Yun Qi

Rhein exerts pro- and anti-inflammatory actions by targeting IKKβ inhibition in LPS-activated macrophages.

Because steroids and cyclooxygenase inhibitors may cause serious side effects, the IκB kinase (IKK) β/nuclear factor-κB (NF-κB) system has become an intriguing candidate anti-inflammatory target. Rhein, the active metabolite of diacerein, possesses anti-inflammatory ability with a gastrointestinal protective effect. However, in a preliminary study, we accidentally found that rhein showed both anti- and proinflammatory activities in lipopolysaccharide (LPS)-activated macrophages. Thus, in this study, we explored the underlying molecular mechanisms of the dual effects of rhein. In LPS-activated macrophages, rhein inhibits NF-κB activation and sequentially suppresses its downstream inducible nitric oxide synthase, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) transcription and supernatant nitric oxide and IL-6 levels by inhibiting IKKβ (IC50 ≈ 11.79μM). But in the meantime, rhein enhances the activity of caspase-1 by inhibiting intracellular (in situ) IKKβ, in turn increasing the IL-1β and high-mobility-group box 1 release, which can be amplified by rhein׳s reductive effect on intracellular superoxide anion. Unexpectedly, it is because of IKKβ inhibition that rhein significantly enhances TNF-α secretion and phagocytosis in macrophages with or without LPS. These results indicate that rhein exerts anti- and proinflammatory activities by targeting IKKβ inhibition, providing a molecular mechanism for the unanticipated role of rhein in macrophages. Furthermore, our study also highlights the potential complications of IKKβ inhibitor (e.g., rhein, diacerein, etc.) application in inflammation disorders, for the overall effects of IKKβ inhibition in various organ systems and disease processes are not easily predictable under all circumstances.

Antifatigue activity of phenylethanoid‐rich extract from Cistanche deserticola

A phenylethanoid‐rich extract (ECD) of Cistanche deserticola Y.C. Ma, a holoparasitic plant and a valuable traditional Chinese medicine, was evaluated for antifatigue activity in ICR mice. ECD (0.25, 0.50, 1.00 g/kg) was administered orally to mice for 3 weeks. The swimming time to exhaustion was longer in the treatment groups (0.50, 1.00 g/kg) than in the control group (p < 0.01). The serum creatine kinase, lactate dehydrogenase and lactic acid levels were decreased significantly in the treatment groups compared with the control group, while the contents of hemoglobin and glucose were increased significantly. In conclusion, ECD appeared to enhance the swimming capacity of mice by decreasing muscle damage, delaying the accumulation of lactic acid and by improving the energy storage. These results provide scientific evidence for the traditional Chinese medical practice of C. deserticola. Copyright

Lipid-soluble extracts from Salvia miltiorrhiza inhibit production of LPS-induced inflammatory mediators via NF-κB modulation in RAW 264.7 cells and perform antiinflammatory effects in vivo.

Salvia miltiorrhiza, a traditional Chinese herbal medicine, is used to treat various inflammatory diseases. In the present study, the antiinflammatory effects of S. miltiorrhiza lipid‐soluble extracts (SMLE) were demonstrated in vitro and in vivo, along with its underlying mechanism of action. SMLE significantly inhibited the production of NO, TNF‐α, IL‐1β and IL‐6 in lipopolysaccharides (LPS)‐stimulated RAW 264.7 cells. SMLE also inhibited the LPS‐induced degradation of IκB‐α in the cytoplasm and the translocation of p65 to the nucleus in RAW 264.7 cells. In addition, SMLE inhibited the production of intracellular reactive oxygen species (ROS) and the surface expression of CD14 induced by LPS. In animal models, intraperitoneal administration of SMLE increased the survival rate of endotoxemia and sepsis in mice. The topical administration of SMLE significantly inhibited ear edema induced by PMA. It was found that SMLE inhibits the LPS‐induced gene and protein expression of iNOS, TNF‐α, IL‐1β and IL‐6 in macrophages by blocking NF‐κB activation, and these effects are mediated, at least in part, through the inhibition of intracellular ROS generation and the surface expression of CD14. The results suggest a possible therapeutic application of SMLE in inflammatory diseases and provide scientific evidence in support of the traditional Chinese medical practice of treatment with S. miltiorrhiza. Copyright

Curcumol exhibits anti-inflammatory properties by interfering with the JNK-mediated AP-1 pathway in lipopolysaccharide-activated RAW264.7 cells.

