Sodium butyrate ameliorates thiram-induced tibial dyschondroplasia and gut microbial dysbiosis in broiler chickens.

Thiram is a dithiocarbamate pesticide widely used in agriculture as a fungicide for storing grains to prevent fungal diseases. However, its residues have threatened the safety of human beings and the stability of the ecosystem by causing different disease conditions, e.g., tibial dyschondroplasia (TD), which results in a substantial economic loss for the poultry industry. So, the research on TD has a great concern for the industry and the overall GDP of a country. In current study, we investigated whether different concentrations (300, 500, and 700 mg/kg) of sodium butyrate alleviated TD induced under acute thiram exposure by regulating osteogenic gene expression, promoting chondrocyte differentiation, and altering the gut microbial community. According to the findings, sodium butyrate restored clinical symptoms in broilers, improved growth performance, bone density, angiogenesis, and chondrocyte morphology and arrangement. It could activate the signal transduction of the Wnt/ß-catenin pathway, regulate the expression of GSK-3ß and ß-catenin, and further promote the production of osteogenic transcription factors Runx2 and OPN for restoration of lameness. In addition, the 16S rRNA sequencing revealed a significantly different community composition among the groups. The TD group increased the abundance of the harmful bacteria Proteobacteria, Subdoligranulum, and Erysipelatoclostridium. The sodium butyrate enriched many beneficial bacteria, such as Bacteroidetes, Verrucomicrobia, Faecalibacterium, Barnesiella, Rikenella, and Butyricicoccus, etc., especially at the concentration of 500 mg/kg. The mentioned concentration significantly limited the intestinal disorders under thiram exposure, and restored bone metabolism.

RNA-Seq analysis reveals critical transcriptome changes caused by sodium butyrate in DN mouse models.

Diabetic nephropathy (DN)-a common complication of diabetes-is the primary cause of end-stage renal disease. Sodium butyrate (NaB) is a short-chain fatty acid (SCFA) that is a metabolic product of intestinal bacterium, and its protective effect on the kidney has been reported in cases of DN. However, its underlying mechanism remains unclear. The aim of the present study was to investigate the effect of NaB on globe transcriptome changes in DN. In our study, 8-week-old male db/db mice suffering from DN were randomly divided into two groups: the DN+NaB group (DN mice treated with NaB, 5 g/kg/day) and the DN group (DN mice treated with saline). Further, normal db/m mice were used as the normal control (NC) group. The blood glucose, body weight, urinary microalbumin and urinary creatinine of mice were measured for all three groups. Whole-transcriptome analysis was performed by RNA sequencing (RNA-Seq) to evaluate the profiling of long non-coding RNAs (lncRNAs) and messenger RNAs (mRNAs). Bioinformatics analysis was performed to predict the potential NaB-related lncRNAs and genes in DN. The expressions of lncRNAs and mRNAs were tested using the quantitative real-time polymerase chain reactions (qRT-PCRs) in renal tissues and mesangial cells treated with NaB. The results of the present study demonstrated that NaB ameliorated renal dysfunction in DN mice. Moreover, RNA-Seq results identified that some lncRNAs and mRNAs were reversely changed in the DN+NaB group in comparison to those in the DN group. Additionally, the integrated co-expression networks of NaB-related lncRNAs revealed that these lncRNAs interacted with 155 key mRNAs. Furthermore, the co-expression network of inflammation-related lncRNAs and mRNAs demonstrated that those reversed lncRNAs and mRNAs also play essential roles in the inflammatory response. In summary, the present study suggests that NaB ameliorates diabetes-induced renal dysfunction and regulates transcriptome changes in DN.

Sodium Butyrate Exacerbates Parkinson's Disease by Aggravating Neuroinflammation and Colonic Inflammation in MPTP-Induced Mice Model.

