Small molecule deoxynyboquinone triggers alkylation and ubiquitination of Keap1 at Cys489 on Kelch domain for Nrf2 activation and inflammatory therapy.

Activation of nuclear factor erythroid 2-related factor 2 (Nrf2) by Kelch-like ECH-associated protein 1 (Keap1) alkylation plays a central role in anti-inflammatory therapy. However, activators of Nrf2 through alkylation of Keap1-Kelch domain have not been identified. Deoxynyboquinone (DNQ) is a natural small molecule discovered from marine actinomycetes. The current study was designed to investigate the anti-inflammatory effects and molecular mechanisms of DNQ via alkylation of Keap1. DNQ exhibited significant anti-inflammatory properties both in vitro and in vivo. The pharmacophore responsible for the anti-inflammatory properties of DNQ was determined to be the α, ß-unsaturated amides moieties by a chemical reaction between DNQ and N-acetylcysteine. DNQ exerted anti-inflammatory effects through activation of Nrf2/ARE pathway. Keap1 was demonstrated to be the direct target of DNQ and bound with DNQ through conjugate addition reaction involving alkylation. The specific alkylation site of DNQ on Keap1 for Nrf2 activation was elucidated with a synthesized probe in conjunction with liquid chromatography-tandem mass spectrometry. DNQ triggered the ubiquitination and subsequent degradation of Keap1 by alkylation of the cysteine residue 489 (Cys489) on Keap1-Kelch domain, ultimately enabling the activation of Nrf2. Our findings revealed that DNQ exhibited potent anti-inflammatory capacity through α, ß-unsaturated amides moieties active group which specifically activated Nrf2 signal pathway via alkylation/ubiquitination of Keap1-Kelch domain, suggesting the potential values of targeting Cys489 on Keap1-Kelch domain by DNQ-like small molecules in inflammatory therapies.

Leocarpinolide B Attenuates Collagen Type II-Induced Arthritis by Inhibiting DNA Binding Activity of NF-κB.

Rheumatoid arthritis (RA) is a chronic autoimmune disease triggered by a cascading inflammatory response. Sigesbeckia Herba (SH) has long been utilized as a traditional remedy to alleviate symptoms associated with rheumatism. Our previous study found that leocarpinolide B (LB), a sesquiterpene lactone isolated from the whole plant of SH, possesses potent a anti-inflammatory effect on macrophages. This study was designed to evaluate the therapeutic effects of LB on RA, and further investigate the underlying mechanisms. In collagen type II-induced arthritic mice, LB was demonstrated to decrease the production of autoimmune antibodies in serum and inflammatory cytokines in the joint muscles and recover the decreased regulatory T lymphocytes in spleen. Moreover, LB significantly suppressed the inflammatory infiltration, formation of pannus and bone erosion in the paw joints. In vitro testing showed that LB inhibited the proliferation, migration, invasion, and secretion of inflammatory cytokines in IL-1ß-induced human synovial SW982 cells. Network pharmacology and molecular docking suggested NF-κB p65 could be the potential target of LB on RA treatment, subsequent experimental investigation confirmed that LB directly interacted with NF-κB p65 and reduced the DNA binding activity of NF-κB in synovial cells. In conclusion, LB significantly attenuated the collagen type II-induced arthritis, which was at least involved in the inhibition of DNA binding activity of NF-κB through a direct binding to NF-κB p65. These findings suggest that LB could be a valuable lead compound for developing anti-RA drugs.

Sigesbeckia orientalis L. Derived Active Fraction Ameliorates Perioperative Neurocognitive Disorders Through Alleviating Hippocampal Neuroinflammation.

