Antioxidant potential, anti-inflammatory activity, antidiabetic and cardioprotective effect of Microsechium helleri (Peyr. ) Cong / Potencial antioxidante, actividad anti-inflamatoria, efecto antidiabético y cardioprotector de Microsechium helleri (Peyr. ) Cong

Microsechium helleri (Cucurbitaceae) has been used in ethnopharmacological as a lotion to prevent hair loss, diuretic and cathartic, in the region of central Veracruz, Mexico is used as antidiabetic. The antioxidant properties of the hexanic (EHex), chloroformic (ECHCl3) and ethanolic (EEtOH) extracts, were evaluated by 2,2diphenyl-1-pychrylhydrazyl (DPPH) test, the Ferric Reducing/Antioxidant Power (FRAP) and the total phenolic content test. The anti-inflammatory effect was evaluated in the acute ear edema induced with phorbol 12-myristate 13-acetate (TPA) in mouse and the hypoglycemic and cardioprotective effects of the EEtOH were determined in rats. The EEtOH was the most active in the antioxidant potential DPPH test and the ECHCl3 was the best in the FRAP assay and the total polyphenols content. In the anti-inflammatory assay, the ECHCl3 showed the most activity. The EEtOH had the decreased the glucose levels and reduced myocardial damage. The results support the use of this plant in folk medicine in Mexico as antioxidant, anti-inflammatory, hypoglycemic and cardioprotective.

Microsechium helleri (Cucurbitaceae) se utiliza en etnofarmacología como una loción para prevenir la caída del cabello, como diurético y catártico, en la región del centro de Veracruz, México es usado como antidiabético. Las propiedades antioxidantes de los extractos hexánico (EHex), clorofórmico (ECHCl3) y etanólico (EEtOH), se evaluaron mediante la prueba de 2,2difenil-1-psililhidrazilo (DPPH), el poder reductor férrico/poder antioxidante (FRAP) y el contenido fenólico total. El efecto anti-inflamatorio se evaluó en el edema agudo de la oreja inducido con forbol 12-miristato 13-acetato (TPA) en ratones y se determinaron los efectos hipoglucémicos y cardioprotectores del EEtOH en ratas. El EEtOH fue el más activo en la prueba DPPH de potencial antioxidante y el ECHCl3 fue el mejor en el ensayo FRAP y el contenido total de polifenoles. En el ensayo antiinflamatorio, el ECHCl3 mostró la mayor actividad. El EEtOH disminuyó los niveles de glucosa y redujo el daño miocárdico. Los efectos hipoglucémicos y cardioprotector del extracto de EEtOH se determinaron en ratas, donde el extracto disminuyó los niveles de glucosa y redujo el daño miocárdico. Los resultados apoyan el uso de esta planta en la medicina popular en México como antioxidante, anti-inflamatorio, hipoglucemiante y cardioprotector.

Phytochemicals of Periploca aphylla Dcne. ameliorated streptozotocin-induced diabetes in rat

