Characterization of Fruit Development, Antioxidant Capacity, and Potential Vasoprotective Action of Peumo (Cryptocarya alba), a Native Fruit of Chile.

The peumo (Cryptocarya alba) is a native fruit from central Chile that belongs to the Lauraceae family. To characterize the development and the potential health benefits of this edible fruit, quality and physiological parameters, along with antioxidant capacity, were evaluated during three clearly defined developmental stages of the fruit in two seasons. The most distinguishable attributes of ripe fruit were the change in size and color. Low CO2 production and no detectable ethylene levels suggested non-climacteric behavior of the peumo fruit. Peumo demonstrate a significant increase in their antioxidant capacity per 1 g of fresh weight (FW) of the sample, from small to ripe fruit. Higher values in ripe fruit (FRAP: 37.1-38.3 µmol FeSO4/gFW, TEAC: 7.9-8.1 mmol TE/gFW, DPPH: 8.4-8.7 IC50 µg/mL, and ORAC: = 0.19-0.20 mmol TE/gFW) were observed than those in blueberry fruit (FRAP: 4.95 µmol FeSO4/gFW, TEAC: 1.25 mmol TE/gFW, DPPH: 11.3 IC50 µg/mL, and ORAC: 0.032 mmol TE/ gFW). The methanol extracts of ripe fruit displayed the presence of polyphenol acids and quercetin, an ORAC value of 0.637 ± 0.061 mmol TE per g dried weight (DW), and a high cellular antioxidant and anti-inflammatory potential, the latter exceeding the effect of quercetin and indomethacin used as standard molecules. Also, the assay of isolated rat aorta with endothelium-dependent relaxation damage demonstrated that the peumo extract induced vascular protection, depending on its concentration under a high glucose condition. These results demonstrate that these endemic fruits have a good chance as ingredients or foods with functional properties.

A Review of Endothelium-Dependent and -Independent Vasodilation Induced by Phytochemicals in Isolated Rat Aorta.

This review discusses the contribution of the use of the isolated rat aorta (IRA) as a model for the evaluation of extracts and metabolites produced by plants with a vasodilator effect in animals. This model continues to be a valuable approach for the search and development of new phytochemicals consumed as medicinal plants or foods. In most cases, the sources of phytochemicals have been used in folk medicine to treat ailments that include hypertension. In this model, the endothelium is emphasized as a key component that modulates the vessel contractility, and therefore the basal tone and blood pressure. Based on the functional nature of the model, we focused on studies that determined the endothelium-dependent and -independent vasodilatory activity of phytochemicals. We describe the mechanisms that account for aorta contraction and relaxation, and subsequently show the vasoactive effect of a series of phytochemicals acting as vasodilators and its endothelium dependence. We highlight information regarding the cardiovascular benefits of phytochemicals, especially their potential antihypertensive effect. On this basis, we discuss the advantages of the IRA as a predictive model to support the research and development of new drugs that may be of help in the prevention and treatment of cardiovascular diseases, the number one cause of death worldwide.

A Review of the Actions of Endogenous and Exogenous Vasoactive Substances during the Estrous Cycle and Pregnancy in Rats.

Vascular endothelium plays a key role in regulating cardiovascular homeostasis by controlling the vascular tone. Variations in sex hormones during the reproductive cycle of females affect the homeostasis of the cardiovascular system. Also, the evidence shows that estrogens show a cardioprotective effect. On this basis, this study describes some vascular responses induced by vasoactive substances during the estrous cycle in rats. We obtained the information available on this topic from the online databases that included scientific articles published in the Web of Science, PubMed, and Scielo. Many investigations have evaluated the vasoactive response of substances such as acetylcholine and norepinephrine during the estrous cycle. In this review, we specifically described the vascular response to vasoactive substances in rats during the estrous cycle, pregnancy, and in ovariectomized rats. In addition, we discussed the existence of different signaling pathways that modulate vascular function. The knowledge of these effects is relevant for the optimization and development of new treatments for some vascular pathologies.

t-Resveratrol Protects against Acute High Glucose Damage in Endothelial Cells.

