Galloyl flavonoids from Acacia farnesiana pods possess potent anthelmintic activity against Haemonchus contortus eggs and infective larvae.

ETHNOPHARMACOLOGY RELEVANCE: Acacia farnesiana (L.) Willd is a shrub legume used as condiment, medicinal plant and bioactive herbage. This species is used in traditional medicine of several countries to relieve the symptoms of gastrointestinal diseases, diarrhoea, stomach pain and typhoid as well as astringent, antidysenteric and anthelmintic. Some studies have shown that this plant displayed anthelmintic activity against several gastrointestinal nematode parasites of livestock, and also against parasites of human beings, such as malaria. AIM OF THE STUDY: This work describes the isolation and chemical identification of the anthelmintic compounds of Acacia farnesiana pods against eggs and infective larvae of the sheep parasitic nematode Haemonchus contortus. The bio-guided chemical fractioning of A. farnesiana pods using ethyl acetate against H. contortus eggs and infective larvae allowed for the identification of naringenin 7-O-(6″-galloylglucoside) (flavonol group) as the compound responsible for the anthelmintic activity against this important parasitic nematode. MATERIALS AND METHODS: Anthelmintic activity was assessed using the egg hatching inhibition assay (EHI) and mortality tests. A complete hydroalcoholic extract (HA-E) at 12.5-50 mg/mL, an aqueous fraction (Aq-F) at 3.12-25 mg/mL and an ethyl acetate fraction (EtOAc-F) at 3.12-25 mg/mL were analysed in the first selection phase. The purification of compounds through the chromatographic separation of the organic fraction resulted in nine less complex mixtures (C1F1, C1F2, C1F3, C1F4, C2F1, C2F2, C2F3, C2F4 and C2F5) that were assessed at 0.62-5 mg/mL concentrations. In addition, thiabendazole (0.6 mg/mL) and ivermectin (5 mg/mL) were used as positive controls. Likewise, distilled water and 4% methanol were used as negative controls. The bioactive compounds of EtOAc-F were obtained and characterised through chromatographic processes like open column chromatography, thin layer chromatography (TLC), high performance liquid chromatography (HPLC), ultra-performance liquid chromatography (UPLC) and gass chromatography-mass detection (GC-MS). Bioactive compounds were identified by spectroscopy (1H and 13C NMR) and mass spectrometric analysis. Additionally, the H. contortus eggs and infective larvae exposed to the bioactive compounds were observed through environmental scanning electron microscopy (ESEM) and confocal laser scanning microscopy (CLSM). Data were analysed based on a completely randomised design using ANOVA through a general linear model. RESULTS: The EtOAc-F fraction showed the highest ovicidal and larvicidal activities, at close to 100% at 3.12 and 6.25 mg/mL, respectively. The treatments C1F2, C1F3 and C2F3 displayed the main ovicidal activity (80-100%) at 2.5 mg/mL. The major compounds found in these sub-fractions were identified as galloyl derivatives and flavanones, including gallic acid (1), methyl gallate (2), ethyl gallate (3), naringin (4), naringenin 7-O-(4″, 6″-digalloylglucoside) (5), naringenin 7-O-(6″-galloylglucoside) (6) and naringenin (7). Likewise, the ESEM and CLSM images showed that the assessed compounds adhered to the eggshell and the external cuticle of the larvae. CONCLUSION: These results indicate that A. farnesiana pods contain nematocidal compounds and might be promising natural anthelmintic agents against H. contortus. This leguminous plant could be used as a nutraceutical food source for the control of gastrointestinal nematodes in small ruminants.

Promoting laccase sensing activity for catechol detection using LBL assemblies of chitosan/ionic liquid/phthalocyanine as immobilization surfaces.

