Butyrate alleviates inflammatory response and NF-κB activation in human degenerated intervertebral disc tissues

Butyrate has multiple protective effects in inflammation-related intestinal diseases. Previous studies have found that butyrate could inhibit inflammation in rheumatoid arthritis. Inflammation is a pivotal inducement in the degeneration progress of the intervertebral disc. The anti-inflammatory treatment has an apparent curative effect in the symptomatic treatment of spine-related disease. Herein we investigated whether butyrate plays a protective role in degenerated intervertebral disc model. To mimic the lumbar disc local inflammatory environment, human primary nucleus pulposus cells were cultured with interleukin-1β (IL-1β, 10 ng/ml) to build a nucleus pulposus cell inflammation model. Butyrate was added to the cell culture medium to test the effect of butyrate on disc inflammation. Furthermore, a cultured nucleus pulposus tissue model was treated with butyrate (1 mM) to simulate the local treatment of intervertebral disc disease. Herein, we found that butyrate could downregulate the production of the inflammatory mediator caused by IL-1β stimulation in the cell culture model. Additionally, butyrate inhibits the secretion of pro-inflammatory cytokines or graded enzymes in disc tissues from lumbar disc herniation patients. Furthermore, the anti-inflammatory function of butyrate in lumbar disc degenerated model may be caused by inhibiting the activation of the nuclear factor kappa B (NF-κB) signal pathway. This study presents butyrate as a candidate therapeutic method to treat lumbar disc degenerative disease.     

Narirutin fraction from citrus peels attenuates LPS-stimulated inflammatory response through inhibition of NF-κB and MAPKs activation

In this study, we examined the regulatory activity of narirutin fraction from citrus peels on the production of inflammatory mediators managing acute or chronic inflammatory diseases in macrophages. Narirutin fraction inhibited the release, by lipopolysaccharide (LPS)-stimulated macrophages, of nitric oxide (NO) and prostaglandin E₂ (PGE₂) through suppressing the expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2), respectively. The release, by LPS stimulated macrophages, of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) was also reduced by narirutin fraction in a dose-dependent manner. Furthermore, narirutin fraction inhibited the LPS-mediated activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPKs), which are signaling molecules involved in production of pro-inflammatory factors. As a result of these properties, narirutin fraction has the potential to be used as a functional dietary supplement and effective anti-inflammatory agent.     

Lactobacillus johnsonii HY7042 ameliorates Gardnerella vaginalis-induced vaginosis by killing Gardnerella vaginalis and inhibiting NF-κB activation

Hydrogen peroxide-producing lactic acid bacteria (LAB) were isolated from women's vaginas and their anti-inflammatory effects against Gardnerella vaginalis-induced vaginosis were examined in β-estradiol-immunosuppressed mice. Oral and intravaginal treatment with five LABs significantly decreased viable G. vaginalis numbers in vaginal cavities and myeloperoxidase activity in mouse vaginal tissues. Of the LABs examined, Lactobacillus johnsonii HY7042 (LJ) most potently inhibited G. vaginalis-induced vaginosis. This LAB also inhibited the expressions of IL-1β, IL-6, TNF-α, COX-2, and iNOS, and the activation of NF-κB in vaginal tissues, but increased IL-10 expression. Orally administered LJ (0.2 × 10⁸ CFU/mouse) also inhibited the expression of TNF-α by 91.7% in β-estradiol-immunosuppressed mice intraperitoneally injected with LPS. However, it increased IL-10 expression by 63.3% in these mice. Furthermore, LJ inhibited the expressions of the pro-inflammatory cytokines, TNF-α and IL-1β, and the activation of NF-κB in lipopolysaccharide-stimulated peritoneal macrophages. LJ also killed G. vaginalis attached with and without HeLa cells. These findings suggest that LJ inhibits bacterial vaginosis by inhibiting the expressions of COX-2, iNOS, IL-1β, and TNF-α by regulating NF-κB activation and by killing G. vaginalis, and that LJ could ameliorate bacterial vaginosis.     

