Calcium Channels in Postnatal Development of Rat Pancreatic Beta Cells and Their Role in Insulin Secretion.

Pancreatic beta cells during the first month of development acquire functional maturity, allowing them to respond to variations in extracellular glucose concentration by secreting insulin. Changes in ionic channel activity are important for this maturation. Within the voltage-gated calcium channels (VGCC), the most studied channels are high-voltage-activated (HVA), principally L-type; while low-voltage-activated (LVA) channels have been poorly studied in native beta cells. We analyzed the changes in the expression and activity of VGCC during the postnatal development in rat beta cells. We observed that the percentage of detection of T-type current increased with the stage of development. T-type calcium current density in adult cells was higher than in neonatal and P20 beta cells. Mean HVA current density also increased with age. Calcium current behavior in P20 beta cells was heterogeneous; almost half of the cells had HVA current densities higher than the adult cells, and this was independent of the presence of T-type current. We detected the presence of α1G, α1H, and α1I subunits of LVA channels at all ages. The Cav 3.1 subunit (α1G) was the most expressed. T-type channel blockers mibefradil and TTA-A2 significantly inhibited insulin secretion at 5.6 mM glucose, which suggests a physiological role for T-type channels at basal glucose conditions. Both, nifedipine and TTA-A2, drastically decreased the beta-cell subpopulation that secretes more insulin, in both basal and stimulating glucose conditions. We conclude that changes in expression and activity of VGCC during the development play an important role in physiological maturation of beta cells.

Actividad antiinflamatoria y analgésica de un extracto orgánico del alga roja Galaxaura rugosa (J. Ellis & Solander) J.V. Lamouroux / Anti-inflammatory and analgesic activity of an organic extract from the red alga Galaxaura rugosa (J. Ellis & Solander) J.V. Lamouroux

INTRODUCCIÓN: el alga roja Galaxaura rugosa (J. Ellis & Solander) J.V. Lamouroux (Galaxauraceae) es una de las especies más abundantes en la plataforma rocosa del arrecife coralino del archipiélago cubano, sin embargo, poco se conoce de sus propiedades farmacológicas. OBJETIVOS: evaluar la actividad antiinflamatoria y analgésica del extracto en diclorometano del alga roja G. rugosa, así como la composición fitoquímica de esta especie. MÉTODOS: las algas se colectaron en el litoral norte de La Habana. La caracterización fitoquímica del alga se realizó según el Método de Chabra. Para la preparación del extracto se sometió la muestra a extracción Soxhlet con diclorometano a 40 ºC. La actividad antiinflamatoria tópica se estudió en el modelo de edema de la oreja inducido por aceite de Croton en ratones machos OF-1, a las dosis de 10*10-3; 0,125; 0,25; 0,5; 1 y 2 mg/oreja. Se evaluó también la actividad analgésica del extracto en el modelo de contorsiones inducidas por ácido acético al 0,8 %, por vía intraperitoneal (i.p.), a las dosis de 3; 6; 12,5; 25 y 100 mg/kg. RESULTADOS: G. rugosa presentó en su composición fitoquímica compuestos grasos, lactónicos, triterpénicos y/o esteroidales y carbohidratos. El extracto en diclorometano de G. rugosa a partir de la dosis de 0,125 mg/oreja presenta una potente actividad antiinflamatoria (superior al 40 %). El extracto logró reducir las contorsiones en más de un 75 % a partir de la dosis de 6 mg/kg. CONCLUSIONES: los resultados presentados demuestran que el extracto en diclorometano del alga roja G. rugosaestá constituido por una mezcla de compuestos capaces de inhibir con una elevada eficacia farmacológica la respuesta inflamatoria aguda y el dolor inducido por agentes químicos.

