Dehydrocostus lactone alleviates irinotecan-induced intestinal mucositis by blocking TLR4/MD2 complex formation.

BACKGROUND: Irinotecan (CPT-11) is used as chemotherapeutic drug for treatment of colorectal cancer. However, without satisfactory treatments, its gastrointestinal toxicities such as diarrhea and intestinal inflammation severely restrained its clinical application. Roots of Aucklandia lappa Decne. are used as traditional Chinese medicine to relieve gastrointestinal dysfunction and dehydrocostus lactone (DHL) is one of its main active components. Nevertheless, the efficacy and mechanism of DHL against intestinal mucositis remains unclear. PURPOSE: The present study aimed to investigate the protective effects of DHL on CPT-11-induced intestinal mucositis and its underlying mechanisms. METHODS: The protective effect of DHL was investigated in CPT-11-induced mice and lipopolysaccharide (LPS)+CPT-11 induced THP-1 macrophages. Body weight, diarrhea score, survival rate, colon length, and histopathological changes in mice colon and jejunum were analyzed to evaluate the protective effect of DHL in vivo. And DHL on reducing inflammatory response and regulating TLR4/NF-κB/NLRP3 pathway in vivo and in vitro were explored. Moreover, DHL on the interaction between TLR4 and MD2 was investigated. And silencing TLR4 targeted by siRNA was performed to validate the mechanisms of DHL on regulating the inflammation. RESULTS: DHL prevented CPT-11-induced intestinal damage, represented by reducing weight loss, diarrhea score, mortality rate and the shortening of the colon. Histological analysis confirmed that DHL prevented intestinal epithelial injury and improved the intestinal barrier function in CPT-11 induced mice. Besides, DHL significantly downregulated the level of inflammatory cytokines by inhibiting TLR4/NF-κB/NLRP3 signaling pathway in CPT-11-induced mice and LPS+CPT-11-induced THP-1 macrophages. In addition, DHL blocked TLR4/MD2 complex formation. Molecular docking combined with SIP and DARTS assay showed that DHL could bind to TLR4/MD2 and occludes the hydrophobic pocket of MD2. Furthermore, Silencing TLR4 abrogated the effect of DHL on LPS+CPT-11 induced inflammatory response in THP-1 macrophages. Additionally, DHL ameliorate the CPT-11-induced intestinal mucositis without affecting the anti-tumor efficacy of CPT-11 in the tumor xenograft mice. CONCLUSION: This study found that DHL exhibited the anti-inflammatory effects in CPT-11-induced intestinal mucositis by inhibiting the formation of TLR4/MD2 complex and then regulation of NF-κB/NLRP3 signaling pathway. DHL is potentially served as a novel strategy of combined medication with CPT-11.

Oxybaphus himalaicus Mitigates Lipopolysaccharide-Induced Acute Kidney Injury by Inhibiting TLR4/MD2 Complex Formation.

Acute kidney injury (AKI) is described as the abrupt decrease in kidney function always accompanied by inflammation. The roots of Oxybaphus himalaicus Edgew. have long been used in Tibetan folk medicine for the treatment of nephritis. Nevertheless, modern pharmacological studies, especially about the underlying mechanism of O. himalaicus medications, are still lacking. Here, in lipopolysaccharide (LPS)-induced RAW264.7 macrophages, the O. himalaicus extract (OE) showed significant anti-inflammatory activity with the dose dependently reducing the LPS-stimulated release of nitric oxide and the mRNA level and protein expression of inflammatory cytokines and reversed the activation of nuclear factor kappa B (NF-κB). Co-immunoprecipitation assay indicated that OE inhibited Toll-like receptor 4/myeloid differentiation factor 2 (TLR4/MD2) complex formation and further suppressed both myeloid differentiation factor 88 (MyD88)-dependent and TIR-domain-containing adapter-inducing interferon-ß (TRIF)-dependent cascades activation. In addition, OE could restrain NADPH oxidase 2 (NOX2) endocytosis by blocking TLR4/MD2 complex formation to prevent reactive oxygen species production. In LPS-induced AKI mice, OE treatment mitigated renal injury and inflammatory infiltration by inhibiting TLR4/MD2 complex formation. UPLC-MS/MS analysis tentatively identified 41 components in OE. Our results indicated that OE presented significant anti-inflammatory activity by inhibiting TLR4/MD2 complex formation, which alleviated LPS-induced AKI in mice.

[Two new triterpeneoids from roots of Dolomiaea souliei].

The present study analyzed the chemical constituents in dried roots of Dolomiaea souliei. Chromatographic methods, such as normal-phase, and reversed-phase column chromatography, TLC, and preparative HPLC, were applied to separate and purify the petroleum ether extract of D. souliei. The structures of the purified constituents were identified by multiple spectroscopic methods including 1 D NMR, 2 D NMR, IR, UV, and HR-ESI-MS. Fourteen triterpenoids were obtained and identified as bauer-8-ene-3,11-dione-7α-ol(1), bauer-8-ene-3-one-7α,11α-diol(2), 3-oxo-11α-hydroxy-urs-12-ene(3), 3-oxour-12-ene-1ß,11α-diol(4), 3ß,11α-dihydroxy-urs-12-ene(5), taraxast-20-ene-3ß,30-diol(6), 28-hydroxy-3-oxo-12-ursene(7), 3ß-hydroxytaraxast-20-ene-30-aldehyde(8), urs-12-ene-2α,3ß,28-triol(9), 20-hydroxylupan-3-one(10), monogynol A(11), obtusalin(12), 3-oxo, 11α-hydroxy-olean-12-ene(13), and isocabralealactone(14). Among them, compounds 1 and 2 were new compounds. Compounds 4-10, 12, and 14 were isolated from this genus for the first time. Compounds 3 and 11 were obtained from D. souliei for the first time.