Effect In HT-29 Cells Research Articles

Comparison of effects of P-coumaric acid and coumarin on colorectal cancer cell line by inducing apoptosis and autophagy.

Autophagy, as a cellular pathway involved in removing damaged proteins and organelles, performs a vital function in the homeostasis and fate of cells. Natural compounds of coumarin (CO) are found in a variety of herbs. Due to their many medicinal properties, including antitumor and anti-proliferative activity, they are involved in apoptosis and autophagy processes. This investigation desired to analyze the apoptotic and autophagic effects of p-coumaric acid (PCA) and CO on HT-29 cells cultured in fibrin hydrogel. Cell viability and apoptotic and autophagic changes were evaluated by MTT assay, Acridine Orange, 4',6-diamidino-2-phenylindole (DAPI), and monodansylcadaverine (MDC) staining. The expression Bax, Bad, Bcl2, Lc3, Beclin-1, P53 and Atg5 was respectively measured by qRT-PCR and Western blotting. CO (IC50=25 μM) and PCA (IC50=150 μM) had a dose- and time-dependent cytotoxic effect in HT-29 cells. So, the cytotoxic effects of CO were significantly higher than PCA and these differences were also evident in cell morphology investigations. The data illustrated a high expression of pro-apoptotic and pro-autophagic genes and a declined expression of anti-apoptotic and anti-autophagic genes. CO (that was more potent) and p-coumaric acid-induced autophagy via PI3K/Akt/mTOR and AMPK/mTOR signaling on HT-29 cells.

KIF20A Promotes CRC Progression and the Warburg Effect through the C-Myc/HIF-1α Axis.

Colorectal cancer (CRC) is a prevalent form of cancer globally, characterized by a high mortality rate. Therefore, discovering effective therapeutic approaches for CRC treatment is critical. The levels of KIF20A in CRC clinical samples were determined using Western Blot and immunofluorescence assay. SW480 cells were transfected with siRNA targeting KIF20A, while HT-29 cells were transfected with a KIF20A overexpression vector. Cell viability and apoptosis of CRC cells were assessed using CCK-8 and TUNEL analysis. Migration ability was investigated using Transwell. The levels of pyruvate, lactate and ATP were determined through corresponding assay kits. Western Blot was applied to confirm the level of proteins associated with glycolysis, c- Myc, HIF-1α, PKM2 and LDHA. Subsequently, functional rescue experiments were conducted to investigate further the regulatory relationship between KIF20A, c-Myc, and HIF-1α in colorectal cancer (CRC), employing the c-Myc inhibitor 10058-F4 and c-Myc overexpression plasmids. KIF20A was up-regulated in vivo and in vitro in CRC. KIF20A knockdown inhibited cell viability and migration while promoting cell apoptosis in SW480 cells. Conversely, overexpression of KIF20A yielded contrasting effects in HT-29 cells. Moreover, inhibition of KIF20A restrained the pyruvate, lactate production and ATP level, whereas overexpression of KIF20A enhanced the Warburg effect. Western Blot indicated that knockdown KIF20A attenuated the levels of c-Myc, HIF-1α, PKM2 and LDHA. In addition, rescue experiments further verified that KIF20A enhanced the Warburg effect by the KIF20A/c-Myc/HIF-1α axis in CRC. KIF20A, being a crucial regulator in the progression of CRC, has the potential to be a promising therapeutic target for the treatment of CRC.

Anticancer Effects in HT-29 Cells and Anti-Inflammatory Effects on Mouse Splenocytes of Broccoli Cultivated with Deep Sea Water Minerals in Organic Farming

In this study, broccoli grown with deep sea water minerals (DSWMs) confirmed anticancer effects in HT-29 colorectal cancer cells and anti-inflammatory effects in C57BL/6 mouse splenocytes. Natural dream cultured broccoli (NB) grown with DSWMs had elevated sodium (Na) and calcium (Ca) levels and enhanced the expression of p53 and p21, both of which are associated with cell cycle arrest in HT-29 colorectal cancer cells. It also decreased the expression of Bax, Bad, Bim, Bak, caspase-9, and caspase-3. In lipopolysaccharide (LPS)-treated C57BL/6 mouse splenocytes, NB produced little nitric oxide (NO). ELISA research indicated that NB decreased IL-1β, IL-6, TNF-α, IFN-γ, and IL-12 expression while increasing NK cell activity. As a result, broccoli cultivated with deep water minerals has better anticancer and anti-inflammatory properties than conventional and organic farming.