The abnormal production of short chain fatty acid (SCFAs) caused by gut microbial dysbiosis plays an important role in the pathogenesis and progression of Parkinson's disease (PD). This study sought to evaluate how butyrate, one of SCFAs, affect the pathology in a subacute 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride (MPTP) treated mouse model of PD. Sodium butyrate (NaB; 165 mg/kg/day i.g., 7 days) was administrated from the day after the last MPTP injection. Interestingly, NaB significantly aggravated MPTP-induced motor dysfunction (P < 0.01), decreased dopamine (P < 0.05) and 5-HT (P < 0.05) levels, exacerbated declines of dopaminergic neurons (34%, P < 0.05) and downregulated expression of tyrosine hydroxylase (TH, 47%, P < 0.05), potentiated glia-mediated neuroinflammation by increasing the number of microglia (17%, P < 0.05) and activating astrocytes (28%, P < 0.01). In vitro study also confirmed that NaB could significantly exacerbate pro-inflammatory cytokines expression (IL-1ß, 4.11-fold, P < 0.01; IL-18, 3.42-fold, P < 0.01 and iNOS, 2.52-fold, P < 0.05) and NO production (1.55-fold, P < 0.001) in LPS-stimulated BV2 cells. In addition, NaB upregulated the expression of pro-inflammatory cytokines (IL-6, 3.52-fold, P < 0.05; IL-18, 1.72-fold, P < 0.001) and NLRP3 (3.11-fold, P < 0.001) in the colon of PD mice. However, NaB had no effect on NFκB, MyD88 and TNF-α expression in PD mice. Our results indicate that NaB exacerbates MPTP-induced PD by aggravating neuroinflammation and colonic inflammation independently of the NFκB/MyD88/TNF-α signaling pathway.

RIFM fragrance ingredient safety assessment, hexyl isovalerate, CAS Registry Number 10032-13-0.

The existing information supports the use of this material as described in this safety assessment. Hexyl isovalerate was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data from read-across analog hexyl isobutyrate (CAS # 2349-07-7) show that hexyl isovalerate is not expected to be genotoxic. Data on read-across analog propyl (2S)-2-(1,1-dimethylpropoxy)-propanoate (CAS # 319002-92-1) provide a calculated MOE >100 for the repeated dose toxicity and reproductive toxicity endpoints. Data from read-across analog hexyl 2-methylbutyrate (CAS # 10032-15-2) do not indicate that hexyl isovalerate is a skin sensitizer. The phototoxicity/photoallergenicity endpoints were evaluated based on UV spectra; hexyl isovalerate is not expected to be phototoxic/photoallergenic. The local respiratory toxicity endpoint was evaluated using the TTC for a Cramer Class I material, and the exposure to hexyl isovalerate is below the TTC (1.4 mg/day). The environmental endpoints were evaluated; hexyl isovalerate was found not to be PBT as per the IFRA Environmental Standards, and its risk quotients, based on its current volume of use in Europe and North America (i.e., PEC/PNEC), are <1.

Improved in vivo antitumor effect of a daunorubicin - GnRH-III bioconjugate modified by apoptosis inducing agent butyric acid on colorectal carcinoma bearing mice.

Compared to classical chemotherapy, peptide-based drug targeting is a promising therapeutic approach for cancer, which can provide increased selectivity and decreased side effects to anticancer drugs. Among various homing devices, gonadotropin-releasing hormone-III (GnRH-III) peptide represents a suitable targeting moiety, in particular in the treatment of hormone independent tumors that highly express GnRH receptors (e.g. colon carcinoma). We have previously shown that GnRH-III[(4)Lys(Ac),(8)Lys(Dau = Aoa)] bioconjugate, in which daunorubicin was attached via oxime linkage to the (8)Lys of a GnRH-III derivative, exerted significant in vivo antitumor effect on subcutaneously developed HT-29 colon tumor. In contrast, results of the study reported here indicated that this compound was not active on an orthotopically developed tumor. However, if Lys in position 4 was acylated with butyric acid instead of acetic acid, the resulting bioconjugate GnRH-III[(4)Lys(Bu),(8)Lys(Dau = Aoa)] had significant tumor growth inhibitory effect. Furthermore, it prevented tumor neovascularization, without detectable side effects. Nevertheless, the development of metastases could not be inhibited by the bioconjugate; therefore, its application in combination with a metastasis preventive agent might be necessary in order to achieve complete tumor remission. In spite of this result, the treatment with GnRH-III[(4)Lys(Bu),(8)Lys(Dau = Aoa)] bioconjugate proved to have significant benefits over the administration of free daunorubicin, which was used at the maximum tolerated dose.

High butyric acid amounts induce oxidative stress, alter calcium homeostasis, and cause neurite retraction in nerve growth factor-treated PC12 cells.

