Metabolites in Conocarpus erectus leaves attenuate α-amylase activity by modulating amino acid residues of α-amylase: an in vitro and docking study / Los metabolitos en las hojas de Conocarpus erectus atenúan la actividad de la α-amilasa al modular los residuos de aminoácidos de la α-amilasa: un estudio in vitro y de acoplamiento

The antioxidant activity and the inhibitory potential of α-amylase of lyophilized hydroethanolic extracts of Conocarpus erectus leaves obtained by ultrasonication were determined. The most potent extract was subjected to ultra-high performance liquid chromatography system equipped with mass spectrometer for metabolite identification. The identified metabolites were docked in α-glucosidase to assess their binding mode. The results revealed that 60% ethanolic extract exhibited highest ferric reducing antioxidant power (4.08 ± 0.187 mg TE/g DE) and α-amylase inhibition (IC50 58.20 ± 1.25 µg/mL. The metabolites like ellagic acid, 3-O-methyl ellagic acid, ferujol, 5, 2 ́-dihydroxy-6,7,8-trimethyl flavone and kaempferol glucoside were identified in the extract and subjected to molecular docking studies regarding α-amylase inhibition. The comparison of binding affinities revealed 3-O-methyl ellagic acid as most effective inhibitor of α-amylase with binding energy of -14.5911 kcal/mol comparable to that of acarbose (-15.7815 kcal/mol). The secondary metabolites identified in the study may be extended further for functional food development with antidiabetic properties.

Se determinó la actividad antioxidante y el potencial inhibidor de la α-amilasa de extractos hidroetanólicos liofilizados de hojas de Conocarpus erectus obtenidos por ultrasónicación. El extracto más potente se sometió a un sistema de cromatografía líquida de ultra alto rendimiento equipado con un espectrómetro de masas para la identificación de metabolitos. Los metabolitos identificados se acoplaron en α-glucosidasa para evaluar su modo de unión. Los resultados revelaron que el extracto etanólico al 60% exhibió el mayor poder antioxidante reductor férrico (4.08 ± 0.187 mg TE/g DE) e inhibición de la α-amilasa (IC50 58.20 ± 1.25 µg/mL. Los metabolitos como el ácido elágico, 3-O-metil elágico ácido, ferujol, 5, 2 ́-dihidroxi-6,7,8-trimetil flavona y kaempferol glucósido se identificaron en el extracto y se sometieron a estudios de acoplamiento molecular con respecto a la inhibición de la α-amilasa. La comparación de las afinidades de unión reveló 3-O-metil El ácido elágico como inhibidor más eficaz de la α-amilasa con una energía de unión de -14,5911 kcal/mol comparable a la de la acarbosa (-15,7815 kcal/mol). Los metabolitos secundarios identificados en el estudio pueden ampliarse aún más para el desarrollo funcional de alimentos con propiedades antidiabéticas.

Biological properties and phytochemical characterization from Miconia chamissois Naudin aqueous extract / Propiedades biológicas y caracterización fitoquímica del extracto acuoso de Miconia chamissois Naudin

The objective of this study was to evaluate biological and phytochemical properties of the aqueous extract from the leaves of Miconia chamissois Naudin (AEMC). Phytochemical properties were assessed by analyzing the chromatographic profile and the polyphenol content of AEMC. Biological properties evaluation was conducted based on cytotoxicity assay and by evaluating the antioxidant, antimicrobial, and enzymatic inhibition activities. Results indicated the presence of phytochemicals in AEMC such as flavonoids and polyphenols, including rutin, isoquercitrin and vitexin derivatives. AEMC showed antioxidant activity, which may be attributed to the high polyphenolic content. Moreover, AEMC demonstrated in vitro enzyme inhibition activity against tyrosinase and alpha-amylase, as well as showed low cytotoxicity. On the other hand, AEMC exhibited weak antimicrobial activity against S. aureusand C. albicans. Thus, AEMC is a promising alternative in search of potential drugs for the treatment of diseases induced by oxidative stress and inflammation, conditions due to hyperpigmentation processes, such as melisma, as well as for diabetes.

