Kyung-Ah Kim

High Fat Diet-Induced Gut Microbiota Exacerbates Inflammation and Obesity in Mice via the TLR4 Signaling Pathway

Background & Aims While it is widely accepted that obesity is associated with low-grade systemic inflammation, the molecular origin of the inflammation remains unknown. Here, we investigated the effect of endotoxin-induced inflammation via TLR4 signaling pathway at both systemic and intestinal levels in response to a high-fat diet. Methods C57BL/6J and TLR4-deficient C57BL/10ScNJ mice were maintained on a low-fat (10 kcal % fat) diet (LFD) or a high–fat (60 kcal % fat) diet (HFD) for 8 weeks. Results HFD induced macrophage infiltration and inflammation in the adipose tissue, as well as an increase in the circulating proinflammatory cytokines. HFD increased both plasma and fecal endotoxin levels and resulted in dysregulation of the gut microbiota by increasing the Firmicutes to Bacteriodetes ratio. HFD induced the growth of Enterobecteriaceae and the production of endotoxin in vitro. Furthermore, HFD induced colonic inflammation, including the increased expression of proinflammatory cytokines, the induction of Toll-like receptor 4 (TLR4), iNOS, COX-2, and the activation of NF-κB in the colon. HFD reduced the expression of tight junction-associated proteins claudin-1 and occludin in the colon. HFD mice demonstrated higher levels of Akt and FOXO3 phosphorylation in the colon compared to the LFD mice. While the body weight of HFD-fed mice was significantly increased in both TLR4-deficient and wild type mice, the epididymal fat weight and plasma endotoxin level of HFD-fed TLR4-deficient mice were 69% and 18% of HFD-fed wild type mice, respectively. Furthermore, HFD did not increase the proinflammatory cytokine levels in TLR4-deficient mice. Conclusions HFD induces inflammation by increasing endotoxin levels in the intestinal lumen as well as in the plasma by altering the gut microbiota composition and increasing its intestinal permeability through the induction of TLR4, thereby accelerating obesity.

Prevertebral soft tissue swelling after anterior cervical discectomy and fusion with plate fixation

Airway complications after anterior cervical surgery are rare but potentially lethal. The purpose of this study was to identify the natural course of prevertebral soft tissue swelling after one- or two-level anterior cervical discectomy and fusion (ACDF) in order to prevent lethal airway obstruction after ACDF. Eighty-seven patients scheduled for one- or two-level ACDF were studied prospectively. Lateral radiographs of the cervical spine were taken preoperatively, postoperatively on the day of surgery and on the first, second, third, fourth, and fifth days after operation. Prevertebral soft tissue was measured from C2 to C6 on cervical spine lateral radiographs. The anteroposterior (AP) thickness of the prevertebral soft tissue was measured at each cervical level from C2 to C6. Prevertebral soft tissue swelling occurred postoperatively and increased markedly on the second day after operation. The maximum swelling was found on the second and third days. In fusions above C5 swelling was most prominent at C2, 3. Gradual decrease in swelling was observed after the fourth postoperative day. Prominent swelling was noted at the second, third, and fourth cervical levels. There was no significant difference in swelling when comparing one-level and two-level ACDF. Only one patient required reintubation (1.1%). In conclusion, in this prospective study of 87 patients fused at one or two levels in the cervical spine peak prevertebral soft tissue swelling was observed on the second and third days after the surgery.RésuméLes complications aériennes après chirurgie cervicale antérieure sont rares mais potentiellement léthales. Le sujet de ce travail est d’étudier l’évolution de l’œdème prévertébral après discectomie antérieure et fusion à un ou deux niveaux ( ACDF) pour prévenir une obstruction aérienne. 87 patients devant avoir un ACDF a un ou deux niveaux étaient étudiés prospectivement. Des radiographies de profil de la colonne cervicale ont été faites avant l’opération, après l’opération le jour de la chirurgie, puis les premier, deuxième, troisième, quatrième et cinquième jours après. Les parties molles prévertébrales étaient mesurées de C2 à C6 sur ces radiographies. L’œdème prévertébral apparaissait en postopératoire et avait une augmentation marqué le deuxième jour après la chirurgie. Dans les fusions au-dessus de C5 l’œdème prédominait en C2, C3. La régression de l’œdème était observée après le quatrième jour post-opératoire. Un œdème prononcé était noté aux deuxième, troisième et quatrième niveau cervical. Il n’y avait pas de différence significative dans l’oedème en comparant un et deux niveaux de discectomie-fusion. Seulement 1 patient a eu besoin d’une ré-intubation (1,1%). En conclusion , dans cette série, l’acmé de l’œdème prévertébral était observée les deuxième et troisième jours après l’opération.