Lactobacillus helveticus HY7801 ameliorates vulvovaginal candidiasis in mice by inhibiting fungal growth and NF-κB activation

The anti-inflammatory effects of hydrogen peroxide-producing lactic acid bacteria (LAB) against Candida albicans-induced vulvovaginal candidiasis in β-estradiol-immunosuppressed mice were examined. Oral and intravaginal treatment with these LABs significantly decreased the level of viable C. albicans within the vaginal cavity as well as the quantitated myeloperoxidase activity in the vaginal tissues when compared with control untreated mice. Out of all of the LABs tested, Lactobacillus helveticus HY7801 (LH) most potently inhibited vulvovaginal candidiasis. LH also inhibited the expression of the pro-inflammatory cytokines including TNF-α, IL-1β and IL-6, and inflammatory enzymes, COX-2 and iNOS, as well as the activation of NF-κB. However, the addition of LH led to an increase in IL-10 cytokine expression in the vaginal tissues. In addition, the decrease of Lactobacillaceae and the increase of Pasteurellaceae caused by treatment with C. albicans were reversed with oral and intravaginal administration of LH, suggesting a potential shift in the vaginal microflora present. Addition of LH was toxic to C. albicans in vitro when cultured with HeLa cells. Oral administration of LH inhibited lipopolysaccharide (LPS)-induced TNF-α and IL-1β expressions in β-estradiol-immunosuppressed mice but reversed the expression of anti-inflammatory cytokine IL-10 in comparison to levels observed in the normal control group. LH also inhibited the expression of the pro-inflammatory cytokines, TNF-α and IL-1β, and the activation of NF-κB in LPS-stimulated peritoneal macrophages. Based on these findings, LH may ameliorate vulvovaginal candidiasis by suppressing the NF-κB pathway, as well as through inhibition of the growth of C. albicans.     

Zhen-wu-tang attenuates cationic bovine serum albumin-induced inflammatory response in membranous glomerulonephritis rat through inhibiting AGEs/RAGE/NF-κB pathway activation

Zhen-wu-tang (ZWT), a traditional Chinese compound formula recorded in the Treatise on Febrile Diseases, has significant inhibitory effects on inflammatory damage and oxidative lesions in rats, but its mechanism of action remains unclear. The aim of the present study was to explore whether the anti-inflammatory and anti-oxidative effects of ZWT were mediated by the AGEs/RAGE/NF-κB signaling pathway in rats with cationic bovine serum albumin (C-BSA)-induced membranous glomerulonephritis (MGN). We found that ZWT significantly reduced the production of malondialdehyde (MDA), but enhanced the superoxide dismutase (SOD) activity. The ELISA results showed that ZWT not only reduced the serum levels of AGEs but also decreased the release of inflammatory mediators (TNF-α, IL-1β, and IL-6). Meanwhile, HE staining showed that pathological kidney injury was alleviated by ZWT. In addition, ZWT suppressed the expression of RAGE1 and NF-κB p65, as well as the nuclear translocation of NF-κB p65. The accumulation of AGEs, oxidative lesions and inflammation damage were reduced by an AGE inhibitor. Thus, the present study demonstrates that AGEs play a role in the pathogenesis of MGN and that AGE inhibition could reduce the inflammatory reactions and oxidative lesions in MGN. In general, ZWT attenuated MGN, in part, by inhibiting the AGEs/RAGE/NF-κB pathway.     

Inhibition of LPS-induced NO production and NF-κB activation by a sesquiterpene fromSaussurea lappa

To elucidate the molecular mechanisms for the suppression of LPS-induced nitric oxide (NO) production by a dehydrocostus lactone (DL) from Saussurea lappa, we examined the preventive effect of this compound on NF-kappaB activation in LPS-treated RAW 264.7 macrophages and U937 human monocytic cells. The results suggest that the suppression of NO production is mediated by the inhibitory action on the i-NOS gene expression through the inactivation of NF-kappaB and this sesquiterpene lactone can act as a pharmacological inhibitor of the NF-kappaB activation.     

Hsa_circ_0001204 modulates inflammatory response of macrophages infected by Mycobacterium tuberculosis via TLR4/NF-κB signalling pathway

Circular RNAs (circRNAs) play a vital role in the regulation of Mycobacterium tuberculosis (M.tb) by macrophages. In this project, the potential role of hsa_circ_0001204 in M.tb-infected macrophages is explored. Hsa_circ_0001204 was determined in the patients with tuberculosis (TB) and M.tb-infected macrophages. Its effect on the survival of M.tb and the apoptosis and inflammation of M.tb-infected macrophages was evaluated. Toll-like receptor 4/nuclear factor-κB (TLR4/NF-κB) signalling was detected by western blotting and immunofluorescence. TB patients and M.tb-infected THP-1 cells showed the significant downregulation of hsa_circ_0001204. Upregulating hsa_circ_0001204 reduced M.tb survival and suppressed the apoptosis and inflammatory response of THP-1 cells. The TLR4/NF-κB signalling pathway could be inhibited by hsa_circ_0001204 overexpression, which was activated by M.tb-infection. Hsa_circ_0001204 confers protective effects in M.tb-infected THP-1 cells, at least partly via the inhibition of TLR4/NF-κB signalling pathway.     