BACKGROUND@#Periploca aphylla is used by local population and indigenous medicine practitioners as stomachic, tonic, antitumor, antiulcer, and for treatment of inflammatory disorders. The aim of this study was to evaluate antidiabetic effect of the extract of P. aphylla and to investigate antioxidant and hypolipidemic activity in streptozotocin (STZ)-induced diabetic rats.@*METHODS@#The present research was conducted to evaluate the antihyperglycemic potential of methanol extract of P. aphylla (PAM) and subfractions n-hexane (PAH), chloroform (PAC), ethyl acetate (PAE), n-butanol (PAB), and aqueous (PAA) in glucose-overloaded hyperglycemic Sprague-Dawley rats. Based on the efficacy, PAB (200 mg/kg and 400 mg/kg) was tested for its antidiabetic activity in STZ-induced diabetic rats. Diabetes was induced via intraperitoneal injection of STZ (55 mg/kg) in rat. Blood glucose values were taken weekly. HPLC-DAD analysis of PAB was carried out for the presence of various polyphenols.@*RESULTS@#HPLC-DAD analysis of PAB recorded the presence of rutin, catechin, caffeic acid, and myricetin. Oral administration of PAB at doses of 200 and 400 mg/kg for 21 days significantly restored (P < 0.01) body weight (%) and relative liver and relative kidney weight of diabetic rats. Diabetic control rats showed significant elevation (P < 0.01) of AST, ALT, ALP, LDH, total cholesterol, triglycerides, LDL, creatinine, total bilirubin, and BUN while reduced (P < 0.01) level of glucose, total protein, albumin, insulin, and HDL in serum. Count of blood cells and hematological parameters were altered in diabetic rats. Further, glutathione peroxidase, catalase, superoxide dismutase, glutathione reductase, and total soluble protein concentration decreased while concentration of thiobarbituric acid reactive substances and percent DNA damages increased (P < 0.01) in liver and renal tissues of diabetic rats. Histopathological damage scores increased in liver and kidney tissues of diabetic rats. Intake of PAB (400 mg/kg) resulted in significant improvement (P < 0.01) of above parameters, and results were comparable to that of standard drug glibenclamide.@*CONCLUSION@#The result suggests the antihyperglycemic, antioxidant, and anti-inflammatory activities of PAB treatment in STZ-compelled diabetic rat. PAB might be used as new therapeutic agent in diabetic patients to manage diabetes and decrease the complications.

Chemical characterization of the antioxidant, antihyperglycemic and antihypertensive capacities of red rice (Oryza sativa L. ) whole flour / Caracteristicas físico-químicas, capacidad antioxidante, anti-hiperlucémica y antihipertensiva de la harina de arroz rojo (Oryza sativa L. )

Oryza sativa L. rice has large amounts of proteins and minerals, besides presenting several pigmented varieties. Red rice is distinguishable due to its great nutritional value compared to the regular white variety. Its red pericarp pigmentation is due to the bioactive compounds that are responsible for its health benefits. The objective of this study was to evaluate the physical-chemical characterization, antioxidant, antihyperglycemic and antihypertensive capacity of flours of three different red rice cultures (Rubi, Virgínia and Pequeno). All samples presented specific levels of carbohydrates for cereals with low fat content and excellent levels of protein and resistant starch. In addition, the samples had a high antioxidant, antihyperglycemic and antihypertensive capacity. Antihyperglycemic capacities were measured as percent inhibition for amylase (56.7-76.5%) and glycosidase (81.0-76.6%), respectively, and antihypertensive capacity as the percentage inhibition of the angiotensin converting enzyme (38.4-34.7%). In addition, Pequeno flour presented the best results for antioxidant and antihyperglycemic capacity in comparison to the two flours tested. Thus, all red rice flours can be a source of functional compounds when added to food.

El arroz integral (Oryza sativa L.) posee importantes cantidades de proteínas, vitaminas, minerales y fitoquímicos. El arroz rojo se destaca por su gran valor nutricional. La pigmentación roja del pericarpio está asociado al contenido de compuestos bioactivos, que están directamente relacionados a los beneficios de salud humana. Teniendo en cuenta lo antes expuesto se propuso evaluar las caracteristicas físico-químicas, capacidad antioxidante, anti-hiperglucémica y antihipertensiva de las harinas de tres diferentes cultivos de arroz rojo (Rubí, Virginia y Pequeño). Todas las muestras presentaron niveles específicos de carbohidratos para cereales con bajo contenido de grasa y altos contenidos de proteína y almidón resistente. Además, las muestras presentaron una alta capacidad antioxidante, anti-hiperglucémica y antihipertensiva. La capacidad anti-hiperglicémica se midió en porcentaje de inhibidores de α-amilasa (56.7-76.5%) y α-glucosidasa (81.0-76.6%), respectivamente; y capacidad antihipertensiva como el porcentaje de inhibición de la enzima convertidora de la angiotensina (38.4-34.7%). El cultivar Pequeño presentó mayor capacidad antioxidante y anti-hiperglucémica en comparación a los demás cultivares. Así, todas las harinas de arroz rojo pueden ser vehículos de compuestos funcionales en los alimentos.

