Decoding the secrets of longevity: unraveling nutraceutical and miRNA-Mediated aging pathways and therapeutic strategies

MicroRNAs (miRNAs) are short RNA molecules that are not involved in coding for proteins. They have a significant function in regulating gene expression after the process of transcription. Their participation in several biological processes has rendered them appealing subjects for investigating age-related disorders. Increasing data indicates that miRNAs can be influenced by dietary variables, such as macronutrients, micronutrients, trace minerals, and nutraceuticals. This review examines the influence of dietary factors and nutraceuticals on the regulation of miRNA in relation to the process of aging. We examine the present comprehension of miRNA disruption in age-related illnesses and emphasize the possibility of dietary manipulation as a means of prevention or treatment. Consolidating animal and human research is essential to validate the significance of dietary miRNA control in living organisms, despite the abundance of information already provided by several studies. This review elucidates the complex interaction among miRNAs, nutrition, and aging, offering valuable insights into promising areas for further research and potential therapies for age-related disorders.

The journey of boswellic acids from synthesis to pharmacological activities

There has been a lot of interest in using naturally occurring substances to treat a wide variety of chronic disorders in recent years. From the gum resin of Boswellia serrata and Boswellia carteri, the pentacyclic triterpene molecules known as boswellic acid (BA) are extracted. We aimed to provide a detailed overview of the origins, chemistry, synthetic derivatives, pharmacokinetic, and biological activity of numerous Boswellia species and their derivatives. The literature searched for reports of B. serrata and isolated BAs having anti-cancer, anti-microbial, anti-inflammatory, anti-arthritic, hypolipidemic, immunomodulatory, anti-diabetic, hepatoprotective, anti-asthmatic, and clastogenic activities. Our results revealed that the cytotoxic and anticancer effects of B. serrata refer to its triterpenoid component, including BAs. Three-O-acetyl-11-keto-BA was the most promising cytotoxic molecule among tested substances. Activation of caspases, upregulation of Bax expression, downregulation of nuclear factor-kappa B (NF-kB), and stimulation of poly (ADP)-ribose polymerase (PARP) cleavage are the primary mechanisms responsible for cytotoxic and antitumor effects. Evidence suggests that BAs have shown promise in combating a wide range of debilitating disease conditions, including cancer, hepatic, inflammatory, and neurological disorders.

Computational Amendment of Parenteral In Situ Forming Particulates' Characteristics: Design of Experiment and PBPK Physiological Modeling

Lipid and/or polymer-based drug conjugates can potentially minimize side effects by increasing drug accumulation at target sites and thus augment patient compliance. Formulation factors can present a potent influence on the characteristics of the obtained systems. The selection of an appropriate solvent with satisfactory rheological properties, miscibility, and biocompatibility is essential to optimize drug release. This work presents a computational study of the effect of the basic formulation factors on the characteristics of the obtained in situ-forming particulates (IFPs) encapsulating a model drug using a 21.31 full factorial experimental design. The emulsion method was employed for the preparation of lipid and/or polymer-based IFPs. The IFP release profiles and parameters were computed. Additionally, a desirability study was carried out to choose the optimum formulation for further morphological examination, rheological study, and PBPK physiological modeling. Results revealed that the type of particulate forming agent (lipid/polymer) and the incorporation of structure additives like Brij 52 and Eudragit RL can effectively augment the release profile as well as the burst of the drug. The optimized formulation exhibited a pseudoplastic rheological behavior and yielded uniformly spherical-shaped dense particulates with a PS of 573.92 ± 23.5 nm upon injection. Physiological modeling simulation revealed the pioneer pharmacokinetic properties of the optimized formulation compared to the observed data. These results assure the importance of controlling the formulation factors during drug development, the potentiality of the optimized IFPs for the intramuscular delivery of piroxicam, and the reliability of PBPK physiological modeling in predicting the biological performance of new formulations with effective cost management.

