ABSTRACT
Background & objectives: The human gut microbiota play a significant role in nutritional processes. The concept of probiotics has led to widespread consumption of food preparations containing probiotic microbes such as curd and yogurt. Curd prepared at home is consumed every day in most homes in southern India. In this study the home-made curd was evaluated for lactic acid bacteria (LAB) with probiotic potential. Methods: Fifteen LAB (12 lactobacilli, 1 lactococcus, 2 Lleuconostoc) and one yeast isolated from home-made curd were evaluated for resistance to acid, pepsin, pancreatin and bile salts; antimicrobial resistance; intrinsic antimicrobial activity; adherence to Caco-2 epithelial cells; ability to block pathogen adherence to Caco-2 cells; ability to inhibit interleukin (IL)-8 secretion from HT-29 epithelial cells in response to Vibrio cholerae; and ability to induce anti-inflammatory cytokine expression in THP-1 monocyte cells. Results: Llactobacillus abundance in fermenting curd peaked sharply at 12 h. Nine of the strains survived exposure to acid (pH 3.0) for at least one hour, and all strains survived in the presence of pancreatin or bile salts for 3 h. None showed haemolytic activity. All were resistant to most antimicrobials tested, but were sensitive to imipenem. Most strains inhibited the growth of Salmonella Typhimurium while five inhibited growth of V. cholerae O139. Seven strains showed adherence to Caco-2 cells ranging from 20-104 per cent of adherence of an adherent strain of Escherichia coli, but all inhibited V. cholerae adherence to Caco-2 cells by 20-100 per cent. They inhibited interleukin-8 secretion from HT-29 cells, in response to V. cholerae, by 50-80 per cent. Two strains induced IL-10 and IL-12 messenger ribonucleic acid (mRNA) expression in THP-1 cells. Interpretation & conclusions: LAB in curd had properties consistent with probiotic potential, but these were not consistent across species. LAB abundance in curd increased rapidly at 12 h of fermentation at room temperature and declined thereafter.
ABSTRACT
OBJECTIVE@#To explore anti-enteric properties of Dillenia pentagyna Roxb. (D. pentagyna) fruit extract fractions of different polarities by comparative antimicrobial activity against municipal sewage microflora and to assess its urease inhibition potential.@*METHODS@#Different polar fractions of D. pentagyna fruit extracts were studied by antimicrobial susceptibility test with several adjustments in this resource limited setup. Tests were done against municipal sewage microbes at various bacterial load (initially with 1.0 McFarland followed by 1.5 McFarland) using basal (nutrient agar) and selective medium (MacConkey's agar with and without supplementation of 5% NaCl). All assays statistically scaled with a gradient for uniformity and comparison with ciprofloxacin standard. Fraction with highest activity was studied for urease inhibition potential by kinetic method.@*RESULTS@#DP-47 separated by 30% ethyl acetate (EtOAc) in CHCl3 from CHCl3 extract had slightly higher antimicrobial potency (y=0.758x+7.571) as dissolved in methanol than in dimethylsulfoxide (y=0.300x+6.000). EtOAc extract fractioned by 10% methanol in EtOAc (DP-43) was more potent antimicrobial (y=1.428x+8.392) and soluble in water. Butanol extract fractioned by water (DP-50) showed highest antimicrobial potency (y=3.384x+2.000) than both DP-47 and DP-43 in disk diffusion assays. In higher microbial load DP-50 was potent antimicrobial (y=1.538x+3.000) and completely inhibited any vegetative growth at lower load of 0.5 McFarland. In selective environment DP-50 was effective (y=1.076x+7.500 in MacConkey's, y=1.307x+6.000 in 5% NaCl supplemented). It was evident that enteric pathogens may not easily develop resistance against DP-50 and at high concentration it inhibited urease activity by 94.87%. The standard inhibition by thiourea (1%) is 33.914%.@*CONCLUSIONS@#Highly polar fraction of D. pentagyna Roxb. fruit extract DP-50 have potential antimicrobial activity against sewage microflora in basal and selective culture indicating its potential against non-fastidious, coliforms and Vibrio pathogens. Urease inhibition indicates efficacy against Helicobactor pylory.
ABSTRACT
Objective: To explore anti-enteric properties of Dillenia pentagyna Roxb. (D. pentagyna) fruit extract fractions of different polarities by comparative antimicrobial activity against municipal sewage microflora and to assess its urease inhibition potential. Methods: Different polar fractions of D. pentagyna fruit extracts were studied by antimicrobial susceptibility test with several adjustments in this resource limited setup. Tests were done against municipal sewage microbes at various bacterial load (initially with 1.0 McFarland followed by 1.5 McFarland) using basal (nutrient agar) and selective medium (MacConkey's agar with and without supplementation of 5% NaCl). All assays statistically scaled with a gradient for uniformity and comparison with ciprofloxacin standard. Fraction with highest activity was studied for urease inhibition potential by kinetic method. Results: DP-47 separated by 30% ethyl acetate (EtOAc) in CHCl