INTRODUCTION: the red alga Galaxaura rugosa (J. Ellis & Solander) J.V. Lamouroux (Galaxauraceae) is one of the most abundant species on the rocky platform of the Cuban coral reef. However, little is known about its pharmacological properties. OBJECTIVES: evaluate the anti-inflammatory and analgesic activity of a dichloromethane extract from the red alga G. rugosa and determine the phytochemical composition of the species. METHODS: the algae were collected from the northern coast of Havana. Phytochemical characterization of the alga was performed using Chabra's method. The extract was obtained with a Soxhlet device with dichloromethane at 40 ºC. Topical anti-inflammatory activity was studied with the croton oil ear edema test model in male OF-1 mice at doses of 10*10-3, 0.125, 0.25, 0.5, 1 and 2 mg/ear. The analgesic activity of the extract was evaluated on a model of writhing induced by 0.8 % acetic acid administered intraperitoneally (i.p.) at doses of 3, 6, 12.5, 25 and 100 mg/kg. RESULTS: phytochemical analysis of G. rugosa revealed the presence of fatty, lactonic, triterpenic and/or steroidal compounds, as well as carbohydrates. The dichloromethane extract of G. rugosa at the dose of 0.125 mg/ear displayed a potent anti-inflammatory activity (above 40 %). The extract reduced writhing by more than 75 % with a dose of 6 mg/kg. CONCLUSIONS: results show that dichloromethane extract of the red alga G. rugosa is composed of a mixture of compounds capable of inhibiting the acute inflammatory response and the pain induced by chemical agents with a high pharmacological efficacy. composed of a mixture of compounds capable of inhibiting the acute inflammatory response and the pain induced by chemical agents with a high pharmacological efficacy.

Actividad antiinflamatoria y analgésica de un extracto orgánico del alga roja Galaxaura rugosa (J. Ellis & Solander) J.V. Lamouroux / Anti-inflammatory and analgesic activity of an organic extract from the red alga Galaxaura rugosa (J. Ellis & Solander) J.V. Lamouroux

Introducción: el alga roja Galaxaura rugosa (J. Ellis & Solander) J.V. Lamouroux (Galaxauraceae) es una de las especies más abundantes en la plataforma rocosa del arrecife coralino del archipiélago cubano, sin embargo, poco se conoce de sus propiedades farmacológicas. Objetivos: evaluar la actividad antiinflamatoria y analgésica del extracto en diclorometano del alga roja G. rugosa, así como la composición fitoquímica de esta especie. Métodos: las algas se colectaron en el litoral norte de La Habana. La caracterización fitoquímica del alga se realizó según el Método de Chabra. Para la preparación del extracto se sometió la muestra a extracción Soxhlet con diclorometano a 40 ºC. La actividad antiinflamatoria tópica se estudió en el modelo de edema de la oreja inducido por aceite de Croton en ratones machos OF-1, a las dosis de 10*10-3; 0,125; 0,25; 0,5; 1 y 2 mg/oreja. Se evaluó también la actividad analgésica del extracto en el modelo de contorsiones inducidas por ácido acético al 0,8 por ciento, por vía intraperitoneal (i.p.), a las dosis de 3; 6; 12,5; 25 y 100 mg/kg. Resultados: G. rugosa presentó en su composición fitoquímica compuestos grasos, lactónicos, triterpénicos y/o esteroidales y carbohidratos. El extracto en diclorometano de G. rugosa a partir de la dosis de 0,125 mg/oreja presenta una potente actividad antiinflamatoria (superior al 40 por ciento). El extracto logró reducir las contorsiones en más de un 75 por ciento a partir de la dosis de 6 mg/kg. Conclusiones: los resultados presentados demuestran que el extracto en diclorometano del alga roja G. rugosa está constituido por una mezcla de compuestos capaces de inhibir con una elevada eficacia farmacológica la respuesta inflamatoria aguda y el dolor inducido por agentes químicos(AU)