The Potent and Selective Histamine H3 Receptor Antagonist E169 Counteracts Cognitive Deficits and Mitigates Disturbances in the PI3K/AKT/GSK-3β Signaling Pathway in MK801-Induced Amnesia in Mice

The role of histamine H3 receptors (H3Rs) in memory and the prospective of H3R antagonists in pharmacological control of neurodegenerative disorders, e.g., Alzheimer's disease (AD), is well-accepted. Therefore, the procognitive effects of acute systemic administration of H3R antagonist E169 (2.5-10 mg/kg, i.p.) on MK801-induced amnesia in C57BL/6J mice using the novel object recognition test (NORT) were evaluated. E169 (5 mg) provided a significant memory-improving effect on MK801-induced short- and long-term memory impairments in NORT. The E169 (5 mg)-provided effects were comparable to those observed with the reference phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 and were abrogated with the H3R agonist (R)-α-methylhistamine (RAMH). Additionally, our results demonstrate that E169 ameliorated MK801-induced memory deficits by antagonism of H3Rs and by modulation of the level of disturbance in the expression of PI3K, Akt, and GSK-3β proteins, signifying that E169 mitigated the Akt-mTOR signaling pathway in the hippocampus of tested mice. Moreover, the results observed revealed that E169 (2.5-10 mg/kg, i.p.) did not alter anxiety levels and locomotor activity of animals in open field tests, demonstrating that performances improved following acute systemic administration with E169 in NORT are unrelated to changes in emotional response or in spontaneous locomotor activity. In summary, these obtained results suggest the potential of H3R antagonists such as E169, with good in silico physicochemical properties and stable retained key interactions in docking studies at H3R, in simultaneously modulating disturbed brain neurotransmitters and the imbalanced Akt-mTOR signaling pathway related to neurodegenerative disorders, e.g., AD.

Simultaneous Antagonism at H3R/D2R/D3R Reduces Autism-like Self-Grooming and Aggressive Behaviors by Mitigating MAPK Activation in Mice

Dysregulation in brain neurotransmitters underlies several neuropsychiatric disorders, e.g., autism spectrum disorder (ASD). Also, abnormalities in the extracellular-signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) pathway pave the way for neuroinflammation, neurodegeneration, and altered learning phenotype in ASD. Therefore, the effects of chronic systemic administration of the multiple-targeting antagonist ST-713 at the histamine H3 receptor (H3R) and dopamine D2/D3 receptors (D2/D3R) on repetitive self-grooming, aggressive behaviors, and abnormalities in the MAPK pathway in BTBR T + Itpr3tf/J (BTBR) mice were assessed. The results showed that ST-713 (2.5, 5, and 10 mg/kg, i.p.) mitigated repetitive self-grooming and aggression in BTBR mice (all p < 0.05), and the ameliorative effects of the most promising dose of ST-713 (5 mg/kg, i.p.) on behaviors were completely abrogated by co-administration of the H3R agonist (R)-α-methylhistamine or the anticholinergic drug scopolamine. Moreover, the elevated levels of several MAPK pathway proteins and induced proinflammatory markers such as tumor necrosis factor (TNF-α), interleukin-1β (IL-1β), and IL-6 were significantly suppressed following chronic administration of ST-713 (5 mg/kg, i.p.) (all p < 0.01). Furthermore, ST-713 significantly increased the levels of histamine and dopamine in hippocampal tissue of treated BTBR mice (all p < 0.01). The current observations signify the potential role of such multiple-targeting compounds, e.g., ST-713, in multifactorial neurodevelopmental disorders such as ASD.

Revisiting Preclinical Observations of Several Histamine H3 Receptor Antagonists/Inverse Agonists in Cognitive Impairment, Anxiety, Depression, and Sleep-Wake Cycle Disorder

