School of Life Science and Engineering, Foshan University, Foshan 528225, China.
School of Life Science and Engineering, Foshan University, Foshan 528225, China.
Phytomedicine. 2024 Dec;135:156159. doi: 10.1016/j.phymed.2024.156159. Epub 2024 Oct 17.
Volatile oil from fresh Clausena lansium (Lour.) Skeels (Rutaceae) (common name Wampee) has been previously extracted by our group from fresh C. lansium leaf and its components were qualitative and quantitatively analyzed by GC-MS. It altered the cell membrane permeability of Staphylococcus aureus and reduced the levels of inflammation factors. However, previous in vivo reports on the anti-inflammatory and the antibacterial properties against S. aureus are scarce.
HYPOTHESIS/PURPOSE: To evaluate the protective in vivo effects of Wampee leaves volatile oil emulsion (WVOE) against S. aureus-induced pneumonia and elucidate the underlying mechanisms of action.
Wild-type and nucleotide oligomerization domain-like receptor protein 3 (NLRP3)-deficient mice were used. Mice were treated with WVOE for 7 days, and subjected to S. aureus infection by nasal administration on day 5 for 48 h. Lung and blood samples were collected for assessing lung damage and protein abundance. Lung bacterial load, wet/dry ratio, C-reactive protein (CRP) levels, inflammatory cytokines secretion, and lung histopathological injury were examined.
WVOE effectively reduced lung bacterial load, wet/dry ratio, and CRP levels increased following S. aureus infection in mice. WVOE decreased the secretion of inflammatory cytokines (IL-6 and TNF-α) and lung histopathological injury, and suppressed the NF-κB pathway and NLRP3 inflammasome activation. NLRP3 mice exhibited lower bacterial load, inflammatory cytokines levels and lung histopathological injury compared with mice in the model group. Autophagy was enhanced in S. aureus-infected mice, with higher levels of p-mTOR, Beclin-1, Atg 16L1, Atg7, p62, p-p62, and LC3II. WVOE administration restored the autophagy related protein levels. Autophagy was inhibited in NLRP3 mice of the control and model groups, and WVOE lost its ability to regulate the autophagy-related proteins enhanced upon S. aureus infection. WVOE enhanced autophagy to alleviate lung injury by inhibiting NLRP3-targeted P62. Furthermore, compared with the 3MA + model group, WVOE reduced the bacterial load and CRP levels, pulmonary septa narrowing, and congestion. NLRP3 protein expression increased due to autophagy inhibition. WVOE exerted a pharmacological effect through the PI3K/AKT/mTOR pathway.
WVOE regulated the PI3K/AKT/mTOR pathway and enhanced autophagy, with NLRP3 playing a crucial role. WVOE exhibited protective effects against S. aureus-induced pneumonia by inhibiting NLRP3 inflammasome activation and enhancing autophagy. These findings expand the understanding of antibacterial properties of WVOE, and provide novel insights into the therapeutic potential of WVOE in managing S. aureus infections.
我们课题组曾从鲜枳棋子（芸香科）叶中提取挥发性油，并通过 GC-MS 对其成分进行定性和定量分析。该挥发性油能改变金黄色葡萄球菌细胞膜的通透性，降低炎症因子水平。然而，目前关于其抗金黄色葡萄球菌的体内抗炎和抗菌作用的报道还很少。
假设/目的：评估枳棋子叶挥发油乳剂（WVOE）对金黄色葡萄球菌诱导性肺炎的体内保护作用，并阐明其作用机制。
使用野生型和核苷酸寡聚化结构域样受体蛋白 3（NLRP3）缺陷型小鼠。用 WVOE 处理小鼠 7 天，第 5 天经鼻腔给予金黄色葡萄球菌感染 48 小时。采集肺和血液样本，评估肺损伤和蛋白丰度。检测肺细菌负荷、湿/干比、C 反应蛋白（CRP）水平、炎症细胞因子分泌和肺组织病理学损伤。
WVOE 能有效降低金黄色葡萄球菌感染小鼠的肺细菌负荷、湿/干比和 CRP 水平。WVOE 降低了炎症细胞因子（IL-6 和 TNF-α）的分泌和肺组织病理学损伤，并抑制了 NF-κB 通路和 NLRP3 炎性体的激活。与模型组小鼠相比，NLRP3 小鼠的细菌负荷、炎症细胞因子水平和肺组织病理学损伤均较低。金黄色葡萄球菌感染小鼠的自噬增强，p-mTOR、Beclin-1、Atg16L1、Atg7、p62、p-p62 和 LC3II 水平升高。WVOE 给药后自噬相关蛋白水平恢复。NLRP3 野生型和模型组小鼠的自噬受到抑制，WVOE 失去了调节金黄色葡萄球菌感染诱导的自噬相关蛋白的能力。WVOE 通过抑制 NLRP3 靶向的 P62 增强自噬，从而减轻肺损伤。此外，与 3MA+模型组相比，WVOE 降低了细菌负荷和 CRP 水平，减轻了肺间隔变窄和充血。自噬抑制导致 NLRP3 蛋白表达增加。WVOE 通过 PI3K/AKT/mTOR 通路发挥药理作用。
WVOE 调节 PI3K/AKT/mTOR 通路并增强自噬，NLRP3 在此过程中起关键作用。WVOE 通过抑制 NLRP3 炎性体激活和增强自噬，对金黄色葡萄球菌诱导性肺炎发挥保护作用。这些发现扩展了我们对 WVOE 抗菌特性的认识，并为 WVOE 在治疗金黄色葡萄球菌感染方面的治疗潜力提供了新的见解。