Neuroinflammation is closely related to the pathogenesis of perioperative neurocognitive disorders (PNDs), which is characterized by the activation of microglia, inflammatory pathways and the release of inflammatory mediators. Sigesbeckia orientalis L. (SO) is a traditional Chinese medicine which demonstrates anti-inflammatory activities in different models. In this study, we aim to isolate the active fraction from the extract of SO with higher anti-inflammatory potential and confirm if the selected fraction exerts neuroprotection against the development of PND in an animal model. Moreover, the components in the selected fraction would be determined by UPLC-PDA analysis. Three fractions were prepared by column chromatography packed with three different macroporous resins. Anti-inflammatory activities of prepared fractions were accessed in microglial BV2 cultures by nitric oxide release, gene expression of inflammatory cytokines and activation of inflammatory JNK and NF-kB pathway molecules. Our results demonstrated that the fraction prepared from D101 macroporous resin (D101 fraction) exhibited a more potent anti-neuroinflammatory effect. The neuroprotective effect of D101 fraction was further examined in postoperative mice. Our results showed that surgery-induced cognitive dysfunction was attenuated by the D101 fraction treatment. This fraction also reduced microglial activation, inflammatory cytokines and inhibiting JNK and NF-kB pathway molecules in the hippocampus. In addition, surgery induced dendritic spine loss while D101 fraction ameliorated the spine loss in the hippocampus. For safety concerns, anti-thrombotic effect was examined by tail bleeding assay and no significant change of the bleeding pattern was found. UPLC-PDA analysis indicated that flavonoids (rutin, isochlorogenic acid A, isochlorogenic acid C) and terpenoid (darutoside) were the most important components in the D101 fraction. Our results support a therapeutic, as well as the translational potential for D101 fraction in ameliorating postoperative neuroinflammation and subsequent PND in the clinical setting without increasing bleeding tendencies.

Brij-functionalized chitosan nanocarrier system enhances the intestinal permeability of P-glycoprotein substrate-like drugs.

The highly expressed P-glycoprotein (Pgp) in the intestine plays a key role in preventing drugs across the intestinal epithelium, which linked by tight junctions (TJs). Thus increasing the oral bioavailability of Pgp substrate-like drugs (PSLDs) remains a great challenge. Herein, we construct a nanocarrier system derived from Brij-grafted-chitosan (BC) to enhance the oral bioavailability and therapeutic effect of berberine (BBR, a typical PLSD) against diabetic kidney disease. The developed BC nanoparticles (BC-NPs) are demonstrated to improve the intestinal permeability of BBR via transiently and reversibly modulating the intercellular TJs (paracellular pathway) and Pgp-mediated drug efflux (transcellular pathway). As compared to free BBR and chitosan nanoparticles, the BC-NPs enhanced the relative oral bioavailability of BBR in rats (4.4- and 2.7-fold, respectively), and the therapeutic potency of BBR in renal function and histopathology. In summary, such strategy may provide an effective nanocarrier system for oral delivery of BBR and PSLDs.

Sigesbeckia orientalis L. Extract Alleviated the Collagen Type II-Induced Arthritis Through Inhibiting Multi-Target-Mediated Synovial Hyperplasia and Inflammation.

Excessive proliferation and inflammation of synovial fibroblasts accelerate and decorate the pathological process of rheumatoid arthritis (RA). Sigesbeckia orientalis L. (SO) is one of the main plant sources for Sigesbeckiae Herba (SH) which has been used traditionally in treating various forms of arthritis and rheumatic pain. However, the anti-arthritic mechanisms of SO are still not clearly understood. In this study, we investigated the therapeutic effects and the underlying mechanisms of SO against collagen type II (C II)-induced RA in rats as well as the interleukin (IL)-1ß-induced human synovial SW982 and MH7A cells. For the in vivo studies, thirty-six Wistar male rats were randomly arranged to six groups based on the body weight, and then C II-induced to RA model for 15 days, followed by treatment with the 50% ethanolic extract of SO (SOE, 0.16, 0.78, and 1.56 g/kg) for 35 days. The results suggested that SOE significantly inhibited the formation of pannus (synovial hyperplasia to the articular cavity) and attenuated the cartilage damaging and bone erosion in the CIA-induced rats' hind paw joints. Moreover, SOE decreased the production of C-reactive protein (CRP) in the serum and the expression of IL-6 and IL-1ß in the joint muscles, as well as recovered the decreased regulatory T lymphocytes. The results obtained from the in vitro studies showed that SOE (50, 100, and 200 µg/ml) not only inhibited the proliferation, migration, and invasion of human synovial SW982 cells but also decreased the IL-1ß-induced expression of IL-6 and IL-8 both in SW982 and MH7A cells. Besides, SOE reduced the expression of COX-2, NLRP3, and MMP9, and increased the expression of MMP2 in the IL-1ß-induced SW982 cells. Furthermore, SOE blocked the activation of NF-κB and reduced the phosphorylation of MAPKs and the expression of AP-1. In conclusion, SOE attenuated the C II-induced RA through inhibiting of MAPKs/NF-κB/AP-1-mediated synovial hyperplasia and inflammation.

Sigesbeckia glabrescens Makino extract attenuated the collagen-induced arthritis through inhibiting the synovial hyperplasia and inflammation.