Butyric acid (BA) is a common secondary metabolite by-product produced by oral pathogenic bacteria and is detected in high amounts in the gingival tissue of patients with periodontal disease. Previous works have demonstrated that BA can cause oxidative stress in various cell types; however, this was never explored using neuronal cells. Here, we exposed nerve growth factor (NGF)-treated PC1(2) cells to varying BA concentrations (0.5, 1.0, 5.0 mM). We measured total heme, H(2)O(2), catalase, and calcium levels through biochemical assays and visualized the neurite outgrowth after BA treatment. Similarly, we determined the effects of other common periodontal short-chain fatty acids (SCFAs) on neurite outgrowth for comparison. We found that high (1.0 and 5.0 mM) BA concentrations induced oxidative stress and altered calcium homeostasis, whereas low (0.5 mM) BA concentration had no significant effect. Moreover, compared to other SCFAs, we established that only BA was able to induce neurite retraction.

Docosahexaenoic acid attenuates oxidative stress and protects human gingival fibroblasts against cytotoxicity induced by hydrogen peroxide and butyric acid.

OBJECTIVE: The oxidative burst of the host cells associated with bacterial pathogen infection contributes to the destruction of periodontal tissue. The present study investigates the effect of docosahexaenoic acid (DHA) on human gingival fibroblast (HGF) viability and ROS generation. METHODS: The cell viability by MTT assay, ROS level using H2DCF-DA probe, and protein thiol content were measured in HGFs after 24h preincubation with different concentrations of DHA followed by treatment with H2O2. The cell death rate was determined by Annexin V/propidium iodide staining, and mitochondrial membrane potential (ΔΨm) was examined by MitoTracker Red probe in H2O2- and butyric acid-treated HGFs. The fatty acid composition of plasma membranes after incubation with DHA was determined by gas chromatography mass spectrometry. RESULTS: DHA preincubation in a dose-dependent manner increased the viability of HGFs exposed to H2O2 and decreased ROS generation compared to the control cells. In HGFs preincubated with 30µM DHA, the ΔΨm significantly increased in both H2O2- and butyric acid-treated cells. Moreover, incubation with DHA preserved the protein thiol level as effectively as N-acetylcysteine. Application of 50µM DHA increased the quantity of viable cells, decreased the number of necrotic cells after H2O2 treatment, and protected HGFs from apoptosis induced by butyric acid. DHA in the plasma membranes of these HGFs represented about 6% of the total amount of fatty acids. CONCLUSIONS: These results demonstrate that enrichment of HGFs with DHA reduces ROS generation and enhances the mitochondrial membrane potential protecting the fibroblasts against cytotoxic factors.

Synthesis, spectroscopic, X-ray crystal structure, biological and DNA interaction studies of organotin(IV) complexes of 2-(4-ethoxybenzylidene) butanoic acid.

Six organotin(IV) carboxylates of the type R2SnL2 [R=CH3 (1), n-C4H9 (2), n-C8H17 (3)] and R3SnL [R=CH3 (4), n-C4H9 (5), C6H5 (6), where L=2-(4-ethoxybenzylidene) butanoic acid, have been synthesized and characterized by elemental analysis, FT-IR and NMR ((1)H, (13)C). The complex (1) was also analyzed by single crystal X-ray analysis. The complexes were screened for antimicrobial, cytotoxic and anti-tumor activities. The results showed significant activity in each area of the activity with few exceptions. DNA interactions studies of ligand HL and representative complex 2 were investigated by UV-Visible absorption spectroscopy and viscosity measurements. The results showed that both ligand HL and complex 2 interact with SS-DNA via intercalation as well as minor groove binding.

Effects of acute hypoxia/acidosis on intracellular pH in differentiating neural progenitor cells.

The response of differentiating mouse neural progenitor cells, migrating out from neurospheres, to conditions simulating ischemia (hypoxia and extracellular or intracellular acidosis) was studied. We show here, by using BCECF and single cell imaging to monitor intracellular pH (pH(i)), that two main populations can be distinguished by exposing migrating neural progenitor cells to low extracellular pH or by performing an acidifying ammonium prepulse. The cells dominating at the periphery of the neurosphere culture, which were positive for neuron specific markers MAP-2, calbindin and NeuN had lower initial resting pH(i) and could also easily be further acidified by lowering the extracellular pH. Moreover, in this population, a more profound acidification was seen when the cells were acidified using the ammonium prepulse technique. However, when the cell population was exposed to depolarizing potassium concentrations no alterations in pH(i) took place in this population. In contrast, depolarization caused an increase in pH(i) (by 0.5 pH units) in the cell population closer to the neurosphere body, which region was positive for the radial cell marker (GLAST). This cell population, having higher resting pH(i) (pH 6.9-7.1) also responded to acute hypoxia. During hypoxic treatment the resting pH(i) decreased by 0.1 pH units and recovered rapidly after reoxygenation. Our results show that migrating neural progenitor cells are highly sensitive to extracellular acidosis and that irreversible damage becomes evident at pH 6.2. Moreover, our results show that a response to acidosis clearly distinguishes two individual cell populations probably representing neuronal and radial cells.

