Chemo-biological evaluation of antidiabetic activity of Mentha arvensis L. and its role in inhibition of advanced glycation end products

Background: There has been enormous curiosity in the development of alternative plant based medicinesto control diabetes, oxidative stress and related disorders. One of the therapeutic approaches is to reducepostprandial release of glucose in the blood. Two key enzymes that are involved in reducing postprandialglucose are a-amylase and a-glucosidase. Mentha arvensis L. has been traditionally used by several tribesas a medicinal plant to treat various disorders.Objective: The present study was undertaken to test M. arvenisis L. for inhibition of postprandialhyperglycemia.Material and method: We performed various in vitro and in vivo tests to evaluate efficacy of M. arvenisis L.for antidiabetic activity (postprandial hyperglycemia).Results: Methanolic extract of M. arvensis L. leaves showed DPPH free radical scavenging activity (morethan 78% mg/ml) and high antiglycation potential (more than 90% inhibition of AGE formation). Methanolic extract also showed remarkable inhibitory effects on a-amylase (more than 50% mg/ml) and aglucosidase (68% mg/ml) and significant inhibition of postprandial hyperglycemia in starch induced diabetic Wistar rats.Conclusion: The non-insulin dependent antidiabetic or inhibition of postprandial hyperglycemic activityof methanolic extract of M. arvensis L. leaves was shown by using in vitro and in vivo approaches in thepresent study.© 2018 Transdisciplinary University, Bangalore and World Ayurveda Foundation. Publishing Services byElsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Inhibición de la a-amilasa por medio de extractos de plantas medicinales como tratamiento complementario/alternativo de la diabetes y la caries / Inhibition of a a-amylase by means of extracts of medicinal plants as complementary/alternative treatment of diabetes and caries

Los inhibidores selectivos de la α-amilasa salival y pancreática humana, son un medio eficaz para controlar los niveles de azúcar en la saliva y la sangre, durante el control de la caries y la diabetes. En la presente revisión, después de identificar las principales funciones de la enzima, se discutieron exponen algunas de las respuestas observadas después de la exposición de la α-amilasa a las plantas, en escala molecular y entera. Diferentes tipos de moléculas de plantas medicinales actúan como inhibidores de la α-amilasa, como una terapia alternativa o complementaria en el tratamiento de la diabetes en y en el control de uno de los factores de la formación la caries (dieta) (AU)

Selective inhibitors of human salivary and pancreatic α-amylase are an effective means of controlling saliva and blood sugar levels in the management of caries and diabetes. In the present review, after identifying the main functions of the enzyme, it was exposed some of the observed responses after exposure to α-amylase at the molecular and whole plants scale. Different types of medicinal plants molecules have been found to act as α-amylase inhibitors, as an alternative or complementary therapy in the management of diabetes and control to one of the predisposing factors to caries (diet) (AU)

Possible Hypoglycemic Attributes of Morus indica 1. and Costus speciosus: An in vitro Study

Introduction: Medicinal plants have been reported to play an important role in modulating glycemic responses; they are also known to have preventive and therapeutic implications in disorders of carbohydrate and lipid metabolism. This study reports the possible hypoglycemic effects of Morus indica (Mulberry) and Costus speciosus (Insulin plant) in an in vitro system. Methods: Glucose adsorption, diffusion and starch hydrolysis of Mulberry leaf powder (MLP) and Insulin plant powder (IPP) were studied using in vitro techniques that simulated gastrointestinal conditions and compared with commercial dietary fibre sources such as wheat bran (WB), acarbose (ACB) and guar gum (GG) at three different levels (2, 4, and 6 %). Results: The glucose binding capacity of both Morus indica.L (MLP) and Costus speciosus (IPP)increased with increased levels and was significantly high compared to wheat bran and acarbose. At higher levels (4 and 6 %), the diffusion rate of glucose was lower compared to wheat bran, acarbose and guar gum. The a-amylase inhibitory effect was significantly high in MLP (51%) and IPP (18%) compared to WB (8%). The effect of samples on glucose diffusion was also studied in a system comprising of starch-a-amylase sample. The glucose diffusion rate was significantly low in the systems where MLP (6%) and IPP (6%) were used compared to the positive control and to commercial sources of fibre (ACB and GG). Conclusion: The data reveals that the samples may lower the rate of glucose absorption and as a result, decrease postprandial hyperglycemia by these mechanisms.