Pharmacological evaluation of Rhazya stricta root extract / Evaluación farmacológica del extracto de raíz de Rhazya stricta

The present study aimed to screen the Rhazya stricta Decne root for its antihyperglycemic and antioxidants potential through invitro assays along with phytochemical and elemental analyses. The crude extract was prepared through maceration and fractionated using solvent-solvent extraction technique. The spectroscopic studies indicated the presence of various phytochemical classes in the extract and its fractions. The antioxidant assays showed notable results along with a good concentration of phenolic and flavonoid contents. Enzyme inhibition assays demonstrated glucose-lowering effects by inhibiting the enzyme activity which could reduce post-prandial blood glucose level. The Dipeptidyl peptidase-IV (DPP-IV) inhibition assay results showed the novel DPP-IV inhibition activity of the plant extract and all fractions showed noteworthy enzyme inhibition and antihyperglycemic activity. Conclusively, the Rhazya stricta root extract displayed its antioxidant and antihyperglycemic potential due to the presence of various classes of phytochemicals and micro-nutrients.

El presente estudio tuvo como objetivo examinar la raíz de Rhazya stricta Decne por su potencial antihiperglicémico y antioxidante a través de ensayos in vitro junto con análisis fitoquímicos y elementales. El extracto crudo se preparó por maceración y se fraccionó usando una técnica de extracción solvente-solvente. Los estudios espectroscópicos indicaron la presencia de varias clases fitoquímicas en el extracto y sus fracciones. Los ensayos antioxidantes mostraron resultados notables junto con una importante concentración de contenido fenólico y flavonoide. Los ensayos de inhibición enzimática demostraron efectos reductores de la glucosa al inhibir la actividad enzimática que podría reducir el nivel de glucosa posprandial en sangre. Los resultados del ensayo de inhibición de Dipeptidyl peptidase-IV (DPP-IV) mostraron la nueva actividad de inhibición de DPP-IV del extracto de la planta y todas las fracciones mostraron una notable inhibición enzimática y actividad antihiperglicémica. En conclusión, el extracto de raíz de Rhazya stricta Decne mostró su potencial antioxidante y antihiperglicémico debido a la presencia de varias clases de fitoquímicos y micronutrientes.

BAY 41-2272 activates host defence against local and disseminated Candida albicans infections

In our previous study, we have found that 5-cyclopropyl-2-[1-(2-fluoro-benzyl)-1H-pyrazolo[3,4-b]pyridine-3-yl]-pyrimidin-4-ylamine (BAY 41-2272), a guanylate cyclase agonist, activates human monocytes and the THP-1 cell line to produce the superoxide anion, increasing in vitro microbicidal activity, suggesting that this drug can be used to modulate immune functioning in primary immunodeficiency patients. In the present work, we investigated the potential of the in vivo administration of BAY 41-2272 for the treatment of Candida albicans and Staphylococcus aureus infections introduced via intraperitoneal and subcutaneous inoculation. We found that intraperitoneal treatment with BAY 41-2272 markedly increased macrophage-dependent cell influx to the peritoneum in addition to macrophage functions, such as spreading, zymosan particle phagocytosis and nitric oxide and phorbol myristate acetate-stimulated hydrogen peroxide production. Treatment with BAY 41-2272 was highly effective in reducing the death rate due to intraperitoneal inoculation of C. albicans, but not S. aureus. However, we found that in vitro stimulation of peritoneal macrophages with BAY 41-2272 markedly increased microbicidal activities against both pathogens. Our results show that the prevention of death by the treatment of C. albicans-infected mice with BAY 41-2272 might occur primarily by the modulation of the host immune response through macrophage activation. .

Hypolipidemic and hypoglycemic effects of Centella asiatica (L.) extract in vitro and in vivo.