In Vitro Effect of the Cell-Free Supernatant of the Lactobacillus casei Strain IMAU60214 against the Different Pathogenic Properties of Diarrheagenic Escherichia coli

Enteroaggregative Escherichia coli (EAEC) and enterohemorrhagic E. coli (EHEC) are E. coli pathotypes associated with unmanageable diarrhea in children and adults. An alternative to the treatment of infections caused by these microorganisms is the use of the bacteria of the Lactobacillus genus; however, the beneficial effects on the intestinal mucosa are specific to the strain and species. The interest of this study consisted of analyzing the coaggregation properties of Lactobacillus casei IMAU60214, as well as the effect of cell-free supernatant (CSF) on growth and anti-cytotoxic activity in a cell model of the human intestinal epithelium for an agar diffusion assay (HT-29) and the inhibition of biofilm formation on plates of DEC strains of the EAEC and EHEC pathotypes. The results showed that L. casei IMAU60214 exhibits time-dependent coaggregation (35–40%) against EAEC and EHEC that is similar to the control E. coli ATCC 25922. The CSF showed antimicrobial activity (20–80%) against EAEC and EHEC depending on the concentration. In addition, the formation and dispersion of biofilms of the same strains decrease, and the proteolytic pre-treatment with catalase and/or proteinase K (1 mg/mL) of CSF reduces the antimicrobial effect. When evaluating the effect in HT-29 cells pre-treated with CFS on the toxic activity induced by the EAEC and EHEC strains, a reduction of between 30 and 40% was observed. The results show that L. casei IMAU60214 and its CSF have properties that interfere with some properties associated with the virulence of the EAEC and EHEC strains that cause intestinal infection, which supports their use for the control and prevention of infections caused by these bacteria.

Purification of phenoloxidase from Haliotis discus hannai and its anti-inflammatory activity in vitro

Haliotis discus hannai, a food with a high protein content, is widely consumed in Asian countries. It is known to have antioxidant, anticancer, and antibacterial effects. Since the biological significance of H. discus hannai hemolymph has not been widely studied, the objective of the present study was to purify phenoloxidase (PO) and investigate its immunological effects on human colonic epithelial cells. PO was purified through ammonium sulfate precipitation and one step column chromatography. The molecular weight of the protein was about 270 kDa. When PO was mixed with Gram-negative bacteria-derived lipopolysaccharide (LPS) at various ratios (10:1–1:10, w/w), the amount of residual LPS was reduced. PO at concentrations up to 200 μg/mL was not cytotoxic to HT-29 cells. The inflammatory response induced by LPS in HT-29 cells was regulated when the concentration of PO was increased. With increasing concentration of PO, production levels of pro-inflammatory cytokines, cytokines associated with hyperimmune responses such as IL4, IL-5, and INF-γ, and prostaglandin 2 (PGE2) were regulated. It was thought that simultaneous treatment with PO and LPS anti-inflammatory effects in HT-29 cells showed by regulating the ERK1/2-mediated NF-κB pathway. Results of this study suggest that H. discus hannai hemolymph is involved in the regulation of Gram-negative bacteria-related inflammatory immune responses in human colonic epithelial cells.

Improvement of the In Vitro Cytotoxic Effect on HT-29 Colon Cancer Cells by Combining 5-Fluorouacil and Fluphenazine with Green, Red or Brown Propolis.