Curcumol is one of the major components of the essential oil of Rhizoma Curcumae, a common traditional Chinese medicine with anti-inflammatory properties. However, the anti-inflammatory activity and the underlying molecular mechanisms of this compound remain unclear. In the present study, the anti-inflammation effect of curcumol on lipopolysaccharide (LPS)-induced RAW264.7 cells is demonstrated along with its underlying mechanisms. We show that curcumol inhibits LPS-induced NO production by suppressing iNOS mRNA expression and protein level but not iNOS activity. Moreover, curcumol inhibits LPS-induced production of TNF-α, IL-1β and IL-6 at both the transcriptional and translational levels. Further investigations reveal that these effects mainly act via suppressing JNK-mediated AP-1 rather than the NF-κB pathway; these effects include a decrease in the phosphorylation level of JNK and a direct inhibition of the activity of p-JNK. These data provide scientific molecular evidence that curcumol may be a potential lead compound for a novel anti-inflammatory drug because of its inhibitory activity on the production of various inflammatory mediators.

Shuang-Huang-Lian exerts anti-inflammatory and anti-oxidative activities in lipopolysaccharide-stimulated murine alveolar macrophages

Shuang-Huang-Lian (SHL) is a traditional Chinese compound formula prepared from Lonicerae Japonicae Flos, Scutellariae Radix and Fructus Forsythiae. In this study, we demonstrate the anti-inflammatory and anti-oxidative activities of SHL in lipopolysaccharide (LPS)-stimulated murine alveolar macrophages (MH-S). SHL significantly reduces the transcriptional and translational levels of iNOS and COX-2 as well as the production of NO and prostaglandin E2 (PGE2). It also suppresses the transcription and translation of inflammatory cytokines production, such as TNF-α, IL-1β and IL-6. These inhibitory effects mainly act via ERK1/2- and p38-mediated AP-1 rather than the NF-κB pathway. In parallel with the anti-inflammatory activity, SHL suppresses LPS-induced intracellular total ROS levels by weakening NADPH oxidase activity, enhancing SOD activity and increasing GSH content. In addition, SHL directly scavenges OH and O2(-). Thus, our study elucidates the anti-inflammatory and anti-oxidative mechanisms of SHL in LPS-stimulated MH-S.

Evaluation of the intestinal transport of a phenylethanoid glycoside-rich extract from Cistanche deserticola across the Caco-2 cell monolayer model.

Phenylethanoid glycosides (PhGs), a class of polyphenolic compounds, are considered one of major bioactive constituents of Cistanche deserticola Y.C. Ma (CD), whose extract is orally used in traditional Chinese medicine. Although previous pharmacological studies have reported that PhGs exert many activities, their intestinal transport profiles have not been clarified. In this study, we investigated the intestinal permeability of a PhG-rich extract (PRE) from CD as an integrated system in the Caco-2 cell monolayer model using a bioassay system. The results showed that PRE is primarily transported via poorly absorbed passive diffusion down a concentration gradient without efflux, which provides the pharmacokinetic basis for the clinical application of PhGs in CD. We also determined the intestinal permeability of three major PhGs [acteoside (AC), isoacteoside (IS) and echinacoside (EC)] by HLPC. Furthermore, we developed a novel HPLC-fluorescence detection method to accurately determine the flux amount of AC and IS. As expected, the transport characteristics of the three PhGs are consistent with those of PRE, indicating that the present bioassay system is appropriate and reliable for the evaluation of the transport characteristics of active ingredient groups (AIG) in PRE. Moreover, this system may also be suitable for other plant extracts given appropriate bioactivity.

Shuang-Huang-Lian Attenuates Lipopolysaccharide-Induced Acute Lung Injury in Mice Involving Anti-Inflammatory and Antioxidative Activities

Shuang-Huang-Lian (SHL) is a common traditional Chinese preparation extracted from Lonicerae Japonicae Flos, Scutellariae Radix, and Fructus Forsythiae. In this study, we demonstrate the anti-inflammatory and antioxidative effects of SHL on lipopolysaccharide- (LPS-) induced acute lung injury (ALI) in mice. SHL reduced the lung wet/dry weight ratio, lowered the number of total cells in the bronchoalveolar lavage fluid, and decreased the myeloperoxidase activity in lung tissues 6 h after LPS treatment. It also inhibited the overproduction of proinflammatory cytokines (TNF-α, IL-1β, and IL-6) in the bronchoalveolar lavage fluid. Histological studies demonstrated that SHL attenuated LPS-induced interstitial edema, hemorrhage, and the infiltration of neutrophils into the lung tissue. Moreover, SHL could also enhance the superoxide dismutase and catalase activities, increase the reduced glutathione content, and decrease the malondialdehyde content. The present results suggest that SHL possesses anti-inflammatory and antioxidative properties that may protect mice against LPS-induced ALI.

