Antimicrobial compounds detected in Bocconia arborea extracts by a direct bioautographic method

Background. Among the numerous in vitro methods for studying the antimicrobial activity of plant drugs, bioautography has found widespread applications, especially for the detection of new compounds in complex plant extracts. Methods. This paper describes the results obtained during the application of the bioautographic method to detect antimicrobial compounds in a chloroformic extract of leaves and steams of Bocconia arborea, a plant used profusely in traditional medicine for the treatment of diverse infectious disease. Results and Conclusions. The method allows for the detection of spots of growth inhibition of cultures directly in the extract thin layer chromatographic plate previously dispersed with a broth culture containing the microorganisms. The procedure also allowed for the detection of the presence of several products in the B. arborea extract with considerable activity against five different microorganisms. Additonally, the method allowed the determiantion that the antimicrobial activity is due to compounds of probable alkaloid origin

Historia natural y herbolaria medicinal / Natural history and medicinal herbaria

Ensayo dividido en tres tiempos, que intenta un análisis comparativo sobre la forma en que miraban a la naturaleza las dos culturas enfrentadas en el siglo XVI: los exploradores y los naturalistas.

Quercetin glycosides in Psidium guajava L: leaves and determination of a spasmolytic principle

The traditional herbal remedy from Psidium guajava leaves had been medically proposed in mexico as effective treatment of acute diarrhea. A methanolic leaf extract was subjected to a bioassay-guided isolation of spasmolytic constituents. Six fractions were separated on a polyvinylpolypyrrolidine (PVPP) columm using a water methanol-gradient. The fraction containing flavonols inhibited peristalsis of guinea pig ileum in vitro. A trace of quercetin aglycone together with five glycosides was isolated from this active fraction and identified as quercentin 3-O-alpha-L-arabinoside (guajaravin); quercetin 3-O-ß-D-glucoside (isoquercetin); quercetin 3-O-ß-D-galactoside (hyperin); quercetin 3-O-ß-L-rhamnoside (quercitrin) and quercetin 3-O-gentobioside. Biological activity of each pure compound was studied in the same bioassay. Obtained results suggets that the spasmolytic activity of the Psidium guajava leaf remedy is mainly due to the aglycone quercetin, present in the leaf and in the extract mainly in the form of live flavonols, and whose effect is produced when these products are hydrolyzed by gastrointestinal fluid

Calcium-antagonist effect of quercetin and its relation with the spasmolytic properties of Psidium guajava L

The antidiarrheal properties of water ad methanolic extracts of Psidium guajava leaves have been demonstrated with anteriority and their spasmolytic effect was attributed to quercetin, a flavonoid conatined in this plant. The present paper reports the intestinal smooth muscle relaxation produced by quercetin on isolated guinea pig ileum previously contracted by a depolarizing KCl solution. Quercetin also inhibited intestinal contraction induced by different concentrations of calcium, shifting the contraction curve to the right showing a clear clacium-antagonistic efecct. Quercetin effect on ileal and aortic smooth muscles ar compared, the ileum being more sensitive to this flavonoid. The clacium antagonist property of quercetin is discussed and also its contribution to explain the spasmolytic effect of this popular herbal remedy

Modelo de perfusión intraluminal del íleon del cobayo in vitro en el estudio de propiedades antidiarréicas de la guayaba (Psidium guajava) / Intraluminal perfusion model of in vitro guinea pig's ileum as a model of study of the antidiarrheic properties of the guava (Psidium guajava)

Este trabajo describe un modelo in vitro para valorar extractos de plantas medicinales a los que se les atribuyen propiedades antidiarréicas. La preparación se realiza con un segmento de ileón de cobayo que se coloca en una cámara de perfusión especialmente diseñada para hacer pasar por la luz intestinal el producto bajo estudio, mientras se estímula eléctricamente el tejido. Cuando el producto posee acción espasmolítica se registra la modificación que provoca sobre la amplitud del reflejo peristáltico. El modelo se ensayó en el estudio de las propiedades antidiarréicas de diversos extractos de hojas de guayaba (Psidium guajava Linn.). Se discuten las ventajas de esta preparación particularmente útil para el estudio de extractos íntegros de plantas medicinales que suelen administrarse por vía oral

Propiedades farmacológicas in vitro de algunos extractos de Mimosa tenuiflora (tepescohuite) / In vitro pharmacological properties of some extracts of Mimosa tenuiflora (tepescohuite)

Se investigaron las propiedades de varios extractos de corteza de tepescohuite, Mimosa tenuiflora (Willd.) Poir. utilizando modelos biológicos in vitro, se observó que el extracto de acetato de etilo, cuyo contenido en taninos fue elevado, presentó actividad antimicrobiana; el extracto butanólico, rico en alcaloides, modificó de manera importante la excitabilidad de la musculatura lisa. Los extractos butanólico y metanólico produjeron hemólisis, posiblemente atribuible a su contenido en saponinas. Se discute la variedad de compuestos con propiedades biodinámicas que contiene este producto natural

Efecto producido por la fracción de alcaloides de Mimosa tenuiflora (tepescohuite) sobre el reflejo peristáltico del íleon de cobayo / The effect produced by the alkaloidal fraction of Mimosa tenuiflora (tepescohuite) upon the peristaltic reflex in quinea pig's ilium

De la corteza de tepescohuite, Mimosa tenuiflora (Willd.)Poir. Se obtuvo una fracción de alcaloides compuesta por una indolalquilamina acompañada de otras tres bases monoritarias. Se demuestra que esta fracción es la responsable del efecto inhibidor del reflejo peristáltico descrito en un trabajo anterior