Postprandial hyperglycemia in diabetic and nondiabetic subjects is associated with endothelial dysfunction. Evidence shows that high glucose generates oxidative stress and a pro-inflammatory state promoting the development of cardiovascular diseases. trans-Resveratrol (t-RV) has been shown to reduce cardiovascular risk. To determine whether t-RV acts as a protector against acute high glucose (AHG)-induced damage, two in vitro models, rat aortic rings (RAR) and human umbilical vein endothelial cells (HUVEC) were used. RAR pretreated with AHG (25 mM D-glucose) for 3 h dramatically decreased the endothelium-dependent relaxation (EDR) induced by acetylcholine in phenylephrine (PE)-precontracted vessels. However, coincubation with t-RV significantly mitigated the damage induced by AHG on EDR. Pretreatment with AHG did not affect the vasodilation induced by sodium nitroprusside. HUVEC treated with t-RV decreased cytotoxicity and reduced radical oxygen species production induced by AHG. Taken together, these results suggest that t-RV can mitigate the AHG-induced EDR damage through a mechanism involving ROS scavenging and probably an increase in the bioavailability of NO.

Vasodilatory properties of Solanum crispum Ruiz & Pav. a South American native plant / Propiedad vasodilatadora de Solanum crispum Ruiz & Pav. una planta nativa de América de Sur

Solanum crispum Ruiz & Pav. (S. crispum) is a southern South American native plant that is usually used in traditional medicine for the treatment of symptoms associated with both, acute and chronic ailments. Enema and infusion of leaves and stems are used to treat fever, headache, inflammation and hypertension. In this study, we aim to assess the vasoactive effect of hydroalcoholic extracts of S. crispum on isolated rat aorta rings. The hydroalcoholic extract of S. crispum induced a vasodilatory effect (42.6 +/- 4.1 percent) in aortic rings precontracted with phenylephrine (0.1 μM). The aortic relaxation was largely endothelium-dependent and mediated by nitric oxide (NO). The endothelium- and NO-dependence was demonstrated by a drastic fall in the dilatation induced by the extract when the endothelium was removed (10.6 +/- 2.3 percent) and when nitric oxide synthase (NOS) was inhibited (12.3 +/- 2.5 percent) by nitro-L-arginine (L-NNA). This result supports the popular use of S. crispum in the treatment of hypertension that may be due, at least in part, to the vasodilator effect of one o more compounds present in their leaves and stems. Further studies should be performed to clarify this phenomenon.

Solanum crispum Ruiz & Pav. (S. crispum) es una planta nativa de América del Sur meridional que se utiliza generalmente en medicina tradicional para el tratamiento de los síntomas asociados con dolencias agudas y crónicas. El enema y la infusión de las hojas y tallos se utilizan para tratar la fiebre, el dolor de cabeza, la inflamación y la hipertensión. El objetivo de este estudio fue evaluar el efecto vasoactivo de un extracto hidroalcohólico de S. crispum en anillos aislados de aorta de rata. El extracto hidroalcohólico de S. crispum indujo un efecto vasodilatador (42,6 +/- 4,1 por ciento) en anillos aórticos precontraídos con fenilefrina (0,1 μM). La relajación de la aorta fue en gran parte dependiente del endotelio y mediada por el óxido nítrico (NO). La dependencia de endotelio y NO se demostró por una caída drástica de la dilatación inducida por el extracto cuando el endotelio fue removido (10,6 +/- 2,3 por ciento) y cuando se inhibió la óxido nítrico sintasa (NOS) (12,3 +/- 2,5 por ciento) mediante nitro-L-arginina (L-NNA). Este resultado apoya el uso popular de S. crispum en el tratamiento de la hipertensión que puede ser debido, al menos en parte, al efecto vasodilatador de uno o más compuestos presentes en sus hojas y tallos. Se deben realizar más estudios para aclarar este fenómeno.

