The Extract of Ramalina litoralis Inhibits Osteoclast Differentiation

Effects and Mechanisms of Rhus chinensis Mill. Fruits on Suppressing RANKL-Induced Osteoclastogenesis by Network Pharmacology and Validation in RAW264.7 Cells

Rhus chinensis Mill. fruits are a kind of widely distributed edible seasoning, which have been documented to possess a variety of biological activities. However, its inhibitory effect on osteoclast formation has not been determined. The objective of this study was to evaluate the effect of the fruits on osteoclast differentiation of RAW264.7 cells, induced by receptor activator of nuclear factor-κB ligand (RANKL) and to illuminate the potential mechanisms using network pharmacology and western blots. Results showed that the extract containing two organic acids and twelve phenolic substances could effectively inhibit osteoclast differentiation in RANKL-induced RAW264.7 cells. Network pharmacology examination and western blot investigation showed that the concentrate essentially decreased the expression levels of osteoclast-specific proteins, chiefly through nuclear factor kappa-B, protein kinase B, and mitogen-activated protein kinase signaling pathways, particularly protein kinase B α and mitogen-activated protein kinase 1 targets. Moreover, the extract likewise directly down regulated the expression of cellular oncogene Fos and nuclear factor of activated T-cells cytoplasmic 1 proteins. Citric acid, quercetin, myricetin-3-O-galactoside, and quercetin-3-O-rhamnoside were considered as the predominant bioactive ingredients. Results of this work may provide a scientific basis for the development and utilization of R. chinensis fruits as a natural edible material to prevent and/or alleviate osteoporosis-related diseases.

Barrier protective functions of hederacolchiside-E against HMGB1-mediated septic responses

The role of high mobility group box 1 (HMGB1) has been recognized as important, and suppression of HMGB1 release and restoration of vascular barrier integrity are regarded as potentially promising therapeutic strategies against sepsis. Hederacolchiside-E (HCE), namely 3-O-{α-L-rhamnopyranosyl (1→2)-[β-D-glucopyranosyl(1→4)]-α-L-arabinopyranosyl}-28-O-[α-L-rhamnopyranosyl (1→4)-β-D-glucopyranosyl(1→6)-β-D-glucopyranosyl ester, is a bidesmosidic oleanane saponin first isolated in 1970 from the leaves of Hedera colchica. We tested our hypothesis that HCE inhibits HMGB1-induced vascular hyperpermeability and thereby increases the survival of septic mouse model from suppression of HMGB1 release upon lipopolysaccharide (LPS)-stimulation. In LPS-activated human endothelial cells and a sepsis mouse model by cecal ligation and puncture (CLP), antiseptic activity of HCE was investigated from suppression of vascular permeability, pro-inflammatory proteins, and tissue injury markers. Post-treatment of HCE significantly suppressed HMGB1 release both in LPS-activated human endothelial cells and the CLP-induced sepsis mouse model. HCE inhibited hyperpermeability and alleviated HMGB1-mediated vascular disruptions, and reduced sepsis-related mortality and tissue injury in mice. Our results suggest that reduction of HMGB1 release and septic mortality by HCE may be useful for the drug candidate of sepsis, indicating a possibility of successful repositioning of HCE.

Fisetin Suppresses Pulmonary Inflammatory Responses Through Heme Oxygenase-1 Mediated Downregulation of Inducible Nitric Oxide Synthase

The effects of a mixture of fisetin on cytokine-mediated pulmonary damages have not been studied, despite its known antiviral, neuroprotective, and anti-inflammatory activities. Using lipopolysaccharide (LPS)-activated human pulmonary artery endothelial cells (HPAECs), we determined the effects of fisetin on the induction of heme oxygenase-1 (HO-1), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2). In the lung tissue of LPS-treated mice, fisetin was also evaluated for its effect on the regulation of iNOS and tumor necrosis factor (TNF)-α. In LPS-activated HPAECs, fisetin increased nuclear factor erythrocyte 2-related factor 2-antioxidant response element (Nrf2-ARE) reporter activity through the nuclear translocation of Nrf2, and the expression of HO-1, and decreased IL-1β and iNOS/NO production. In particular, the suppression of iNOS/NO expression by the administration of fisetin was dependent on HO-1. Current findings indicate that the anti-inflammatory activity of fisetin was due to its HO-1 dependent downregulation of p-STAT-1 and nuclear factor kappa B (NF-κB) and the resultant inhibition of iNOS, and also suggest TNF-α as a potential target for HO-1. We propose that administration of fisetin may be a novel approach, ideal for the treatment of inflammatory pulmonary disease.