Introduction: the red alga Galaxaura rugosa (J. Ellis & Solander) J.V. Lamouroux (Galaxauraceae) is one of the most abundant species on the rocky platform of the Cuban coral reef. However, little is known about its pharmacological properties. Objectives: evaluate the anti-inflammatory and analgesic activity of a dichloromethane extract from the red alga G. rugosa and determine the phytochemical composition of the species. Methods: the algae were collected from the northern coast of Havana. Phytochemical characterization of the alga was performed using Chabra's method. The extract was obtained with a Soxhlet device with dichloromethane at 40 ºC. Topical anti-inflammatory activity was studied with the croton oil ear edema test model in male OF-1 mice at doses of 10*10-3, 0.125, 0.25, 0.5, 1 and 2 mg/ear. The analgesic activity of the extract was evaluated on a model of writhing induced by 0.8 percent acetic acid administered intraperitoneally (i.p.) at doses of 3, 6, 12.5, 25 and 100 mg/kg. Results: phytochemical analysis of G. rugosa revealed the presence of fatty, lactonic, triterpenic and/or steroidal compounds, as well as carbohydrates. The dichloromethane extract of G. rugosa at the dose of 0.125 mg/ear displayed a potent anti-inflammatory activity (above 40 percent). The extract reduced writhing by more than 75 percent with a dose of 6 mg/kg. Conclusions: results show that dichloromethane extract of the red alga G. rugosa is composed of a mixture of compounds capable of inhibiting the acute inflammatory response and the pain induced by chemical agents with a high pharmacological efficacy(AU)

Insights into the toxicological properties of a low molecular weight fraction from Zoanthus sociatus (Cnidaria).

The phylum Cnidaria is an ancient group of venomous animals, specialized in the production and delivery of toxins. Many species belonging to the class Anthozoa have been studied and their venoms often contain a group of peptides, less than 10 kDa, that act upon ion channels. These peptides and their targets interact with high affinity producing neurotoxic and cardiotoxic effects, and even death, depending on the dose and the administration pathway. Zoanthiniaria is an order of the Subclass Hexacorallia, class Anthozoa, and unlike sea anemone (order Actiniaria), neither its diversity of toxins nor the in vivo effects of the venoms has been exhaustively explored. In this study we assessed some toxicological tests on mice with a low molecular weight fraction obtained by gel filtration in Sephadex G-50 from Zoanthus sociatus crude extract. The gel filtration chromatogram at 280 nm revealed two major peaks, the highest absorbance corresponding to the low molecular weight fraction. The toxicological effects seem to be mostly autonomic and cardiotoxic, causing death in a dose dependent manner with a LD50 of 792 µg/kg. Moreover, at a dose of 600 µg/kg the active fraction accelerated the KCl-induced lethality in mice.

Anti-inflammatory and antinociceptive activities of methanolic extract from red seaweed Dichotomaria obtusata

The aim of the present work was to investigate the anti-inflammatory and antinociceptive effects of methanolic extract from D. obtusata using classic models in mice (croton oil-induced ear edema and acetic acid-induced writhing) and a phospholipase A2 activity test. Qualitative analysis of the chemical composition of seaweed was also determined by extraction with solvents of increasing polarity and precipitation and color tests. Results of qualitative chemical study showed the presence of lactonic and phenolic compounds, reduced carbohydrates, other sugars, flavonoids, fatty compounds, triterpenes and steroids. The extract inhibited mouse ear edema in a dose-dependent manner with an efficacy higher than 90% and a mean effective dose of 4.87µg/ear, while intraperitoneal administration presented a moderate activity. The extract did not inhibit phospholipase A2 activity. In the writhing test, the intraperitoneal administration of the extract showed a strong antinociceptive activity (80.2%), while the oral route showed a lower efficacy. In conclusion, this study demonstrated the anti-inflammatory and antinociceptive effects of methanol extract of D. obtusata in experimental models, suggesting its therapeutic potential in the treatment of peripheral painful and/or inflammatory pathologies.

O objetivo do presente trabalho foi investigar os efeitos antiinflamatórios e antinociceptivos de um extrato metanólico de D. obtusata, utilizando modelos clássicos em ratos (teste do edema de orelha induzido por óleo de cróton e teste de contorções induzidas por ácido acético) e um teste de atividade de fosfolipase A2. A análise qualitativa da composição química das algas foi também determinada através de extração com solventes de polaridade crescente e testes de precipitação e cor. Os resultados do estudo de química qualitativa mostraram a presença de compostos lactônicos e fenólicos, hidratos de carbono reduzidos e outros açúcares, flavonoides, compostos graxos, triterpenos e esteroides. O extrato inibiu o edema de orelha dos ratos de um modo dependente da dose com eficácia superior a 90% e dose média efetiva de 4.87µg/orelha, enquanto a administração intraperitoneal apresentou atividade moderada. O extrato não inibiu a atividade da fosfolipase A2. No teste de contorção, a administração intraperitoneal do extrato mostrou forte atividade antinociceptiva (80,2%), enquanto a administração oral mostrou menor eficácia. Em conclusão, este estudo demonstrou os efeitos antiinflamatórios e antinociceptivos do extrato metanólico de D. obtusata em modelos experimentais, sugerindo seu potencial terapêutico no tratamento de patologias dolorosas periféricas e/ou inflamatórias.