D282, a non-nucleoside inhibitor of influenza virus infection that interferes with de novo pyrimidine biosynthesis.

BACKGROUND: The discovery of novel influenza virus inhibitors remains an important priority in light of the emergence of drug-resistant viruses. Toward this end, a library of over 6,000 compounds was tested for antiviral activity. METHODS: Strains of influenza virus were evaluated by cytopathic effect (CPE) inhibition and virus yield reduction assays. Intracellular nucleoside triphosphate pools were analysed by strong anion exchange HPLC. Dihydroorotate dehydrogenase inhibition assays were conducted. Influenza virus-infected mice were treated for 5 days with D282. RESULTS: A non-nucleoside, 4-[(4-butylphenyl)amino]-2-methylene-4-oxo-butanoic acid (D282), was discovered that inhibited influenza A and B virus CPE by 50% at 6-31 µM (giving selectivity indices of >13 to >67, based on cytotoxicity of >400 µM in stationary cell cultures). Ribavirin (positive control) was active at 14-44 µM (yielding selectivity indices of >9 to >29, with >400 µM toxicity). D282 and ribavirin inhibited virus yield by 90% at 9.5 ±3.3 and 10.8 ±3.2 µM, respectively. The antiviral activity of D282 in vitro was reversed by addition of uridine, cytidine and orotic acid. D282 exhibited an uncompetitive inhibition of mouse liver dihydroorotate dehydrogenase (inhibitor constant [Ki] of 2.3 ±0.9 µM, Michaelis constant [Km] of 150 ±16 µM). Because cellular pyrimidine biosynthesis was inhibited, D282-treated cells had decreased uridine triphosphate and cytidine triphosphate levels. D282 (≤100 mg/kg/day) failed to prevent death of mice infected with influenza. CONCLUSIONS: D282 was active against influenza A and B viruses by inhibiting de novo pyrimidine biosynthesis. Although effective in vitro, the compound, like others in its class, was devoid of antiviral activity in infected mice.

Reactivation of latent HIV-1 by a wide variety of butyric acid-producing bacteria.

Latently infected cells harbor human immunodeficiency virus type 1 (HIV-1) proviral DNA copies integrated in heterochromatin, allowing persistence of transcriptionally silent proviruses. It is widely accepted that hypoacetylation of histone proteins by histone deacetylases (HDACs) is involved in maintaining the HIV-1 latency by repressing viral transcription. HIV-1 replication can be induced from latently infected cells by environmental factors, such as inflammation and co-infection with other microbes. It is known that a bacterial metabolite butyric acid inhibits catalytic action of HDAC and induces transcription of silenced genes including HIV-1 provirus. There are a number of such bacteria in gut, vaginal, and oral cavities that produce butyric acid during their anaerobic glycolysis. Since these organs are known to be the major site of HIV-1 transmission and its replication, we explored a possibility that explosive viral replication in these organs could be ascribable to butyric acid produced from anaerobic resident bacteria. In this study, we demonstrate that the culture supernatant of various bacteria producing butyric acid could greatly reactivate the latently-infected HIV-1. These bacteria include Fusobacterium nucleatum (commonly present in oral cavity, and gut), Clostridium cochlearium, Eubacterium multiforme (gut), and Anaerococcus tetradius (vagina). We also clarified that butyric acid in these culture supernatants could induce histone acetylation and HIV-1 replication by inhibiting HDAC. Our observations indicate that butyric acid-producing bacteria could be involved in AIDS progression by reactivating the latent HIV provirus and, subsequently, by eliminating such bacterial infection may contribute to the prevention of the AIDS development and transmission.

Formic acid triggers the "Acid Crash" of acetone-butanol-ethanol fermentation by Clostridium acetobutylicum.

