Nematocidal effects of natural phytoregulators jasmonic acid and methyl-jasmonate against Pratylenchus zeae and Helicotylenchus spp.

The aim of this study was to evaluate the nematocidal effects of natural phytoregulators jasmonic acid (JA) and methyl-jasmonate (MJ) against plant parasitic nematodes Pratylenchus zeae (Graham) (Pratylenchidae) and Helicotylenchus spp. (Hoplolaimidae). Both JA and MJ promoted elevated percentages of mortality in P. zeae and Helicotylenchus spp. after 12 and 24 h of nematodes exposition at different concentrations of jasmonates. Considering the potential use of jasmonates as biofertiliser added now for their nematocidal effects, our results are of relevance in terms of biotechnological application.

Erysothrine, an alkaloid extracted from flowers of Erythrina mulungu Mart. ex Benth: evaluating its anticonvulsant and anxiolytic potential.

In this study, we isolated the alkaloid erysothrine from the hydroalcoholic extract of flowers from E. mulungu and screened for its anticonvulsant and anxiolytic actions based on neuroethological and neurochemical experiments. Our results showed that the administration of erysothrine inhibited seizures evoked by bicuculline, PTZ, NMDA and most remarkably, kainic acid. Also, erysothrine induced an increase in the number of entries but not in the time spent in the open arms of the EPM. However, we did not notice any alterations in the light-dark choice or in the open-field tests. In preliminary neurochemistry tests, we also showed that erysothrine (0.001-10 µg/mL) did not alter the GABA or glutamate synaptossomal uptake and binding. Altogether, our results describe an alkaloid with anticonvulsant activity and mild anxiolytic activity that might be considered well tolerated as it does not alter the general behavior of the animals in the used doses.

Anticonvulsant profile of the alkaloids (+)-erythravine and (+)-11-α-hydroxy-erythravine isolated from the flowers of Erythrina mulungu Mart ex Benth (Leguminosae-Papilionaceae).

Neural mechanisms underlying the onset and maintenance of epileptic seizures involve alterations in inhibitory and/or excitatory neurotransmitter pathways. Thus, the prospecting of novel molecules from natural products that target both inhibition and excitation systems has deserved interest in the rational design of new anticonvulsants. We isolated the alkaloids (+)-erythravine and (+)-11-α-hydroxy-erythravine from the flowers of Erythrina mulungu and evaluated the action of these compounds against chemically induced seizures in rats. Our results showed that the administration of different doses of (+)-erythravine inhibited seizures evoked by bicuculline, pentylenetetrazole, and kainic acid at maximum of 80, 100, and 100%, respectively, whereas different doses of (+)-11-α-hydroxy-erythravine inhibited seizures at a maximum of 100% when induced by bicuculline, NMDA, and kainic acid, and, to a lesser extent, PTZ (60%). The analysis of mean latency to seizure onset of nonprotected animals, for specific doses of alkaloids, showed that (+)-erythravine increased latencies to seizures induced by bicuculline. Although (+)-erythravine exhibited very weak anticonvulsant action against seizures induced by NMDA, this alkaloid increased the latency in this assay. The increase in latency to onset of seizures promoted by (+)-11-α-hydroxy-erythravine reached a maximum of threefold in the bicuculline test. All animals were protected against death when treated with different doses of (+)-11-α-hydroxy-erythravine in the tests using the four chemical convulsants. Identical results were obtained when using (+)-erythravine in the tests of bicuculline, NMDA, and PTZ, and, to a lesser extent, kainic acid. Therefore, these data validate the anticonvulsant properties of the tested alkaloids, which is of relevance in consideration of the ethnopharmacological/biotechnological potential of E. mulungu.