In vitro study revealed that pancreatic lipase inhibitory activity of C. asiatica extract was significantly higher than rutin but lower than orlistat, an anti-obesity drug. α-Amylase inhibitory activities of C. asiatica extract and rutin were significantly lower than acarbose, an anti-diabetic drug. Inhibition of α-glucosidase activity by C. asiatica extract, rutin, and acarbose was not different. The in vivo study substantiated the in vitro results. C. asiatica extract (1000 and 2000 mg/4 mL/kg), rutin (1000 mg/4 mL/kg), and orlistat (45 mg/4 mL/kg) significantly decreased plasma glucose, triglyceride and total cholesterol levels in lipid emulsion-induced hyperlipidemic rats at 3 h. However, plasma aspartate aminotransferase and alanine aminotransferase levels did not show significant change. The present work further supports that the C. asiatica extract and its bioactive rutin may help managing hypolipidemic and hypoglycemic effects.

Insulin secreting and α-glucosidase inhibitory activity of hexane extract of Annona squamosa Linn. in streptozotocin (STZ) induced diabetic rats.

The hexane extract of A. squamosa (ASHE) in 100 and 400 mg/kg body weight dose raised the insulin level when compared with Glimepiride (1 mg/kg) and also inhibited α-glucosidase activity when compared with Acarbose (10 mg/kg) in streptozotocin induced diabetic rats. The ASHE significantly reduced peak blood glucose (Gp30) and area under curve (AUC) in diabetic rats in oral glucose (OGTT) and oral sucrose (OSTT) tolerance test, but there was more reduction of Gp30 value than AUC in OSTT. Thus, it can be suggested that the ASHE, has hypoglycemic role at 2 levels, i.e. it acts as secretagogue and also inhibits the intestinal enzymes, responsible for glucose metabolism.

Antidiabetic and hypolipidemic effects of different fractions of coccinia cordifolia L. on normal and streptozotocin-induced diabetic rats

The present study was carried out to observe the antidiabetic and hypolipidemic effects of petroleum-ether, ethyl acetate and chloroform fractions isolated from ethanolic extract of the leaves of Coccinia cordifolia Linn. [150 mg/kg body weight] on normal and streptozotocin [STZ]-induced diabetic rats for one day experiment. Single doses [150 mg/kg, i.p.] of C. cordifolia extracts were given to normal and diabetic rats. The fasting blood glucose [FBG], serum triglyceride [TG] and serum total cholesterol [TC] levels were investigated in normal and STZ-diabetic rats on 0, 1, 2, 3, 6, 10, 16, and 24[th] hours. In normoglycemic rats the pet-ether and ethyl acetate fractions of C. cordifolia reduced blood glucose level significantly [39.66% and 40.68% at 16[th] and 24[th] hour respectively]. In the STZ-diabetic rats pet-ether and ethyl acetate fractions also reduced blood glucose level significantly [50.39% and 50% at 10[th] and 24[th] hour respectively]. Ethyl acetate fraction is most effective which reduced total cholesterol level by 31.04% and 36.69% in normal and STZ-diabetic rats respectively. Ethyl acetate fraction reduced triglyceride level by 43.82% and 42.01% in normal and STZ-diabetic rats respectively. Our results indicate that pet-ether and ethyl acetate fractions of C. cordifolia have potentiality against diabetes

Hypoglycemic and other related effects of Boswellia glabra in alloxan-induced diabetic rats.

The hypoglycemic effect of the aqueous extract of the leaves and roots of Boswellia glabra was examined using alloxan-induced diabetic rats. A single oral administration of Boswellia glabra leaf and root extract decreased the blood glucose level. The continued use of leaf and root extract for 28 days produced significant hypoglycemic effects; also there was a decrease in serum glucose, cholesterol, triglyceride, urea and creatinine levels and enzyme activities (alkaline phosphatase and glucose-6-phosphatase). Ultra structural studies of beta cell of alloxan-induced diabetic rats treated with root extract showed numerous granulated sacs in comparison to rats treated with leaf extract. Thus, rats treated with root extract showed less degranulated sacs and more number of filled secretory granules in comparison to diabetic rats. Thus the use of aqueous extract of Boswellia glabra increased the synthesis of secretory granules in the beta-cell.

