Amino acid HPLC-FLD analysis of spirulina and its protective mechanism against the combination of obesity and colitis in wistar rats.

Objective: The cafeteria diet (CD), designed as an experimental diet mimicking the obesogenic diet, may contribute to the pathogenesis of inflammatory bowel diseases (IBD). This study delves into the influence of spirulina (SP) on obesity associated with colitis in Wistar rats. Methods: The amino acids composition of SP was analyzed using HPLC-FLD. Animals were equally separated into eight groups, each containing seven animals and treated daily for eight weeks as follows: Control diet (SD), cafeteria diet (CD) group, CD + SP (500 mg/kg) and SD + SP. Ulcerative colitis was provoked by rectal injection of acetic acid (AA) (3 % v/v, 5 ml/kg b.w.) on the last day of treatment in the following groups: SD + AA, SD + AA + SP, CD + AA, and CD + AA + SP. Results: Findings revealed that UC and/or CD increased the abdominal fat, weights gain, and colons. Moreover, severe colonic alteration, perturbations in the serum metabolic parameters associated with an oxidative stress state in the colonic mucosa, defined by overproduction of reactive oxygen species (ROS) and increased levels of plasma scavenging activity (PSA). Additionally, obesity exacerbated the severity of AA-induced UC promoting inflammation marked by the overexpression of pro-inflammatory cytokines. Significantly, treatment with SP provided notable protection against inflammation severity, reduced histopathological alterations, attenuated lipid peroxidation (MDA), and enhanced antioxidant enzyme activities (CAT, SOD, and GPX) along with non-enzymatic antioxidants (GSH and SH-G). Conclusions: Thus, the antioxidant effects and anti-inflammatory proprieties of SP could be attributed to its richness in amino acids, which could potentially mitigate inflammation severity in obese subjects suffering from ulcerative colitis. These results imply that SP hold promise as a therapeutic agent for managing of UC, particularly in individuals with concomitant obesity. Understanding SP's mechanisms of action may lead novel treatment strategies for inflammatory bowel diseases and hyperlipidemia in medical research.

Prophylactic Coloprotective Effect of Urtica dioica Leaves against Dextran Sulfate Sodium (DSS)-Induced Ulcerative Colitis in Rats.

Background and Objectives: Urtica dioica, a source of bioactive functional compounds, provides nutritional and gastrointestinal therapeutic benefits. This study attempted to investigate the prophylactic coloprotective action of an aqueous extract of Urtica dioica (AEUD) on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC). Materials and Methods: Phenolic compounds, total sugar, and mineral levels were determined in AEUD. Then, AEUD at different doses (50, 100, and 200 mg/kg, BW, p.o.) and mesalazine (MESA) as a standard treatment (100 mg/kg, BW, p.o.) were given orally for 21 days. Acute colitis was induced by administering drinking water with 5% (w/v) DSS for 7 days. Body weight variation, fecal occult blood, and stool consistency were determined daily. The severity of colitis was graded according to colon length, disease activity index (DAI), histological evaluations, and biochemical alterations. Rats orally administered DSS regularly developed clinical and macroscopic signs of colitis. Results: Due to its richness in phenolic and flavonoid compounds (247.65 ± 2.69 mg EAG/g MS and 34.08 ± 0.53 mg EQt/g MS, respectively), AEUD markedly ameliorated DAI, ulcer scores, colon length shortening, colonic histopathological changes, and hematological and biochemical modifications. Taken together, AEUD treatment notably (p < 0.01) suppressed DSS-induced UC by reducing oxidative stress via lowering MDA/H2O2 production and stimulating the effect of enzyme antioxidants as well as attenuating inflammation by decreasing CRP levels by 79.5% between the DSS and DSS + AEUD-50 groups compared to the MESA group (75.6%). Conclusions: AEUD was sufficient to exert a coloprotective effect that might be influenced by its bioactive compounds' anti-inflammatory and antioxidant capabilities.

Chromatographic Analyses of Spirulina (Arthrospira platensis) and Mechanism of Its Protective Effects against Experimental Obesity and Hepatic Steatosis in Rats.