Arctigenin ameliorates inflammation in vitro and in vivo by inhibiting the PI3K/AKT pathway and polarizing M1 macrophages to M2-like macrophages.

Seeds of Arctium lappa, containing arctigenin and its glycoside arctiin as main constituents, have been used as a diuretic, anti-inflammatory and detoxifying agent in Chinese traditional medicine. In our preliminary study, arctigenin inhibited IKKβ and NF-κB activation in peptidoglycan (PGN)- or lipopolysaccharide (LPS)-induced peritoneal macrophages. To understand the anti-inflammatory effect of arctigenin, we investigated its anti-inflammatory effect in LPS-stimulated peritoneal macrophages and on LPS-induced systemic inflammation as well as 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in mice. Arctigenin inhibited LPS-increased IL-1β, IL-6 and TNF-α expression in LPS-stimulated peritoneal macrophages, but increased LPS-reduced IL-10 and CD204 expression. Arctigenin inhibited LPS-induced PI3K, AKT and IKKβ phosphorylation, but did not suppress LPS-induced IRAK-1 phosphorylation. However, arctigenin did not inhibit NF-κB activation in LPS-stimulated PI3K siRNA-treated peritoneal macrophages. Arctigenin suppressed the binding of p-PI3K antibody and the nucleus translocation of NF-κB p65 in LPS-stimulated peritoneal macrophages. Arctigenin suppressed blood IL-1β and TNF-α level in mice systemically inflamed by intraperitoneal injection of LPS. Arctigenin also inhibited colon shortening, macroscopic scores and myeloperoxidase activity in TNBS-induced colitic mice. Arctigenin inhibited TNBS-induced IL-1β, TNF-α and IL-6 expression, as well as PI3K, AKT and IKKβ phosphorylation and NF-κB activation in mice, but increased IL-10 and CD204 expression. However, it did not affect IRAK-1 phosphorylation. Based on these findings, arctigenin may ameliorate inflammatory diseases, such as colitis, by inhibiting PI3K and polarizing M1 macrophages to M2-like macrophages.

Comparative Analysis of the Gut Microbiota in People with Different Levels of Ginsenoside Rb1 Degradation to Compound K

Panax ginseng (family Araliaceae) which contains ginsenoside Rb1 as a main constituent is traditionally used as a remedy for cancer, inflammation, stress, and ageing. The ginsenoside Rb1 in orally administered ginseng is metabolized to bioactive compounds by gut microbiota before their absorptions to the blood. However, its metabolizing activities in individuals are significantly different as we previously demonstrated. Here, we selected 5 samples with fecal activity potently metabolizing ginsenoside Rb1 to compound K (FPG; metabolic activity, 0.058±0.029 pmol/min/mg) and 5 samples with fecal activity non-metabolizing ginsenoside Rb1 to compound K (FNG) from a pool of 100 subjects investigated in a previous study and analyzed fecal microbiota by 16S rRNA gene pyrosequencing. Taxonomy-based analysis showed that the population levels of Firmicutes and Proteobacteria in FPG were lower than in FNG, but those of Bacteroidetes and Tenericutes in FPG were higher than in FNG. At the genus level, the population levels of Clostridiales_uc_g, Oscillibacter, Ruminococcus, Holdemania, and Sutterella in FPG were significantly higher than in FNG, but that of Leuconostoc in FPG was lower than in FNG. The population levels of Bacteroides and Bifidobacterium, which potently metabolizes ginsenoside Rb1 to compound K were dramatically increased in FPG. The gut microbiota compositions of FPG and FNG were segregated on PCO2 by Principal Coordinate Analysis. Intestinal bacterial metabolism of ginseng, particularly ginsenoside Rb1, may be dependent on the composition of gut microbiota, such as Ruminococcus spp., Bacteroides spp. and Bifidobacterium spp.