Effect of a novel insulinotropic agent, succinic acid monoethyl ester, on lipids and lipoproteins levels in rats with streptozotocin-nicotinamide-induced type 2 diabetes.

In the present study, the effect of succinic acid monoethyl ester (EMS) on the pattern of lipids and lipoproteins in streptozotocin-nicotinamide induced type 2 diabetes was investigated. Type 2 diabetes was induced in male Wistar rats by single intraperitoneal injection (i.p.) of 45 mg/kg streptozotocin, 15 min after the i.p administration of 110 mg/kg body weight of nicotinamide. The carboxylic nutrient EMS was administered intraperitonially at a dose of 8 micromol/g body weight for 30 days. At the end of experimental period, the effect of EMS on plasma glucose, insulin, thiobarbituric acid reactive substances (TBARS) and hydroperoxide (HP) and serum triglycerides (TG), phospholipids (PL), free fatty acids (FFA), total cholesterol (TC), very low density lipoprotein-cholesterol (VLDL-C) and low density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C) and the percentage of antiatherogenic index (AAI) (ratio of HDL-C to total cholesterol) were studied. Administration of EMS to diabetic rats resulted in a significant reduction in the elevated levels of plasma glucose, TBARS and hydroperoxides as well as TG, PL, FFA, TC,VLDL-C and LDC-C levels. The decreased plasma insulin and serum HDL-C and percentage of AAI in diabetic rats were also reversed towards near normal. The effect produced by EMS was compared with metformin, a reference drug. The results indicates that the administration of EMS and metformin to nicotinamide-streptozotocin diabetic rats normalized plasma glucose, insulin concentrations and caused marked improvement in altered lipids, lipoprotein and lipid peroxidation markers during diabetes. Our results show the antihyperlipidemic properties of EMS and metformin in addition to its antidiabetic action. Moreover, the antihyperlipidemic effect could represent a protective mechanism against the development of atherosclerosis.

Insulin analogues: a short review

For people with type 1 or type 2 diabetes, soluble human insulin [HI] is commonly used to replace mealtime insulin by subcutaneous injection, and the protaminated form [NPH] addresses basal requirements. However, due to its intrinsic self-association, soluble HI absorption is slow, resulting in insulin kinetics that do not resemble those of normal physiology. Insulin analogues have been developed from HI to retain its metabolic action but with improved absorption kinetics. This editorial discusses the range of currently available insulin analogues and their benefits to treatment of insulin-requiring diabetes. Short-acting analogues IAsp and lispro both have alterations in their amino acid sequences which reduces self-association behavior, allowing more rapid absorption from the subcutis. These analogues can therefore be injected immediately before eating, and not 30 mm before as recommended for soluble HI. Studies have shown that IAsp and lispro provide 1better PPG control and can lower HbA[1]c further than HI. These short-acting analogues have been incorporated into 'biphasic' preparations: BIAsp 30 and Mix25, comprising rapid-acting [30% and 25%, respectively] and protaminated, intermediate-acting [70% and 75%, respectively] analogue. The biphasic profile of these premixes can thus address both mealtime and basal needs. Type 2 patients can use premix analogues from once- to thrice-daily as required, and type I patients can use them thrice-daily instead of basal-bolus therapy. Studies with type 2 patients have shown better PPG control with premixes, and more patients reach HbA[1]c targets than with human or analogue basal insulins. Furthermore, the increased risk of hypoglycaemia normally associated with intensive therapy seems to be reduced with premix treatment. The main limitations of the commonly-prescribed NPH are its characteristic plasma peak and variable absorption kinetics, which can cause hypo- or hyper glycaemia. The basal analogues IDet and lGlarg have been engineered to achieve a long duration of action with a less pronounced insulin peak. Trials have shown the efficacy of lDet and IGlarg to be similar to NPH, but with less hypoglycaemia. Moreover, IDet is associated with less pharmacokinetic/pharmacodynamic variability and less weight gain than NPH. Currently available insulin analogues can closely mimic the insulin profile of a healthy individual, thus enabling type 1 or type 2 patients to achieve and maintain glycaemic targets, with less hypoglycaemia than with conventional insulins. The mitogenic potential of insulin analogues is discussed

