Jin-Ju Jeong

Ginsenosides Rg5 and Rh3 protect scopolamine-induced memory deficits in mice

ETHNOPHARMACOLOGICAL RELEVANCE Panax ginseng (family Araliaceae) is traditionally used as a remedy for cancer, inflammation, stress and aging. AIM OF STUDY To explore whether ginsenosides Rg5 and Rh3, the main constituents of heat-processed ginseng (the root of Panax ginseng), could protect memory deficit. MATERIALS AND METHODS We isolated ginsenosides Rh3 and Rg5 from heated-processed ginseng treated with and without human feces, respectively. Then we investigated their protective effects on memory impairment using the passive avoidance, Y-maze and Morris water maze tasks in mice. Memory deficit was induced in mice by the intraperitoneal injection of scopolamine. RESULTS Ginsenosides Rg5 or Rh3 increased the latency time reduced by scopolamine in passive avoidance test. Treatment with ginsenoside Rg5 or Rh3 significantly reversed the lowered spontaneous alteration induced by scopolamine in Y-maze task. Ginsenoisde Rg5 or Rh3 (10 mg/kg) significantly shortened the escape latencies prolonged by treatment with scopolamine on the last day of training trial sessions in Morris water maze task. Furthermore, ginsenosides Rg5 and Rh3 inhibited acetylcholinesterase activity in a dose-dependent manner, with IC50 values of 18.4 and 10.2 μM, respectively. The inhibitory potency of ginsenoside Rh3 is comparable with that of donepezil (IC50=9.9 μM). These ginsenosides also reversed hippocampal brain-derived neurotrophic factor (BDNF) expression and cAMP response element-binding protein (CREB) phosphorylation reduced by scopolamine. Of them, ginsenoside Rh3 more potently protected memory deficit. CONCLUSIONS Ginsenoside Rg5 and its metabolite ginsenoside Rh3 may protect memory deficit by inhibiting AChE activity and increasing BDNF expression and CREB activation.

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.

Anti-inflammatory effects of ginsenoside Rg1 and its metabolites ginsenoside Rh1 and 20(S)-protopanaxatriol in mice with TNBS-induced colitis

Ginsenoside Rg1, one of the main constituents of Panax ginseng, exhibits anti-inflammatory effect. In a preliminary study, it was observed that ginsenoside Rg1 was metabolized to 20(S)-protopanaxtriol via ginsenosides Rh1 and F1 by gut microbiota. We further investigated the anti-inflammatory effects of ginsenoside Rg1 and its metabolites in vitro and in vivo. Ginsenosides Rg1, Rh1, and 20(S)-protopanaxtriol inhibited the activation of NF-κB activation, phosphorylation of transforming growth factor beta-activated kinase 1 and interleukin (IL)-1 receptor-associated kinase, and expression of tumor necrosis factor-α and IL-1β in lipopolysaccharide (LPS)-stimulated macrophages. They also inhibited the binding of LPS to toll-like receptor 4 on the macrophages. Orally administered ginsenoside Rg1, Rh1, or 20(S)-protopanaxtriol inhibited 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colon shortening, myeloperoxidase activity, and expression of IL-1β, IL-17, and tumor necrosis factor-α in mice with TNBS-induced colitis. They did not only inhibit TNBS-induced NF-κB activation, but also restored TNBS-induced Th17/Treg imbalance. They restored IL-10 and Foxp3 expression. Moreover, they inhibited Th17 cell differentiation in vitro. Of these metabolites, in vitro and in vivo anti-inflammatory effect of 20(S)-protopanaxtriol was the most potent, followed by Rh1. These findings suggest that ginsenoside Rg1 is metabolized to 20(S)-protopanaxtriol via ginsenosides Rh1 and F1 and these metabolites particularly 20(S)-protopanaxtriol, may ameliorate inflammatory disease such as colitis by inhibiting the binding of LPS to TLR4 on macrophages and restoring the Th17/Treg imbalance.

Ursolic Acid Isolated from the Seed of Cornus officinalis Ameliorates Colitis in Mice by Inhibiting the Binding of Lipopolysaccharide to Toll-like Receptor 4 on Macrophages