Cancer is regard as one of the key factors of mortality and morbidity in the world. Treatment is mainly based on chemotherapeutic drugs that, when used in targeted therapies, have serious side effects. 5-fluorouracil (5-FU) is a drug commonly used against colorectal cancer (CRC), despite its side effects. Combination of this compound with natural products is a promising source in cancer treatment research. In recent years, propolis has become the subject of intense pharmacological and chemical studies linked to its diverse biological properties. With a complex composition rich in phenolic compounds, propolis is described as showing positive or synergistic interactions with several chemotherapeutic drugs. The present work evaluated the in vitro cytotoxic activity of the most representative propolis types, such as green, red and brown propolis, in combination with chemotherapeutic or CNS drugs on HT-29 colon cancer cell lines. The phenolic composition of the propolis samples was evaluated by LC-DAD-ESI/MSn analysis. According to the type of propolis, the composition varied; green propolis was rich in terpenic phenolic acids and red propolis in polyprenylated benzophenones and isoflavonoids, while brown propolis was composed mainly of flavonoids and phenylpropanoids. Generally, for all propolis types, the results demonstrated that combing propolis with 5-FU and fluphenazine successfully enhances the in vitro cytotoxic activity. For green propolis, the combination demonstrated an enhancement of the in vitro cytotoxic effect compared to green propolis alone, at all concentrations, while for brown propolis, the combination in the concentration of 100 μg/mL gave a lower number of viable cells, even when compared with 5-FU or fluphenazine alone. The same was observed for the red propolis combination, but with a higher reduction in cell viability. The combination index, calculated based on the Chou-Talalay method, suggested that the combination of 5-FU and propolis extracts had a synergic growth inhibitory effect in HT-29 cells, while with fluphenazine, only green and red propolis, at a concentration of 100 μg/mL, presented synergism.

WIN Symposium 2022 - Abstract Poster Presentations.

WIN Symposium 2022 - Abstract Poster Presentations.

Investigation of the potential antitumor activity of PLK1 inhibitor SBE13 in colon cancer cell line HT29

Background: High levels of Polo-like kinase 1 (PLK1), which have been found to be abnormally expressed in many tumor types, are known to contribute to tumorigenesis and poor prognosis. Therefore, specific targeting of PLK1 is an important strategy for cancer therapy. In this study, it was aimed to investigate the cytotoxic effect of SBE13, one of the PLK1 inhibitors, against HT29 colon adenocarcinoma cells and its apoptotic potential.
 Methods: The cytotoxic effect of SBE13 on HT29 was determined by XTT colorimetric assay. Flow cytometry was also used to determine apoptosis. 
 Results: SBE13 showed a dose-dependent cytotoxic effect in HT29 cells and its IC50 value was calculated as 11.79 µM for 48 h. Moreover, the Annexin V binding assay revealed that SBE13 treatment significantly increased the apoptosis in HT29 cells.
 Conclusion: Generally, SBE13 exerts a cytotoxic effect promoted by apoptosis in colon cancer cells HT29. Although the anticancer efficacy of SBE13 in colon cancer is promising, this potential effect should be reinforced by further studies.

Diosmetin Exerts Synergistic Effects in Combination with 5-Fluorouracil in Colorectal Cancer Cells.

5-Fluorouracil (5-FU) is a chemotherapeutic medication commonly used to treat colorectal cancer (CRC); however, the drug-associated adverse effects and toxicity have greatly affected its clinical use. Exploring another therapeutic strategy that lowers the toxicity of 5-FU while having a synergistic effect against CRC is thus a viable option. Diosmetin, a natural flavonoid, has been shown to inhibit the proliferation of many cancer cells, including CRC cells. This study aims to investigate the synergistic effect of diosmetin and 5-FU on HCT116 and HT29 colorectal cancer cells and to explore the apoptotic activity of this combination. The MTT assay was used to assess the viability of cells treated with monotherapy and combination therapy. The combination index (CI) and dose reduction index (DRI) were calculated using the CompuSyn software (version 1.0). The SynergyFinder 2.0 software was used to calculate the synergy score, while the Combenefit software was employed to perform isobologram analysis and synergism determination. The AO/PI double staining technique was used to detect the apoptotic characteristics of cells, whereas the flow cytometry technique was used to investigate the apoptosis induction and cell cycle arrest in cells. The combination of 5-FU and diosmetin showed a synergistic effect in HCT116 cells with a mean CI value of 0.66 ± 0.4, and an additive effect in HT29 cells with a CI value of 1.0 ± 0.2. The DRI of 5-FU in HCT116 cells was three times lower in the combination therapy compared to monotherapy of 5-FU. AO/PI microscopic examination and Annexin V analysis revealed that the combination-treated cells had more apoptotic cells than the monotherapy-treated cells, which was activated mainly through intrinsic apoptosis pathway. HCT116 cell death was confirmed by mitotic arrest in the G2/M phase. Our findings suggest that 5-FU/diosmetin combination exhibits synergistic effect against HCT116 cancer cells, and potentially reduces the unfavorable adverse effect of 5-FU while enhancing the anticancer efficacy by inducing apoptosis and interrupting mitosis. Further research studies are needed to validate the combination’s anti-tumorigenic activities in a xenograft animal model.

