ÚLTIMOS AVANCES EN LA QUÍMICA Y ACTIVIDADES BACTERIOLÓGICAS EN LAS PLANTAS MEDICINALES= Medicinal plants, last advances on chemistry and bacteria activities on the medicinal herbs

cf. Schang, Rev. med. vet. (Buenos Aires) 11, (1929).  The seeds of cockleburs (Xanthium cavanillesii Schou) when given after a 24-hr. fast to about 1.7 kg. rabbits at the rate of 20 to 30 g. caused death.  Small seedling plants were also fatal at the rate of 30 g. per rabbit.  Guinea pigs weighing about 450 g. were killed by 10 g. of seeds, cotyledons, or seedlings.  Suckling pigs that weighed about 5 kg. were killed by 5 g. of seeds or by 16 to 31 g. of cotyledons or seedlings.  Damage to the kidneys was the most obvious symptom and other post morten findings, such as lesions in the liver or derangements in the blood, were probably referable to antecedent renal damage.  Tests indicated that a saponin was present.  Methods for controlling the plant as a weed are presented.  323 references not referred to are included.

The present study was designed to examine the effects of a sesquiterpene lactone isolated from Artemisia douglasiana Besser (dehydroleucodine), a xanthanolide sesquiterpene isolated from Xanthium cavanillesii Schouw (xanthatin) and a semisynthetic butenolide (3-benzyloxymethyl-5H-furan-2-one) on mast cell degranulation induced by compound 48/80.  Peritoneal mast cells from male adult Sprague-Dawley rats were purified in Percoll, preincubated in the presence of test lactones (dehydroleucodine, xanthatin or 3-benzyloxymethyl-5H-furan-2-one) and then challenged with the mast cell activator compound 48/80 (10 microg/ml).  Concentration-response and kinetic studies of mast cell serotonin release evoked by compound 48/80, evaluation of mast cell viability and morphology by light and electron microscopy, and comparative studies using ketotifen and sodium chromoglycate were carried out.  Serotonin release studies, carried out together with morphological studies, showed the effectiveness of the above lactones to stabilize mast cells.  The comparative study with ketotifen and sodium chromoglycate, well known mast cell stabilizers, showed the following order of potency dehydroleucodine=xanthatin>3-benzyloxymethyl-5H-furan-2-one> or =ketotifen/sodium chromoglycate to inhibit mast cell serotonin release induced by compound 48/80.  The present study provides the first strong evidence in favour of the hypothesis that dehydroleucodine, xanthatin and 3-benzyloxymethyl-5H-furan-2-one inhibit compound 48/80-induced serotonin release from peritoneal mast cells, acting thus as mast cell stabilizers.  Our findings may provide an insight into the design of novel pharmacological agents which may be used to regulate the mast cell response.

The preventive effect of natural xanthanolides as well as a series of synthetic derivatives on ulcer formation induced by absolute ethanol in rats was examined.  Among the compounds tested, xanthatin gave the strongest protective activity.  The inhibitory action exerted by this molecule on the lesions induced by 0.6N HCl and 0.2N NaOH was highly significant, reducing ulceration in the range of 58-96% at a dose from 12.5 to 100mg/kg.  These results appear to confirm that the presence of a non-hindered alpha,beta-unsaturated carbonyl group seems to be an essential structural requirement for the gastric cytoprotective activity of these compounds.  In order to explore this possibility, a theoretical conformational analysis was performed.  We suggest that the mechanism of protection would involve, at least in part, a nucleophylic attack of the sulfhydryl group from the biological molecules present in the gastric mucosa to electrophylic carbons accessible in suitable Michael acceptors.

Three outbreaks of Xanthium cavanillesii intoxication occurred in the spring in the State of Rio Grande do Sul, southern Brazil.  All outbreaks were observed in paddocks with sandy soils in flood plains along water streams.  The paddocks had been under water, and after water withdrawal cattle were introduced to those areas which had seedlings of X cavanillesii and shortage of other forage.  Mortality varied between 3 and 58%.  Most animals were found dead or died a few hours after observation of clinical signs.  The main lesion was a swollen liver with acute diffuse centrilobular necrosis.  The disease was produced experimentally by feeding cotyledons at 0.75 and 1% bw in calves, and at 1.5 and 2% bw in sheep.  Clinical signs and gross and microscopic lesions were similar to those observed in field cases.  X cavanillesii in the 4-leaf stage with the attached cotyledons was also toxic for cattle and sheep, but the same plant without cotyledons lost its liver toxicity.  The lethal dose of cotyledons divided in 5 daily doses was not toxic for cattle and sheep, demonstrating the non-cumulative effect of the plant.