Lactobacillus pentosus var. plantarum C29 ameliorates memory impairment and inflammaging in a d-galactose-induced accelerated aging mouse model

Aging is associated with Alzheimers disease (AD), cardiovascular disease and cancer. Oxidative stress is considered as a major factor that accelerates the aging process. To understand the ability of lactic acid bacteria to ameliorate memory impairment caused by aging, we investigated the effect of Lactobacillus pentosus var. plantarum (C29), which is known to protect against scopolamine-induced memory impairment, on oxidative stress (D-galactose)-induced memory impairment in mice. D-Galactose was subcutaneously injected to 20-week old male C57BL/6J mice for 10 weeks, with oral administration of C29 for the final 5 weeks. Excessive intake of D-galactose not only impaired memory, which was indicated by passive avoidance, Y-maze, and Morris water-maze tasks, but also reduced the expression of brain-derived neurotrophic factor (BDNF) and hippocampal doublecortin (DCX) and the activation of cAMP response element-binding protein (CREB). C29 treatment ameliorated D-galactose-induced memory impairment and reversed the suppression of BDNF and DCX expression and CREB activation. Moreover, C29 decreased the expression of a senescence marker p16 and inflammation markers p-p65, p-FOXO3a, cyclooxygenase (COX)-2, and inducible NO synthase (iNOS). C29 treatment inhibited D-galactose-induced expression of M1 polarization markers tumor necrosis factor-α and arginase II, and attenuated the d-galactose-suppressed expression of M2 markers IL-10, arginase I and CD206. Taken together, these findings suggest that C29 may ameliorate memory impairment and M1 macrophage-polarized inflammation caused by aging.

β-Sitosterol attenuates high-fat diet-induced intestinal inflammation in mice by inhibiting the binding of lipopolysaccharide to toll-like receptor 4 in the NF-κB pathway.

SCOPE β-Sitosterol, a common phytosterol, has been shown to exhibit anti-inflammatory effects. Here, we investigated the effect of β-sitosterol on high-fat diet (HFD) induced colitis in mice and on LPS-stimulated mouse intestinal macrophages. METHODS AND RESULTS C57BL/6J mice were maintained on an LFD (10 kcal% fat), an HFD (60 kcal% fat), or an HFD with β-sitosterol (20 mg/kg) administration for 8 weeks. The increased levels of body weight and epididymal fat pad weight as well as the concentrations of circulating proinflammatory cytokines and LPS in HFD mice compared with LFD mice were decreased by oral administration of β-sitosterol. The HFD-induced colonic inflammation evidenced by the increased expression of proinflammatory cytokines and the activation of nuclear factor kappa B (NF-κB) in the colon was also inhibited by β-sitosterol. In LPS-stimulated intestinal macrophages, β-sitosterol inhibited the production of proinflammatory cytokines and inflammatory enzymes as well as NF-κB activation. In addition, β-sitosterol significantly prevented the binding of LPS to intestinal as well as peritoneal macrophages. Furthermore, β-sitosterol potently inhibited the interaction between LPS and toll-like receptor 4 in intestinal macrophages transfected with control siRNA or MyD88 siRNA. CONCLUSION These findings indicate that β-sitosterol ameliorates HFD-induced colitis by inhibiting the binding of LPS to toll-like receptor 4 in the NF-κB pathway.

Timosaponin AIII and its metabolite sarsasapogenin ameliorate colitis in mice by inhibiting NF-κB and MAPK activation and restoring Th17/Treg cell balance.

The rhizome of Anemarrhena asphodeloides (AA, family Liliaceae), which contains furostanol and spirostanol saponins, is a typical herbal medicine that improves learning and memory in rats and inhibits inflammation. In a preliminary study, timosaponin AIII, one of AA main constituents, was metabolized to sarsasapogenin by gut microbiota and inhibited NF-κB activation in lipopolysaccharide (LPS)-stimulated macrophages. Here we have investigated the anti-inflammatory effects of AIII and sarsasapogenin in vitro and in vivo. Both AIII and sarsasapogenin potently inhibited NF-κB and MAPK activation, as well as IRAK1, TAK1, and IκBα phosphorylation in LPS-stimulated macrophages. Further, AIII and sarsasapogenin inhibited the binding of LPS to macrophage Toll-like receptor 4, as well as polarization of M2 to M1 macrophages. Oral administration of AIII and sarsasapogenin inhibited 2,3,4-trinitrobenzene sulfonic acid (TNBS)-induced colon shortening and myeloperoxidase activity in mice, along with reducing NF-κB activation and interleukin (IL)-1β, tumor necrosis factor (TNF)-α, and IL-6 levels, while simultaneously increasing IL-10. Both compounds inhibited Th17 cell differentiation in colonic lamina propria, but induced Treg cell differentiation. Further, AIII and sarsasapogenin inhibited the differentiation of splenic CD4(+) T cells into Th17 cells in vitro. The vitro and in vivo anti-inflammatory effects of sarsasapogenin were more potent than AIII. These results suggest that orally administered AIII may be metabolized to sarsasapogenin by gut microbiota, which may ameliorate inflammatory diseases such as colitis by inhibiting TLR4-NF-κB/MAPK signaling pathway and restoring Th17/Treg cell balance.