The Three-Herb Formula Shuang-Huang-Lian stabilizes mast cells through activation of mitochondrial calcium uniporter

Mast cells (MCs) are key effector cells of IgE-FcεRI- or MrgprX2-mediated signaling event. Shuang-Huang-Lian (SHL), a herbal formula from Chinese Pharmacopoeia, has been clinically used in type I hypersensitivity. Our previous study demonstrated that SHL exerted a non-negligible effect on MC stabilization. Herein, we sought to elucidate the molecular mechanisms of the prominent anti-allergic ability of SHL. MrgprX2- and IgE-FcεRI-mediated MC activation in vitro and in vivo models were developed by using compound 48/80 (C48/80) and shrimp tropomyosin (ST), respectively. Our data showed that SHL markedly dampened C48/80- or ST-induced MC degranulation in vitro and in vivo. Mechanistic study indicated that cytosolic Ca2+ (Ca2+[c]) level decreased rapidly and sustainably after SHL treatment, and then returned to homeostasis when SHL was withdrawn. Moreover, SHL decreases Ca2+[c] levels mainly through enhancing the mitochondrial Ca2+ (Ca2+[m]) uptake. After genetically silencing or pharmacologic inhibiting mitochondrial calcium uniporter (MCU), the effect of SHL on the Ca2+[c] level and MC degranulation was significantly weakened. Simultaneously, the activation of SHL on Ca2+[m] uptake was completely lost. Collectively, by activating MCU, SHL decreases Ca2+[c] level to stabilize MCs, thus exerting a remarkable anti-allergic activity, which could have considerable influences on clinical practice and research.

Suppressive effects of irisflorentin on LPS-induced inflammatory responses in RAW 264.7 macrophages

Irisflorentin, a naturally occurring isoflavone, is an abundant active constituent in Rhizoma Belamcandae. Although some chemical studies have been reported, pharmacological actions of irisflorentin are not well studied. In this study, we demonstrate the anti-inflammatory activity of irisflorentin in lipopolysaccharides (LPS)-stimulated RAW 264.7 macrophages. Irisflorentin markedly reduces the transcriptional and translational levels of inducible nitric oxide synthase (iNOS) as well as the production of NO. Furthermore, it also significantly inhibits TNF-α, IL-1β and IL-6 at both the transcriptional and translational levels. These effects mainly act via ERK1/2 - and p38-mediated the activator protein-1 (AP-1) rather than the nuclear factor-κB (NF-κB) pathway. Thus, our study elucidates the anti-inflammatory mechanism of irisflorentin in LPS-activated RAW 264.7 macrophages.

Dietary Flavone Tectochrysin Exerts Anti‐Inflammatory Action by Directly Inhibiting MEK1/2 in LPS‐Primed Macrophages

SCOPE In this study, we investigate the underlying molecular mechanism of the effect of tectochrysin on LPS-primed macrophages. METHODS AND RESULTS As measured by western blot, RT-PCR, and ELISA, tectochrysin inhibits extracellular signal-related kinase 1/2 (ERK1/2) phosphorylation and sequentially suppressed downstream inducible nitric oxide synthase (iNOS), tumor necrosis factor-α (TNF-α), and IL-6 transcription as well as the NO, TNF-α, and IL-6 in supernatant, but it does not affect extracellular signal-regulated kinase (MEK) phosphorylation levels. An enzyme reaction study shows that tectochrysin exerted an inhibitory effect on ERK1/2 phosphorylation by inactivating phosphorylated MEK1/2. Moreover, tectochrysin decreases arginase II expression in LPS-primed RAW264.7 macrophages via reduction of NO production. Tectochrysin also suppresses inflammatory mediator release in peritoneal lavage fluid and in the serum of LPS-induced endotoxemia mice. CONCLUSION Our data indicate that by directly inactivating p-MEK1/2, tectochrysin decreases the phosphorylation level of ERK and subsequently suppresses activator protein-1 (AP-1) activation to reduce pro-inflammatory mediator production, suggesting that tectochrysin has great potential for use in a nutritional preventive strategy against inflammation-related diseases.