1.25 μL/mL strongly inhibited the mycelial growth and spore germination of target fungi. The coatings comprising CHI and MPEO or CHI and MVEO at the different tested concentrations delayed the growth of decay-causing fungi in artificially contaminated tomato fruit during storage at either room temperature or low temperature. The assayed coatings preserved the quality of cherry tomato fruit during storage, in terms of physicochemical and sensory attributes. These results indicate that coatings comprising CHI and MPEO or CHI and MVEO represent promising postharvest treatments to prevent common postharvest mold infections in cherry tomato fruit during storage without affecting the quality of the fruit.

Antinociceptive activity of discretamine isolated from Duguetia moricandiana

The phytochemical study of Duguetia moricandiana Mart. (Annonaceae) yielded the isolation of the alkaloid which was identified by spectral analysis as discretamine. The evaluation of antinociceptive activity carried out by the acetic acid-induced writhing, formalin and hot plate tests in mice, suggests a potent antinociceptive effect. Discretamine (5, 10 and 20 mg kg−1, i.p.) significantly reduced the number of writhes similarly at all doses tested and the number of paw licks during the first phase of formalin test when compared to control. The effect of discretamine on hot plate response provides a confirmation of its central effect. These results indicate antinociceptive properties of this alkaloid.

In vitro evaluation of schistosomicidal activity of essential oil of Mentha x villosa and some of its chemical constituents in adult worms of Schistosoma mansoni.

This study aimed to determine the composition of the essential oil of Mentha x villosa and to evaluate its biological effects in vitro on adult worms of S. mansoni. Rotundifolone (70.96 %), limonene (8.75 %), trans-caryophyllene (1.46 %), and β-pinene (0.81 %) were shown to be the major constituents of this oil. Adult worms of S. mansoni were incubated with different concentrations of the essential oil (1, 10, 100, 250, 500, and 1000 µg/mL) and of its constituents rotundifolone (0.7, 3.54, 7.09, 70.96, 177.4, 354.8, and 700.96 µg/mL), limonene (43.75 µg/mL), trans-caryophyllene (7.3 µg/mL), and β-pinene (4.03 µg/mL). No schistosomicidal activity was identified at the trans-caryophyllene and β-pinene concentrations studied. However, use of the essential oil (10 µg/mL), rotundifolone (7.09 µg/mL), and limonene (43.75 µg/mL) resulted in decreased worm motility continuing until 96 hours of observation. At higher concentrations (100 and 70.96 µg/mL, respectively), both the essential oil and rotundifolone caused mortality among adult worms of S. mansoni. The positive control praziquantel caused the death of all parasites after 24 h of evaluation. The results from this study suggest that the essential oil of Mentha x villosa presents schistosomicidal efficacy.

Azaphenanthrene alkaloids with antitumoral activity from Anaxagorea dolichocarpa Sprague & Sandwith (Annonaceae).

Phytochemical investigation of Anaxagorea dolichocarpa Sprague & Sandwith led to isolation of three azaphenanthrene alkaloids: eupolauramine, sampangine and imbiline 1. Their chemical structures were established on the basis of spectroscopic data from IR, HR-ESI-MS, NMR (including 2D experiments) and comparison with the literature. Sampangine and imbiline 1 are being described in the Anaxagorea genus for the first time. Eupolauramine and sampangine show concentration-dependent antitumoral activity in leukemic cells K562 with IC50 of 18.97 and 10.95 µg/mL, respectively.

Antinociceptive Activity of Ethanol Extract from Duguetia chrysocarpa Maas (Annonaceae)

The ethanol extract from the fruits of Duguetia chrysocarpa was evaluated for its antinociceptive activity in chemical and thermal models of nociception in mice. The intraperitoneal administration of the ethanol extract (100, 200, and 400 mg/kg body weight) showed a dose-dependent inhibition of acetic-acid-induced abdominal writhes. The extract also produced a significant inhibition of both phases of the formalin test in all doses tested and increased the reaction time in hot-plate test at dose of 200 mg/kg. The data obtained suggest that the antinociceptive effect of the extract may be mediated via both peripheral and central mechanisms. The phytochemical investigation yielded the isolation of the benzenoid derivative 3-methoxy-4-ethoxy benzoic acid which is being reported for the first time in this genus.

Ultrastructural changes in Schistosoma mansoni male worms after in vitro incubation with the essential oil of Mentha x Villosa huds

Introduction: The essential oil Mentha x villosa (MVEO) has a wide range of actions, including antibacterial, antifungal, antiprotozoal and schistosomicidal actions. The present study aimed to investigate the ultrastructural changes of MVEO on the tegument of adult Schistosoma mansoni. Materials and Methods: Different concentrations of MVEO were tested on S. mansoni adult worms in vitro. Ultrastructural changes on the tegument of these adult worms were evaluated using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Results: The MVEO caused the death of all worms at 500 μg mL-1 after 24 h. After 24h of 500 μg mL-1 MVEO treatment, bubble lesions were observed over the entire body of worms and they presented loss of tubercles in some regions of the ventral portion. In the evaluation by TEM, S. mansoni adult worms treated with MVEO, 500 μg mL-1, presented changes in the tegument and vacuoles in the syncytial matrix region. Glycogen granules close to the muscle fibers were visible. Conclusion: The ability of MVEO to cause extensive ultrastructural damage to S. mansoni adult worms correlates with its schistosomicidal effects and confirms earlier findings with S. mansoni.