New 1H-Benzo[f]indazole-4,9-diones Conjugated with C-Protected Amino Acids and Other Derivatives: Synthesis and in Vitro Antiproliferative Evaluation.

1H-Benzo[f]indazole-4,9-dione derivatives conjugated with C-protected amino acids (glycine, l-alanine, l-phenylalanine and l-glutamic acid) 6a-l were prepared by chemically modifying the prenyl substituent of 3-methyl-7-(4-methylpent-3-enyl)-1H-benzo[f]indazole-4,9-dione 2 through epoxidation, degradative oxidation, oxidation and N-acyl condensation reactions. The chemical structures of the synthesized compounds were elucidated by analyzing their IR, ¹H-NMR and (13)C-NMR spectral data together with elemental analysis for carbon, hydrogen and nitrogen. The preliminary in vitro antiproliferative activity of the synthesized derivatives was evaluated on KATO-III and MCF-7 cell lines using a cell proliferation assay. The majority of the derivatives exhibited significant antiproliferative activity with IC50 values ranging from 25.5 to 432.5 µM. These results suggest that 1H-benzo[f]indazole-4,9-dione derivatives are promising molecules to be researched for developing new anticancer agents.

p-Coumaric acid reduces high glucose-mediated impairment of endothelium-dependent relaxation in rat aorta / Ácido p-cumárico reduce el deterioro mediado por alta glucosa de la relajación dependiente de endotelio en aorta de rata

p-Coumaric acid (p-CA) is an ubiquitous plant metabolite with antioxidant, anti-inflammatory, and anticancer properties. The present study was designed to evaluate the preventive effects of p-CA on endothelium-dependent impairment produced by high glucose (HG) (D-Glucose 25 mM) in isolated rat thoracic aorta. Aortic rings obtained from male Sprague-Dawley rats were mounted in an organ bath and pretreated for 3 h with D-Glucose 5 mM, HG and HG plus p-CA (1, 10 and 100 uM). After this period of time endothelium-dependent relaxation was tested by cumulative addition of acetylcholine (ACh) in pre-contracted rings with phenylephrine (PE) (0.1 μM). p-CA elicited a moderate endothelium-dependent vasodilatory effect (Emax= 29.28 +/- 1.89 percent, N=6; pD2= 6.075 +/- 0.184, N=6). When aortic rings were pre-incubated for 3 h with HG, Emax for ACh decreased dramatically from 87.69 +/- 2.59 percent (N=6) to 40.54 +/- 1.78 percent (N=6). The negative effect of HG was partially reverted in rings co-incubated with p-CA in a concentration-dependent manner as shown for Emax values to each p-CA concentration: 1 uM (48.57 +/- 1.82 percent), 10 uM (60.81 +/- 1.80 percent) and 100 uM (64.51 +/- 1.80 percent). The action of p-CA was associated with a significant change in Emax. No statistical difference in pD2 was observed. Our results clearly show that p-CA protect ACh-induced endothelial-dependent relaxation affected by HG in isolated rat aortic rings.

El ácido p-cumárico (p-CA) es un metabolito ubicuo en plantas, con propiedades antioxidantes, anti-inflamatoria, y anticancerígenas. El presente estudio fue diseñado para evaluar los efectos preventivos de p-CA sobre la relajación dependiente de endotelio, deteriorada por niveles altos de glucosa (HG) (D-glucosa 25 mM) en aorta torácica aislada de rata. Los anillos aórticos obtenidos de ratas macho Sprague-Dawley se montaron en un baño de órganos y fueron pre-tratados durante 3 h con D-glucosa 5 mM, HG, y HG más de p-CA (1, 10 y 100 uM). Después de este período de tiempo se evaluó la relajación dependiente de endotelio mediante la adición acumulativa de acetilcolina (ACh) en anillos pre-contraídos con fenilefrina (PE) (0,1 uM). p-CA mostró un moderado efecto vasodilatador dependiente de endotelio (Emax = 29,28 +/- 1,89 por ciento, N = 6; pD2 = 6,075 +/- 0,184, N = 6). Cuando los anillos aórticos se pre-incubaron durante 3 h con HG, la Emax para ACh se redujo drásticamente desde 87,69 +/- 2,59 por ciento (N = 6) a 40,54 +/- 1,78 por ciento (N = 6). El efecto negativo de HG se revirtió parcialmente, de manera dependiente de concentración, en los anillos co-incubados con p-CA tal como lo muestra el valor de Emax para cada concentración de p-CA: 1 u M (48,57 +/- 1,82 por ciento), 10 uM (60,81 +/- 1,80 por ciento) y 100 uM (64,51 +/- 1,80 por ciento). La acción de p-CA se asoció con un cambio significativo en la Emax. No se observó diferencia estadísticamente significativa en el pD2. Nuestros resultados muestran claramente que p-CA protege la relajación dependiente de endotelio inducida por ACh, la cual es afectada por HG en anillos aislados de aorta de rata.

