Search Results (9)

Background/Objectives: Engineered nanomaterials, particularly silver nanoparticles (AgNPs), have emerged as promising tools in oncology due to their ability to enhance tumor targeting and minimize off-target effects. This study investigates the cytotoxic effects of two different types of AgNPs—citrate-coated (AgNPs-cit) and EG₆OH-coated (AgNPs-EG₆OH)—on colorectal cancer (CRC) cell lines and healthy colonocytes, aiming to assess their potential as selective therapeutic agents. Methods: AgNPs-cit and AgNPs-EG₆OH were synthesized and characterized for size and surface properties. LoVo (microsatellite instability-high) and HT-29 (microsatellite stable) CRC cell lines, along with primary colonocyte cultures from healthy mucosal tissues, were exposed to these nanoparticles. Cytotoxicity was assessed through MTT assays, while morphological changes were observed using fluorescence microscopy. Internalization of the nanoparticles was evaluated by confocal microscopy. Results: AgNPs-cit exhibited significant cytotoxicity in LoVo cells, reducing viability and inducing morphological changes indicative of programmed cell death, especially after 48 h of exposure. In contrast, AgNPs-EG₆OH showed minimal effects on LoVo cells and no significant toxicity on HT-29 cells or primary colonocytes. Confocal microscopy confirmed nanoparticle internalization, with surface functionalization influencing the distribution patterns within cells. Conclusions: This study demonstrates that surface functionalization significantly influences the cytotoxicity of AgNPs, with citrate-coated nanoparticles showing selective effects on microsatellite instability-high CRC cells. These findings underscore the potential of surface-modified nanoparticles for targeted cancer therapy and highlight the importance of tailoring nanoparticle design to optimize therapeutic efficacy while minimizing off-target effects. Full article

Cystathionine gamma-lyase (CSE) and TNF-α are now recognized as key regulators of intestinal homeostasis, inflammation, and wound healing. In colonic epithelial cells, both molecules have been shown to influence a variety of biological processes, but the specific interactions between intracellular signaling pathways regulated by CSE and TNF-α are poorly understood. In the present study, we investigated these interactions in normal colonocytes and an organoid model of the healthy human colon using CSE-specific pharmacological inhibitors and siRNA-mediated transient gene silencing in analytical and functional assays in vitro. We demonstrated that CSE and TNF-α mutually regulated each other’s functions in colonic epithelial cells. TNF-α treatment stimulated CSE activity within minutes and upregulated CSE expression after 24 h, increasing endogenous CSE-derived H₂S production. In turn, CSE activity promoted TNF-α-induced NF-ĸB and ERK1/2 activation but did not affect the p38 MAPK signaling pathway. Inhibition of CSE activity completely abolished the TNF-α-induced increase in transepithelial permeability and wound healing. Our data suggest that CSE activity may be essential for effective TNF-α-mediated intestinal injury response. Furthermore, CSE regulation of TNF-α-controlled intracellular signaling pathways could provide new therapeutic targets in diseases of the colon associated with impaired epithelial wound healing. Full article

The fermentation of dietary fibres in the human colon generates short-chain fatty acids (SCFAs) that potentially mediate the health benefits associated with high fibre intake. In the colonic lumen, SCFAs support gut health and stimulate the release of the appetite-regulating hormones glucagon-like peptide 1 (GLP-1) and peptide-YY (PYY). In addition, SCFAs act as fuel for colonocytes and serve as precursors for substrate metabolism in the liver. The SCFAs that ultimately reach the systemic circulation may influence physiological processes in organs at a distance. Yet, when consuming plant-based fermented foods containing SCFAs, the SCFAs are absorbed in the small intestine and will not reach the colon, which might affect their physiological effects. We hypothesise that, compared to colonic delivery, a larger fraction of SCFAs will reach the systemic circulation and that the stimulation of gut hormone release will be less pronounced. To test this hypothesis, we designed two randomised crossover human intervention studies in healthy participants in which SCFAs will be targeted either to the small intestine (test day 1) or colon (test day 2) using standard capsules or capsules with a colon delivery coating, respectively. Study 1 will assess the systemic bioavailability of postprandial concentrations of labelled SCFAs after oral administration of stable isotope 13C-labelled SCFAs and intravenous administration of ²H-labelled SCFAs. In study 2, postprandial concentrations of GLP-1 and PYY, glucose, and insulin will be quantified after the administration of capsules with unlabelled SCFAs. These studies will clarify the importance of the site of administration on the kinetics of SCFAs and the gut hormone release that will contribute to elucidating the role of SCFAs as health-supporting metabolites. Full article