Kinetics of fungal extracellular a-amylase from Fusarium solani immobilized in calcium alginate beads.

Extracellular a-amylase mass produced by Fusarium solani using mango kernel as substrate was immobilized in calcium alginate beads through entrapment technique. Maximum enzyme immobilization efficiency was achieved in 2 mm size beads formed by 6.5 % (w/v) of sodium alginate in 2% (w/v) calcium chloride. The catalytic properties of the immobilized a-amylase were compared with that of free enzyme (soluble). The activity yield of the immobilized enzyme was 81% of the free enzyme. The immobilized enzyme showed optimum activity at pH 4.5-6.0 and temperature 40 ºC, in contrast to the free enzyme at 5.5 and 30ºC, respectively. Thermal stability of the immobilized enzyme was found to be more than the free enzyme over a longer time interval. The immobilized enzyme retained activity upto 20% of optimum even after 180 min. While the free enzyme lost its 80% activity after 60 min and lost total activity down to zero by 120 min. The kinetic constants, viz., KM (Michaelis constant), Vmax and activation energy were affected by immobilization. However, the immobilized a-amylase in calcium alginate beads supports its long term storage which has immense industrial applications.

Optimization of thermostable á- amylase production by Streptomyces erumpens MTCC 7317 in solid-state fermentation using cassava fibrous residue

Production of á- amylase under solid state fermentation by Streptomyces erumpens MTCC 7317 was investigated using cassava fibrous residue, one of the major solid waste released during extraction of starch from cassava (Manihot esculenta Crantz). Response surface methodology (RSM) was used to evaluate the effect of the main variables, i.e., incubation period (60 h), moisture holding capacity (60 percent) and temperature (50(0)C) on enzyme production by applying a full factorial Central Composite Design. Varying the inoculum concentration (5-25 percent) of S. erumpens showed that 15 percent inoculum (v/w, 2.5 x 10(6) CFU/ml) was the optimum for á- amylase production. Among the different nitrogen sources supplemented, beef extract was most suitable for enzyme production. The application of S. erumpens enzyme in liquefaction of soluble starch and cassava starch was studied. The maximum hydrolysis of soluble starch (85 percent) and cassava starch (70 percent) was obtained with the application of 5 ml crude enzyme (17185 units) after 5 h of incubation.

Modificación fíiica del almidón de yuca y evalución de la susceptibilidad a laa hidrólisis enzimática por una alfa miilasa / Physial modificaation of cassava starh and evaluation of susceptibillity to enzyme hydrolysis by alpha amylase / Modificção físicca do amido de mandiocay avaliação do susceptibilidadee à hidrólise enzimática com uma alfa mmilase

Almidón de yuca comercial (variedad MTAI8) se sometió a modificación física por sinéresis, extrusión, gelatinización y secado por rodillos. Al almidón nativo y a los almidones modificados se les determinó su morfología, cristalinidad, distribución molecular y susceptibilidad a la hidrólisis enzimática con una alfa amilasa porcina pancreática. En los almidones modificados físicamente se incrementó el grado de hidrólisis, en comparación con el almidón nativo. Sin embargo no se observaron diferencias estadísticamente significativas en el grado de hidrólisis entre los almidones modificados. El patrón de difracción de rayos X tipo A, presentado por el almidón de yuca nativo y su propiedad birrefringente se alteraron por los pretratamientos, presentándose difractogramas de estructuras amorfas y pérdida de la cruz de malta en los almidones modificados. La microscopía electrónica de barrido (MEB) demostró alteración en la apariencia y estructura del gránulo nativo, dando lugar a partículas de formas irregulares con superficies fragmentadas y rugosas como resultado del proceso de modificación. La cromatografía de exclusión sobre sepharosa 6B confirmó la desaparición de la fracción de alto peso molecular presente en el almidón nativo, con el consecuente incremento de las fracciones de bajo peso molecular en los almidones modificados.