El objetivo de este estudio fue detectar las propiedades biológicas y fitoquímicos del extracto acuoso de las hojas de Miconia chamissois Naudin (AEMC). Las propiedades fitoquímicas se evaluaron analizando el perfil cromatográfico y el contenido de polifenoles de AEMC. La evaluación de las propiedades biológicas se realizó en base al ensayo de citotoxicidad y evaluando las actividades de inhibición antioxidante, antimicrobiana y enzimática. Los resultados indicaron la presencia de fitoquímicos en AEMC, como flavonoides y polifenoles, que incluyen derivados de rutina, isoquercitrina y vitexina. AEMC mostró una actividad antioxidante considerable, que puede atribuirse al alto contenido polifenólico. Además, AEMC exhibió actividad de inhibición enzimática in vitro contra tirosinasa y alfa-amilasa, así como mostró baja citotoxicidad. Por otro lado, AEMC demostró actividad antimicrobiana débil contra S. aureusy C. albicans. Por lo tanto, AEMC es una alternativa prometedora en busca de posibles drogas para el tratamiento de enfermedades inducidas por el estrés oxidativo y la inflamación, afecciones debidas a procesos de hiperpigmentación, como el melasma, así como para la diabetes.

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. .

Antioxidant properties and in vitro alpha-amylase and alpha-glucosidase inhibitory properties of phenolics constituents from different varieties of corchorus spp.

This study investigated the phenolic constituents, antioxidant properties and effect of aqueous extracts from some Corchorus species [C. aestuans, C. bougoudo, C. capsularis, C. olitorius and C. urtifolicus] on alpha-amylase and alpha-glucosidase activities in vitro. Gas Chromatography with Flame Ionization Detector [GC-FID] was used to characterize the phenolic constituents. Aqueous extracts were prepared weight/volume [w/v] and their effects on alpha-amylase and alpha-glucosidase activities, Fe[2+] induced lipid peroxidation, and 1,1-diphenyl[-2] picrylhydrazyl [DPPH] radical scavenging properties were determined. Fe[2+] chelating abilities and Ferric Reducing Antioxidant Power [FRAP] properties were also studied. The predominant phenolics detected by GCFID were kaempferol, rutin, apigenin, luteolin, caffeic acid and quercetin. The results showed that all the Corchorus species significantly [P < 0.05] inhibited alpha-amylase and alpha-glucosidase activities dose-dependently [0-8 micro g/ml]. C. olitorius had the highest alpha-amylase inhibitory ability while C. bougoudo demonstrated the maximum alpha-glucosidase inhibition. However, all the Corchorus species inhibited alpha-glucosidase better than alpha-amylase and also exhibited antioxidant properties. The enzyme inhibitory and antioxidant properties exhibited by the Corchorus species could be attributed to their phenolic constituents and vitamin C content; a possible mechanism by which Corchorus species could elicit therapeutic effects on type 2 diabetes mellitus as obtained in folklore medicine

Study of alpha-amylase and urease inhibitory activities of Melilotus indicus [Linn.] All

Melilotus indicus [Linn.] All. is a small herb distributed throughout Pakistan and has a number of ethnomedicinal uses. It is also consumed as a vegetable. In the present work, we are reporting the alpha-amylase and urease inhibitory activities of methanolic extract of M. indicus and its sub-fractions in different solvents. Both the methanolic extract and its fractions in chloroform, ethyl acetate, n-butanol and water showed remarkable inhibitory activities against alpha-amylase with the IC[50] values being 1.29, 1.45, 1.07, 1.45 and 2.10 mg/mL respectively. The efficacy of the methanolic extract was comparable with that of acarbose [1.20 mg/mL], while the ethyl acetate fraction was more potent. The urease inhibitory activities of methanolic extract and chloroform, ethyl acetate, n-butanol and water fractions were more prominent with IC[50] values being 0.95, 0.89, 1.53, 0.98 and 4.90 microg/mL respectively. The activity of methanolic extract was slightly higher than that of thiourea [0.97 microg/mL] which in turn was slightly higher than that of n-butanolic fraction. The chloroform fraction showed the highest anti-urease activity. All the plant samples showed enzyme inhibitory activity in a dose-dependent manner. Moreover, they were manifold more effective against urease than alpha-amylase. The combination of the plant extract with acarbose considerably increased the potency of the latter. The findings suggest that enzyme inhibitory activities of the vegetable M. indicus may have pharmacological significance against diabetes mellitus and gastrointestinal ulcers.