Protein binding of glipizide using equilibrium dialysis technique: effects of hydrogen ion concentration, drug concentration and ionic strength

The objective of this research was to investigate the effects of hydrogen ion concentration, drug concentration and ionic strength on the binding affinity of glipizide to albumin protein. Different buffer solutions of different pH values (pH 6.7, 7.5 and 8.5), different drug concentrations (2.45 mg, 4.82 mg and 9.42 mg), and phosphate buffer solutions pH 7.5 of different ionic strength (0.1, 0.4 and 1.0) were prepared. The effects of pH, drug concentration and ionic strength on the amount of glipizide bounded to 0.25 g bovine albumin was investigated. As the pH of the solution was increased from pH 6.4 to pH 8.5, milligrams drug bounded to gram protein (r value) decreased from 8.2 mg to 3.84 mg/g protein. Also as the ionic strength of the solution was increased from 0.1 to 1.0, the r value decreased from 10.76 mg to 3.96 mg/g protein. However, the r value did not change significantly with increasing of drug from 2.45 mg to 9.42 mg/25 ml. The r value was 7.36 mg/g protein when concentration of the drug was 2.45 mg/25 ml and 7.4 mg/g protein when the concentration of the drug was 9.42 mg/25 ml. This study demonstrated that factors such as high pH and high ionic strength can alter drug-protein binding and consequently increase free drug in plasma and increase bioavailability of slightly water insoluble drug such as antidiabetic drugs.

Preliminary evaluation of glipizide spheres and compacts from spheres prepared by cross-linking technique

The objective of this research was to use the natural polymer Carrageenan to obtain controlled release spheres loaded with glipizide using the cross-linking technique. The effect of polymer level and drug load were investigated. The drug was dispersed in Carrageenan solution and the dispersion was dropped by a device containing 3 disposable syringes into cross-linking solution containing 3 calcium chloride. After 15 minutes residence time, the spheres were collected by decantation and dried in hot air oven at 38 degrees C +/- 2 degrees C for 24 hours. The dried spheres were successfully compacted into tablets using rotary Manesty B-3B machine equipped with 12/32 inches round flat face punches, target tablet weight was 400 mg +/- 5. As the polymer level was increased in the sphere formulation, the drug release rate was increased. However, as the drug level was increased in the sphere formulation, the release rate was decreased. This trend was also true for tablets compacted from spheres. The scanning electron microscope photographs supported the dissolution data. More cracks and rough surface were observed in tablets compacted from spheres containing high polymer level and low drug level.

Chromium contents of some widely used indigenous hypoglycemic herbal drugs

Chromium and other trace elements of some hypoglycemic plants, Gymnema sylvestre. Momordica charantia, Caralluma edulis and Berberus lycium, widely used as herbal drugs by local practitioner were determined by Atomic absorption Spectrophotometry [ASS] and Flameless Atomic Absorption Spectrophotometry. Chromium contents of these herbal drugs were compared with the reported daily requirements and experimental therapeutic concentration and relationship of chromium contents with their hypoglycemic activity was examined

Mode of action of three structurally different hypoglycemic agents: a comparative study.

The mechanism of dose-dependent hypoglycemic effect, the margin of safety and ED50 of three structurally unrelated compounds, tolbutamide (TB), centpiperalone (CP) and a swerchirin-containing fraction (SWI) from the plant Swertia chirayita, were investigated in experimental models. After a single oral administration of TB, CP and SWI to groups of normal and streptozotocin (STZ)-induced mild and severe diabetic rats, the blood sugar lowering effect and ED50 of the agents were determined. Plasma Immuno Reactive Insulin (IRI) levels and the degree of islet beta cell degranulation were assayed using RIA and histochemical staining, respectively, in normal rats treated with the agents. The percent blood sugar lowering, increase in IRI levels and beta cell degranulation were highest in CP treated normal rats (69, 124 and 75%, respectively). In addition, CP was the only agent found active in STZ-induced severely diabetic rats (P < 0.01). In STZ-mild diabetic rats, however, TB was more effective than CP and SWI. By analysis of data using Anova method, it is concluded that CP is more effective than SWI (P < 0.01) and TB. However, SWI an impure natural product showed better blood sugar lowering than tolbutamide which is a drug in use.