Composition and Antimicrobial Activity of the Leaf Essential Oils of Duguetia gardneriana Mart. and Duguetia moricandiana Mart. (Annonaceae)

Abstract As part of their continuing studies on the constituents of the genus Duguetia, these authors have studied the composition and antimicrobial activity of the essential oils obtained from the leaves of two species, and the results are reported here. A hydrodistilled oils obtained from the leaves of Duguetia gardneriana and Duguetia moricandiana were analyzed by GC/MS. The oils showed a total of 33 components. Germacrene D (28.1%), viridiflorene (24.0%), β-pinene (12.6%), α-pinene (9.1%) and β-caryophyllene (5.6%) were found to be the major individual constituents of D. gardneriana oil. The leaf oil of D. moricandiana was dominated by germacrene D (44.3%), α-pinene (13.0%), viridiflorene (9.3%), β-pinene (9.2%) and β-caryophyllene (6.8%). The oils were tested for their antimicrobial activity against 11 pathogenic microorganisms using standard gel diffusion method. The essential oil of D. gardneriana showed activity against Staphylococcus aureus and Candida guilliermondii, while the essential oil of D. moricandiana was more active against Staphylococcus aureus and Candida albicans.

Ultrastructural study of morphological changes in Schistosoma mansoni after in vitro exposure to the monoterpene rotundifolone

INTRODUCTION: Schistosomiasis, a parasitic disease caused by trematode flatworms of the genus Schistosoma, affects more than 200 million people worldwide, and its control is dependent on a single drug, praziquantel. Here, we report the in vitro effect of rotundifolone, a monoterpene isolated from Mentha x villosa (Lamiaceae), on Schistosoma mansoni adult worms. METHODS: The in vitro effect of rotundifolone on adult Schistosoma mansoni was evaluated by analysis of behavior and mortality and through a scanning electron microscopic analysis of ultrastructural changes in the tegument of the worms. RESULTS: At concentrations of 3.54 and 7.09μg/mL-1 rotundifolone, no worm mortality was observed at any of the sampling intervals. A minor reduction in movement of the tail, suckers, and gynecophoral canal membrane was observed after 96 h of exposure to 7.09μg/mL-1 rotundifolone. At 70.96μg/mL-1, a lack of movement was observed from 72h onwards and all worms were deemed dead; similar effects were observed at 48h with 177.4μg/mL-1, and at 24h with 354.8μg/mL-1 and 700.96μg/mL-1. Rotundifolone also caused death of all parasites and separation of coupled pairs into individual males and females after 24h at 354.8μg/mL-1. CONCLUSIONS: The main changes in the tegument induced by the different ROT treatments were: after 24h incubation, bubble lesions spread over the entire body and loss of tubercles occurred in some regions of the ventral region.

Chemical composition and antimicrobial activity of essential oil from leaves of Maytenus obtusifolia Mart. (Celastraceae).

Abstract The essential oil of the leaves of Maytenus obtusifolia (Celastraceae) was analyzed using both GC and GC/MS. The results revealed 17 constituents among which octadeca-9,12,15-trienol (31.1%), hexadenoic acid (30.0%), methyl linoleate (5.7%) and dodecanoic acid (4.6%) bore the largest percentages. The antimicrobial activity of M. obtusifolia oil was studied using the agar diffusion test on 13 strains of bacteria, and against fungus and yeast. The oil showed significant antimicrobial activity against Sthaphylococcus aureus (ATCC 6538), Escherichia coli (ATCC 18739), Listeria monocytogenes (ATCC 9610), Candida albicans (ATCC 13803), Candida tropicalis (LM 37), Candida guilliermondii (LM V70) and Aspergillus flavus (LM 247).

The anxiolytic-like effect of 6-styryl-2-pyrone in mice involves GABAergic mechanism of action

The present work aims to investigate the anxiolytic activity of 6-styryl-2-pyrone (STY), obtained from Aniba panurensis, in behavioral tests and amino acids dosage on male Swiss mice. The animals were treated with STY (1, 10 or 20 mg), diazepam (DZP 1 or 2 mg/kg) or imipramine (IMI 30 mg/kg). Some groups were administered with flumazenil, 30 min before administration of the STYor DZP. The behavioral tests performed were open field, rota rod, elevated plus maze (EPM), hole-board (HB) and tail suspension test (TST). After behavioral tests, these animals were sacrificed and had their prefrontal cortex (PFC), hippocampus (HC) and striatum (ST) dissected for assaying amino acids (aspartate- ASP, glutamate- GLU, glycine- GLY, taurine- TAU and Gamma-aminobutyric acid- GABA). In EPM test, STY or DZP increased the number of entries and the time of permanence in the open arms, but these effects were reverted by flumazenil. In the HB test, STY increased the number of head dips however this effect was blocked by flumazenil. The effects of the STY on amino acid concentration in PFC showed increased GLU, GABA and TAU concentrations. In hippocampus, STY increased the concentrations of all amino acids studied. In striatum, STY administration at lowest dose reduced GLU concentrations, while the highest dosage caused the opposite effect. GLI, TAU and GABA concentrations increased with STY administration at highest doses. In conclusion, this study showed that STY presents an anxiolytic-like effect in behavioral tests that probably is related to GABAergic mechanism of action.