Dietary fibers include non-digestible plant carbohydrates, lignin and resistant starch. Dietary fibers provide immune, cardiovascular, metabolic and intestinal beneficial effects in humans. Fibers naturally present in foods (fruits, vegetables, legumes, cereals) or used as supplements have different physical, chemical and functional profiles. This narrative review provides an update to the knowledge on the effects of dietary fibers in healthy subjects and in children with gastrointestinal disorders. Soluble fibers are digested by gut bacteria, producing short-chain fatty acids and energy for colonocytes, and may exert prebiotic effects that promote the growth of bifidobacteria and lactobacilli. Non-soluble fibers are bulking agents and may improve intestinal transit. The exact amount and characteristics of the fiber requirement in infants and children need to be further established. There are limited data evaluating fibers in children with gastrointestinal disorders. The low intake of fibers has been associated with constipation, but the intake of excessive fibers is not recommended as it may cause flatulence and abdominal discomfort. Certain fibers (particularly psyllium in irritable bowel syndrome) have shown beneficial effects in children with gastrointestinal disorders, but the limited and heterogenous data do not currently allow a specific recommendation. Full article

Several studies have reported improved disease symptomatology in ulcerative colitis (UC) patients consuming a gluten free diet. This observation coupled with diversity depletion in the gut microbiota of UC patients led us to hypothesize that UC-associated enteric microbes differentially metabolize dietary gluten to produce immunogenic products that promote inflammation. Gluten concentration in stool was determined using gluten-specific ELISA, and gluten intake was assessed by food frequency questionnaire (FFQ) in UC (n = 12) and healthy controls (HC; n = 13). Gluten-metabolizing bacteria were isolated on minimal media supplemented with 1% gluten from UC and HC and identified by 16S rRNA profiling. Cell-free culture media from gluten metabolizing gut bacterial isolates was assessed for immunogenicity in vitro using HT29 colonocytes. Compared to HC, UC patients did not consume gluten differently (Mann–Whitney; p > 0.10) and exhibited equivalent levels of gluten in their feces (Mann–Whitney; p = 0.163). The profile of gluten-degrading bacteria isolated from UC stool was distinct (Chi-square; p ≤ 0.0001). Compared with Enterococcus isolates, products of gluten degradation by Bacillus strains induced higher IL8 and lower occludin (Mann–Whitney; p = 0.002 and p = 0.059, respectively) gene expression in colonocytes irrespective of whether they originated from UC or healthy gut. Members of HC and UC microbiota exhibit gluten-degrading ability, metabolites of which influence genes involved in inflammation and barrier function in enteric colonocyte cultures. Preliminary findings of this study warrant further investigations into the mechanisms by which gut microbiota contribute to UC pathogenesis through gluten degradation. Full article

(1) Phytic acid (PA) is a component of cereal seeds and legumes, therefore its consumption is much higher in a vegan and vegetarian diet compared to a conventional diet. The diet is the main driver of metabolic activity of gut microbiota, therefore, the ability to degrade phytates by the microbiota of vegans significantly exceeds that of the gut microbiota of omnivores. The aim of the study was to investigate the early phase of the immune response of colonocytes treated with an enzymatic hydrolysate of phytic acid (hPA120) and gut bacteria. (2) Cell lines derived from healthy (NCM460D) and cancer (HCT116) colonic tissue and fecal bacteria from vegan (V) and omnivorous (O) donors were investigated. Fecal bacteria were grown in mucin and phytic acid supplemented medium. Cultured bacteria (BM) were loaded onto colonocytes alone (V BM and O BM) or in combination with the phytate hydrolysate (V BM + hPA120 and O BM + hPA120). After a treatment of 2 h, bacterial adhesion, secretion of cytokines, and the expression of genes and proteins important for immune response were determined. (3) All bacteria-treated colonocytes increased the expression of IL8 compared to controls. The significant increase of the secreted IL-8 (p < 0.01) in both cell lines was observed for O BM and O BM + hPA120. The increase of TNF, IL-1β, and IL-10 secretion in healthy colonocytes (V BM alone and with hPA120 treatments; p < 0.05) and for TNF and IL-10 in cancer cells (treatments except O BM + hPA120 and V BM, respectively; p > 0.05) were stated. A comparison of solely the effect of hPA120 on bacteria-treated colonocytes (BM vs. BM + hPA120) showed that hPA120 decreased expression of NFkB1 and TNFR (p < 0.001) in healthy colonocytes. In cancer colonocytes, the expression of TLR4 and IL1R increased after BM + hPA120 treatment, whereas the secretion of IL-8 and MYD88 and TNFR expression decreased (p < 0.01). (4) The investigated hPA120 showed a differentiated modulatory activity on the immune response of healthy and cancer human colonocytes. Especially when analyzed independently on the gut bacteria origin, it reduced the proinflammatory response of HCT116 cells to gut bacteria, while being neutral for the bacteria-treated healthy colonocytes. Full article