Solvent production by Clostridium acetobutylicum collapses when cells are grown in pH-uncontrolled glucose medium, the so-called "acid crash" phenomenon. It is generally accepted that the fast accumulation of acetic acid and butyric acid triggers the acid crash. We found that addition of 1 mM formic acid into corn mash medium could trigger acid crash, suggesting that formic acid might be related to acid crash. When it was grown in pH-uncontrolled glucose medium or glucose-rich medium, C. acetobutylicum DSM 1731 containing the empty plasmid pIMP1 failed to produce solvents and was found to accumulate 0.5 to 1.24 mM formic acid intracellularly. In contrast, recombinant strain DSM 1731 with formate dehydrogenase activity did not accumulate formic acid intracellularly and could produce solvent as usual. We therefore conclude that the accumulation of formic acid, rather than acetic acid and butyric acid, is responsible for the acid crash of acetone-butanol-ethanol fermentation.

Enhanced butyric acid tolerance and bioproduction by Clostridium tyrobutyricum immobilized in a fibrous bed bioreactor.

Repeated fed-batch fermentation of glucose by Clostridium tyrobutyricum immobilized in a fibrous bed bioreactor (FBB) was successfully employed to produce butyric acid at a high final concentration as well as to adapt a butyric-acid-tolerant strain. At the end of the eighth fed-batch fermentation, the butyric acid concentration reached 86.9 ± 2.17 g/L, which to our knowledge is the highest butyric acid concentration ever produced in the traditional fermentation process. To understand the mechanism and factors contributing to the improved butyric acid production and enhanced acid tolerance, adapted strains were harvested from the FBB and characterized for their physiological properties, including specific growth rate, acid-forming enzymes, intracellular pH, membrane-bound ATPase and cell morphology. Compared with the original culture used to seed the bioreactor, the adapted culture showed significantly reduced inhibition effects of butyric acid on specific growth rate, cellular activities of butyric-acid-forming enzyme phosphotransbutyrylase (PTB) and ATPase, together with elevated intracellular pH, and elongated rod morphology.

Increased susceptibility to tumor necrosis factor-alpha in butyric acid-induced apoptosis is caused by downregulation of cFLIP expression in Jurkat T cells.

Butyric acid is one of the major extracellular metabolites of periodontopathic Gram-negative bacteria. We previously demonstrated that butyric acid induced apoptosis in human T cells. In the present study, we examined the interaction between butyric acid and TNF-alpha in Jurkat T-cell apoptosis. Simultaneous treatment with TNF-alpha enhanced butyric acid-induced apoptosis by promoting caspase activity more than was achieved by either reagent alone. We examined which genes were associated with the increased susceptibility to TNF-alpha caused by butyric acid, and revealed that expression of cFLIP decreased with increased concentrations of butyric acid. Furthermore, exogenous expression of cFLIP protein suppressed the enhancing effect by TNF-alpha in the apoptosis. These results suggest that butyric acid downregulates cFLIP expression and increases the susceptibility to TNF-alpha by activating caspases via the death receptor signal.

In vitro effects of hydrochloric acid and various concentrations of acetic, propionic, butyric, or valeric acids on bioelectric properties of equine gastric squamous mucosa.

OBJECTIVE: To compare the effects of hydrochloric acid (HCl) and various concentrations of volatile fatty acids (VFAs) on tissue bioelectric properties of equine stomach nonglandular (NG) mucosa. SAMPLE POPULATION: Gastric tissues obtained from 48 adult horses. PROCEDURES: NG gastric mucosa was studied by use of Ussing chambers. Short-circuit current (Isc) and potential difference (PD) were measured and electrical resistance (R) and conductance calculated for tissues after addition of HCl and VFAs (5, 10, 20, and 40 mM) in normal Ringer's solution (NRS). RESULTS: Mucosa exposed to HCl in NRS (pH of 1.5 and, to a lesser extent, 4.0) had a significant decrease in Isc, PD, and R, whereas tissues exposed to acetic acid at a pH of < 4.0, propionic and butyric acids at a pH of

Genotoxicity of 4-hydroxy-2-nonenal in human colon tumor cells is associated with cellular levels of glutathione and the modulation of glutathione S-transferase A4 expression by butyrate.