Novel factor Xa inhibitor, maslinic acid, with antiplatelet aggregation activity

As antithrombotic effects of maslinic acid (MA) have not yet been studied, MA-mediated downregulation of coagulation factor Xa (FXa) and platelet aggregation was studied. We show that MA inhibited the enzymatic activity of FXa and platelet aggregation, induced by adenosine diphosphate (ADP) and a thromboxane A₂ (TXA₂ ) analog, U46619 with a similar antithrombotic efficacy to rivaroxaban, a direct FXa inhibitor used as a positive control. Mechanistically, MA suppressed U46619- or ADP-induced phosphorylation of myristoylated alanine-rich C kinase substrate, and the expression of P-selectin, and activated PAC-1 in platelets. MA increased generation of nitric oxide, but downregulated excessive secretion of endothelin-1 in ADP- or U46619-treated human umbilical vein endothelial cells. In arterial and pulmonary thrombosis mouse model, MA showed prominent anticoagulant and antithrombotic effects. Our data suggest MA as a candidate molecule for a new class of drugs targeting anti-FXa and antiplatelet.

Inhibitory functions of maslinic acid, a natural triterpene, on HMGB1-mediated septic responses

BACKGROUND

Maslinic acid (MA), a natural triterpenoid from Olea europaea, prevents oxidative stress and pro-inflammatory cytokine generation. High mobility group box 1 (HMGB1) has been recognized as a late mediator of sepsis, and the inhibition of the release of HMGB1 and the recovery of vascular barrier integrity have emerged as attractive therapeutic strategies for the management of sepsis.

METHODS

We tested the hypothesis that MA induces sirtuin 1 and heme oxygenase-1, which inhibit the release of HMGB1 in lipopolysaccharide (LPS)-stimulated cells, thus inhibiting HMGB1-induced hyperpermeability and increasing the survival of septic mice. MA was administered after LPS or HMGB1 challenge, and the antiseptic activity of MA was determined based on permeability, the activation of pro-inflammatory proteins, and the production of markers for tissue injury in HMGB1-activated human umbilical vein endothelial cells (HUVECs) and a cecal ligation and puncture (CLP)-induced sepsis mouse model.

RESULTS

MA significantly reduced the release of HMGB1 in LPS-activated HUVECs and attenuated the CLP-induced release of HMGB1. Additionally, MA alleviated HMGB1-mediated vascular disruption and inhibited hyperpermeability in mice, and in vivo analysis revealed that MA reduced sepsis-related mortality and tissue injury.

CONCLUSION

Taken together, the present results suggest that MA reduced HMGB1 release and septic mortality and thus may be useful in the treatment of sepsis.

Maslinic Acid Ameliorates Inflammation via the Downregulation of NF-κB and STAT-1

