Key Laboratory of Tropical Translational Medicine of Ministry of Education, NHC Key Laboratory of Control of Tropical Disease Control, School of Tropical Medicine, Hainan Medical University, Haikou, Hainan, 571199, China.
Key Laboratory of Tropical Translational Medicine of Ministry of Education, NHC Key Laboratory of Control of Tropical Disease Control, School of Tropical Medicine, Hainan Medical University, Haikou, Hainan, 571199, China.
J Ethnopharmacol. 2023 Jun 12;309:116353. doi: 10.1016/j.jep.2023.116353. Epub 2023 Mar 10.
Ageratum conyzoides L. (Asteraceae), a well-known and widely distributed traditional tropical medicinal herb, has been used to treat diverse diseases. Our preliminary research has shown that aqueous extracts of A. conyzoides leaf (EAC) have anti-inflammatory activity. However, the detailed underlying anti-inflammatory mechanism of EAC is still unclear.
To determine the anti-inflammatory mechanism of action of EAC.
The major constituents of EAC were identified by ultra-performance liquid chromatography (UPLC) combined with quadrupole-time-of-flight mass/mass spectrometry (UPLC-Q-TOF-MS/MS). LPS and ATP were used to activate the NLRP3 inflammasome in two types of macrophages (RAW 264.7 and THP-1 cells). The cytotoxicity of EAC was measured by the CCK8 assay. The levels of inflammatory cytokines and NLRP3 inflammasome-related proteins were detected by ELISA and western blotting (WB), respectively. The oligomerization of NLRP3 and ASC and the resulting inflammasome complex formation were observed by immunofluorescence. The intracellular reactive oxygen species (ROS) level was measured by flow cytometry. Finally, an MSU-induced peritonitis model was established to evaluate the anti-inflammatory effects of EAC in vivo.
Twenty constituents were identified in the EAC. Kaempferol 3,7-diglucoside, 1,3,5-tricaffeoylquinic acid, and kaempferol 3,7,4'-triglucoside were found to be the most potent ingredients. EAC significantly reduced the levels of IL-1β, IL-18, TNF-α, and caspase-1 in the two types of activated macrophages, implying that EAC can inhibit the activation of the NLRP3 inflammasome. A mechanistic study revealed that EAC inhibited NLRP3 inflammasome activation by blocking NF-κB signalling pathway activation and scavenging the level of intracellular ROS to prevent NLRP3 inflammasome assembly in macrophages. Furthermore, EAC attenuated the in vivo expression of inflammatory cytokines by suppressing NLRP3 inflammasome activation in a peritonitis mouse model.
Our results demonstrated that EAC inhibited inflammation by suppressing NLRP3 inflammasome activation, highlighting that this traditional herbal medicine might be used to treat NLRP3 inflammasome-driven inflammatory diseases.
苍耳（菊科）是一种广为人知且分布广泛的传统热带药用草本植物，已被用于治疗多种疾病。我们的初步研究表明，苍耳叶水提物（EAC）具有抗炎活性。然而，EAC 的详细抗炎机制尚不清楚。
确定 EAC 的抗炎作用机制。
采用超高效液相色谱（UPLC）结合四极杆飞行时间质谱/质谱联用（UPLC-Q-TOF-MS/MS）鉴定 EAC 的主要成分。LPS 和 ATP 用于激活两种巨噬细胞（RAW 264.7 和 THP-1 细胞）中的 NLRP3 炎性体。通过 CCK8 测定法测定 EAC 的细胞毒性。通过 ELISA 和蛋白质印迹（WB）分别检测炎症细胞因子和 NLRP3 炎性体相关蛋白的水平。通过免疫荧光观察 NLRP3 和 ASC 的寡聚化以及由此产生的炎性体复合物的形成。通过流式细胞术测量细胞内活性氧（ROS）水平。最后，建立 MSU 诱导的腹膜炎模型，以评估 EAC 在体内的抗炎作用。
鉴定出 EAC 中的 20 种成分。山奈酚 3,7-二葡萄糖苷、1,3,5-三咖啡酰奎宁酸和山奈酚 3,7,4'-三葡萄糖苷被发现是最有效的成分。EAC 显著降低了两种激活巨噬细胞中 IL-1β、IL-18、TNF-α 和半胱天冬酶-1 的水平，表明 EAC 可以抑制 NLRP3 炎性体的激活。机制研究表明，EAC 通过阻断 NF-κB 信号通路的激活和清除细胞内 ROS 水平来抑制 NLRP3 炎性体在巨噬细胞中的组装，从而抑制 NLRP3 炎性体的激活。此外，EAC 通过抑制 NLRP3 炎性体在腹膜炎小鼠模型中的激活来减轻体内炎症细胞因子的表达。
我们的结果表明，EAC 通过抑制 NLRP3 炎性体的激活来抑制炎症，这突显了这种传统草药可能用于治疗 NLRP3 炎性体驱动的炎症性疾病。