The cellular production of 4-hydroxy-2-nonenal (HNE), a product of endogenous lipid peroxidation, constitutes a genotoxic risk factor for carcinogenesis. Our previous studies have shown that human HT29 colon cells developed resistance toward HNE injury after treatment with butyrate, a diet-associated gut fermentation product. This resistance was attributed to the induction of certain glutathione S-transferases (hGSTP1-1, hGSTM2-2, and hGSTA1-1) and also for the tripeptide glutathione (GSH) synthesizing enzymes. In the present study, we have investigated in HT29 cells whether hGSTA4-4, which has a high substrate specificity for HNE, was also inducible by butyrate and, thus, could contribute to the previously observed chemoresistance. In addition, we investigated if cellular depletion of GSH by L-buthionine-S,R-sulfoximine (BSO) enhances chemosensitivity to HNE injury in HT29 cells. Incubation of HT29 cells with butyrate (2-4 mM) significantly elicited a 1.8 to 3-fold upregulation of steady state hGSTA4 mRNA over 8-24 h after treatment. Moreover, 4 mM butyrate tended to increase hGSTA4-4 protein concentrations. Incubation with 100 microM BSO decreased cellular GSH levels by 77% without significant changes in cell viability. Associated with this was a 2-fold higher level of HNE-induced DNA damage as measured by the comet assay. Collectively, the results of this study and our previous work indicate that the genotoxicity of HNE is highly dependent on cellular GSH status and those GSTs that contribute toward HNE conjugation, including hGSTA4-4. Since HNE contributes to colon carcinogenesis, the favorable modulation of the GSH/GST system by butyrate may contribute to chemoprevention and reduction of the risks.

Cytotoxicity of anticancer drugs incorporated in solid lipid nanoparticles on HT-29 colorectal cancer cell line.

Solid lipid nanoparticles (SLN) carrying cholesteryl butyrate (chol-but), doxorubicin and paclitaxel had previously been developed, and the antiproliferative effect of SLN formulations versus conventional drug formulations was here evaluated on HT-29 cells. The 50% inhibitory concentration (IC(50) values were interpolated from growth curves obtained by trypan blue exclusion assay. In vitro cytotoxicity of SLN carrying chol-but (IC(50 72 h) 0.3 +/- 0.03 mM vs >0.6 mM) and doxorubicin (IC(50 72 h) 81.87 +/- 4.11 vs 126.57 +/- 0.72 nM) was higher than that of conventional drug formulations. Intracellular doxorubicin was double after 24 h exposure to loaded SLN versus the conventional drug formulation, at the highest concentration evaluated by flow cytometry. In vitro cytotoxicities of paclitaxel-loaded SLN and conventional drug formulation (IC(50 72 h) 37.36 +/- 6.41 vs 33.43 +/-1.17 nM) were similar. Moreover, the combination of low concentrations of chol-but SLN (0.1-0.2 mM) and doxorubicin (1.72 nM) or paclitaxel (1.17 nM) exerted a greater-than-additive antiproliferative effect at 24 h exposure, while the combination of Na-but and doxorubicin or paclitaxel did not. These preliminary in vitro results suggest that SLN could be proposed as alternative drug delivery system.

Human gingival fibroblasts rescue butyric acid-induced T-cell apoptosis.

We previously demonstrated that butyric acid, an extracellular metabolite from periodontopathic bacteria, induces cytotoxicity and apoptosis in murine thymocytes, splenic T cells, and human Jurkat T cells. In this study, we used a cell-to-cell interaction system to examine the contribution of gingival fibroblasts to the regulation of T-cell death induced by butyric acid. Butyric acid slightly suppressed fibroblast viability in a concentration-dependent fashion. However, DNA fragmentation assays indicated that butyric acid did not induce apoptosis for up to 21 h in human gingival fibroblasts (Gin 1, F41-G, and H. pulp cells). The culture supernatants were assayed for interleukin 1alpha (IL-1alpha), IL-1beta, IL-6, IL-8, IL-11, tumor necrosis factor alpha, and transforming growth factor beta, but only the IL-6, IL-8, and IL-11 levels were significantly increased by addition of butyric acid. Butyric acid- or Fas-induced Jurkat-cell apoptosis was attenuated when Jurkat cells were cocultured with either F41-G or Gin 1 cells that had been preincubated for 6 h with butyric acid. IL-8 slightly stimulated butyric acid- or Fas-induced Jurkat-cell apoptosis in a dose-dependent manner, although a low dose of IL-8 had a mildly inhibitory effect on apoptosis. In contrast, IL-6 and IL-11 significantly suppressed butyric acid- or Fas-induced apoptosis in a dose-dependent fashion. Furthermore, the addition of monoclonal antibodies against human IL-6 and IL-11 to cocultures of gingival fibroblasts and Jurkat cells partially eliminated T-cell recovery. These results suggest that the proinflammatory cytokines such as IL-6 and IL-11, produced in fibroblasts stimulated with butyric acid, are involved in the attenuation of T-cell apoptosis by gingival fibroblasts.