Isolated aorta model and its contribution to phytopharmacology / Modelo de aorta aislada y su contribución a la fitofarmacología

Since the early 50's until now the isolated thoracic aorta has been a traditional and productive model for pharmacological studies. This experimental model has been closely related to Doctor Robert Furchgott's research. The discovery of the role of endothelium in the vasorelaxation induced by acetylcholine (ACh), represented a milestone in biological sciences and also had an important consequence on the isolated aorta preparation. In this work, we describe the isolated aorta technique and the improvements made in Doctor Penna's laboratory at Facultad de Medicina, Universidad de Chile, as well as the Mexican contribution. Since endothelium plays a key role on vascular relaxation and its dysfunction is one of first indicators (biomarker) of cardiovascular diseases, the isolated aorta model is a valuable preparation. Considering the great amount of phytochemical present in many natural sources, like vegetables, fruits and medinal plants, we expect this model to continue delivering significant contributions to the knowledge in pharmacology and phytopharmacology.

Desde principios de los años 50 hasta ahora la aorta torácica aislada ha sido un modelo tradicional y productivo para estudios farmacológicos. Este modelo experimental ha estado estrechamente relacionado con la investigación realizada por el Doctor Robert Furchgott. El descubrimiento de la función del endotelio en la vasodilatación inducida por la acetilcolina (ACh), representó un hito en las ciencias biológicas y también tuvo una consecuencia importante en la preparación de aorta aislada. En este trabajo se describe la técnica de aorta aislada y las mejoras realizadas en el laboratorio del Doctor Penna en la Facultad de Medicina, Universidad de Chile, así como la contribución de investigadores mexicanos. Puesto que el endotelio juega un papel clave en la relajación vascular y su disfunción es uno de los primeros indicadores (biomarcadores) de enfermedad cardiovascular, el modelo de aorta aislada es una valiosa preparación. Teniendo en cuenta la gran cantidad de fitoquímicos presentes en muchas fuentes naturales como verduras, frutas y plantas medicinales, podemos esperar que este modelo continúe entregando importantes aportes al conocimiento en farmacología y fitofarmacología.

Glucose and lactate regulate maitotoxin-activated Ca2+ entry in spermatogenic cells: the role of intracellular [Ca2+].

Maitotoxin (MTX), a potent polyether marine biotoxin, induces Ca(2+) entry in different mammalian cells by activation of Ca(2+) channels. The identity and modulation of the MTX-activated Ca(2+) entry pathway is not known. In this work, we show, for the first time, that glucose and lactate can modulate the excitability of spermatogenic cell MTX-activated Ca(2+) channels. Physiological and pharmacological evidences indicate that glucose and lactate differentially affect MTX-activated Ca(2+) entry mainly through changes that these substrates induce on intracellular Ca(2+) stores and the concentration of intracellular Ca(2+) ([Ca(2+)](i)) in spermatogenic cells. Our findings strongly suggest that MTX-activated Ca(2+) channels in spermatogenic cells can be regulated by a Ca(2+)-CaM-dependent protein kinase.