Comprobación de la actividad hipoglicemiante y captadora de radicales libres oxigenados de los principios activos de Curatella americana L / Comprobation of the hypoglycemic and capture of oxigenated of radical free of the active principles of Curatella american L

La actividad hipoglicemiante - antidiabética de una fracción del extracto clorofórmico de la corteza de Curatella americana L. ("chaparro") fue evaluada en ratones normoglicémicos y en ratas diabéticas por aloxano, en ensayos agudos y de administración crónica. Junto con los niveles de glicemia se determinó el nivel de insulina (Enzymun - Test insulina, técnica ELISA). Se probó también la actividad contra radical superóxido (Sistema Xantina / Xantina Oxidasa), radical hidroxilo (sistema H2O2/Fe a la 3 - EDTA/Ascorbato) y ácido hipocloroso (Sistema NaOCl / H2SO4). Se encontró un importante efecto antihiperglicemiante, un efecto protector contra la diabetes aloxánica y disminución de la glicemia en el estado diabético. Los extractos mostraron una marcada actividad contra radical superóxido y menos importante contra HOCl. La actividad contra radicales hidroxilo y peroxilo estuvo interferida por el vehículo (MeOH). La actividad antidiabética del extracto podría estar mediada por los supuestos atrapadores de "Especies Oxígeno -Reactivas"

Biologically active principles isolated from Salacia oblonga wall.

From the petroleum ether extract of the root bark of Salacia Oblonga wall, two biologically active fractions have been isolated by column and thin layer chromatography. The methanol eluted fraction of the extract absorbed on a column of silica gel at a concentration of 50 micrograms/ml showed 100 percent cytotoxicity on Ehrlich ascites tumour cells. The chloroform eluted fraction of the pet. ether extract and a fluorescent compound separated from it by TLC demonstrated about 60% and 76% hypoglycemic potency of an equal dose of tolbutamide (250 mg/kg) in albino rats. The results indicate the therapeutic importance of S. Oblonga wall.

Rol de magnesio en la eficacia de fármacos hipoglicemiantes / Role of magnesium in the efficacy of hypoglycemic agents

El objetivo de este trabajo fue el de demostrar que la deficiencia de magnesio inhibe el uso de glucosa, estimulada por la insulina, basal y exógena, e hipoglicemiantes orales. Se utilizaron 21 ratas albinas (250-300 g) a las cuales se les extrajo el músculo sóleo, para incubación en medio Ringer-Krebs, con presencia o ausencia de magnesio y con una cantidad conocida de glucosa (6 x 10 a la menos 3 mol?L). El dosaje de las muestras obtenidas de los medios se realizó antes y después de la incubación, con una prueba de glucosa enzimática, realizándose las lecturas en espectrofotómetro. El estudio se dividió en tres etapas: en la primera, se vió la interacción con calcio y magnesio; en la segunda, la interacción con insulina a una concentración de 1mU/L; y en la tercera, la interacción con hipoglicemiantes orales: clorpropamida y glibenclamida. Observamos mayor utilización de glucosa por parte del músculo en los medios que contenían tanto calcio como magnesio, que en los que no tenían magnesio pero sí calcio, esto se vió tanto con la insulina basal como exógena. En la interacción con sulfonilúreas existió una disminución del uso de glucosa en el medio sin magnesio; siendo mayor ésta conla sulfonlúrea de primera generación que con la de segunda generación. Estos resultados nos sugieren que los niveles de utilización tisular de glucosa basal y estimulada por la hipoglicemiantes son dependientes de la concentración de magnesio, encontrándose disminuida en situaciones de hipomagnesemia.