Maslinic acid (MA), a natural compound of the triterpenoid group derived from olive, prevents the generation of pro-inflammatory cytokines and oxidative stress. In human umbilical vein endothelial cells (HUVECs) treated with lipopolysaccharide (LPS), we characterized the effects of MA on the regulation of heme oxygenase (HO)-1, cyclooxygenase (COX-)2, and inducible nitric oxide synthase (iNOS). MA was tested in the lung tissues of LPS-treated mice, to determine its effect on levels of iNOS expression and representative inflammatory mediators such as interleukin (IL)-1α and tumor necrosis factor (TNF)-α. We show that MA induced the expression of HO-1, reduced LPS-induced NF-κB-luciferase activity, and inhibited iNOS/NO and COX-2/PGE2, resulting in the downregulation of STAT-1 phosphorylation. Furthermore, our data show that MA induced the nuclear translocation of Nrf2, increased the binding of Nrf2 to ARE, and decreased IL-1α production in LPS-treated HUVECs. The MA-induced reduction in iNOS/NO expression was reversed by RNAi suppression of HO-1. In mice treated with LPS, MA significantly downregulated levels of iNOS in lung tissue and TNF-α in the bronchoalveolar lavage fluid. Taken together, our findings indicate that MA exerts a critical anti-inflammatory effect by modulating iNOS via the downregulation of NF-κB and p-STAT-1. Thus, we propose that MA may be an ideal substance to treat inflammatory diseases.

Rg x 3 6 5 , a Rare Protopanaxatriol-Type Ginsenoside Fraction from Black Ginseng, Suppresses Inflammatory Gene iNOS via the Iinhibition of p-STAT-1 and NF- κ B

Black ginseng (BG), which is ginseng that has been steamed and dried nine times, and its main protopanaxatriol-type ginsenosides Rg4, Rg6, Rh4, and Rg2 have been reported to exhibit various forms of biological activity, including antiseptic, antidiabetic, wound-healing, immune-stimulatory, and anti-oxidant activity. The aim of the this study was to examine the effects ofRgx 3 6 5 (a rare protopanaxatriol-type ginsenoside fraction; Rg2, Rg4, Rg6, Rh1, and Rh4) on heme oxygenase-1 (HO-1) induction and on the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX-)2 in lipopolysaccharide (LPS)-activated human pulmonary artery endothelial cells (HPAECs).Rgx 3 6 5 was tested to determine its effect on iNOS protein expression and inflammatory markers (interleukin [IL]-1β and tumor necrosis factor [TNF]-α ) in the lung tissue of LPS-treated mice. The results showed thatRgx 3 6 5 induced the expression of HO-1, reduced LPS-activated NF-κ B-luciferase activity, and inhibited iNOS/NO and COX-2/PGE2, which contributed to the inhibition of STAT-1 phosphorylation. In particular,Rgx 3 6 5 induced the translocation of Nrf2 from the cytosol to the nucleus by increasing Nrf2-ARE activity and decreased IL-1β production in LPS-activated HPAECs. This reduction in iNOS/NO expression due toRgx 3 6 5 was reversed by siHO-1 RNA transfection. In LPS-treated mice,Rgx 3 6 5 significantly reduced lung tissue iNOS protein levels and TNF-α levels in the bronchoalveolar lavage fluid. In conclusion, these findings indicate thatRgx 3 6 5 has a critical anti-inflammatory effect due to its ability to regulate iNOS via the inhibition of p-STAT-1 and NF-κ B, and thus it may be suitable for the treatment of inflammatory disease.

Suppressive functions of collismycin C in TGFBIp-mediated septic responses

Transforming growth factor β-induced protein (TGFBIp) is an extracellular matrix protein; its expression by several cell types is greatly increased by TGF-β. TGFBIp is released by primary human umbilical vein endothelial cells (HUVECs) and functions as a mediator of experimental sepsis. 2,2'-Bipyridine-containing natural products are generally accepted to have antimicrobial, cytotoxic and anti-inflammatory properties. We hypothesized that a 2,2'-bipyridine containing natural product, collismycin C, could reduce TGFBIp-mediated severe inflammatory responses in human endothelial cells and mice. Here we investigated the effects and underlying mechanisms of collismycin C against TGFBIp-mediated septic responses. Collismycin C effectively inhibited lipopolysaccharide-induced release of TGFBIp and suppressed TGFBIp-mediated septic responses. In addition, collismycin C suppressed TGFBIp-induced sepsis lethality and pulmonary injury. This suppression of TGFBIp-mediated and CLP-induced septic responses indicates that collismycin C is a potential therapeutic agent for various severe vascular inflammatory diseases, with inhibition of the TGFBIp signaling pathway as the mechanism of action.