Prebiotic and Synbiotic Modifications of Beta Oxidation and Lipogenic Gene Expression after Experimental Hypercholesterolemia in Rat Liver.

Background and aims: Non-alcoholic fatty liver disease (NAFLD) is characterized by the presence of fat in hepatocytes because of decreased ß-oxidation and increased lipogenesis. Prebiotics, probiotics, and synbiotic have modulatory effects on intestinal microbiota and may influence the gut-liver axis. Our aim was to evaluate the effects of prebiotic, probiotics, and synbiotic on liver histopathology and gene expression related to ß-oxidation and lipogenesis after hypercholesterolemia. Methods: Wistar male adult rats (n = 40) were submitted to hypercholesterolemic conditions (HPC) (60 days). On Day 30 of HPC, rats were subdivided in 5 groups: negative control (NC): without HPC + Gv (distilled water); positive control (PC): with HPC + Gv (distilled water); prebiotic (PRE): HPC + Gv with prebiotic (Fiber FOS®); probiotic (PRO): HPC + Gv with probiotic strains Gv (Probiatop®); and synbiotic (SYN): HPC + Gv with synbiotic (Simbioflora®). All rats were sacrificed on Day 30 post-treatment. Blood was collected to verify total serum cholesterol, and liver tissue was sampled to verify histopathological changes and gene expression. Gene expression related to ß-oxidation (PPAR-α and CPT-1) and lipogenesis (SREBP-1c, FAS and ME) was evaluated in liver tissue using RT-qPCR. Results: PC had higher cholesterol levels when compared to NC. PRE and SYN rats had lower cholesterol levels than PC. PC rats showed more histopathological changes than NC rats; PRE and SYN rats showed fewer alterations than PC rats. PPAR-α was expressed at higher levels in SYN and PC rats compared with PRE and PRO rats. CPT-1 expression was similar in all groups. SREBP-1c was expressed at higher levels in PC rats compared with NC rats; levels were lower in SYN rats compared with PRO rats; levels were lower in PRE rats compared with PC and PRO rats. FAS was expressed at lower levels in PRE rats compared with SYN rats. ME expression was lower in PC rats compared with NC rats. Conclusion: Prebiotic and synbiotic supplementation improve hepatic alterations related to hypercholesterolemia. These changes appear to be mediated by altered expression of genes related to ß-oxidation and lipogenesis.

Influence of intestinal microbiota on body weight gain: a narrative review of the literature.

In recent decades, experimental and clinical studies have associated the development of obesity with the composition of the gut microbiota. Mechanisms potentially involved in the contribution of gut microbiota to body weight gain include changes in energy extraction from the diet and the modulation of lipid metabolism, endocrine functions, and the immune system. The host's specific genetic heritage, the type and amount of food intake, chronic inflammation, reduced body energy expenditure, and exposure to obesogenic pollutants are also potential contributing factors. The pathophysiological processes involved in the relationship between gut microbiota and obesity are not fully understood, and further studies are needed to establish whether differences in gut bacterial diversity between obese and normal body weight individuals are the cause or a consequence of obesity.

Immunohistochemical assessment of mucosal cytokine profile in acetic acid experimental colitis.

UNLABELLED: Experimental colitis induced by acetic acid has been used extensively as a model for intestinal inflammatory disease. Colonic tissue lesions of intestinal inflammatory disease patients seem to be related to the increased local production of pro-inflammatory cytokines (IL-1, IL-6, TNF-alpha, and IFN-gamma). PURPOSE: To assess the cytokine expression pattern identified through immunohistochemistry in colonic mucosa after experimental colitis induced by acetic acid and establish the relationship between this pattern and the presence of macroscopic lesions. MATERIALS AND METHODS: Adult male Wistar rats (n = 39) were divided at random into 4 groups: NC45 and NC24 (control without colitis; sacrificed at 45 minutes and 24 hours, respectively); and WC45 and WC24 (with experimental colitis induced by acetic acid; sacrificed at 45 minutes and 24 hours, respectively). Macroscopic and microscopic alterations in colonic tissue were evaluated, and cytokine expression was assessed through immunohistochemistry. RESULTS: After 24 hours, IL-1 expression was greater in the groups with colitis when compared to the groups without colitis. IL-4 expression was higher in the WC45 group. There was an increase in both INF-gamma and IL-6 related to the presence of necrosis of the colonic mucosa in the groups with colitis for both periods evaluated. CONCLUSION: The immunohistochemical technique was efficient for the analysis of various cytokine expressions in the colonic tissue. There was an increase in the IL-1 pro-inflammatory cytokines as well as in IL-6 and IFN-gamma associated with the presence of colonic necrosis. Experimental colitis induced by acetic acid is a useful model for the development of studies assessing the role of cytokines in the inflammation of mucosa as well as anti-cytokine therapies.