Cassava starch (MTAI 8 variety) was subjected to syneresis, gelatinization, extrusion and processing by drum dryers. The morphology, crystallinity, molecular weight distribution and susceptibility to enzyme hydrolysis by porcine pancreatic a-amylase were determined before and after the physical treatments. The physically modified starches increased the extent of a-amylolysis, compared to the native one. However, there were not significant differences in the degree of amylolisis between the treatments during the procedure. Both the X-ray pattern type-A, presentedinthecassavastarch, and its birrefringent property, observed in polarized light, were altered by the treatments causing amorphous structures and the loss of the Maltese cross. When the modified starches were observed n scann ng electron micrographs (SEM), an alteration in the appearance and structure of the native granule was shown, where particles with irregular shape and fragmented and wrinkled surfaces could be seen as a result of the modification process. The profile of the size exclusion chromatography on sepharose 6B showed two characteristic fractions of high and low molecular weight in the native starch, while in modified starches only one peak was obtained showing low molecular weight. The data showed that the treatments modified the physical structure of the starch granule, allowing more accessibility for the enzyme to the amorphous and crystalline regions of starch.

Amido de mandioca comercial (variedade MTAI 8) foi submetido a modificação física por sinérese, extrusão, gelatinização e secado por tambor. Foram determinados para o amido nativo e os amidos modificados a sua morfologia, cristalinidade, distribuição molecular y susceptibilidade à hidrólise enzimática com uma alfa amilase porcina pancreática. Nos amidos modificados fisicamente foi verificado um aumento do nível de hidrólise, em comparação com o amido nativo. Porém, não se observaram diferenças estatisticamente significativas no nível de hidrólise entre os almidões modificados. O padrão de difracção de raios-X tipo A apresentado pelo amido de mandioca nativo e a sua propriedade birrefringente, foram alterados pelos prétratamentos, apresentando-se difractogramas de estruturas amorfas y perda da cruz de malta nos almidões modificados. A microscopia electrónica de barrido (MEB) demonstrou alteração na aparência e estrutura do granulo nativo, dando lugar a partículas de formas irregulares com superfícies fragmentadas e rugosas como resultado do processo de modificação. A cromatografia de exclusão sobre sepharosa 6B corroborou a desaparição da fracção de alto peso molecular presente no amido nativo, com o consequente aumento das fracções de baixo peso molecular nos almidões modificados.

PURIFICACIÓN Y CARACTERIZACIÓN DE a-AMILASA DE PENICILLIUM COMMUNE PRODUCIDA MEDIANTE FERMENTACIÓN EN FASE SÓLIDA / PURIFICATION AND CHARACTERIZATION OF a-AMYLASE FROM PENICILLIUM COMMUNE PRODUCED BY SOLID STATE FERMENTATION / PURIFICAÇÃO E CARACTERIZAÇÃO DA a-AMILASA DE PENICILLIUM COMMUNE PRODUZIDA MEDIANTE FERMENTAÇÃO EM FASE SÓLIDA

Este estudio reporta la purificación y caracterización parcial de una a-amilasa producida por Penicillium commune mediante fermentación en fase sólida, empleando yuca blanca colombiana (Manihot esculenta Crantz) como soporte. La enzima fue purificada por precipitación fraccionada con sulfato de amonio, cromatografía de intercambio aniónico (DEAE-Sephadex A-50), cromatografía de filtración por gel (Sephadex G-75) y cromatografía de intercambio catiónico (CM-Sephadex C-50) obteniendo una actividad específica final de 314,82 U/mg, un grado de purificación del orden de 62 y un rendimiento de 9%. La purificación hasta la homogeneidad fue confirmada por SDS-PAGE. El peso molecular estimado fue 35 kDa. La enzima mostró máxima actividad de hidrólisis de almidón soluble con pH 6,0, y estabilidad en un intervalo de pH de 5,0-7,0. La estabilidad térmica de la enzima se presentó en el intervalo de temperatura 0-50 °C y su temperatura óptima fue 70 °C. Los iones Ca2+,Ba2+ y Ag+ aumentaron significativamente la actividad de la enzima, siendo el ión Ca2+ el que tuvo el más alto poder activador. Cu2+ no alteró significativamente la actividad de la enzima, mientras que Li+ yFe3+ la disminuyeron ligeramente (13%), y Co2+ y Hg2+ la disminuyeron 25% y 40% respectivamente. Los valores de Km y Vmáx fueron calculados usando la linealización de Lineweaver-Burk, con el resultado Km = 0,48 mg/mL y Vmáx = 5,85 µmol glucosa/min. Entre los principales productos de hidrólisis del almidón de yuca se encuentran la maltosa y la glucosa, este resultado proporciona evidencia de que la enzima es capaz de romper los enlaces glicosídicos a-1,4 del almidón, comportamiento característico de una a-amilasa.