Actividad antileishmanial de seis extractos de organismos marinos / Antileishmanial activity of six extracts from marine organisms

Introducción: las infecciones causadas por protozoos del género Leishmania constituyen un problema de salud mundial con una alta prevalencia en países subdesarrollados. En la actualidad no existe una vacuna contra esta enfermedad y el tratamiento utilizado es deficiente, por lo que la búsqueda de medicamentos más efectivos y seguros constituye una urgente necesidad. Objetivo: evaluar la actividad antileishmanial in vitro de 6 extractos acuosos e hidroalcohólicos de organismos marinos. Métodos: se determinó la actividad frente a promastigotes y amastigotes de Leishmania amazonensis, así como su toxicidad frente a macrófagos peritoneales de ratones BALB/c. Resultados: en el ensayo de promastigotes los extractos de Bryothamnion triquetrum, Bunodosoma granulifera, Halimeda opuntia, y Physalia physalis mostraron una inhibición del crecimiento a concentraciones menores de 100 µg/mL; mientras que frente a amastigotes, estos 2 últimos extractos fueron los más activos y menos tóxicos con un índice de selectividad de 6 y 8, respectivamente. Conclusiones: teniendo en cuenta estos resultados se consideró que los extractos de H. opuntia y P. physalis mostraron una promisoria actividad, por lo que se sugiere continuar los estudios de su actividad in vivo.

Introduction: infections caused by protozoa of the genus Leishmania are a global health problem with a high prevalence in underdeveloped countries. There is no vaccine against this disease at present and the treatment used is poor, so the search for more effective and safe medicines is an urgent need. Objective: to assess the in vitro antileishmanial activity of six aqueous and hydroalcohol extracts from marine organisms. Methods: the activity of six extracts against Leishmania amazonensis promastigots and amastigots as well as their toxicity against peritoneal macrophages in BALB/c mice. Results: in the promastigot assay, the extracts from Bryothamnion triquetrum, Bunodosoma granulifera, Halimeda opuntia and Physalia physalis showed growth inhibition at concentrations lower than 100 µg/mL whereas in amastigots, these last two extracts were the most active and least toxic with a selectivity index of 6 and 8 respectively. Conclusions: taking these results into account, it was considered that the H. opuntia and P. physalis extracts showed a promising activity, so it is suggested that further studies on its in vivo activity be conducted.

Actividad antileishmanial de seis extractos de organismos marinos / Antileishmanial activity of six extracts from marine organisms

Introducción: las infecciones causadas por protozoos del género Leishmania constituyen un problema de salud mundial con una alta prevalencia en países subdesarrollados. En la actualidad no existe una vacuna contra esta enfermedad y el tratamiento utilizado es deficiente, por lo que la búsqueda de medicamentos más efectivos y seguros constituye una urgente necesidad. Objetivo: evaluar la actividad antileishmanial in vitro de 6 extractos acuosos e hidroalcohólicos de organismos marinos. Métodos: se determinó la actividad frente a promastigotes y amastigotes de Leishmania amazonensis, así como su toxicidad frente a macrófagos peritoneales de ratones BALB/c. Resultados: en el ensayo de promastigotes los extractos de Bryothamnion triquetrum, Bunodosoma granulifera, Halimeda opuntia, y Physalia physalis mostraron una inhibición del crecimiento a concentraciones menores de 100 Ág/mL; mientras que frente a amastigotes, estos 2 últimos extractos fueron los más activos y menos tóxicos con un índice de selectividad de 6 y 8, respectivamente. Conclusiones: teniendo en cuenta estos resultados se consideró que los extractos de H. opuntia y P. physalis mostraron una promisoria actividad, por lo que se sugiere continuar los estudios de su actividad in vivo(AU)