The performance of electrochemical laccase-based biosensors can be improved by immobilizing the enzyme on composite Layer-by-Layer (LbL) supports in which materials with complementary functions are combined. LbL films are formed by layers combining an electrocatalytic material which favors electron transfer (sulfonated copper phthalocyanine, CuPcS(-)), an ionic liquid which enhances the electrical conductivity of the layers (1-butyl-3-methylimidazolium tetrafluoroborate, IL(+)) and a material able to promote enzyme immobilization (chitosan, CHI(+)). Composite films with different structures have been demonstrated to be efficient electrocatalysts, producing an increase in the magnitude of the responses towards catechol. The most intense and reproducible electrocatalytic effect was observed when a layer of the CuPcS(-) was placed on top of a layer formed by a mixture of CHI(+) + IL(+) to obtain [CHI(+) + IL(+)|CuPcS(-)]2 films. Biosensors with laccase immobilized on the surface of the LbL layers [CHI(+) + IL(+)|CuPcS(-)]2|Lac showed mediated electron transfer between the redox enzyme and the film and a reproducibility of device-to-device performance of 4.1%. The amperometric biosensor showed a sensitivity of 0.237 A·M-1 and a linear detection range from 2.4 µM to 26 µM for catechol. The excellent Limit of detection (LOD) of 8.96·10-10 M (3·σ /m) is one order of magnitude lower than that obtained in similar studies. A Michaelis-Menten constant of 3.16 µM confirms excellent enzyme-substrate affinity.

Galloyl derivatives from Caesalpinia coriaria exhibit in vitro ovicidal activity against cattle gastrointestinal parasitic nematodes.

Gastrointestinal nematodes (GIN) are responsible for enormous economic losses worldwide. The use of anthelmintic drugs reduces the parasitic burden in ruminants. However, the excessive use of these drugs triggers anthelmintic resistance in these parasites, which leads to a worrisome inefficacy of most of the commercially available antiparasitic drugs. Caesalpinia coriaria is an arboreal legume possessing medical properties, although the antiparasitic potential of this plant against animal parasitic nematodes has not yet been studied. The aim of this study was to assess the in vitro ovicidal activity of a hydro-alcoholic extract (HA-E) from C. coriaria fruits against GIN and to identify the compounds responsible for this activity through an egg hatch inhibition (EHI) assay. GIN eggs obtained from cattle faeces were used in bio-guided assays. The HA-E was subjected to a liquid-liquid extraction using water and ethyl acetate to obtain two fractions, an organic fraction (EtOAc-F, 27% yield) and an aqueous (Aq-F, 73% yield) fraction. The chromatographic fractionation of the EtOAc-F (2 gr) was performed on a glass column packed with silica gel and eluted with dichloromethane/methanol with 10% ascending polarity. The bioactive compounds were analysed using high-performance liquid chromatography (HPLC) with UV detection, nuclear magnetic resonance (NMR) spectroscopy and mass spectroscopy (MS). The HA-E extract and the EtOAc-F showed ovicidal activity at a LC50 of 0.92 and 0.16 mg/mL, respectively. A concentration-dependant effect was observed in both treatments. Chromatographic fractionation of the EtOAc-F, allowed for the isolation and characterisation of three important compounds: methyl gallate (1), gallic acid (2) and an unidentified compound (UC). The bioactive molecules (2 and UC) displayed an ovicidal activity close to 100% at 1 mg/mL concentration. The results of this work show that gallic acid (2) isolated from C. coriaria fruits is responsible for its ovicidal activity. The use of Caesalpinia coriaria could be explored in future studies as an environmentally-friendly alternative for the control of GIN in ruminants.

Utilidad de la fitoterapia en Atención Primaria. Trastornos gastrointestinales / Usefulness of the phytotherapy in primary health care: gastrointestinal disorders

El uso tradicional de las plantas medicinales para el tratamiento de diversas enfermedades por los diferentes pueblos es muy antiguo. Actualmente los trabajos en experimentación animal así como los estudios clínicos han confirmado la utilidad de la fitoterapia. Los trastornos intestinales (estreñimiento y diarrea), son con frecuencia tratados con plantas medicinales, siendo en Atención Primaria donde tienen una utilidad considerable. Este trabajo es una revisión de las propiedades, actividades y usos de diferentes plantas para diversos trastornos intestinales en Atención Primaria (AU)