No abstract

Prebiotics are used to influence the growth, colonization, survival, and activity of probiotics, and enhance the innate immunity, thus improving the health status of the host. The survival, growth, and activity of probiotics are often interfered with by intrinsic factors and indigenous microbes in the gastrointestinal tract. In this study, Bulnesia sarmienti aqueous extract (BSAE) was evaluated for the growth-promoting activity of different strains of Lactobacillus acidophilus, and a simple, precise, cost-effective high-performance liquid chromatography (HPLC) method was developed and validated for the determination of active prebiotic ingredients in the extract. Different strains of L. acidophilus (probiotic) were incubated in de Man, Rogosa, and Sharpe (MRS) medium with the supplementation of BSAE in a final concentration of 0.0%, 1.0%, and 3.0% (w/v) as the sole carbon source. Growth of the probiotics was determined by measuring the pH changes and colony-forming units (CFU/mL) using the microdilution method for a period of 24 hours. The HPLC method was designed by optimizing mobile-phase composition, flow rate, column temperature, and detection wavelength. The method was validated according to the requirements of a new method, including accuracy, precision, linearity, limit of detection, limit of quantitation, and specificity. The major prebiotic active ingredients in BSAE were determined using the validated HPLC method. The rapid growth rate of different strains of L. acidophilus was observed in growth media with BSAE, whereas the decline of pH values of cultures varied in different strains of probiotics depending on the time of culture. (+)-Catechin and (-)-epicatechin were identified on the basis of their retention time, absorbance spectrum, and mass spectrometry fragmentation pattern. The developed method met the limit of all validation parameters. The prebiotic active components, (+)-catechin and (-)-epicatechin, were quantified as 1.27% and 0.71% (w/w), respectively, in crude extract, and 6.36±0.06 μg/mL and 4.47±0.41 μg/mL (mean±standard deviation), respectively, in a prebiotic capsule of BSAE by HPLC analysis. BSAE contains the active components of prebiotics and enhances the growth of L. acidophilus.

The objective of this study was to evaluate and compare the antitumor activity of different solvent fractions (ethanol, dichloromethane, ethyl acetate, butanol and water) of the Auricularia auricula-judae 70% ethanol extract on the P388D1 macrophage and sarcoma 180 cells. A dose-dependent antitumor activity of each solvent fraction (from 0.01 mg/ml to 0.3 mg/ml) was shown against both cell types. These cytotoxic effects of all the tested fractions were confirmed on the MTT and SRB assays, without statistical differences each other. IC50 value of dichloromethane fraction was 94.2 μg/ml against sarcoma 180 cells lower than any other solvent fractions. The potent antitumor effect of the dichloromethane (DCM) fraction was also found against solid tumor in BALB/c mice. The splenomegaly and higher splenic index were found in tumor-bearing mice, with the DCM fraction returning to the negative control values. Thus, the results indicated the dichloromethane fraction may have potential ingredients as antitumor candidates.

E. coli is one of the most important food borne pathogen, which could be transmitted by milk and milk products. To assess the role of dairy milk as the source of drug resistant E. coli, we examined 50 raw dairy milk samples (25-farm milk + 25-market milk) from some selected areas of Bangladesh by cultural, morphological, biochemical and antimicrobial sensitivity tests. In the preliminary observation, the mean total aerobic mesophilic count of market and farm raw milk samples were 8.98 and 8.68 log CFU/ml, while mean coliform count were 4.20 and 3.03 log CFU/ml respectively. Thirty-three E. coli isolates were recovered from collected samples (66% 33 of 50) and this pathogen was more prevalent in market milk (76%, 19 of 25) than farm milk (56%, 14 of 25). In addition, most of the isolated E. coli exhibited resistance against ampicillin and cefotaxime. This result shows that, the raw dairy milk and its products could be a source of human drug resistant E. coli.