Ursolic acid, which was isolated from an ethanol extract of Cornus officinalis seed, potently inhibited nuclear factor κ light-chain enhancer of activated B cells (NF-κB) activation in lipopolysaccharide (LPS)-stimulated peritoneal macrophages. Therefore, we investigated the anti-inflammatory mechanism of ursolic acid in LPS-stimulated macrophages and colitic mice. Ursolic acid inhibited phosphorylation of interleukin 1 receptor-associated kinase (IRAK)1, TAK1, inhibitor of nuclear factor κB kinase subunit β (IKKβ), and IκBα as well as activation of NF-κB and MAPKs in LPS-stimulated macrophages. Ursolic acid suppressed LPS-stimulated interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, cyclooxygenase (COX)-2, and inducible NO synthetase (iNOS) expression as well as PGE2 and NO levels. Ursolic acid not only inhibited the Alexa Fluor 488-conjugated LPS-mediated shift of macrophages but also reduced the intensity of fluorescent LPS bound to the macrophages transiently transfected with or without MyD88 siRNA. However, ursolic acid did not suppress NF-κB activation in peptidoglycan-stimulated macrophages. Oral administration of ursolic acid significantly inhibited 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colon shortening and myeloperoxidase (MPO) activity in mice. Ursolic acid also suppressed TNBS-induced COX-2 and iNOS expression as well as NF-κB activation in colon tissues. Ursolic acid (20 mg/kg) also inhibited TNBS-induced IL-1β, IL-6, TNF-α by 93, 86, and 85%, respectively (p < 0.05). However, ursolic acid reversed TNBS-mediated downregulation of IL-10 expression to 79% of the normal control group (p < 0.05). On the basis of these findings, ursolic acid may ameliorate colitis by regulating NF-κB and MAPK signaling pathways via the inhibition of LPS binding to TLR4 on immune cells.

Mangiferin ameliorates colitis by inhibiting IRAK1 phosphorylation in NF-κB and MAPK pathways.

Mangiferin, a main constituent of the root of Anemarrhena asphodeloides and the leaves of Mangifera indica, inhibits NF-κB activation in macrophages. Therefore, we investigated effect of mangiferin on 2,3,4-trinitrobenzene sulfonic acid (TNBS)-induced colitis in mice and its anti-inflammatory mechanism in lipolysaccharide (LPS)- or peptidoglycan-stimulated mouse peritoneal macrophages. Mangiferin inhibited phosphorylation of nuclear factor-kappaB (NF-κB), interleukin-1 receptor-associated kinase 1 (IRAK1), and mitogen-activated protein kinases (MAPK) in peptidoglycan- or LPS-stimulated peritoneal macrophages. Mangiferin in the presence of SN50 inhibited LPS-stimulated NF-κB activation more potently than mangiferin alone. Mangiferin inhibited interaction of fluorescent p-IRAK1 antibody to LPS-stimulated peritoneal macrophages, but increased binding of fluorescent IRAK1 antibody. Mangiferin did not influence interaction of fluorescent LPS to toll-like receptor-4 on the macrophages. Molecular peak of mangiferin bound to IRAK1 was detected in the macrophages by mass analysis. Mangiferin (10 μM) inhibited LPS-stimulated expression of TNF-α, IL-1β and IL-6 by 81.0%, 89.5% and 88.3%, respectively, whereas it increased IL-10 expression by 131.8% compared to LPS-nontreated group. Mangiferin furthermore inhibited colon shortening, macroscopic score, and colonic myeloperoxidase activity in TNBS-induced colitic mice. Mangiferin inhibited TNBS-induced IRAK1 phosphorylation and NF-κB activation. Mangiferin suppressed TNBS-induced up-regulation of cyclooxygenase-2 and inducible NO synthase. Furthermore, mangiferin (20mg/kg) significantly inhibited TNF-α by 78%, IL-1β by 82%, and IL-6 expressions by 88% (P<0.05), but induced IL-10 expression to 79% of the normal control group (P<0.05). Based on these findings, mangiferin may ameliorate inflammatory diseases such as colitis by regulating NF-κB and MAPK signaling pathways through the inhibition of IRAK1 phosphorylation.

Anti-inflammatory mechanism of exogenous C2 ceramide in lipopolysaccharide-stimulated microglia.

Ceramide is a major molecule among the sphingolipid metabolites which are produced in the brain and other organs and act as intracellular second messengers. Although a variety of physiological roles of ceramide have been reported in the periphery and central nervous systems, the role of ceramide in microglial activation has not been clearly demonstrated. In the present study, we examined the effects of exogenous cell permeable short chain ceramides on microglial activation in vitro and in vivo. We found that C2, C6, and C8 ceramide and C8 ceramide-1-phosphate inhibited iNOS and proinflammatory cytokines in lipopolysaccharide (LPS)-stimulated BV2 microglial cells and rat primary microglia. In addition, the administration of C2 ceramide suppressed microglial activation in the brains of LPS-exposed mice. By HPLC and LC/MS/MS analyses, we found that C2 ceramide on its own, rather than its modified form (i.e. ceramide-1-phosphate or long chain ceramides), mainly work by penetrating into microglial cells. Further mechanistic studies by using the most effective C2 ceramide among the short chain ceramides tested, revealed that C2 ceramide exerts anti-inflammatory effects via inhibition of the ROS, MAPKs, PI3K/Akt, and Jak/STAT pathways with upregulation of PKA and hemeoxygenase-1 expressions. Interestingly, we found that C2 ceramide inhibits TLR4 signaling by interfering with LPS and TLR4 interactions. Therefore, our data collectively suggests the therapeutic potential of short chain ceramides such as C2 for neuroinflammatory disorders such as Alzheimers disease and Parkinsons disease.

