Characterization of Lactobacillus fermentum UCO-979C, a probiotic strain with a potent anti-Helicobacter pylori activity

Background: Helicobacter pylori is considered as the main risk factor in the development of gastric cancer. In the present study, we performed a detailed characterization of the probiotic properties and the anti-H. pylori activity of a previously isolated lactobacillus strain ­ Lactobacillus fermentum UCO-979C ­ obtained from human gut. Results: The strain tolerated pH 3.0; grew in the presence of 2% bile salts; produced lactic acid and hydrogen peroxide; aggregated in saline solution; showed high hydrophobicity; showed high adherence to glass; Caco-2 and gastric adenocarcinoma human cells (AGS) cells; showed an efficient colonization in Mongolian Gerbils; and potently inhibited the growth and urease activity of H. pylori strains. L. fermentum UCO-979C significantly inhibited H. pylori-induced IL-8 production in AGS cells and reduced the viability of H. pylori. With regard to innocuousness, the strain UCO-979C was susceptible to several antibiotics and did not produce histamine or beta-haemolysis in blood agar containing red blood cells from various origins. Conclusion: The results demonstrated that L. fermentum UCO-979C is a very good candidate as a probiotic for the protection of humans against H. pylori infections.

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.

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

Los polifenoles antioxidantes extraídos del epicarpio de Palta (Persea americana var. Hass) inhiben la ureasa de Helicobacter pylori / Antioxidant polyphenols extracted from Avocado epicarp (Persea americana var. Hass) inhibit Helicobacter pylori urease

Chronic infection by Helicobacter pylori produce chronic gastritis leading to other more severe pathologies as peptic ulcer and gastric adenocarcinoma. New anti-H. pylori agents has been found in natural products, particularly polyphenols. The inhibition of enzymes such us urease appears to be an interesting strategy by which polyphenols could limit the colonization by H. pylori. From the exocarp of Persea americana (avocado fruit), we obtain a procyanidin-rich extract with a 77 percent of gallic acid equivalents (GAE). Such procyanidins derived from epicatechin. with a mean degree of polymerization DPm = 6.10. The antioxidant capacity was assessed by different methods as TEAC-DPPH, TEAC-CUPRAC, TEAC-FRAP, TEAC-crocin. The extract shown inhibitory activity against H. pylori urease with an IC50 = 1.02 ug GAE/mL. In order to obtain clusters of procyanidins with different molecular weights, avocado peel extract was fractioned. A clear relation between the molecular size of procyanidins and their urease inhibitory activity was observed.

La infección crónica por Helicobacter pylori produce gastritis crónica o patologías más severas como la úlcera péptica y adenocarcinoma gástrico. Nuevos agentes anti-H. pylori se han encontrado en los productos naturales, donde destacan los polifenoles. La inhibición de enzimas como la ureasa, resulta ser una estrategia interesante mediante la cual los polifenoles pueden limitar la colonización por H. pylori. A partir del epicarpio del fruto de Persea americana (palto) se obtuvo un extracto polifenólico (77 por ciento de EAG), rico en procianidinas derivadas de epicatequina, con un grado de polimerización DPm = 6.10. La capacidad antioxidante fue evaluada mediante TEAC-DPPH, TEAC-CUPRAC, TEAC-FRAP, TEAC-crocina. El extracto mostró una actividad inhibitoria de la ureasa de H. pylori con un IC50 = 1.02 ug EAG/mL. El fraccionamiento de las procianidinas permitió agruparlas según su peso molecular, observándose una clara relación entre su tamaño y la capacidad de inhibir la ureasa.

In vitro inhibition of Helicobacter pylori urease with non and semi fermented Camellia sinensis.

PURPOSE: Helicobacter pylori is the etiological agent in duodenal and peptic ulcers. The growing problem of antibiotic resistance by the organism demands the search for novel compounds, especially from natural sources. This study was conducted to evaluate the effect of Camellia sinensis extracts on the urease enzyme that is a major colonization factor for H. pylori. METHODS: Minimum inhibitory concentrations of nonfermented and semifermented C. sinensis methanol: water extracts were assessed by broth dilution method. Examination of the urease function was performed by Mc Laren method, and urease production was detected on 12% SDS polyacrylamide gel electrophoresis from whole cell and membrane bound proteins. RESULTS: Both extracts had inhibitory effects against H. pylori and urease production. At a concentration of 2.5 mg/ml of nonfermented extract and 3.5 mg/ml of semifermented extract the production of Ure A and Ure B subunits of the urease enzyme were inhibited completely. A concentration of 4 mg/ml of nonfermented and 5.5 mg/ml of semifermented extract were bactericidal for H. pylori. CONCLUSIONS: C. sinensis extracts, especially the nonfermented, could reduce H. pylori population and inhibit urease production at lower concentrations. The superior effect of nonfermented extract is due to its rich polyphenolic compounds and catechin contents.

Selección de parámetros para tratamientos térmicos en soja mediante inactivación de enzimas / Selection of parameters for the thermal treatment of soybean by enzyme inactivation

Se informan los efectos del tratamiento térmico, calor seco y húmedo, sobre el grano de soja y productos molidos, evaluados mediante la activación ureásica, antitrípica y dispersibilidad de proteínas. En la operación de inactivación enzimática se consideraron los parámetros siguientes: tiempo y temperatura de exposición, humedad y tamaño de la partícula. De los distintos tratamientos térmicos aplicados en este trabajo se dedujo que las condiciones de procesos adecuados para obtener un producto apto para consumo humano, son: grano de soja molido humectado (25% de humedad) sometido a una corriente de vapor (97-C) durante un período de cuatro a ocho minutos