Ulcerative colitis (UC) patients often avoid foods containing fermentable fibers as some can promote symptoms during active disease. Pectin has been identified as a more protective fermentable fiber, but little has been done to determine the interaction between pectin and bioactive compounds present in foods containing that fiber type. Quercetin and chlorogenic acid, two bioactives in stone fruits, may have anti-cancer, anti-oxidant, and anti-inflammatory properties. We hypothesized that quercetin and chlorogenic acid, in the presence of the fermentable fiber pectin, may suppress the expression of pro-inflammatory molecules, alter the luminal environment, and alter colonocyte proliferation, thereby protecting against recurring bouts of UC. Rats (n = 63) received one of three purified diets (control, 0.45% quercetin, 0.05% chlorogenic acid) containing 6% pectin for 3 weeks before exposure to dextran sodium sulfate (DSS, 3% for 48 h, 3x, 2 wk separation, n = 11/diet) in drinking water to initiate UC, or control (no DSS, n = 10/diet) treatments prior to termination at 9 weeks. DSS increased the fecal moisture content (p < 0.05) and SCFA concentrations (acetate, p < 0.05; butyrate, p < 0.05). Quercetin and chlorogenic acid diets maintained SLC5A8 (SCFA transporter) mRNA levels in DSS-treated rats at levels similar to those not exposed to DSS. DSS increased injury (p < 0.0001) and inflammation (p < 0.01) scores, with no differences noted due to diet. Compared to the control diet, chlorogenic acid decreased NF-κB activity in DSS-treated rats (p < 0.05). Quercetin and chlorogenic acid may contribute to the healthy regulation of NF-κB activation (via mRNA expression of IκΒα, Tollip, and IL-1). Quercetin enhanced injury-repair molecule FGF-2 expression (p < 0.01), but neither diet nor DSS treatment altered proliferation. Although quercetin and chlorogenic acid did not protect against overt indicators of injury and inflammation, or fecal SCFA concentrations, compared to the control diet, their influence on the expression of injury repair molecules, pro-inflammatory cytokines, SCFA transport proteins, and NF-κB inhibitory molecules suggests beneficial influences on major pathways involved in DSS-induced UC. Therefore, in healthy individuals or during periods of remission, quercetin and chlorogenic acid may promote a healthier colon, and may suppress some of the signaling involved in inflammation promotion during active disease. Full article

The AHCC standardized extract of cultured Lentinula edodes mycelia, and the standardized extract of Asparagus officinalis stem, trademarked as ETAS, are well known supplements with immunomodulatory and anticancer potential. Several reports have described their therapeutic effects, including antioxidant and anticancer activity and improvement of immune response. In this study we aimed at investigating the effects of a combination of AHCC and ETAS on colorectal cancer cells and biopsies from healthy donors to assess the possible use in patients with colorectal cancer. Our results showed that the combination of AHCC and ETAS was synergistic in inducing a significant decrease in cancer cell growth, compared with single agents. Moreover, the combined treatment induced a significant increase in apoptosis, sparing colonocytes from healthy donors, and was able to induce a strong reduction in migration potential, accompanied by a significant modulation of proteins involved in invasiveness. Finally, combined treatment was able to significantly downregulate LGR5 and Notch1 in SW620 cancer stem cell (CSC) colonospheres. Overall, these findings support the potential therapeutic benefits of the AHCC and ETAS combinatorial treatment for patients with colorectal cancer. Full article

The colonic epithelium is never exposed to a single factor, therefore studies on the effect of combinations of factors naturally and persistently present in the intestines are of special importance for understanding the phenomena occurring at this place. The aim of the study was to investigate the combined effect of 1 mM phytate and 1 mM butyrate (PA1B1) on cell lines derived from cancer (HCT116 and HT-29) and healthy (NCM460D) human colonic epithelium. Colorimetric and flow cytometry methods were used to determine the proliferation rate, cell cycle, and apoptosis. Selected markers of proliferation, inflammatory, and survival pathways were investigated at the mRNA and/or protein level. The combination of phytate and butyrate disturbed the cell cycle and triggered apoptosis and/or death in both studied cancer colonocytes to a higher extent compared to healthy colonocytes. Moreover, in healthy colonocytes, phytate activated the survival pathway without stimulation of inflammatory response. This may indicate that the response of healthy colonocytes to phytate protects colonic epithelium from the loss of integrity and tightness that would occur if inflammation developed. Based on the obtained results we postulate that studies on both cancer and/or healthy colonocytes should be carried out in the presence of butyrate as the permanent component of colonic contents. This should be of special importance when anti-proliferative/pro-apoptotic activity or inflammatory status of colonocytes is to be investigated. Full article