MDM2 promotes rheumatoid arthritis via activation of MAPK and NF-κB

Murine double minute-2 (MDM2) has pleiotropic roles in immune activation and regulation. However, the role of MDM2 in rheumatoid arthritis (RA) remains unknown. We undertook this study to investigate the role of MDM2 in rheumatoid arthritis (RA). Fibroblast-like synoviocytes (FLS) were isolated from 25 patients with active RA and 25 patients with osteoarthritis (OA). FLS were stimulated in the presence or absence of IL-1β in vitro. Mice with collagen-induced arthritis (CIA) were treated with Nutlin-3a (100 mg/kg) or vehicle twice daily for 2 weeks. MDM2 expression was determined by Western blot. MDM2 was down-regulated by specific gene silencing. The concentrations of pro-inflammatory cytokines and matrix metalloproteinases (MMPs) were analyzed using enzyme-linked immunosorbent assay (ELISA). The pathways of mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) were investigated by Western blot. Arthritis scoring and histological analysis were conducted. MDM2 expression was significantly higher in RA-FLS than in OA-FLS. MDM2 protein expression was positively correlated with disease activity of RA. MDM2 promoted the production of TNF-α, IL-6, MMP1 and MMP13 through MAPK and NF-κB pathways in RA-FLS. Nutlin-3a treatment decreased the arthritis severity and joint damage in CIA. Nutlin-3a also inhibited the activation of MAPK and NF-κB in arthritic joints. In conclusion, MDM2 inhibition exhibits anti-inflammatory activity and MDM2 might be a new therapeutic target for RA.     

The inhibition of TNF-α-induced NF-κB activation by marine natural products

The deregulated activation of NF-κB is associated with cancer development and inflammatory diseases. With an aim to find new NF-κB inhibitors, we purified and characterized compounds from extracts of the Fijian sponge Rhabdastrella globostellata, the crinoid Comanthus parvicirrus, the soft corals Sarcophyton sp. nov. and Sinularia sp., and the gorgonian Subergorgia sp. after an initial screening of 266 extracts from different marine origins.Results obtained show that selected purified compounds had a cytotoxic effect on the human leukaemia cell line K562, inhibited both TNF-α-induced NF-κB-DNA binding as well as TNF-α-induced IκBα degradation and nuclear translocation of p50/p65. Furthermore, we observed the inhibition of NF-κB activation induced by an overexpression of IKKβ. Interestingly, natural products inhibited IKKβ kinase as well as the 26S proteasome proteolytic activity.     

Tetrandrine suppresses amyloid-β-induced inflammatory cytokines by inhibiting NF-κB pathway in murine BV2 microglial cells

Microglial cells play an important role in mediating neuroinflammation in Alzheimer's disease (AD) by production of a series of proinflammatory mediators and clearance of Aβ peptides and senile plaques. Tetrandrine, a bisbenzylisoquinoline alkaloid isolated from the Chinese herb Radix Stephania tetrandra, has been demonstrated to decrease the expression of proinflammatory mediators by inhibition of NF-κB activation. Here we investigated whether tetrandrine may affect the phagocytosis of microglia and the expression of cytokines and NF-κB in murine BV2 microglial cells. We found that fibrillar Amyloid-β (fAβ) induced phagocytosis of microglia and dramatically increased the levels of interleukin 1 beta (IL-1β) and tumor necrosis factor alpha (TNF-α) as well as the expression of phospho NF-κB p65 in microglia cultures. The treatment with tetrandrine resulted in downregulation of phospho NF-κB p65 expression and strikingly reduced the production of IL-1β and TNF-α. However, tetrandrine did not affect fAβ induced phagocytosis of microglia. In conclusion, tetrandrine can decrease microglial detriment of neurotoxicity while maintaining microglial benefit of neuroprotection. Tetrandrine may be an efficacious and promising remedy in the treatment of AD.