Dietary Interventions Ameliorate Infectious Colitis by Restoring the Microbiome and Promoting Stem Cell Proliferation in Mice.

Decreases in short-chain-fatty-acids (SCFAs) are linked to inflammatory bowel disease (IBD). Yet, the mechanisms through which SCFAs promote wound healing, orchestrated by intestinal stem cells, are poorly understood. We discovered that, in mice with Citrobacter rodentium (CR)-induced infectious colitis, treatment with Pectin and Tributyrin diets reduced the severity of colitis by restoring Firmicutes and Bacteroidetes and by increasing mucus production. RNA-seq in young adult mouse colon (YAMC) cells identified higher expression of Lgr4, Lgr6, DCLK1, Muc2, and SIGGIR after Butyrate treatment. Lineage tracing in CR-infected Lgr5-EGFP-IRES-CreERT2/ROSA26-LacZ (Lgr5-R) mice also revealed an expansion of LacZ-labeled Lgr5(+) stem cells in the colons of both Pectin and Tributyrin-treated mice compared to control. Interestingly, gut microbiota was required for Pectin but not Tributyrin-induced Lgr5(+) stem cell expansion. YAMC cells treated with sodium butyrate exhibited increased Lgr5 promoter reporter activity due to direct Butyrate binding with Lgr5 at -4.0 Kcal/mol, leading to thermal stabilization. Upon ChIP-seq, H3K4me3 increased near Lgr5 transcription start site that contained the consensus binding motif for a transcriptional activator of Lgr5 (SPIB). Thus, a multitude of effects on gut microbiome, differential gene expression, and/or expansion of Lgr5(+) stem cells seem to underlie amelioration of colitis following dietary intervention.

Performance of weaner rabbits fed a concentrate diet supplemented with pawpaw leaves.

This experiment investigated the performance of weaner rabbits fed concentrate diets supplemented with pawpaw leaves (PPL). Twenty-four male weaner rabbits aged 5 weeks, weighing between 350 and 450 g were used. Concentrate diet was supplemented with PPL in ratios 100:0, 70:30, 50:50 and 30:70. Rabbits were randomly allotted to the four diets in a completely randomised design for 8 weeks, with six rabbits per diet. Results showed that rabbits supplemented with 30 and 50 % PPL had higher (P < 0.05) dry matter intake to sole concentrate. At 70 % PPL, dry matter intake did not vary with other treatments. Weight gain was higher (P < 0.05) in rabbits fed 30 and 50 % PPL than sole concentrate. Rabbits fed 70 % PPL had lower (P < 0.05) weight gain to animals fed 30 % PPL but gained similarly (P > 0.05) to those fed on 50 % PPL and sole concentrate. Feed conversion ratio improved (P < 0.05) in animals fed 30, 50 and 70 % PPL. Rabbits fed 30 % PPL had the highest (P < 0.05) protein efficiency ratio. Rabbits had higher dry matter digestibility (P < 0.05) with PPL supplementation than sole concentrate while crude protein and fibre digestibility was higher with 30 and 50 % PPL. Haematological and serum parameters in rabbits were unaltered with feeding PPL. It is concluded that weaner rabbits can utilise PPL as supplement to concentrate diet at 30 to 70 % dry matter with positive responses in performance and nutrient digestibility without deleterious effect on the physiological status of the rabbits.

Salicylic acid alters antioxidant and phenolics metabolism in Catharanthus roseus grown under salinity stress.

BACKGROUND: Salicylic acid (SA) acts as a potential non-enzymatic antioxidant and a plant growth regulator, which plays a major role in regulating various plant physiological mechanisms. The effects of salicylic acid (SA; 0.05 mM) on physiological parameters, antioxidative capacity and phenolic metabolism, lignin, alkaloid accumulation in salt stressed Catharanthus roseus were investigated. MATERIALS AND METHODS: Catharanthus roseus seeds were grown for two months in a glass house at 27-30°C in sunlight, and then divided into four different groups and transplanted with each group with the following solutions for one month: group I (non-saline control), group II, 100 mM NaCl, group III, 0.05 mM SA, group IV, 100 mM NaCl+0.05 mM SA and to determine the physiological parameters (DW, FW, WC), chlorophyll contents, carotenoid contents, lipid peroxidation, phenolics, lignin, alkaloid and enzymatic assays in each leaf pairs and roots. RESULTS: SA exhibited growth-promoting property, which correlated with the increase of dry weight, water content, photosynthetic pigments and soluble proteins. SA has additive effect on the significant increase in phenylalanine ammonia-lyase (PAL) activity, which is followed by an increase in total soluble phenolics and lignin contents in all leaf pairs and root of C. roseus. SA enhances malondialdehyde content in all leaf pairs and root. The antioxidant enzymes (catalase, glutathione reductase, glutathione-S-tranferase, superoxide dismutase, peroxidase) as well as alkaloid accumulation increased in all treatments over that of non-saline control but the magnitude of increase was found more in root. Further, the magnitude of increase of alkaloid accumulation was significantly higher in 100 mM NaCl, but highly significant was found in presence of 0.05 mM SA and intermediate in presence of both 0.05 mM SA+100 mM NaCl. CONCLUSION: We concluded that applied SA to salt stress, antioxidant and phenolic metabolism, and alkaloid accumulation were significantly altered and the extent of alteration varied between the SA and salt stress.