Aislamiento e identificación de compuestos con actividad antiobesidad y antiadipogénica de Thevetia peruviana / Isolation and identification of anti-obesity and anti-adipogenic compounds from Thevetia peruviana

Thevetia peruviana ha sido utilizada en la medicina tradicional mexicana por sus efectos adelgazantes. Para la identificación de las fracciones y los compuestos activos de T. peruviana se utilizó cromatografía en columna abierta y las fracciones obtenidas se evaluaron en ratones con obesidad inducida con glutamato monosódico. Como control positivo se utilizó Orlistat y los tratamientos se administraron oralmente una vez al día durante 8 semanas. La fracción con mayor actividad fue sub-fraccionada y, con la intención de evitar el uso de más ratones, los productos fueron seleccionados por su capacidad para inhibir la adipogénesis en la línea celular 3T3-L1. Los animales tratados con la fracción F-B mostraron un aumento de peso significativamente menor y mantuvieron la sensibilidad a la insulina, así como, niveles significativamente más bajos de colesterol y triglicéridos. El análisis de GC-MS indicó que esta fracción activa está compuesta principalmente por los ácidos palmítico (1), oleico (2) y octadacanoico (3), 2-palmitoil glicerol (4), 2-oleoil glicerol (5) así como la estigmastenona (6).

Thevetia peruviana has been used in Mexican traditional medicine for its slimming effects. Active fractions and compounds from T. peruviana were isolated and identified by means of gravitational open-column chromatography, and the fractions were evaluated on mice with MonoSodium Glutamate-induced obesity. Orlistat was used as positive control, and treatments were administered, orally, once a day for 8 weeks. The fraction with higher activity was sub-fractioned and, with the intention of avoiding using more mice, the fractions were analyzed by evaluating their capability to inhibit adipogenesis in the 3T3-L1 cell line. Animals treated with the F-B fraction revealed a significantly smaller weight increase and maintained adequate insulin sensitivity, and significantly lower blood levels of cholesterol and triglycerides. The active compounds that demonstrated greatest adipogenesis inhibition were palmitic acid (1), oleic acid (2), octadecanoic acid (3), 2-palmitoyl glycerol (4), 2-oleoyl glycerol (5) and stigmastenone (6).

Influence of two hypoglycemic Cucurbitaceae (Cucurbita ficifolia Bouché and Ibervillea sonorae Greene) on ATP-sensitive potassium channels in rat aortic rings / Influencia de dos Cucurbitaceae (Cucurbita ficifolia Bouché e Ibervillea sonorae Greene) sobre los canales de potasio sensibles a ATP en anillos aórticos de rata

Cucurbita ficifolia Bouché fruit containing D-chiro-inositol and Ibervillea sonorae Greene root containing cucurbitane-type glycosides are used to control diabetes in Mexico. Although the hypoglycemic effect of both plants has been demonstrated and some active compounds proposed, their mechanisms are still unknown. The aim of this study was to determine if the incubation with both aqueous extracts avoids the inhibition of contraction induced by phenylephrine similarly to glibenclamide in rat aortic rings. The hypoglycemic aqueous extracts of C. ficifolia and I. sonorae were characterized for their content of either D-chiro inositol or cucurbitanes respectively, and then we assayed the characterized extracts in vitro on the diazoxide-induced relaxation of rat aortic rings precontracted with phenylephrine, using as positive control glibenclamide. I. sonorae extract blocked the KATP channels in a concentration-dependent manner (p < 0.05), whereas C. ficifolia extract had no effect on these channels. I. sonorae extract produces a hypoglycemic effect through a similar mechanism to sulphonylureas in this experimental model; however, hypoglycemic action of C. ficifolia extract should be explained by an independent KATP channels mechanism.

Los frutos de Cucurbita ficifolia conteniendo D-quiro-inositol y las raíces de Ibervillea sonorae conteniendo glucósidos tipo cucurbitano son empleados en el control de la diabetes en México. Aunque el efecto hipoglucémico de ambas plantas ha sido demostrado y se han propuesto algunos de sus compuestos activos, aún se desconoce su mecanismo de acción. El objetivo de este estudio fue determinar si la incubación con ambos extractos acuosos evita la inhibición de la contracción inducida por fenilefrina de manera similar a la glibenclamida en anillos aórticos de rata. Los extractos acuosos hipoglucémicos de C. ficifolia e I. sonorae fueron caracterizados en su contenido de D-quiro inositol o cucurbitanos, respectivamente y entonces fueron estudiados en un modelo in vitro en la relajación inducida por diazóxido en anillos aórticos previamente contraídos con fenilefrina, usando como control positivo glibenclamida. El extracto de Ibervillea sonorae bloqueó los canales KATP de manera dosis-dependiente (p < 0.05), mientras que Cucurbita ficifolia no tuvo efecto en esos canales. El extracto de I. sonorae produce efecto hipoglucémico a través de un mecanismo similar al de las sulfonilureas en este modelo experimental; por su parte, la acción hipoglucemiante del extracto de C. ficifolia debe ser explicado mediante un mecanismo independiente de los canales KATP.