BACKGROUND: Sigesbeckia glabrescens Makino (SG) has been traditionally used for rheumatism and joint protection. However, the anti-arthritic effects and underling mechanisms of SG have not been demonstrated. In this study, we investigated the anti-arthritic effects and mechanisms of SG extract (SGE) on collagen-induced arthritic rats and interleukin (IL)-1ß-stimulated human synovial SW982 cells. METHODS: Rats were induced to arthritis by collagen for 15 days and then received SGE treatment for 35 days. The body weight and arthritis severity score of the rats were monitored weekly. At the end of the experiment, the radiographic and histological changes of rats' hind paw were obtained; the serum C-reactive protein was detected by enzyme-linked immunosorbent assay (ELISA); the expression levels of interleukin (IL)- 1ß, IL6 and IL-10 in the joint muscles were determined by ELISA and immunohistochemical staining; and the level of regulatory T cells (Tregs) in the spleen was detected using flow cytometry. In addition, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and scratch wound healing assay were used to evaluate the proliferation of SW982 synovial cells. ELISA, western blot and immunofluorescence staining were used to investigate the anti-inflammatory mechanisms of SGE on IL-1ß-induced SW982 cells and joint muscles of CIA rats. RESULTS: SGE attenuated the collagen-induced hind paw swelling, cartilage damage and bone erosion. SGE inhibited the synovial hyperplasia to the articular cavity in the toe joint and ankle. Moreover, SGE decreased the production of C-reactive protein in serum and the expression of IL-6, IL-1ß, cyclooxygenase-2 (COX-2) and phosphorylation of NF-κB p65 in the joint muscles. SGE also recovered the decreased Tregs. Results from the in vitro experiments showed that SGE not only inhibited the proliferation and migration of human synovial cell but also inhibited the IL-1ß-induced expression of IL-6 and IL-8. Similarly, SGE inhibited the activation of NF-κB and the expression of COX-2. CONCLUSIONS: SGE attenuated the collagen-induced arthritis through inhibiting the synovial hyperplasia and inflammation.

Leocarpinolide B attenuates LPS-induced inflammation on RAW264.7 macrophages by mediating NF-κB and Nrf2 pathways.

Macrophages-mediated inflammation is involved in the regulation of rheumatoid arthritis (RA). Sigesbeckiae Herba (SH) has been traditionally used for rheumatism. However, the bioactive ingredients of SH are still unclear. Recently, we isolated a compound (Leocarpinolide B, LB) from SH and identified its potent anti-inflammatory and antioxidant effects on RAW264.7 macrophages for the first time. LB effectively inhibited excessive production of nitric oxide (NO), prostaglandin E2 (PGE2), cytokines (IL-6, TNF-α and MCP-1), and the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthases (iNOS) in lipopolysaccharide (LPS)-induced RAW264.7 cells. LB blocked the degradation of inhibitor of kappa B (IκBα) and translocation of nuclear factor kappa B (NF-κB) p65. Additionally, LB reduced the intracellular reactive oxygen species, and increased the expression of heme oxygenase-1 (HO-1) and the translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) in the presence or absence of LPS. The results suggested that LB might be one of the bioactive components of SH, and be potential for the treatment of RA and valuable to be further investigated.

Comprehensive comparison on the anti-inflammatory effects of three species of Sigesbeckia plants based on NF-κB and MAPKs signal pathways in vitro.