Actividad antioxidante y antihiperglucemiante de la especie medicinal Oreocallis grandiflora (Lam.) R. Br., al sur del Ecuador / Antioxidant and antihyperglycemic activity of the medicinal specie Oreocallis grandiflora (Lam.) R. Br., in southern Ecuador

In this study we evaluated the antioxidant and antihyperglycemic activity in vitro of the extracts obtained with solvents: hexane, ethyl acetate and methanol, of the medicinal plant Oreocallis grandiflora (cucharillo), collected in the Saraguro indian community of the province Loja, southern Ecuador. The antioxidant activity was evaluated by the tests: DPPH, FOLIN-CIOCALTEU and beta-CLAMS, while the antihyperglycemic activity was determined by inhibition assay á-amylase and alpha-glucosidase. The samples were diluted to different concentrations and the reading was performed in a UV spectrophotometer, using as positive control á-tocopherol for DPPH and Folin-ciocalteu test, trolox for beta-CLAMS test, and Glucobay® for testing alpha-amylase and alpha-glucosidase.The results are expressed as IC50, these show that the methanol extract of Oreocallis grandiflora has inhibitory effect on alpha-amylase, the IC50 is 109 ug/ml, compared to 126 ug/ ml of Glucobay®. It also shows inhibitory effect on á-glucosidase, the IC50 is 3 ug/ml compared to 1316 ug/ml of Glucobay®. It also shows antioxidant activity, its IC50 is 15 ug/ml compared to 5 ug/ml of á-tocopherol.

En el presente trabajo se evaluó la actividad antioxidante y antihiperglucemiante in vitro de los extractos obtenidos con los solventes: hexano, acetato de etilo y metanol, de la planta medicinal Oreocallis grandiflora (cucharillo), recolectada en la comunidad indígena de Saraguro en la provincia de Loja, al sur del Ecuador. La actividad antioxidante fue evaluada a través de los ensayos: DPPH, FOLIN-CIOCALTEU y beta-CLAMS, mientras que la actividad antihiperglucemiante fue determinada por el ensayo de inhibición de alfa- amilasa y alfa-glucosidasa. El extracto metanólico de Oreocallis grandiflora presenta efecto inhibitorio sobre la enzima alfa-amilasa, su concentración inhibitoria (CI50) es de 109 ug/ml, frente a 126 ug/ml del control positivo Glucobay®. Además, muestra efecto inhibitorio sobre la enzima alfa-glucosidasa, su concentración inhibitoria (CI50) es de 3 ug/ml, frente a 1316 ug/ml del Glucobay®. Muestra también actividad antioxidante, su concentración inhibitoria (CI50) es de 15 ug/ml, frente a 5 ug/ml del alfa-tocoferol.

Study of phenolic content and urease and alpha-amylase inhibitory activities of methanolic extract of rumex acetosella roots and its sub-fractions in different solvents

The present study aimed to establish relationship between urease and alpha-amylase inhibitory activities on the one hand and on the other between anti-enzymatic activities and total phenolic contents of the methanolic extract of roots of Rumex acetosella and its fractions in various solvents. The methanolic extract and its fractions in chloroform, ethyl acetate, n-butanol and water showed remarkable inhibitory activities against both urease and alpha-amylase, there was a close correspondence between urease and alpha-amylase inhibitory activities of the plant samples. The n-butanol fraction which had the highest total phenolic content [252.19 +/- 2.32 micro g of Gallic Acid Equivalents/mg of dry mass of the sample] showed prominent activity against both urease and alpha-amylase indicating a possible role of phenolics in inhibiting the activities of these enzymes. The samples displayed enzyme inhibitory activities in a dose dependent manner and their effectiveness was comparable with that of the standards, thiourea [for urease] and acarbose [for alphaamylase]. The samples were manifold more effective against urease than alpha-amylase; 2.8 mg/mL of MeOH extract produced about 81% inhibition in alpha-amylase activity, while only 10 micro g/mL of the extract was required to create the same inhibition in urease activity. The IC[50] values of methanolic, chloroform, ethyl acetate, n-butanolic, aqueous and standard solutions were 1.29, 1.31, 1.90, 1.38, 0.85 and 1.20 [mg/mL] respectively against alpha-amylase and 0.99, 3.89, 1.76, 0.91, 0.85 and 0.97 [micro g/mL] respectively against urease. The total phenolic content in MeOH, hexane, chloroform, ethyl acetate, n-butanol and water fractions was 108.88 +/- 2.65, 43.70 +/- 1.90, 34.44 +/- 2.30, 230.71 +/- 1.78, 252.19 +/- 2.32 and 94.07 +/- 2.25 respectively

In vitro alpha-amylase inhibition and antioxidant activities of methanolic extract of amaranthus caudatus Linn