Exploration of p53 plus interferon-beta gene transfer for the sensitization of human colorectal cancer cell lines to cell death

ABSTRACT While treatments for colorectal cancer continue to improve, some 50% of patients succumb within 5 years, pointing to the need for additional therapeutic options. We have developed a modified non-replicating adenoviral vector for gene transfer, called AdRGD-PG, which offers improved levels of transduction and transgene expression. Here, we employ the p53-responsive PG promoter to drive expression of p53 or human interferon-β (hIFNβ) in human colorectal cancer cell lines HCT116wt (wtp53), HCT116−/- (p53 deficient) and HT29 (mutant p53). The HCT116 cell lines were both easily killed with p53 gene transfer, while combined p53 and hIFNβ cooperated for the induction of HT29 cell death and emission of immunogenic cell death (ICD) markers. Elevated annexinV staining and caspase 3/7 activity point to cell death by a mechanism consistent with apoptosis. P53 gene transfer alone or in combination with hIFNβ sensitized all cell lines to chemotherapy, permitting the application of low drug doses while still achieving significant loss of viability. While endogenous p53 status was not sufficient to predict response to treatment, combined p53 and hIFNβ provided an additive effect in HT29 cells. We propose that this approach may prove effective for the treatment of colorectal cancer, permitting the use of limited drug doses.

An RP-LC-UV-TWIMS-HRMS and Chemometric Approach to Differentiate between Momordicabalsamina Chemotypes from Three Different Geographical Locations in Limpopo Province of South Africa.

Momordica balsamina leaf extracts originating from three different geographical locations were analyzed using reversed-phase liquid chromatography (RP-LC) coupled to travelling wave ion mobility (TWIMS) and high-resolution mass spectrometry (HRMS) in conjunction with chemometric analysis to differentiate between potential chemotypes. Furthermore, the cytotoxicity of the three individual chemotypes was evaluated using HT-29 colon cancer cells. A total of 11 molecular species including three flavonol glycosides, five cucurbitane-type triterpenoid aglycones and three glycosidic cucurbitane-type triterpenoids were identified. The cucurbitane-type triterpenoid aglycones were detected in the positive ionization mode following dehydration [M + H − H2O]+ of the parent compound, whereas the cucurbitane-type triterpenoid glycosides were primarily identified following adduct formation with ammonia [M + NH4]+. The principle component analysis (PCA) loadings plot and a variable influence on projection (VIP) analysis revealed that the isomeric pair balsaminol E and/or karavilagen E was the key molecular species contributing to the distinction between geographical samples. Ultimately, based on statistical analysis, it is hypothesized that balsaminol E and/or karavilagen E are likely responsible for the cytotoxic effects in HT-29 cells.