Introduction: infections caused by protozoa of the genus Leishmania are a global health problem with a high prevalence in underdeveloped countries. There is no vaccine against this disease at present and the treatment used is poor, so the search for more effective and safe medicines is an urgent need. Objective: to assess the in vitro antileishmanial activity of six aqueous and hydroalcohol extracts from marine organisms. Methods: the activity of six extracts against Leishmania amazonensis promastigots and amastigots as well as their toxicity against peritoneal macrophages in BALB/c mice. Results: in the promastigot assay, the extracts from Bryothamnion triquetrum, Bunodosoma granulifera, Halimeda opuntia and Physalia physalis showed growth inhibition at concentrations lower than 100 Ág/mL whereas in amastigots, these last two extracts were the most active and least toxic with a selectivity index of 6 and 8 respectively. Conclusions: taking these results into account, it was considered that the H. opuntia and P. physalis extracts showed a promising activity, so it is suggested that further studies on its in vivo activity be conducted(AU)

[Antileishmanial activity of six extracts from marine organisms]. / Actividad antileishmanial de seis extractos de organismos marinos.

INTRODUCTION: infections caused by protozoa of the genus Leishmania are a global health problem with a high prevalence in underdeveloped countries. There is no vaccine against this disease at present and the treatment used is poor, so the search for more effective and safe medicines is an urgent need. OBJECTIVE: to assess the in vitro antileishmanial activity of six aqueous and hydroalcohol extracts from marine organisms. METHODS: the activity of six extracts against Leishmania amazonensis promastigots and amastigots as well as their toxicity against peritoneal macrophages in BALB/c mice. RESULTS: in the promastigot assay, the extracts from Bryothamnion Iriquetrum, Bunodosoma granulifera, Halimeda opuntia and Physalia physalis showed growth inhibition at concentrations lower than 100 microg/mL whereas in amastigots, these last two extracts were the most active and least toxic with a selectivity index of 6 and 8 respectively. CONCLUSIONS: taking these results into account, it was considered that the H. opuntia and P. physalis extracts showed a promising activity, so it is suggested that further studies on its in vivo activity be conducted.

Genotoxic assessment of aqueous extract of Rhizophora mangle L (mangle rojo) by spermatozoa head assay / Evaluación genotóxica del extracto acuoso de Rhizophora mangle L (mangle rojo) mediante el ensayo de la cabeza del espermatozoide

INTRODUCTION: the aqueous extract bark of Rhizophora mangle L. (red mangrove) has traditionally been used in Cuban folk medicine due to its wide array of curative properties: astringent, haemostatic, febrifuge and antifungal. Previous chemical characterization studies of the liophylized aqueous extract bark, revealed that tannins are the main components, although the presence of other compounds such as epicatechin, catechin, clorogenic, gallic and ellagic acids, as well as galotannins have been also described. OBJECTIVE: this work was designed to determine if any components of the extracts has the ability to produce genotoxic effects in germ cells of Cenp:NMRI mouse models using the abnormal shape of spermatozoa test. METHODS: the lyophilized aqueous extract bark was given by oral gavages (500, 1000 and 2000 mg of total solids /kg bw) in three series of the classical protocol of Wyrobeck and Bruce, in intervals of 24 hrs for 5 days. RESULTS: in series I, the animals were sacrificed on day 4 after starting the administration. In series II the animals were sacrificed on day 21 while in series III the day of sacrificed was the 35th. CONCLUSIONS: no cytotoxic effect was observed in the 3 series and in all doses proved and only the highest dose of the extract in the series I provoked a slight genotoxic effect when increase the percentage in the number of abnormal spermatozoa.