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.

A prebiotic fiber increases the formation and subsequent absorption of compound K following oral administration of ginseng in rats

Background Gut microflora play a crucial role in the biotransformation of ginsenosides to compound K (CK), which may affect the pharmacological effects of ginseng. Prebiotics, such as NUTRIOSE, could enhance the formation and consequent absorption of CK through the modulation of gut microbial metabolic activities. In this study, the effect of a prebiotic fiber (NUTRIOSE) on the pharmacokinetics of ginsenoside CK, a bioactive metabolite of ginsenosides, and its mechanism of action were investigated. Methods Male Sprague–Dawley rats were given control or NUTRIOSE-containing diets (control diet + NUTRIOSE) for 2 wk, and ginseng extract or vehicle was then orally administered. Blood samples were collected to investigate the pharmacokinetics of CK using liquid chromatography–tandem mass spectrometry. Fecal activities that metabolize ginsenoside Rb1 to CK were assayed with fecal specimens or bacteria cultures. Results When ginseng extract was orally administered to rats fed with 2.5%, 5%, or 10% NUTRIOSE containing diets, the maximum plasma concentration (Cmax) and area under the plasma concentration–time curve values of CK significantly increased in a NUTRIOSE content-dependent manner. NUTRIOSE intake increased glycosidase activity and CK formation in rat intestinal contents. The CK-forming activities of intestinal microbiota cultured in vitro were significantly induced by NUTRIOSE. Conclusion These results show that prebiotic diets, such as NUTRIOSE, may promote the metabolic conversion of ginsenosides to CK and the subsequent absorption of CK in the gastrointestinal tract and may potentiate the pharmacological effects of ginseng.

Hepatoprotective effects of Rubus coreanus miquel concentrates on liver injuries induced by carbon tetrachloride in rats

As well-being foods pursuing healthy life are becoming popular, interest in Rubus coreanus Miquel (RCM) fruit, a type of Korean blackberry, is increasing due to its medicinal actions including protecting the liver, brightening the eyes, and alleviating diabetes. This study was carried out to evaluate the hepatoprotective effects of RCM concentrates on liver injuries induced by carbon tetrachloride (CCl4) in rats. RCM, produced in June ~ July 2008 at Chunbook, Gochang (South Korea), was finely mashed. The seeds were removed and the juices were condensed. Thirty-two Sprague-Dawley rats were divided into four groups according to treatment: normal (eight rats), CCl4, 1% RCM, and 2% RCM. Experimental diets were provided to the experimental animals for 4 weeks. We measure total cholesterol, high density lipoprotein-cholesterol (HDL-C), aspartate amino transferase (AST), alanine amino transferase (ALT), and alkaline phosphatase (ALP) levels. Part of the livers was isolated for histopathological evaluation, and analyzed for lipid peroxide (TBARS), superoxide dismutase (SOD) and liver proteins. The activities of serum AST, ALT, and ALP were elevated following CCl4 administration. Levels of hepatic TBARS were also significantly increased in the CCl4 groups. However, hepatic TBARS levels and the activities of serum enzymes were markedly reduced by supplementation with the RCM concentrates (P < 0.05). Hepatic SOD activity increased in the RCM concentrates group versus CCl4 groups. Histopathological examination revealed massive necrosis in the centrilobular area and degenerative changes caused by CCl4 were ameliorated by dietary supplementation with RCM concentrates. These results suggest that RCM concentrates have hepatoprotective effects and may improve the symptoms of liver injuries.