Curcumin functions as a MEK inhibitor to induce a synthetic lethal effect on KRAS mutant colorectal cancer cells receiving targeted drug regorafenib

Curcumin, a major yellow pigment and spice in turmeric and curry, has been demonstrated to have an anticancer effect in human clinical trials. Mutation of KRAS has been shown in 35%-45% of colorectal cancer, and regorafenib has been approved by the US FDA to treat patients with colorectal cancer. Synthetic lethality is a type of genetic interaction between two genes such that simultaneous perturbations of the two genes result in cell death or a dramatic decrease of cell viability, while a perturbation of either gene alone is not lethal. Here, we reveal that curcumin significantly enhanced the growth inhibition of regorafenib in human colorectal cancer HCT 116 cells (KRAS mutant) to a greater extent than in human colorectal cancer HT-29 cells (KRAS wild-type), producing an additive or synergistic effect in HCT 116 cells and causing an antagonistic effect in HT-29 cells. Flow cytometric analysis showed that the addition of curcumin elevated apoptosis and greatly increased autophagy in HCT 116 cells but not in HT-29 cells. Mechanistically, curcumin behaved like MEK-specific inhibitor (U0126) to enhance regorafenib-induced growth inhibition, apoptosis and autophagy in HCT 116 cells. Our data suggest that curcumin may target one more gene other than mutant KRAS to enhance regorafenib-induced growth inhibition (synthetic lethality) in colorectal cancer HCT 116 cells, indicating a possible role of curcumin in regorafenib-treated KRAS mutant colorectal cancer.

Triterpenoids from Cassia fistula L. regulate p53 & ERK2 genes to induce apoptosis in HT-29 colon cancer cells

Abstract Incidence of colon cancer is on a rise in the current decade. Though there are several modern means of medication to tackle the disease they cause several side effects. Hence, as an alternative means to reduce such risks, phytotherapeutics stands as a contemporary focus. Our study explored the anticancer efficacy of three triterpenoids, derived from ethyl acetate extract of Cassia fistula L., against human colon cancer cell line (HT-29). Of the three, compound 1 and 2 were found to be non-toxic on normal VERO cells but cytotoxic to cancer cells with 50 μM and 40 μM as their IC50 concentrations respectively. Apoptotic features such as chromatin condensation, DNA fragmentation, membrane leakage and enhanced depolarization of mitochondrial membrane, with subsequent cell cycle arrest at S-phase and G2/M phase were observed. RT-PCR analysis revealed that both the compounds produced upregulation of p53 expression and downregulation of ERK2 expression. The rates of invasion and metastasis were significantly decreased on exposure to the compounds. Furthermore, antioxidant activity was evident on destruction of cancer cells. Docking results showed stable interactions between the compounds and the cancer targets (p53 & ERK2). The data suggests that both the compounds exhibit high antiproliferative effect in HT-29 cells and are promising as alternative cancer therapeutics.

Gamma-Irradiated Chrysin Improves Anticancer Activity in HT-29 Colon Cancer Cells Through Mitochondria-Related Pathway.

Irradiation technology can improve the biological activities of natural molecules through a structural modification. This study was conducted to investigate the enhancement of the anticancer effects of chrysin upon exposure to gamma irradiation. Gamma irradiation induces the production of new radiolytic peaks simultaneously with the decrease of the chrysin peak, which increases the cytotoxicity in HT-29 human colon cancer cells. An isolated chrysin derivative (CM1) exhibited a stronger apoptotic effect in HT-29 cells than intact chrysin. The apoptotic characteristics induced by CM1 in HT-29 cells was mediated through the intrinsic signaling pathway, including the excessive production of included reactive oxygen species, the dissipation of the mitochondrial membrane potential, regulation of the B cell lymphoma-2 family, activation of caspase-9, 3, and cleavage of poly (adenosine diphosphate-ribose) polymerase. Our findings suggest that CM1 can be a potential anticancer candidate for the treatment of colon cancer.