INTRODUCCIÓN: el extracto acuoso de Rhizophora mangle L. (mangle rojo), se ha usado tradicionalmente en Cuba por su amplio espectro de propiedades curativas: como astringente, hemostático, febrífugo y antifúngico. Los estudios previos de caracterización química del extracto acuoso liofilizado de la corteza de la planta revelaron que los taninos son los componentes principales, aunque también se ha descrito la presencia de otros compuestos como las epicatequinas, el ácido clorogénico, ácido gálico y ácido elágico, así como galotaninos. OBJETIVO: el presente estudio fue diseñado para determinar si alguno de los componentes del extracto tiene la capacidad para producir efectos genotóxicos en células germinales de ratones Cenp:NMRI utilizando el ensayo de anormalidades de la cabeza del espermatozoide. MÉTODOS: el extracto liofilizado fue administrado por vía oral (500, 1 000 y 2 000 mg de material vegetal/kg) en 3 series del protocolo clásico de Wyrobeck y Bruce, en intervalos de 24 h por 5 d consecutivos. RESULTADOS: en la serie I los animales fueron sacrificados el dia 4 después de iniciada la administración. En la serie II los animales fueron sacrificados el día 21, mientras que en la serie III fueron sacrificados el día 35. CONCLUSIONES: no se observó efecto citotóxico en las 3 series y en todas las dosis probadas, y solamente la dosis mayor del extracto en la serie I provocó un ligero efecto genotóxico al incrementar el porcentaje de espermatozoides anormales.

Genotoxic assessment of aqueous extract of Rhizophora mangle L (mangle rojo) by spermatozoa head assay / Evaluación genotóxica del extracto acuoso de Rhizophora mangle L (mangle rojo) mediante el ensayo de la cabeza del espermatozoide

INTRODUCTION: the aqueous extract bark of Rhizophora mangle L. (red mangrove) has traditionally been used in Cuban folk medicine due to its wide array of curative properties: astringent, haemostatic, febrifuge and antifungal. Previous chemical characterization studies of the liophylized aqueous extract bark, revealed that tannins are the main components, although the presence of other compounds such as epicatechin, catechin, clorogenic, gallic and ellagic acids, as well as galotannins have been also described. OBJECTIVE: this work was designed to determine if any components of the extracts has the ability to produce genotoxic effects in germ cells of Cenp:NMRI mouse models using the abnormal shape of spermatozoa test. METHODS: the lyophilized aqueous extract bark was given by oral gavages (500, 1000 and 2000 mg of total solids /kg bw) in three series of the classical protocol of Wyrobeck and Bruce, in intervals of 24 hrs for 5 days. RESULTS: in series I, the animals were sacrificed on day 4 after starting the administration. In series II the animals were sacrificed on day 21 while in series III the day of sacrificed was the 35th. CONCLUSIONS: no cytotoxic effect was observed in the 3 series and in all doses proved and only the highest dose of the extract in the series I provoked a slight genotoxic effect when increase the percentage in the number of abnormal spermatozoa(AU)

INTRODUCCIÓN: el extracto acuoso de Rhizophora mangle L. (mangle rojo), se ha usado tradicionalmente en Cuba por su amplio espectro de propiedades curativas: como astringente, hemostático, febrífugo y antifúngico. Los estudios previos de caracterización química del extracto acuoso liofilizado de la corteza de la planta revelaron que los taninos son los componentes principales, aunque también se ha descrito la presencia de otros compuestos como las epicatequinas, el ácido clorogénico, ácido gálico y ácido elágico, así como galotaninos. OBJETIVO: el presente estudio fue diseñado para determinar si alguno de los componentes del extracto tiene la capacidad para producir efectos genotóxicos en células germinales de ratones Cenp:NMRI utilizando el ensayo de anormalidades de la cabeza del espermatozoide. MÉTODOS: el extracto liofilizado fue administrado por vía oral (500, 1 000 y 2 000 mg de material vegetal/kg) en 3 series del protocolo clásico de Wyrobeck y Bruce, en intervalos de 24 h por 5 d consecutivos. RESULTADOS: en la serie I los animales fueron sacrificados el dia 4 después de iniciada la administración. En la serie II los animales fueron sacrificados el día 21, mientras que en la serie III fueron sacrificados el día 35. CONCLUSIONES: no se observó efecto citotóxico en las 3 series y en todas las dosis probadas, y solamente la dosis mayor del extracto en la serie I provocó un ligero efecto genotóxico al incrementar el porcentaje de espermatozoides anormales(AU)