Lactobacillus sakei OK67 ameliorates high-fat diet- induced blood glucose intolerance and obesity in mice by inhibiting gut microbiota lipopolysaccharide production and inducing colon tight junction protein expression

A high-fat diet (HFD) induces obesity and the associated increases in blood glucose and inflammation through changes in gut microbiota, endotoxemia, and increased gut permeability. To counteract this, researchers have suggested that the use of probiotics that suppress production of proinflammatory lipopolysaccharide (LPS). Here, we tested whether Lactobacillus sakei OK67, which inhibits gut microbiota LPS production selected from among the lactic acid bacteria isolated from kimchi, exerted antihypoglycemic or anti-inflammatory effects in HFD-fed mice. Mice were randomly divided into 2 groups and fed an HFD or a low-fat diet for 4 weeks. These groups were further subdivided; 1 subgroup was treated with L sakei OK67 and fed the experimental diet for 4.5 weeks, whereas the other subgroup was fed the experimental diet alone. L sakei OK67 treatment lowered HFD-elevated LPS levels in blood and colonic fluid and significantly decreased HFD-elevated fasting blood glucose levels and the area under the curve in an oral glucose tolerance test. L sakei OK67 treatment inhibited HFD-induced body and epididymal fat weight gains, suppressed HFD-induced tumor necrosis factor-α and interleukin-1β expression and nuclear factor-κB activation in the colon, and significantly increased HFD-suppressed interleukin-10 and tight junction protein expression in the colon. Oral administration of L sakei OK67 significantly downregulated HFD-induced expression of peroxisome proliferator-activated receptor γ, fatty acid synthase, and tumor necrosis factor-α in adipose tissue. In addition, L sakei OK67 treatment strongly inhibited nuclear factor-κB activation in LPS-stimulated peritoneal macrophages. We report that L sakei OK67 ameliorates HFD-induced hyperglycemia and obesity by reducing inflammation and increasing the expression of colon tight junction proteins in mice.

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.

Penta‐O‐galloyl‐β‐D‐glucose ameliorates inflammation by inhibiting MyD88/NF‐κB and MyD88/MAPK signalling pathways

The gallnut of Rhus chinensis MILL and its main constituent penta‐O‐galloyl‐β‐D‐glucose (PGG) inhibited NF‐κB activation in LPS‐stimulated peritoneal and colonic macrophages. Here we have investigated PGG mechanisms underlying anti‐inflammatory effects of PGG in vitro and in vivo.

Neomangiferin modulates the Th17/Treg balance and ameliorates colitis in mice.

BACKGROUND Anemarrhena asphodeloides (Liliaceae family) and Mangifera indica L. (Anacardiaceae family) contain neomangiferin as the main active constituent and have been used to treat inflammation, asthma, and pain. PURPOSE A preliminary study found that neomangiferin inhibited splenic T cell differentiation into Th17 cells and promoted Treg cell production in vitro. Therefore, we examined its anti-colitic effects in vitro and in vivo. METHODS Splenocytes isolated from C57BL/6J mice were treated with neomangiferin. Colitis was either induced in vivo by intrarectal administration of 2,4,6-trinitrobenzene sulfonic acid (TNBS) to C57BL/6J mice or occurred spontaneously in colitis caused by interleukin (IL)-10 knockout at age of 13 weeks. Mice were treated daily with neomangiferin or sulfasalazine. Inflammatory markers, cytokines, enzymes and transcription factors were measured by enzyme-linked immunosorbent assay, immunoblot, and flow cytometry. RESULTS Neomangiferin suppressed retinoic acid receptor-related orphan receptor gamma t (RORγt) and IL-17 expression in IL-6/transforming growth factor β-stimulated Th17 splenocytes and increased IL-10 expression in vitro. Mouse TNBS-induced colon shortening, macroscopic score, and myeloperoxidase activity were inhibited by neomangiferin, which also reduced TNBS-induced activation of nuclear factor-κB and extracellular signal-regulated kinases, as well as expression of inducible nitric oxide synthase and cyclooxygenase-2. In addition, neomangiferin inhibited TNBS-induced expression of tumor necrosis factor-α, IL-17, IL-6, and IL-1β, and increased IL-10 expression. Neomangiferin inhibited TNBS-induced differentiation to Th17 cells and promoted the development of Treg cells. Moreover, in IL-10(-/-) mice, neomangiferin inhibited colonic myeloperoxidase activity, suppressed Th17 cell differentiation, and reduced levels of TNF-α and IL-17. CONCLUSION Neomangiferin may restore the balance between Th17/Treg cells by suppressing IL-17 and RORγt expression and inducing IL-10 and forkhead box P3 expression, thus ameliorating colitis.