Background and Objectives: Obesity is currently a major health problem due to fatty acid accumulation and excess intake of energy, which leads to an increase in oxidative stress, particularly in the liver. The main goal of this study is to evaluate the protective effects of spirulina (SP) against cafeteria diet (CD)-induced obesity, oxidative stress, and lipotoxicity in rats. Materials and Methods: The rats were divided into four groups and received daily treatments for eight weeks as follows: control group fed a standard diet (SD 360 g/d); cafeteria diet group (CD 360 g/d); spirulina group (SP 500 mg/kg); and CD + SP group (500 mg/kg, b.w., p.o.) according to body weight (b.w.) per oral (p.o.). Results: Our results show that treatment with a CD increased the weights of the body, liver, and abdominal fat. Additionally, severe hepatic alteration, disturbances in the metabolic parameters of serum, and lipotoxicity associated with oxidative stress in response to the CD-induced obesity were observed. However, SP treatment significantly reduced the liver alteration of CD feed and lipid profile disorder associated with obesity. Conclusions: Our findings suggest that spirulina has a marked potential therapeutic effect against obesity and mitigates disturbances in liver function parameters, histological alterations, and oxidative stress status.

Emergence of plasmid-mediated colistin-resistance in CMY-2-producing Escherichia coli of lineage ST2197 in a Tunisian poultry farm.

Our study aimed to investigate colistin resistance and the mechanisms involved in a collection of 35 extended-spectrum beta-lactamase (ESBL) and 13 CMY-2-producing E. coli strains which were previously recovered from chicken gut microbiota in Tunisia, as well as to determine the genetic location of mcr genes. Forty-eight ESBL and CMY-2-producing E. coli strains were obtained from 137 fecal samples of healthy chickens during 2013. These strains were tested for colistin resistance by the broth microdilution method, and screened for mcr-1 and mcr-2 genes by PCR. Two of these strains were colistin-resistant (MIC = 8 mg/L). Both harbored the mcr-1 gene, were CMY-2 producers, and were additionally resistant to tetracycline, ciprofloxacin, chloramphenicol, gentamicin, tobramycin and trimethoprim-sulfamethoxazole. They shared phylogroup A, the same pulsed-field gel electrophoresis (PFGE)-pattern, and were typed as ST2197. In both strains, ISApl1 and pap2 were detected upstream and downstream of mcr-1 gene, respectively. The analysis of the two mcr-1-positive strains and their transconjugants by PCR-based replicon typing and S1-PFGE, demonstrated that mcr-1 gene is linked to an IncP plasmid (~242 kb), and blaCMY-2 to an IncI1 plasmid (97 kb). The occurrence of E. coli harboring mcr-1 gene among intestinal microbiota in poultry and its location on a conjugative plasmid could represent a risk for public health. The evolution of this type of resistant microorganisms should be evaluated in the future.

High prevalence of extended-spectrum and plasmidic AmpC beta-lactamase-producing Escherichia coli from poultry in Tunisia.

This study was conducted to detect extended spectrum beta-lactamases (ESBLs) and plasmidic AmpC beta-lactamase (pAmpC-BL)-producing Escherichia coli isolates in industrial poultry samples were collected from healthy chickens of the three farms. Samples were inoculated onto desoxycholate-lactose-agar plates supplemented with cefotaxime (2mg/L). E. coli was identified by biochemical and molecular methods and antibiotic susceptibility testing by the disk diffusion method. Genes encoding ESBLs and pAmpC-BL were detected by PCR and sequencing. Phylogenetic groups were determined by triplex PCR. The molecular typing of strains was done by pulsed field gel electrophoresis (PFGE) and Multilocus Sequence Typing (MLST) in those isolates showing different PFGE patterns. Cefotaxime-resistant E. coli isolates were recovered in 48 of 137 fecal samples (35%), and one isolate/sample was further studied. The following beta-lactamase genes were detected: blaCTX-M-1 (29 isolates, isolated in all three farms), blaCTX-M-15 (5 isolates, confined in farm II), blaCTX-M-14 and blaCMY-2 (one isolate and 13 isolates, respectively, in farm III). The 48 cefotaxime-resistant isolates were distributed into phylogroups: B1 (n=21), A (n=15) and D (n=12). PFGE analysis revealed 19 unrelated patterns: 15 different profiles among ESBL-positive strains and 4 among the CMY-2-positive isolates. The following sequence types-associated phylogroups were detected: a) CTX-M-1-positive strains: lineages ST542-B1, ST212-B1, ST58-B1, ST155-B1 and ST349-D; b) CTX-M-15-positive strain: lineage ST405-D; c) CTX-M-14-positive strain: lineage ST1056-B1; d) CMY-2-positive strains: lineages ST117-D, ST2197-A, and ST155-B1. Healthy chickens constitute an important reservoir of ESBL- and pAmpC-BL-producing E. coli isolates that potentially could be transmitted to humans via the food chain or by direct contact.