ETHNOPHARMACOLOGICAL RELEVANCE: Sigesbeckiae Herba (SH), a traditional anti-inflammatory Chinese herbal medicine, is originated from the plants of Sigesbeckia pubescens Makino (SP), S. orientalis L. (SO) and S. glabrescens Makino (SG). The current studies reported that the chemical constituents in the three species of plants were different. AIM OF THE STUDY: The aim of this study is to provide a systemic comparison on the anti-inflammatory effects and the underlying molecular mechanisms among the three plants based on their effects on nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPKs) signal pathways in vitro. MATERIAL AND METHODS: Twenty-four batches of three Sigesbeckia herbs were collected from different regions of China and extracted with 50% ethanol. The distribution of 6 compounds in the 24 batches of SH extracts were characterized by UPLC analysis. The cytotoxicity of all extracts to RAW264.7 cells in the absence or presence of lipopolysaccharide (LPS) were examined by 3- (4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The anti-inflammatory effects of the extracts were investigated using Griess reagent and enzyme-linked immunosorbent assay. The underlying mechanisms of the representative samples (SP007, SO005 and SG003) for individual species were examined by western blotting and immunofluorescence staining. RESULTS: The estimated average sub-lethal dose (LD15) of SP, SO and SG on RAW264.7 cells were 181.7 ± 15.7, 291.5 ± 33.9 and 317.1 ± 16.3 µg/mL, respectively. In LPS-stimulated RAW264.7 cells, the inhibitory effects of SH species were determined to be SP > SO > SG on NO release, while SP ~ SO > SG on secretion of post-inflammatory cytokines (TNF-α, IL-6 and MCP-1). Moreover, suppression on LPS-induced excessive expressions of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS), as well as the activation of NF-κB and phosphorylation of MAPKs were investigated to be associated to the anti-inflammatory effects for all SH species. CONCLUSIONS: We firstly reported a systemic comparison on the anti-inflammatory properties for the three main plant origins of SH. Although SG showed lower toxicity and less anti-inflammatory effects compared with SP and SO in LPS-induced RAW264.7 cells, comparable inhibitory effects on NF-κB and MAPKs pathways and the reduction of LPS-induced iNOS and COX-2 were observed in the anti-inflammatory process for all Sigesbeckia plants.

Immunomodulatory effects of a new whole ingredients extract from Astragalus: a combined evaluation on chemistry and pharmacology.

BACKGROUND: Water extract (WAE) and ultrafine powder (UFP) are two types of commonly used supplements in preparing various pharmaceutical products and functional foods. However, the correlations of the chemical compositions with the traditional functions between WAE and the herb itself, as well as the potential problems of safety for UFP have been more and more concerned by many doctors and customers. METHODS: In this study, a new whole ingredients extract of Astragalus (WIE) was prepared using the gradient solvent extraction method. The chemical compositions of WIE and WAE were comparatively analysed using spectrophotometric and chromatographic approaches. In addition, the in vivo immunomodulatory effect of WIE, WAE and UFP of Astragalus were comprehensively compared in cyclophosphamide (Cy)-induced immunosuppressive mice. RESULTS: The compositions and contents of main active ingredients (polysaccharides, saponins and flavonoids) in WIE were determined to be more abundant than those in WAE. In Cy-induced immunosuppressive mice, oral administered with low dosage of WIE (equalled to 1.0 g herb/kg/day) for 18 consecutive days significantly improved the immune-related responses (body weight, number of peripheral white blood cells, thymus and spleen indexes, splenocyte proliferations, natural killer cell activity, splenic lymphocyte subset, and serum levels of immunoglobulins G and M). The potency of three Astragalus preparations on immunomodulation was observed to be WIE ≥ UFP > WAE. CONCLUSIONS: WIE maximally retained the chemical integrity of astragalus, and presented better therapeutic effectiveness than UFP and WAE. It can be further developed as new strategy for reasonable use of medicinal/edible herb-derived supplement (extract) for pharmaceutical and healthcare applications.

Brij-grafted-chitosan copolymers with function of P-glycoprotein modulation: Synthesis, characterization and in vitro investigations.

Chitosan (CS), a nature-derived polysaccharide, is a promising nano-carrier material with good biocompatibility and biodegradability. However, the biomedical applications of CS are hindered because of its poor aqueous solubility. To circumvent this drawback, a series of Brij-grafted-chitosan copolymers (BCs) with various grafting degree of Brij-S20 were first developed and reported. The results indicated that the water solubility of BCs (from 9.13 to 9.54 mg/mL) were much higher than that of CS (0.32 mg/mL), due to the broken intra- and/or inter-molecular hydrogen bonds and the decreased initial crystallinity in BCs. The amphiphilic structure of BCs presented lower critical micelle concentration (0.116-0.376 mg/mL) thus facilitating its self-aggregation into micelles for drug encapsulation. Moreover, BCs markedly enhanced the intracellular uptake of rhodamine-123 in MDCK-MDR1 cells. This inhibition on Pgp-mediated efflux was also confirmed by confocal microscopy. In conclusion, BCs could be further developed as polymeric nano-carriers for those drugs with Pgp-mediated efflux.

Comparative comprehension on the anti-rheumatic Chinese herbal medicine Siegesbeckiae Herba: Combined computational predictions and experimental investigations.

