Sesquiterpene lactones-rich fraction from Aucklandia lappa Decne. alleviates dextran sulfate sodium induced ulcerative colitis through co-regulating MAPK and Nrf2/Hmox-1 signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Aucklandia lappa Decne. (ALDE) is the general name for Asteraceae plants Yunmuxiang, which has traditionally been proven to have the efficacy in relieving depression by regulating qi, alleviating cold by warming, attenuating pain in stomach and relieving diarrhea in intestines. Therefore, ALDE is always recommended as an herbal remedy for gastrointestinal dysfunction. AIM OF THE STUDY: The purpose of this study was to explore the therapeutic potential and mechanism of action of the sesquiterpene lactone-rich fraction (SLRF) of ALDE extracts in vivo and in vitro. MATERIALS AND METHODS: An aqueous extract (AE) and SLRF of ALDE were prepared and the contents of the main components were quantified by high performance liquid chromatography (HPLC). The therapeutic effects of the extracts were evaluated in C57BL/6 mice with dextran sulfate sodium (DSS)-induced ulcerative colitis (UC). Body weight, disease activity index (DAI), and colon length were recorded, and histopathological changes in the colon were characterized using hematoxylin and eosin (H&E) staining. The in vitro anti-inflammatory activity and possible mechanisms of the two main sesquiterpene lactones in ALDE (costunolide and dehydrocostus lactone) were studied by quantitative proteomic analysis. Finally, based on bioinformatic analysis, we used polymerase chain reaction (PCR), immunofluorescence, and western blot experiments to verify the anti-inflammatory mechanism of the extracts in C57BL/6 mice. RESULTS: The SLRF of ALDE significantly improved the pathological symptoms and inflammatory pathology of UC, whereas the AE had a weak protective effect. In RAW264.7 cells stimulated with lipopolysaccharide (LPS), costunolide and dehydrocostus lactone significantly reduced the mRNA levels of interleukin (IL)-1ß, IL-6, and tumor necrosis factor (TNF)-α, suggesting that these two sesquiterpene lactones had strong anti-inflammatory activity. Quantitative proteomics results indicated that the anti-inflammatory mechanism of these lactones was associated with the NF-κB/MAPK and Nrf2-Hmox-1 pathways. These results were further validated in SLRF-treated mice. CONCLUSION: This study confirmed that the SLRF of ALDE exerted protective activity against UC by regulating the Nrf2-Hmox-1, NF-κB, and MAPK pathways.

Urolithin A attenuates RANKL-induced osteoclastogenesis by co-regulating the p38 MAPK and Nrf2 signaling pathway.

As a critical regulator of bone resorption. osteoclastogenesis is closely associated with osteoporosis (OP) and commonly induced by receptor activator of nuclear factor-κB ligand (RANKL), suggesting that suppression of inflammation may improve OP. Urolithin A (UroA), an active metabolite of ellagic acid, is known to exert anti-inflammatory and antioxidative effects. However, whether UroA attenuates osteoclastogenesis remains unclear. Using a lipopolysaccharide (LPS)-induced bone loss model, we evaluated the effects of UroA on inflammatory osteoclastogenesis in mice and explored the potential mechanism from RANKL-related signaling pathway. UroA significantly improved LPS-induced bone loss and rescued the imbalance in bone microarchitecture parameters. Hematoxylin&eosin (H&E) and tartrate resistant acid phosphatase (TRAP) staining of femurs showed that UroA suppressed LPS-induced osteoclastogenesis accompanied by the activation of nuclear factor-erythroid 2-related factor 2 (Nrf2) signaling. In RANKL-triggered mouse bone marrow-derived macrophages (BMDMs), UroA inhibited the formation of osteoclasts and Fibrous actin rings (F-actin rings), and decreased TRAP activity. Moreover, UroA significantly decreased mRNA and protein expression of major inflammatory cytokines in LPS-challenged RAW264.7 cells by decreasing the phosphorylation of NF-κB p65, c-Jun N-terminal kinase (JNK), extracellular signal regulated kinase1/2 (Erk1/2), and p38. Furthermore, UroA may activate the Nrf2 signaling pathway by increasing mRNA and protein expression of antioxidant proteins. We conclude that UroA attenuated RANKL-induced osteoclastogenesis by suppressing the p38 mitogen-activated protein kinase (MAPK) pathway and inducing Nrf2 nuclear translocation. Thus, supplementation with UroA may help alleviate inflammation-induced bone loss and bone resorption.

Characterization of the chemical constituents and in vivo metabolic profile of Scutellaria barbata D. Don by ultra high performance liquid chromatography with high-resolution mass spectrometry.

Scutellaria barbata D. Don (S. barbata) is one of the most frequently used anticancer herb medicine in China. Mechanistic understanding of the biological activities of S. barbata is hindered by limited knowledge regarding its components and metabolic profile. In this study, ultra-high-performance liquid chromatography coupled with high resolution mass spectrometry (quadrupole time-of-flight mass spectrometry) was used to identify the chemical constituents in S. barbata and their metabolic profiles in rats. By applying cleavage rules and comparison with reference substances, 89 components were identified in S. barbata, which included 45 flavonoids, 28 diterpenoids, 10 phenolics, and 6 others. A total of 110 compounds, including 32 prototype compounds and 78 metabolites, were identified or tentatively characterized in vivo. Methylation, sulfonation, and glucuronidation were the main metabolic pathways, which could be attributed to the fact that several of the compounds in S. barbata have phenolic hydroxyl groups. This is the first systematic study on the chemical constituents and in vivo metabolic profile of S. barbata. The analytical method features a quick and comprehensive dissection of the chemical composition and metabolic profile of S. barbata and provides a basis for exploring its various biological activities.