A relationship appears to exist between dysfunction of brain histamine (HA) and various neuropsychiatric brain disorders. The possible involvement of brain HA in neuropathology has gained attention recently, and its role in many (patho)physiological brain functions including memory, cognition, and sleep-wake cycle paved the way for further research on the etiology of several brain disorders. Histamine H3 receptor (H3R) evidenced in the brains of rodents and humans remains of special interest, given its unique position as a pre- and postsynaptic receptor, controlling the synthesis and release of HA as well as different other neurotransmitters in different brain regions, respectively. Despite several disappointing outcomes for several H3R antagonists/inverse agonists in clinical studies addressing their effectiveness in Alzheimer's disease (AD), Parkinson's disease (PD), and schizophrenia (SCH), numerous H3R antagonists/inverse agonists showed great potentials in modulating memory and cognition, mood, and sleep-wake cycle, thus suggesting its potential role in neurocognitive and neurodegenerative diseases such as AD, PD, SCH, narcolepsy, and major depression in preclinical rodent models. In this review, we present preclinical applications of selected H3R antagonists/inverse agonists and their pharmacological effects on cognitive impairment, anxiety, depression, and sleep-wake cycle disorders. Collectively, the current review highlights the behavioral impact of developments of H3R antagonists/inverse agonists, aiming to further encourage researchers in the preclinical drug development field to profile the potential therapeutic role of novel antagonists/inverse agonists targeting histamine H3Rs.

A182 THE LACK OF CHROMOGRANIN A IMPACTS COLONIC EPITHELIAL CELLS MARKERS IN AN EXPERIMENTAL MODEL OF ULCERATIVE COLITIS

Background

Ulcerative colitis (UC) is a chronic and acute inflammatory disorder of the colon linked to dysregulated gut mucosal immune response and compromised colonic epithelial barrier function and integrity. Chromogranin-A (CHGA), a pro-peptide secreted by enteroendocrine cells, is highly expressed in colonic tissues of patients with UC. Elevated CHGA has been shown to correlate with UC disease activity and severity. Moreover, complete deletion of CHGA was shown to result in a diminution of pro-inflammatory markers known to disrupt the colonic epithelial barrier function and gut mucosal healing process. However, little is known about the effect of the absence of CHGA on colonic epithelial barrier function and gut mucosal integrity.

Aims

Here, we characterized the impact of the lack of CHGA on the colonic mucosa and epithelial barrier structure and function using CHGA knockout (CHGA-/-) mice treated with dextran sulfate sodium (DSS) to induce colitis.

Methods

13–17 weeks old male C57BL/6 wild-type (CHGA+/+) and C57BL/6 CHGA-/- mice were treated for 5 days with 5% DSS to induced acute colitis, control mice received regular water. CHGA mRNA expression, disease activity index (DAI), and macroscopic score (MS) were analyzed. Distal colonic tissues were isolated, and mRNA expression of markers associated with regenerative stem cells (fast-cycling stem cells [Lgr5+] and reserve stem cells [HOPX+] and [LY6a+], Goblet cells functions mucus barrier mucin 2 [MUC2], resistin-like molecule β [RELMβ], WAP 4-disulphide core domain 2 [WFDC2]) and trefoil factor 3 (TFF3) was evaluated by qRT-PCR.

Results

We validated a beneficial effect of the Lack of CHGA on colitis severity, associated with significantly lower DAI and MS. In colitic CHGA+/+ and CHGA-/- mice, Lgr5+ and HOPX+ were both highly down-regulated, although, compared to CHGA+/+, CHGA-/- mice presented a 10.5fold higher expression of HOPX+. Compared to non-colitic states, Ly6a+ expression was significantly elevated in both colitic CHGA+/+ and CHGA-/- mice, however, no differences in Lgr5+ and Ly6a+ expression were noted between CHGA+/+ and CHGA-/- mice in all conditions. In CHGA+/+ mice, inflammatory conditions led to higher MUC2 and RELMB expression, although, compared to CHGA+/+, these markers were significantly lower in CHGA-/- mice. In colitic conditions, compared to CHGA+/+, CHGA-/- had a significant increase of WFDC2. In non-colitic conditions, mRNA expressions of all markers evaluated between CHGA+/+ and CHGA-/- in this study were unaltered. Finally, no differences were observed in TFF3 gene expression.

Conclusions

These results indicate in the absence of CHGA, the colonic epithelial barrier integrity and function are maintained through the modulation of goblet cells functions and elevated gut mucosa regenerative potential, thus enhancing the mucosal protection to colitis damage.