ETHNOPHARMACOLOGICAL RELEVANCE: Siegesbeckiae Herba (SH) is a traditional anti-rheumatic herbal medicine in China. The SH-derived product is the first licensed traditional herbal medicinal product for the management of rheumatism-induced joint and muscle pain in United Kingdom. The authenticated plant origins listed in the official Chinese Pharmacopeia for SH include Siegesbeckia orientalis L. (SO), S. pubescens Markino (SP) and S. glabrescens Markino (SG). Although the therapeutic effects of these SH species in treating rheumatoid arthritis (RA) are similar, their difference in chemical profiles suggested their anti-rheumatisms mechanisms and effects may be different. AIM OF THE STUDY: This study was designed to comparatively comprehend the chemical and biological similarity and difference of SO, SP and SG for treating rheumatoid arthritis based on the combination of computational predictions and biological experiment investigations. MATERIALS AND METHODS: The reported compounds for SO, SP and SG were obtained from four chemical databases (SciFinder, Combined Chemical Dictionary v2009, Dictionary of Natural Products and Chinese academy of sciences Chemistry Database). The RA-relevant proteins involved in nuclear factor-kappa B (NF-κB), oxidative stress and autophagy signaling pathways were collected from the databases of Kyoto Encyclopedia of Genes and Genomes and Biocarta. The comparative comprehension of SH plants was performed using similarity analysis, molecular docking and compounds-protein network analysis. The chemical characterization of different SH extracts were qualitatively and quantitatively analyzed, and their effects on specific RA-relevant protein expressions were investigated using Western blotting analysis. RESULTS: Chemical analysis revealed that SO contains mainly sequiterpenes and pimarenoids; SP contains mainly pimarenoids, sequiterpenes, and kaurenoids; and SG contains mainly pimarenoids, flavonoids and alkaloids. Moreover, coincided with the predicted results from computational analysis, different SH species were observed to present different chemical constituents, and diverse effects on RA-relevant proteins at the biological level. CONCLUSIONS: The chemical and biological properties of SO, SP and SG were different and distinctive. The systematic comparison between these three confusing Chinese herbs provides reliable characterization profiles to clarify the pharmacological substances in SH for the precise management of rheumatism/-related diseases in clinics.

Discrimination of three Siegesbeckiae Herba species using UPLC-QTOF/MS-based metabolomics approach.

The plant origin is one of the most important factors for the quality control of traditional Chinese medicines (TCMs) and highly affected on their safety and effectiveness in clinical applications. Multi-origin has been widely observed for many TCMs. Siegesbeckiae Herba (SH) is a traditional anti-rheumatic TCM which is originated from the plants of Siegesbeckia pubescens Makino (SP), S. orientalis L. (SO), and S. glabrescens Makino (SG). In the present study, an UPLC-QTOF/MS method were validated and successfully applied for the determination of the chemical profiles in the three SH species. The data were statistical analyzed with the OPLS-DA analysis and One-Way ANOVA F-test. Obvious differences in chemistry were observed in different SH species and 40 components were identified. Finally, 6 components were selected as potential chemical markers for the discrimination of SP, SO and SG based on the characteristic distribution in individual SH species.

Siegesbeckia Orientalis L. Extract Attenuates Postoperative Cognitive Dysfunction, Systemic Inflammation, and Neuroinflammation.

A proportion of patients experience acute or even prolonged cognitive impairment after surgery, a condition known as postoperative cognitive dysfunction (POCD). It is characterized by impairment in different cognitive domains and neuroinflammation has been implicated as one of the inciting factors as strategies targeting inflammation tend to improve cognitive performance. Siegesbeckia Orientails L. (S. Orientails) is a common Chinese medicinal herb used for managing chronic inflammatory diseases. We investigated if pretreatment with S. Orientails before surgery confers any neuroprotective effects in postoperative animals in terms of reducing inflammation and mitigating cognitive impairment. Three-month-old male C57BL/6N mice were fed different doses of S. Orientails extract for 14 days before they underwent a laparotomy. After cognitive testing they were sacrificed on postoperative day (POD) 3. Our results showed that animals with extract pretreatment demonstrated memory improvement in a dose-dependent manner compared with control. Further, evidence for the attenuation of systemic and neuroinflammation was found in the pretreated animals, along with the inhibition of inflammatory pathways and significantly reduced tau phosphorylation in the hippocampus. Taken together, these results demonstrated a neuroprotective effect of S. Orientails in postoperative animals, indicating a therapeutic potential of S. Orientails in minimizing POCD and the possibility of utilizing this traditional Chinese medicine perioperatively.