The present study was aimed to investigate the alpha-amylase inhibition and antioxidant activities of methanolic extract of Amaranthus caudatus Linn [MeAc]. Methanolic extract of Amaranthus caudatus was screened for alpha-amylase inhibition activity by CNPG3 method [2-chloro-p-nitrophenyl-alpha-D-maltotrioside] and antioxidant activity was evaluated by 1,1-diphenyl-2-picryl-hydrazile [DPPH] free radical scavenging, superoxide dismutase [SOD] scavenging, hydroxyl free radical scavenging, nitric oxide [NO] radical scavenging, and 2.2'-azinobis-3-ethylbenzothiazole-6-sulfonic acid [ABTS] radical scavenging assays. MeAc was also screened for non enzymatic hemoglycosylation. The methanolic extract of Amaranthus caudatus showed potent alpha-amylase inhibition activity [IC50 19.233 micro g/ml]. MeAc showed significant antioxidant activity in all the in vitro antioxidant models. Furthermore, the MeAc was found to be extremely effective in scavenging ABTS radical activity [IC50 48.75 +/- 1.1 micro g/ ml] when compared to DPPH [IC50 77.5 +/- 0.4 micro g/ml], SOD [IC50 62.5 +/- 2.1 micro g/ml], hydroxyl [IC50 88.50 +/- 1.8 micro g/ml] and NO [IC50 67.5 +/- 2.2 micro g/ml] scavenging activity. The methanolic extract of A. caudatus showed potent alpha-amylase inhibition and antioxidant activities

Extraction and characterization of alpha-amylase inhibitor from some cereals and legumes

Alpha-amylase inhibitor extracted from different sources, i.e., wheat grains [Sohag 2 and Giza 164], legume seeds such as cow pea [Carim 7 and Giza 3], and kidney bean [Giza 6 and Giza 133] was purified and tested for activity using human salivary and pancreatic alpha-amylase. Results showed that the alpha-amylase inhibitor activity from samples studied were 120 to 285 unit / mg protein. The inhibitor was found to be stable at pH range from 2 to 4. It was also stable to digestion by proteolytic enzymes [pepsin and trypsin]. The inhibition was faster at 37°C than at 25°C, The results showed that the degree of thermal stability of alpha-amylase inhibitor extracted from kidney bean [Giza 133] was at 35-37°C, activity was decreased on 50°C for 5 hr. Increased of pre-incubation time between inhibitor and both alpha-amylase enzymes at 37°C increased the rate of inhibition of these enzymes and the complex formation between them from 60 - 80% in 30 min, while addition of these enzymes to the mixture containing inhibitor and substrate [without pre-incubation] decrease the percent inhibition. Therefore, an evidence of specific interference of the alpha-amylase inhibitor with starch availability was established. Such possibilities will have valuable interest in the field of special dietary food preparations for diabetes and over weight reduction purposes

Agrobacterium-mediated transformation of chickpea with alpha-amylase inhibitor gene for insect resistance.

Chickpea is the world's third most important pulse crop and India produces 75% of the world's supply. Chickpea seeds are attacked by Callosobruchus maculatus and C. chinensis which cause extensive damage. The alpha-amylase inhibitor gene isolated from Phaseolus vulgaris seeds was introduced into chickpea cultivar K850 through Agrobacterium-mediated transformation. A total of 288 kanamycin resistant plants were regenerated. Only 0.3% of these were true transformants. Polymerase chain reaction (PCR) analysis and Southern hybridization confirmed the presence of 4.9 kb alpha-amylase inhibitor gene in the transformed plants. Western blot confirmed the presence of alpha-amylase inhibitor protein. The results of bioassay study revealed a significant reduction in the survival rate of bruchid weevil C. maculatus reared on transgenic chickpea seeds. All the transgenic plants exhibited a segregation ratio of 3:1.

Caracterizacao e sintese dos inibidores de 'alfa'-amilase do feijao (Phaseolus vulgaris) / Characterization and synthesis of 'alfa'-amylase inhibitors of beans (Phaseolus vulgaris)

Inibidores de alfa amilase de feijao (Phaseolus vulgaris) foram caracterizados. O inibidor da variedade jalo apresentou peso molecular de 50kDa (por filtracao em gel), ponto isoeletrico de 4,75 e 9,6 porcento de carboidratos. O inibidor da variedade argentino apresentou peso molecular de 48kDa, ponto isoeletrico de 4,90 e 7,6 porcento de carboidratos. Ambos inibidores apresentaram pH otimo de interacao com alfa amilase pancreatica de porco de 5,0 e, a pH 6,9, a complexacao com a mesma enzima se deu na proporcao de 1:1. Esses resultados, mais a composicao de aminoacidos, indicaram que as caracteristicas desses inibidores sao semelhantes as de outros ja purificados de diferentes variedades de feijao