PARTE UTILIZADA= Used part: Planta entera. 

ACCIÓN FARMACOLÓGICA= Pharmacological action: Como cataplasmas ablandativos, en las contusiones y heridas infectadas; es tóxica para el ganado.

COMPOSICIÓN QUÍMICA= Chemical composition:Two optically active (-) pigments, cordiachrome G (4) and leucocordiachrome H (7), have been isolated from the wood of Patagonula americana. They have the same benzogeijerene skeleton as cordiachrome C with an additional chiral centre; leucocordiachrome H is a quinol. 

ZONA GEOGRÁFICA= Geografical zone: Uruguay. 

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Parte utilizada
Hojas, tallos, semillas y raíz.

Farmacodinamia - Acciones farmacológicas Son pocos aún los estudios llevados a cabo con esta especie. En ensayos de difusión en Agar, los extractos acuoso y clorofórmico de partes aéreas de X. cavanillesii demostraron una importante actividad antimicrobiana frente a Mycobacterium smegmatis y Candida albicans. (Cerdeiras et al., 2005) También se observó actividad inhibitoria sobre Staphylococcus aureus, siendo los compuestos responsables de la actividad derivados seco ambrosanólidos del tipo xantanol. (Cerdeiras et al., 2006) En el área inmunitaria, el extracto acetónico de partes aéreas demostró un potencial inmunomodulador in vivo (ratones) en el test, que mide el índice granulopéctico (actividad fagocítica in vivo), en las tres dosis orales ensayadas: 2, 20 y 200 mg/kg. En cambio, los extractos acuoso y diclorometánico no resultaron activos. (Etcheverry et al., 2005) En úlceras gástricas experimentales (ratas) inducidas con etanol, las xantatinas demostraron reducir las lesiones en un rango entre el 58-96% en las dosis ensayadas: 12,5 a 100 mg/kg. La presencia de grupos carbonilos α y β insaturados parecería jugar un rol fundamental en el mecanismo gastroprotector. (Favier etc al., 2005) Por su parte, las lactonas sesquiterpénicas de X. cavanilliesii demostraron inhibir in vitro agentes promotores de la degranulación de mastocitos. (Penissi et al., 2009) A nivel cutáneo, los extractos hidrofílicos de X. cavanilliesii demostraron acelerar los procesos de cicatrización de heridas. (Schmidt etc al., 2009)

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Origen y distribución: nativa de América del Sur, se extendió a lo largo de subcontinente, especialmente en Argentina y Uruguay, donde crece espontáneamente. Se encuentra en los campos, pastos, a lo largo de las costas y playas de arena. Se considera como maleza y es una planta muy invasora.

Partes usadas: hojas, semillas, raíces.

Propiedades: purgante, antiespasmódica, diurética, anti diarreica, antiulcerogena, antimicrobiana, antiinflamatoria, cicatrizante.

1) GONZALEZ, Matías ; LOMBARDO, Atilio ; VALLARINO, Aida. Plantas de la medicina vulgar del Uruguay. Montevideo : Talleres Gráficos, 1937.

2) MOIR, M.; THOMSON, R.H. Naturally occurring quinones. Part XXIII. Cordiachromes from patagonula americana L. Journal of the Chemical Society, Perkin Transactions 1. 1973, nº15, 1556-1561.
 
3) CAMPORI, A. S., et al. Ratera; Carrado, J. M. The toxicity of the cocklebur. Revista de Medicina y Ciencias Afines . 1946, vol.8, p.633-646.
 
4) PENISSI Alicia B., et al. Novel anti-ulcer alpha,beta-unsaturated lactones inhibit compound 48/80-induced mast cell degranulation. European journal of pharmacology . 2009, vol.612, nº1-3, p.122-130.
 
5) FAVIER, Laura S., et al.  Anti-ulcerogenic activity of xanthanolide sesquiterpenes from Xanthium cavanillesi in rats. Journal of ethnopharmacology. 2005, vol.,100, nº3, p.260-267.
 
6) MENDEZ, M C; DOS SANTOS, R C; RIET-CORREA, F. Intoxication by Xanthium cavanillesii in cattle and sheep in southern Brazil. Veterinary and human toxicology. 1998, vol.40, nº3, p.144-147.

7) Plantas medicinales autóctonas de la Argentina. Bases científicas para su aplicación en atención primaria de la salud / Jorge Alonso y Cristian Jorge Desmarchelier. - 1a ed. - Ciudad Autónoma de Buenos Aires: Corpus Libros Médicos y Científicos, 2015.

8) El uso popular de las plantas medicinales en Uruguay/Grosso, Lilia. - Icei, 2010. -- p. 88