Funding Agencies

CIHR

The histamine H3R and dopamine D2R/D3R antagonist ST-713 ameliorates autism-like behavioral features in BTBR T+tf/J mice by multiple actions

Several brain neurotransmitters, including histamine (HA), acetylcholine (ACh), and dopamine (DA) are suggested to be involved in several brain disorders including cognitive deficits, depression, schizophrenia, anxiety, and narcolepsy, all of which are comorbid with Autism spectrum disorder (ASD). Therefore, the ameliorative effects of the novel multiple-active compound ST-713 with high binding affinities at histamine H3 receptor (H3R), dopamine D2sR and D3R on ASD-like behaviors in male BTBR T+tf/J mice model were assessed. ST-713 (3-(2-chloro-10H-phenothiazin-10-yl)-N-methyl-N-(4-(3-(piperidin-1-yl)propoxy)benzyl)propan-1-amine; 2.5, 5, and 10 mg/kg, i.p.) ameliorated dose-dependently social deficits, and significantly alleviated the repetitive/compulsive behaviors of BTBR mice (all P < 0.05). Moreover, ST-713 modulated disturbed anxiety levels, but failed to obliterate increased hyperactivity of tested mice. Furthermore, ST-713 (5 mg/kg) attenuated the increased levels of hippocampal and cerebellar protein expressions of NF-κB p65, COX-2, and iNOS in BTBR mice (all P < 0.05). The ameliorative effects of ST-713 on social parameters were entirely reversed by co-administration of the H3R agonist (R)-α-methylhistamine or the anticholinergic drug scopolamine. The obtained results demonstrate the potential of multiple-active compounds for the therapeutic management of neuropsychiatric disorders, e.g. ASD.

Role of Neuroinflammation in Autism Spectrum Disorder and the Emergence of Brain Histaminergic System. Lessons Also for BPSD?

Many behavioral and psychological symptoms of dementia (BPSD) share similarities in executive functioning and communication deficits with those described in several neuropsychiatric disorders, including Alzheimer's disease (AD), epilepsy, schizophrenia (SCH), and autism spectrum disorder (ASD). Numerous studies over the last four decades have documented altered neuroinflammation among individuals diagnosed with ASD. The purpose of this review is to examine the hypothesis that central histamine (HA) plays a significant role in the regulation of neuroinflammatory processes of microglia functions in numerous neuropsychiatric diseases, i.e., ASD, AD, SCH, and BPSD. In addition, this review summarizes the latest preclinical and clinical results that support the relevance of histamine H1-, H2-, and H3-receptor antagonists for the potential clinical use in ASD, SCH, AD, epilepsy, and BPSD, based on the substantial symptomatic overlap between these disorders with regards to cognitive dysfunction. The review focuses on the histaminergic neurotransmission as relevant in these brain disorders, as well as the effects of a variety of H3R antagonists in animal models and in clinical studies.

A212 CHROMOFUNGIN PROTECTS AGAINST DSS-INDUCED COLITIS BY REGULATING P-53 APOPTITIC PATHWAY

Background

Development of ulcerative colitis is associated with epithelial apoptosis mediated by p53-apoptotic pathway through the activation B-cell lymphoma 2 (Bcl-2), Bcl-2 associated-X protein (BAX) and Bcl-2 antagonist/killer-1 (BAK1) proteins. Chromofungin (CHR), a chromogranin-A derived peptide expressing a cell penetrating peptide motif, decreased the severity of colitis via the suppression of mucosal and pro-inflammatory macrophages-related p53-dependent apoptosis.

Aims

We aimed to investigate a) whether the gene profile expression of apoptosis could be extended to other p53-associated genes; b) whether the gene expression of some of the p53-apoptosis marker could be confirmed by protein analysis; and c) whether due to the cell penetrating peptide motif, CHR could enter into peritoneal macrophages.

Methods

UC-related colitis was induced in C57BL/6 mice (7 weeks) by administering dextran sulfate sodium (DSS) (5%, 5 days). Preventive CHR (2.5 mg/kg/day) or vehicle treatment started 1-day before colitis induction and lasted for 5-days. Profiler™ PCR Array was performed to screen a panel of 84 genes representative of the p53 signal pathway in colitic whole mucosa distal colonic samples treated or not with CHR. Western blot analysis was performed to confirm individual protein changes. Naïve macrophages were plated overnight and nonadherent cells were removed the next day. Cells were incubated with rhodamined CHR (4 ul) for 5, 10, 20, 30 min before washing and fixing them, detection was made via confocal microscopy.