This study reports the purification and partial characterization of an a-amylase from Penicillium commune produced by solid state fermentation using colombian white tapioca (Manihot esculenta Crantz) as support. The enzyme was purified by ammonium sulphate precipitation, anion exchange chromatography (DEAE-Sep-hadex A-50), gel filtration chromatography (Sephadex G-75) and cation exchange chromatography (CM-Sephadex C-50). A purification factor of 62 with a 9% yield and final specific activity of 314.82 U/mg were recorded. Purification to homogeneity was confirmed by SDS PAGE. The molecular weight was estimated to be 35 kDa. The enzyme shows maximal activity in the soluble starch hydrolysis at pH 6.0, and is stable in a range of pH from 5.0 to 7.0. Thermal stability was in the range of temperature from 0 to 50 °C, and its optimal temperature was 70 °C. Ions Ca2+,Ba2+ and Ag+ significantly increase the activity of the enzyme, with ion Ca2+ as the highest activator. Cu2+ does not alter significantly the activity of the enzyme, whereas Li+ and Fe3+ decrease it slightly (13%) and Co2+ and Hg2+ decrease it 25% and 40% respectively. Km = 0.48 mg/mL and Vmax = 5.85 /xmol glucose/min were calculated using the linearization of Lineweaver-Burk. Among hydrolysis products of tapioca starch are maltose and glucose, this result provides evidence of the enzyme ability to hydrolyze the starch a-1,4 glucosidic linkages, a characteristic behavior of an a-amylase.

Este estudo reporta a purificação e caracterização parcial de uma a-amilasa produzida por Penicillium commune mediante fermentação em fase sólida usando mandioca branca colombiana (Manihot esculenta Crantz) como suporte. A enzima foi purificada por precipitação fraccionada com sulfato de amónio, cromato-grafia de intercambio aniónico (DEAE-Sephadex A-50), cromatografia de filtração por gel (Sephadex G-75) e croma-tografia de intercambio catiónico (CM-Sephadex C-50) obtendo una actividade específica final de 314.82 U/mg, um grau de purificação na ordem de 62 e um rendimento de 9%. A purificação até à homogeneidade foi confirmada por SDS-PAGE. O peso molecular estimado foi de 35 kDa. A enzima mostrou máxima acti-vidade de hidrólises de amido solúvel a pH 6.0, e estabilidade num intervalo de pH de 5.0-7.0. A enzima foi estável num intervalo de temperatura de 0-50 °C, e sua temperatura óptima de reacção foi de 70°C. Íons Ca2+,Ba2+ eAg+ aumentaram significativamente a actividade da enzima, sendo o ião Ca2+, o que teve o mais alto poder indutor. Cu2+ não alterou significativamente a actividade da enzima, enquanto que Li+ eFe3+ a diminuíram ligeiramente (13%), e Co2+ eHg2+ a diminuíram 25% e40% respectivamente. Os valores de Km eVmáx foram calculados usando a linearização de Lineweaver-Burk, obtendo Km = 0.48 mg/mL e Vmáx = 5.85 µmol glucosa/min. Entre os principais produtos de hidrólises do amido de mandioca encontram-se a maltosa e glucosa; este resultado proporciona evidencia de que a enzima é capaz de romper os enlaces glucosídicos a-1,4 do amido, comportamento característico de uma a-amilasa.