Allelotoxicity of Parthenium leaf extracts on cytomorphological behaviour of sunflower (Helianthus annuus).

In recent decades allelopathy has gained much attention in the sustainable agricultural systems. It is necessary to trace out the mechanism of action of allelochemicals of plants on other plants. Allelochemicals of different plants interact differently with each other. In the present context an attempt has been made to study the influence of allelochemicals released by Parthenium on the growth, morphology and cytology of Helianthus annuus, both being strong allelopathic plants. The lower concentration of decomposed Parthenium leaves showed enhancing effect while higher doses depicted suppressive effect on growth and morphology of Helianthus annuus. However, cytological studies of pollen mother cells (PMCs) revealed increase in abnormality percentage with increasing concentration of allelochemicals. This study suggests better understanding of allelochemicals interaction and their incorporation into the betterment of crop.

Characterization of toxin from cheilanthes fern and its effect on lymphocyte proliferation and DNA fragmentation.

Thin layer chromatography of aqueous extract of whole Cheilanthesfarinosa fern indicated the presence of ptaquiloside or ptaquiloside like compound, coinciding Rf values with that of Pterosin B standard. HPLC analysis revealed the presence of 26.3 mg/kg ptaquiloside. In vitro studies of the aqueous extract on lymphocyte culture revealed a correlation between stimulative indices and concentration of aqueous extract. Stimulation in lymphocyte proliferation was in order of bracken > cheilanthes > ConA> ptaquiloside standard. On incubation of lymphocyte with aqueous extract of ferns, no DNA damage was observed in isolated DNA.

Triagem fitoquímica preliminar de tetrapterys multiglandulosa A. Juss. (Malpighiaceae) / Preliminary phytochemical screening of tetrapterys multiglandulosa A. Juss. (Malpighiaceae)

Este trabalho foi desenvolvido com o objetivo de identificar os princípios tóxicos da tetrapterys multigalndulosa A. Juss. Realizou-se triagem fitoquímica nas folhas (brotos e maduras) frescas, através de marcha analítica clássica e Cromatografia em Camada Delgada (CCD) pesquisando-se os seguintes princípios ativos: heterosídeos antrasênicos, saponínicos, flavônicos, cardiotônicos, taninos (hidrolisáveis e condensados), alcalóides (terciários e quaternários), composto esteróides e cumarínicos. Os resultados obtidos mostraram na folha jovem e madura, presença de heterosídeos flavônicos e esteróides. Taninos condensados e alcalóides quaternários foram encontrados somente na folha madura.

Effect of bracken (Pteridium a quilinum) and dryopteris (Dryopteris juxtaposita) fern toxicity in laboratory rabbits.

Experimental studies with Bracken and Dryopteris ferns @ 25% concentrate ration mixture were conducted in rabbits. Fern fed rabbits showed progressive anaemia, leukopaenia, lymphopaenia and relative heterophilia. Significant elevations in serum enzymes like serum glutamate oxaloactate transminase (SGOT), serum glutamate pyruvate transminase (SGPT), alkaline phosphatase (ALP), urea and creatinine levels were seen. Histopathologically, rabbits showed mild to moderate vascular changes in most of visceral organs, vacuolar degenerative changes in hepatocytes, hypersecretory activity in intestine, presence of casts in renal tubules and degenerative changes in renal tubular lining epithelial cells. Dryopteris fed rabbits showed somewhat more severe degenerative and vascular changes in different intervals. A low level of toxic principle ptaquiloside was detected in Bracken and Dryopteris ferns by thin layer chromatography (TLC) and high-pressure liquid chromatography (HPLC) methods.

Chemical and biological demonstration of the presence of monofluoroacetate in the leaves of Palicourea marcgravii St. Hil

Cattle losses in Brazil have been attributed to Palicourea marcgravii St. Hil., a toxic plant for cattle. The crude extract from the leaves of P. marcgravii was successively fractionated using solvents with different polarities to determine whether monofluoroacetic acid and/or some other substance present in the leaves may be responsible for the acute symptoms caused by the plant. Authentic sodium monofluoroacetate (SMFA) was used fopr comparison. The only P. marcgravii fraction which induced seizures and death in intoxicated rats was water soluble. The signs and symptoms induced in the animals by the crude extract and water-soluble fraction were the same as induced by SMFA and included tonic seizures and other actions on the CNS. The dose-lelthality and dose-latency to the 1st seizure curves constructed for the water soluble fraction of the leaf extract (30-100 mg/Kg) and SMFA (0.6-3.0 mg/Kg) were parallel. Five animals per dose were used. The potency ratio of SMFA in relation to the water-soluble fraction of the leaf extract was 53.8 (dose-lethality curve) and 64.1 (dose latency to the 1st seizure curve). The water-soluble fraction contained a substance with hRf = 20 which the same as that of authentic SMFA. The 19F NMR spectra of authentic SMFA and the P. marcgravii water-soluble fraction were identical. These data demosntrate the presence of SMF in the water-soluble fraction of P. marcgravii leaves and show that monofluoroacetate is the active principle repsonsible for the signs and symptoms of acute intoxications

Intoxicación de una familia por Karwinskia humboldtiana (tullidora) / Familial intoxication by Karwinskia humboldtiana (tullidora)

La ingestión del fruto maduro de la Karwinskia humboldtiana, arbusto comúnmente conocido como tullidora o coyotillo, provoca una intoxicación descrita en la bibliografía como una parálisis fláccida, simétrica de los miembros inferiores, progresiva y ascendente, que en casos graves puede causar parálisis bulbar y muerte. Se presenta el caso de una familia en la que diez de sus trece miembros ingirieron accidentalmente el fruto de la tullidora; tres fallecieron: el padre y dos hijas. Además, se describe por primera vez, la determinación de las toxinas en sangre por medio de cromatografía en capa fina. Este método resulta útil para el diagnóstico diferencial con otras polirradiculoneuritis, v.gr. poliomielitis y Síndrome de Guillain-Barre

Neurodepressive action of a piscicidal glycoside of plant, Aesculus indica (Colebr.) in fish.

Sublethal concentration (2.6 mg/l) of a triterpene based piscicidal glycoside of A. indica damaged the neurons, fibre tracts and central correlation sites for gustatory, tactile and visceral sensory impulses in medulla oblongata of fish after prolonged poisoning. The fear, sinking to bottom, lack of schooling and non discriminatory pattern in treated fish were because of neurodepression. The jerky movement, ventilatory inefficiency, swallowing air bubbles and light pinkness of gills were due to the degradation of respiratory centres in the vagal lobes of toxified fish.