Oxidative stress induced apoptosis mediated anticancer activity of Rhus typhina fruits extract in human colon cancer

The present work was tested the anti-proliferation activity of Rhus typhina fruits extract (RTFE) in HEK293 and HT-29 cells, and studied their underlying mechanisms through the analysis of oxidative stress and apoptosis-related genes expressions by flow cytometer and RT-qPCR. In addition, the bioactive constituents were identified from RTFE by chromatography and NMR analysis. Among the various type of the fractions from the RTFE, the ethyl acetate fraction (EAF) was showed the potent anti proliferation effect in HT-29 cells. Thus EAF was selected for the further extensive analysis. Cytotoxcity and RT-qPCR results revealed that the treatment of EAF significantly inhibit the growth of the HT-29 cells by the up regulating of Bax and down regulation of Bcl-2, Survivn, AIF and SOD-2 gene expressions in time and dose dependent manner. Followed by sub G1 accumulation and the G0/G1 phase arrest, ROS production, and mitochondrial transmembrane potential (ΔΨm). Finally, the active anti-proliferations agents such as luteolin and luteolin-7-O-glucuronide were identified from EAF by NMR. This work suggests that EAF could be a functional food to treat the chronic diseases.

Identification of Nrf2/STAT3 axis in induction of apoptosis through sub-G 1 cell cycle arrest mechanism in HT-29 colon cancer cells.

We investigated the role of stattic as an adjuvant molecule to increase the cytotoxicity of 5-fluorouracil (5-FU) through specific inhibition of molecular targets, signal transducer and activator of transcription 3 (STAT3) and nuclear factor erythroid 2-related factor 2 (Nrf2) in HT-29 colon cancer cells. Cytotoxicity and apoptotic effects were investigated by methylthiazolyldiphenyl-​tetrazolium bromide assay and flow cytometry analysis, respectively. Real-time polymerase chain reaction was applied to assess the messenger RNA (mRNA) level of STAT3, Nrf2, and apoptotic genes including Bax, Bcl-xl, and Bcl-2. The antitumor effect of 5-FU in combination with stattic induced synergistic effect in HT-29 cells with combination indexes (CIs) 0.49. Flow cytometric results related to apoptotic confirmed that there was up to 40% increase in the population of apoptotic cells in HT-29 colon cancer cells incubated with 5-FU and stattic compared with control groups. Our data from gene expression determined a substantial diminish in the mRNA levels of the Nrf2 and antiapoptotic gene Bcl-2 along with a noticeable increase in the level of the proapoptotic Bax in HT-29 colon cells that underwent cotreatment with 5-FU and stattic (P < 0.05). Moreover, the results exhibited that stattic can be used as adjuvant chemotherapy besides the 5-FU. This therapeutic approach in colon cancer could mediate 5-FU chemoresistance via modulating therapeutic targets (ie, STAT3 and Nrf2 pathways) and decreased 5-FU-related adverse effects.

Toxicological assessment of magnesium oxide nanoparticles in HT29 intestinal cells.

Nanoparticles (NPs) are increasingly used in different consumer-related areas, for instance in food packaging or as additives, because of their enormous potential. Magnesium oxide (MgO) is an EU-approved food additive (E number 530). It is commonly used as a drying agent for powdered foods, for colour retention or as a food supplement. There are no consistent results regarding the effects of oral MgO NP uptake. Consequently, the aim of this study was to examine the effects of MgO NPs in the HT29 intestinal cell line. MgO NP concentrations ranged from 0.001 to 100μg/ml and incubation times were up to 24h. The cytotoxic and genotoxic potential were investigated. Apoptotic processes and cell cycle changes were analysed by flow cytometry. Finally, oxidative stress was examined. Transmission electron microscopy indicated that there was no cellular uptake. MgO NPs had no cytotoxic or genotoxic effects in HT29 cells and they did not induce apoptotic processes, cell cycle changes or oxidative stress.

Investigating the synergistic effects of gold nanoparticles and electroporation in sensitization of human intestinal colon cancer HT-29 cells to 6MV photon beam