Results

In colitic conditions, an up regulation of 26 genes associated to the p53-dependent apoptosis pathway were detected including Apaf1, Bax, Bbc3, Bcl2, Cradd, Fadd, Cul9, Pmaip1, Tnfrsf10b. In vivo CHR treatment decreased significantly the colitis and was associated with a significant downregulation of 19 genes including the 9 aforementioned when compared with biopsies from colitic groups. Compared to untreated groups, colitic mice treated with CHR demonstrated a significant decrease of BAX and BAK protein and the apoptotic ER stress inducer marker, X-Binding Protein 1. A large number of peritoneal macrophages displayed rhodamine within the all intracellular compartment. The presence of the peptide inside the cell can be visible as early as 5 min and the signal gradually increases.

Conclusions

CHR decreases the inflammatory process via the suppression of a large number of p53-related apoptotic proteins. CHR quickly enters the macrophage but the exact mechanism of entrance needs to be further defined. Targeting functional analysis of CHR may lead in the future to novel therapeutics for UC.

Funding Agencies

CCCNSERC

A260 THE LACK OF CHROMOGRANIN-A MODIFIES THE GUT MICROBIOTA COMPOSITION AND REGULATES EXPERIMENTAL COLONIC INFLAMMATION

Background

Ulcerative colitis (UC)is characterized by distinct changes in the gut microbiome and elevated chromogranin-A (CHGA) level, which seem to be a relevant pathogenetic mechanism.CHGA, a prohormone produced by enterochromaffin (EC) cells and cleaved into several bioactive peptides, regulates experimental colonic inflammation. In the rodent, intra-rectal infusion of catestatin, a Chga-derived peptide, alters the distal colonic microbial composition. However, the interplay between CHGA, as a pro-hormone, and the gut microbiome remains elusive.

Aims

in homoeostatic and pathophysiologic conditions, we investigated the functional consequences of the lack of Chgaon the distal colonic microbiota.

Methods

Acute colitis (5 % dextran sulfate sodium [DSS], 5 days) was induced in Chga-C57BL/6-deficient (Chga-/-) and wild-type (Chga+/+)mice. Feces and mucosa-associated microbiota (MAM) samples were collected and the V4 region of 16s rRNA was subjected to Miseq Illumina sequencing. Alpha diversity was calculated using Shannon’s diversity index. OTU abundances were summarized using the Bray-Curtis index and non-metric multidimensional scaling (NMDS) analysis to visualize microbiome similarities and a permutational analysis of variance (PERMANOVA) to test the significance of groups were performed respectively.

Results

In non-colitic homoeostatic condition, the absence of Chga (Chga-/) significantly increased the bacterial richness and modified the bacterial community composition at the genera level between the groups, represented by increased abundance of Lactobacillus species and reduced abundance of Helicobacter& Oscillospira species compared to Chga+/+mice in fecal and colonic MAM. Moreover, the absence of Chga (Chga-/-) resulted in a significant change in the alpha-diversity of fecal and colonic MAM compared to Chga+/+mice. DSS induced-colitis resulted in a significant microbial dysbiosis in Chga+/+mice, however, deletion of Chgaprotected against DSS-induced colitis and reduced the microbial dysbiosis, reduced the family of Rikenellaceaeand maintained the abundance of Bacteroides species, compared to wild-type (Chga+/+).

Conclusions

The lack of CHGA regulates the biodiversity and the composition of the colonic gut microbiota suggesting a cross-talk between the EC cell and the microbiome. Therefore, targeting CHGA could provide a novel therapeutic strategy by regulating the gut microbiome in physiological and pathophysiological conditions.