Inhibition of acetylcholinesterase activity by hidroalcoholic extractand their fractions of Bouvardia ternifolia (Cav. ) Shcltdl (Rubiaceae) / Inhibición de la actividad de acetilcolinesterasa por el extracto hidroalcohólico y sus fracciones de Bouvardia ternifolia (Cav. ) Shcltdl (Rubiaceae)

The hydroalcoholic extract (BtHA) and its fractions of Bouvardia ternifolia were evaluated as inhibitors of the activity of the acetylcholinesterase enzyme utilizing the in vitro method (Ellman). BtHA inhibited the acetylcholinesterase enzyme competitively (IC50 = 0.6 ug/ml); the ethyl acetate fraction (BtF-AcOEt) caused mixed-type inhibition (IC50 = 0.96 ug/ml). A fraction insoluble on methanol (Bt-Faq-1) showed a mixed-type inhibition (CI50 = 0.96 ug/ml). Finally, the methanol-soluble fraction (Bt-Faq-2), presented complex, mixed-type inhibition that corresponds to the C5 system ( alpha= 0.740 and beta = 0.842). Rutin, quercetin, kaempferol and ursolic acid were detected by HPLC and the concentration of these compounds was different in each fraction.

El extracto hidroalcohólico (BtHA) y fracciones provenientes de Bouvardia ternifolia fueron evaluadas como inhibidores de la enzima acetilcolinesterasa utilizando el método enzimático propuesto por Ellman. BtHA inhibe a la enzima de manera competitiva (IC50 = 0.6 ug/ml); la fracción de acetato de etilo (BtF-AcOEt) provoca una inhibición mixta (IC50 = 0.96 ug/ml). La fracción insoluble en metanol (Bt-Faq-1) mostró una inhibición tipo mixta (CI50 = 0.96 ug/ml). Finalmente la fracción soluble en metanol, Bt-Faq-2, inhibe a la enzima presentando una inhibición mixta que corresponde a un sistema C5 ( alfa= 0.740 and beta= 0.842). Mediante HPLC se detectó rutina, quercetina, canferol y ácido ursólico la concentración de estos compuestos fue diferente en cada fracción.

Efecto de Bursera grandiflora sobre el peso corporal y lipemia en ratones obesos / Effect of Bursera grandiflora on body weight and lipemia in obese mice

Obesity and overweight are clearly related to the caloric intake that leads to a chronic systemic inflammation of low degree. Pharmacological therapy is highly recommended for this disease. Within the Burseraceae family there are species used empirically for the treatment of obesity; one of them, Bursera grandiflora, is also reported for exhibiting anti-inflammatory properties. Evaluate the effect produced by B. grandiflora on a mice model of obesity, its toxicity potential, and chemical identification of the major chemical compound. Mice of the C57B1/6 strain were used. All animals were fed for 8 weeks with a hypercaloric diet. Afterwards, during 7 weeks, animals were daily administered with the hidro-alcoholic extract from B. grandiflora or water (control). At the end of the administration period, plasma cholesterol and triglycerides levels were measured. Moreover, toxicity tests were carried out in mice after acute and chronic administering the B. grandiflora extract. Finally, the main compound in the active extract was identified. Animals treated with the B. grandiflora extract showed a greater food consumption and, paradoxically, without increasing the body weight. Moreover, a decrease of the plasma-triglycerides was observed. Toxicological evaluation showed that the extract administration did not produce any death of the experimental animals or modifications on the organs or behavior. The major compound identified in the extract was scopoletin.

El sobrepeso y la obesidad están claramente vinculados con la ingesta calórica que lleva a la instalación crónica de inflamación sistémica de bajo grado. La terapia farmacológica es altamente recomendable para este padecimiento. Dentro de la familia Burseraceae existen especies utilizadas para el tratamiento de la obesidad, de las cuales, Bursera grandiflora es referida también por su efecto anti-inflamatorio. Evaluar el efecto de B. grandiflora en un modelo de obesidad, su potencial toxicológico, e identificación del compuesto mayoritario. Se utilizaron ratones C57Bl/6 alimentados durante 8 semanas con dieta hipercalórica. Posteriormente, durante 7 semanas se administró diariamente un extracto hidroalcohólico de B. grandiflora o agua (control). Al final se cuantificaron colesterol y triglicéridos. Además, se realizaron pruebas de toxicidad en ratones administrando el extracto de B. grandiflora en forma aguda y subcrónica. Finalmente, se identificó el compuesto mayoritario. Los animales tratados con B. grandiflora registraron el mayor consumo de alimento y, paradójicamente, sin mostrar un crecimiento ponderal y con una disminución de los triglicéridos. Las evaluaciones de toxicología revelaron que la administración del extracto no produjo muertes en los animales de experimentación, ni cambios orgánicos o de comportamiento. El compuesto mayoritario identificado en el extracto activo fue escopoletina.

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