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.

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.

Comprehensive comparison on the anti-inflammation and GC-MS-based metabolomics discrimination between Bupleuri chinense DC. and B. scorzonerifolium Willd.

Bupleuri Radix (BR) is a traditional Chinese medicine and widely used for cold and fever, influenza, inflammation, hepatitis and menstrual diseases. Two authentic medicinal plants of Bupleuri chinense DC. (Beichaihu, BCH) and B. scorzonerifolium Willd. (Nanchiahu, NCH) are recommended by the current Chinese Pharmacopoeia for BR. In the present study, the comparative investigations on the anti-inflammatory effects and gas chromatography-mass spectrometry (GC-MS)-based metabolomics for the species discrimination of BCH and NCH were conducted and reported. The in vitro evaluations indicated that the supercritical fluid extracts (SFEs) (IC50 of 6.39 ± 0.52 and 1.32 ± 0.05 mg (herb)/mL for BCH and NCH) were determined to be more potent than those of the hydro-distillation extracts (HDEs) (IC50 of 203.90 ± 8.08 and 32.32 ± 2.27 mg (herb)/mL for BCH and NCH) against LPS-induced inflammation in RAW264.7 macrophages. The higher anti-inflammatory effects of NCH were associated to its different chemical compositions to the BCH as characterized by the GC-MS analysis. Furthermore, based on the metabolomics and deep chemometric approaches, a minimum combination containing 15 chemical markers was optimized from the identified components and successfully applied for the species discrimination of BCH and NCH. This study not only helps to comparative understand BCH and NCH both in phytochemistry and pharmacology, but also provides the potential chemical markers for improvement of methods for the quality control of BCH and NCH.

Anti-inflammatory/anti-oxidant properties and the UPLC-QTOF/MS-based metabolomics discrimination of three yellow camellia species.

The species of Camellia nitidissima Chi (CC) and C. euphlebia Merr. ex Sealy (CE) are two most important plant sources for commercialized herbal tea (Jinhuacha) worldwide. However, some other species of camellia genus are also sold as alternatives in market due to the great commercial value. In this study, the similarity and difference of CC and CE as well as C.insularis (CI) are comprehensively compared both in chemistry and pharmacology. Based on the ultraperformance liquid chromatography coupled with a hybrid quadrupole orthogonal time-of-flight mass spectrometer(UPLC-QTOF-MS) analysis, a sequential-optimization based new statistical model has been developed by combining the untargeted metabolomics and fingerprint analyses, and successfully applied for chemical pattern recognition and discrimination of three yellow camellias species. The results indicated that CC, CE and CI could be well discriminated with the optimized chemical combination including quercetin-3-O-rhamnoside (C2), okicamelliaside (C4), Kaempferol 7-O-rhamnoside (C6), Corymboside (C9), asiatic acid-glc-rha-xyl (C11) and 3'-methy-4'-glucoside-ellagic acid (C14). Moreover, the 30 % ethanolic extracts of yellow camellias species presented the optimal activities on anti-inflammation/anti-oxidation in LPS-stimulated Raw264.7 macrophages dose-dependently. The averaged 50 % inhibitory concentrations (IC50) on NO production were 754.68 ± 50.96, 1182.39 ± 22.10, 1527.83 ± 106.24 µg(herb)/mL, and ROS production were 311.70 ± 26.57, 332.64 ± 25.46, 917.60 ± 41.36 µg(herb)/mL for CC, CE and CI, respectively. The results indicated a certain similarity of CC and CE, as well as their significant difference from CI.

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.