Immunohistochemical assessment of mucosal cytokine profile in acetic acid experimental colitis

O modelo de colite experimental induzida por ácido acético (CEAA) vem sendo extensamente utilizado em estudos sobre doenças inflamatórias intestinais (DII). Lesões no tecido colônico em portadores de DII parecem estar relacionados à produção local aumentada de citocinas pró-inflamatórias (IL-1, IL-6, TNF-a e IFN-g). OBJETIVO: Avaliar o padrão de expressão de citocinas identificadas por imunohistoquímica em tecido colônico após CEAA e relacioná-lo à presença de lesões macroscópicas. MATERIAL E MÉTODOS: Ratos machos Wistar adultos (n=39) foram submetidos ou não à CEAA e sacrificados para retirada do tecido colônico em dois períodos distintos, perfazendo 4 grupos aleatórios: SC45 e SC24 (sem colite; sacrifício 45 minutos e 24 horas, respectivamente); CC45 e CC24 (com colite; sacrifício 45 minutos e 24 horas, respectivamente). Avaliaram-se alterações macro e microscópicas do cólon e sua expressão de citocinas foi avaliada por imunohistoquímica. RESULTADOS: Após 24 horas, a expressão de IL-1 foi maior no grupo com colite, em relação ao sem colite. IL-4 foi mais expressa no grupo CC45. Houve aumento de INF-g e IL-6, relacionados à presença de necrose da mucosa colônica, nos grupos com colite, em ambos os períodos avaliados. CONCLUSÃO: A técnica de imunohistoquímica foi eficiente para a análise da expressão de citocinas na mucosa colônica. Houve aumento da expressão das citocinas pró-inflamatórias IL-1 e de IL-6 e IFN-g associado à presença de necrose colônica. A CEAA é um bom modelo para o desenvolvimento de estudos destinados a avaliar o papel das citocinas na inflamação da mucosa e terapias anti-citocinas.

A new swivel model for parenteral and enteral infusion in rats.

BACKGROUND: In experimentation with rats submitted to enteral and parenteral infusions for medium to long periods it is necessary to use swivels. With the objective of developing a new biocompatible, safe, efficient, and low cost swivel, the medical and engineering teams of the University of São Paulo joined forces. MATERIAL AND METHODS: After defining the characteristics and criteria for the mechanical design, the new swivel was developed and bench tested for flow, rotation and sealing. Later it was evaluated on rats, after catheterization of jugular vein and stomach (by gastrostomy) for infusion of different solutions at certain concentrations and infusion rates (mean 6.73 days of infusion). RESULTS: The new swivel consisted of two sections of common plastic syringes for injection, together with the rubber seals, a plunger, and a hypodermic needle. The syringe with a slightly smaller diameter rotates inside the larger diameter syringe interconnected with a needle sealed by their respective rubber rings. The bench and animal tests did not reveal any functional defects. There were no blockages or leaks in the swivel and it was reused three times without losing its mechanical properties, after being hygienized and sterilized with ethylene oxide. The cost of producing this swivel is estimated to be no more than $3 US. CONCLUSION: The cooperation between the departments of medical research and mechanical engineering enabled the development of a swivel that is simple and inexpensive to make, yet fully meets the needs of parenteral and enteral infusion in rats. The authors present detailed instructions for the construction of this new swivel.