Introduction: Radiation therapy (RT) is the gold standard treatment for more than half of known tumors. There is increasing evidence that combining radiation therapy with a radiosensitizer can enhance the efficiency of this treatment modality. A radiosensitizer preferably enhances dose at the site of tumor and increases discrimination between tumor and normal surrounding tissues. Gold nanoparticles (GNPs) and electroporation (EP) have shown good potential as radiosensitizers. Therefore, the present study assessed the sensitizing effects of EP, GNPs, and combined EP-GNPs on the dose enhancement factor(DEF) for 6 MV photon energy. Materials and Methods: In this in-vitro study, intestinal colon cancer (HT-29) cells treated with four different protocols: ionizing radiation alone (IR, control group), EP+IR, GNPs+IR and GNPs+EP+IR. Radiosensitization was assessed by colony formation assay at 6 MV photon energy. The survival curve was estimated using MATLAB software and DEF for each combination treatment group was calculated by dividing of LD50 (50% lethal dose) of control group with combination treatment group. Results: when the cells were treated with EP prior to IR the DEF of 1.36 was achieved. Treatment of cells with GNPs immediately before irradiation resulted in DEF of 1.17. In this group, GNPs did not significantly enhance the effect of IR due to having not enough time for GNPs to enter and accumulate in the target cells. However, when EP was added to the protocol of GNPs+IR group, DEF of 2.61 was observed. The observed difference between DEF values of GNPs+IR and GNPs+EP+IR groups can be attributed to the act of EP as a GNPs delivery system in GNPs+EP+IR group. Conclusion: Combined GNPs-EP protocol could induce synergistic effects in HT-29 cells and it can be beneficially used for the treatment of intrinsically less radiosensitive tumors.

Probiotic Bacillus coagulans MTCC 5856 spores exhibit excellent in-vitro functional efficacy in simulated gastric survival, mucosal adhesion and immunomodulation

Probiotic Bacillus coagulans MTCC 5856 spores were evaluated in-vitro for their ability to survive simulated digestion, adhesion to colonic cells and immunomodulatory properties. The spores showed significant survival (92%) during simulated digestion and substantially adhered to the human colonic cells HT-29 (86%) and LS174T (81%) compared with the L. acidophilus control. They exerted marked immunomodulatory effects in HT-29 cells, by reducing IL-8 and increasing IL-10 secretion. Moreover, they exhibited pronounced differential immunomodulatory efficacy in response to lipopolysaccharide-induced inflammation under co-treatment (increased IL-10 and reduced IL-8) relative to post-treatment (reduced IL-8 with no IL-10 detection) in HT-29 cells. This observation supports the application of B. coagulans spores before or during the onset of inflammation to maximise the probiotic benefits in treating inflammatory bowel conditions. The results provide additional evidence of the probiotic properties of B. coagulans spores and support their incorporation into functional foods for improved gut health.

The relationship between standard reduction potentials of catechins and biological activities involved in redox control

Redox homeostasis involves factors that ensure proper function of cells. The excess reactive oxygen species (ROS) leads to oxidative stress and increased risk of oxidative damage to cellular components. In contrast, upon reductive stress, insufficient ROS abundance may result in faulty cell signalling. It may be expected that dietary antioxidants, depending on their standard reduction potentials (E°), will affect both scenarios. In our study, for the first time, we systematically tested the relationship among E°, chemical properties, and biological effects in HT29 cells for a series of structurally different catechins and a major endogenous antioxidant – glutathione (GSH), at both physiological and dietary concentrations. Among chemical antioxidant activity tests, the strongest correlation with E° was seen using a DPPH assay. The values of E° were also highly correlated with cellular antioxidant activity (CAA) values determined in HT29 cells. Our results indicated that physiological concentrations (1–10 µM) of tested catechins stabilized the redox status of cells, which was not exhibited at higher concentrations. This stabilization of redox homeostasis was mirrored by constant, dose and E° independent CAA values, uninhibited growth of HT29 cells, modulation of hydrogen peroxide-induced DNA damage, as well as effects at the genomic level, where either up-regulation of three redox-related genes (ALB, CCL5, and HSPA1A) out of 84 in the array (1 µM) or no effect (10 µM) was observed for catechins. Higher catechin concentrations (over 10 µM) increased CAA values in a dose- and E°-dependent manner, caused cell growth inhibition, but surprisingly did not protect HT29 cells against reactive oxygen species (ROS)-induced DNA fragmentation. In conclusion, dose-dependent effects of dietary antioxidants and biological functions potentially modulated by them may become deregulated upon exposure to excessive doses.