Funding Agencies

CIHR

Current Enlightenment About Etiology and Pharmacological Treatment of Autism Spectrum Disorder

Autistic Spectrum Disorder (ASD) is a complex neurodevelopmental brain disorder characterized by two core behavioral symptoms, namely impairments in social communication and restricted/repetitive behavior. The molecular mechanisms underlying ASD are not well understood. Recent genetic as well as non-genetic animal models contributed significantly in understanding the pathophysiology of ASD, as they establish autism-like behavior in mice and rats. Among the genetic causes, several chromosomal mutations including duplications or deletions could be possible causative factors of ASD. In addition, the biochemical basis suggests that several brain neurotransmitters, e.g., dopamine (DA), serotonin (5-HT), gamma-amino butyric acid (GABA), acetylcholine (ACh), glutamate (Glu) and histamine (HA) participate in the onset and progression of ASD. Despite of convincible understanding, risperidone and aripiprazole are the only two drugs available clinically for improving behavioral symptoms of ASD following approval by Food and Drug Administration (FDA). Till date, up to our knowledge there is no other drug approved for clinical usage specifically for ASD symptoms. However, many novel drug candidates and classes of compounds are underway for ASD at different phases of preclinical and clinical drug development. In this review, the diversity of numerous aetiological factors and the alterations in variety of neurotransmitter generation, release and function linked to ASD are discussed with focus on drugs currently used to manage neuropsychiatric symptoms related to ASD. The review also highlights the clinical development of drugs with emphasis on their pharmacological targets aiming at improving core symptoms in ASD.

The Histamine H3 Receptor Antagonist DL77 Ameliorates MK801-Induced Memory Deficits in Rats

The role of Histamine H3 receptors (H3Rs) in memory, and the prospective of H3R antagonists in pharmacological control of neurodegenerative disorders, e.g., Alzheimer disease (AD) is well-accepted. For that reason, the procognitive effects of the H3R antagonist DL77 on cognitive impairments induced with MK801 were tested in an inhibitory passive avoidance paradigm (PAP) and novel object recognition (NOR) task in adult male rats, using donepezil (DOZ) as a standard drug. Acute systemic pretreatment with DL77 (2.5, 5, and 10 mg/kg, i.p.) significantly ameliorated memory deficits induced with MK801 in PAP (all P < 0.05, n = 7). The ameliorative effect of most promising dose of DL77 (5 mg/kg, i.p.) was reversed when rats were co-injected with the H3R agonist R-(α)-methylhistamine (RAMH, 10 mg/kg, i.p.) (p = 0.701 for MK801-amnesic group vs. MK801+DL77+RAMH group, n = 6). In the NOR paradigm, DL77 (5 mg/kg, i.p.) counteracted long-term memory (LTM) deficits induced with MK801 (P < 0.05, n = 6-8), and the DL77-provided effect was similar to that of DOZ (p = 0.788, n = 6-8), and was reversed when rats were co-injected with RAMH (10 mg/kg, i.p.) (p = 0.877, n = 6, as compared to the (MK801)-amnesic group). However, DL77 (5 mg/kg, i.p.) did not alter short-term memory (STM) impairment in NOR test (p = 0.772, n = 6-8, as compared to (MK801)-amnesic group). Moreover, DL77 (5 mg/kg) failed to modify anxiety and locomotor behaviors of animals innate to elevated-plus maze (EPM) (p = 0.67 for percentage of time spent exploring the open arms, p = 0.52 for number of entries into the open arms, p = 0.76 for percentage of entries into the open arms, and p = 0.73 number of closed arm entries as compared to saline-treated groups, all n = 6), demonstrating that the procognitive effects observed in PAP or NOR tests were unconnected to alterations in emotions or in natural locomotion of tested animals. These results signify the potential involvement of H3Rs in modulating neurotransmitters related to neurodegenerative disorders, e.g., AD.

Antepartum Antibiotic Treatment Increases Offspring Susceptibility to Experimental Colitis: A Role of the Gut Microbiota

Background and aims

Postnatal maturation of the immune system is largely driven by exposure to microbes, and thus the nature of intestinal colonization may be associated with development of childhood diseases that may persist into adulthood. We investigated whether antepartum antibiotic (ATB) therapy can increase offspring susceptibility to experimental colitis through alteration of the gut microbiota.

Methods

Pregnant C57Bl/6 mice were treated with cefazolin at 160 mg/kg body weight or with saline starting six days before due date. At 7 weeks, fecal samples were collected from male offspring after which they received 4% dextran sulfate sodium (DSS) in drinking water for 5 days. Disease activity index, histology, colonic IL-6, IL-1β and serum C-reactive protein (CRP) were determined. The V3-V4 region of colonic and fecal bacterial 16S rRNA was sequenced. Alpha-, beta-diversity and differences at the phylum and genus levels were determined, while functional pathways of classified bacteria were predicted.

Results

ATB influenced fecal bacterial composition and hence bacterial functional pathways before induction of colitis. After induction of colitis, ATB increased onset of clinical disease, histologic score, and colonic IL-6. In addition, ATB decreased fecal microbial richness, changed fecal and colon microbial composition, which was accompanied by a modification of microbial functional pathways. Also, several taxa were associated with ATB at lower taxonomical levels.

Conclusions

The results support the hypothesis that antepartum antibiotics modulate offspring intestinal bacterial colonization and increase susceptibility to develop colonic inflammation in a murine model of colitis, and may guide future interventions to restore physiologic intestinal colonization in offspring born by antibiotic-exposed mothers.

Immunomodulatory effect of ghrelin in the intestinal mucosa

The gastrointestinal tract is the largest endocrine organ in the body and it produces a wide array of hormones and neuropeptides. Ghrelin, a 28-amino acid hormone produced mainly by the X/A-like endocrine cells in the gastric mucosa, has widespread tissue distribution and diverse physiological functions such as hormonal, orexigenic, metabolic, cardiovascular, neurological and immunological activities. Recent research has implicated ghrelin in gastrointestinal pathological conditions and immune system regulation, but its contribution is controversial. Although ghrelin levels are elevated in clinical active inflammatory bowel diseases, confirmation of its exact role using experimental models remains unclear. This review discusses the conflicting effects of ghrelin on intestinal inflammation, through the different possible immune and intracellular mechanisms and highlights new findings.

Phenotypic and genotypic characterization of Staphylococcus aureus isolated from raw camel milk samples

In the present study 320 milk samples collected from 160 apparently healthy camels of three different locations in Sudan were investigated for the presence of Staphylococcus aureus resulting in the isolation of this bacterial pathogen from 28 milk samples from 24 camels. Twenty-five S. aureus were identified phenotypically and by PCR mediated amplification of species-specific genes or gene segments. Investigation of the S. aureus for toxinogenic potential revealed that three S. aureus strains were positive for the enterotoxin encoding gene sec and the genes seg, sei, sem, sen and seo, representing the egc gene cluster. In addition all 25 S. aureus were positive for the superantigen-like encoding gene ssl7 (set1). Partial sequencing of gene sec of the three S. aureus strains yielded an almost complete sequence identity to the sequence of the sec variant sec2. However, all three sec2 genes of the present study showed a deletion of one base causing a frame shift and a corresponding earlier stop codon. According to the present results, the raw camel milk collected from three locations in Sudan seems to be, at least at this stage, of minor importance as vector causing staphylococcal food poisoning.

Hypertonic nasogastric tube feedings: do they cause diarrhea?

Hypertonic NG tube feeding in hospitalized patients, whether on the hospital ward or in the ICU, is considered a common etiology of diarrhea. To evaluate the accuracy of this assumption, five normal volunteers, ten hospitalized postoperative patients with head and neck cancer, and 24 ICU patients were given hypertonic (690 mosm), low residue, lactose-free tube feedings starting at 30 kcal/kg.day. There was no prior history of diarrhea in any of the groups studied. There was a significant difference in albumin levels between the three groups, with an average albumin of 2.8 g/dl in the ICU patient group; different from 4.5 g/dl present in both the normal volunteer and non-ICU hospitalized patient groups (general linear models procedure from SAS, p less than .05) (Duncan test). Diarrhea was not present in the normal volunteers or non-ICU patients during the feedings, but did occur in 3/24 ICU patients. This difference was not significant. The three patients with diarrhea had an average albumin level of 3.0 g/dl, while the other ICU patients had an average albumin of 2.7 g/dl. We conclude that hypertonic NG tube feedings do not cause diarrhea in normal volunteers or postoperative head and neck cancer patients. However, in a small statistically insignificant percent of mechanically ventilated ICU patients, this regimen may cause diarrhea although no risk factors can be identified.