陳明+王舉濤+高華武+雷升萍+朱永恒
[摘要] 通過研究半枝蓮總黃酮(total flavonoids in Scutellaria barbata,TF-SB)對腫瘤細胞自噬以及炎癥小體NLRP3的影響,探討自噬與炎癥小體NLRP3激活的關(guān)系,為進一步探討TF-SB的抗腫瘤機制提供實驗依據(jù)。該研究擬采用人工接種B16-F1細胞株致小鼠黑色素瘤模型,隨機均分為模型對照組、陽性對照組(Rap,1.5 mg·kg-1)、TF-SB高、中、低(200,100,50 mg·kg-1)劑量組,另取健康C57BL/6J小黑鼠作為正常組以備血清檢測對照,每組10只,每日給藥1次,連續(xù)2周,末次藥后30 min處理動物。采用HE染色檢測腫瘤組織病理形態(tài)學改變;采用Western blot法檢測腫瘤組織內(nèi)LC3-Ⅱ/LC3-Ⅰ以及炎癥小體NLRP3,caspase-1,IL-1β,IL-18的蛋白表達水平;采用ELISA法檢測血清炎癥因子IL-1β,IL-18含量。結(jié)果顯示:模型組腫瘤細胞呈明顯異型性及惡性增殖的特點,陽性對照組及TF-SB各劑量組腫瘤組織向周圍侵犯情況明顯減輕、腫瘤組織壞死范圍明顯增大、炎性反應明顯減輕。陽性對照組及TF-SB各劑量組LC3-Ⅱ/LC3-Ⅰ明顯增加,NLRP3,caspase-1,IL-1β,IL-18蛋白表達明顯減少。模型組小鼠血清IL-1β,IL-18含量明顯升高,與正常對照組比較有極顯著性差異(P<0.001),陽性對照組及TF-SB各劑量組血清IL-1β,IL-18含量明顯減少,上述指標各藥物組與模型組比較均有顯著性差異(P<0.05,P<0.01或P<0.001)。實驗結(jié)果表明半枝蓮總黃酮可通過抑制NLRP3炎癥小體的表達、改變腫瘤生長微環(huán)境,從而產(chǎn)生抗腫瘤作用,其機制可能與其誘導腫瘤細胞發(fā)生自噬有關(guān)。
[關(guān)鍵詞] 半枝蓮總黃酮; NLRP3炎癥小體; 自噬
[Abstract] This paper was aimed to investigate the relationship between autophagy and NLRP3 inflammasome activation by studying the effect oftotal flavonoids in Scutellaria barbata (TF-SB) on autophagy in tumor cells and NLRP3 inflammasome, and to provide experimental evidence for further study of the anti-tumor mechanism of TF-SB. Mielanoma models were established by inoculating B16-F1 cell line to mice, and then were randomly divided into 5 groups (n=10 in each group): model control, positive control control(Rap, 1.5 mg·kg-1), and TF-SB low, middle and high groups (50, 100 and 200 mg·kg-1). Meanwhile, healthy C57BL/6J mice were used as normal control group (n=10). The drugs were given once daily for 2 weeks consecutively. Thirty minutes after last treatment, the determinations at endpoint were performed; pathological changes of tumor tissue were evaluated by using HE staining; protein expressions of LC3-II/LC3-I or NLRP3inflammasome/caspase-1/IL-1β and IL-18 in tumor tissues were detected by using Western-blot; and serum levels of IL-1β and IL-18 were detected by using Elisa kit. The results showed that the tumor cells in model group showed obvious atypia and malignant proliferation; the invasion of tumor tissue was significantly reduced, the tumor necrosis area was significantly increased, and the inflammatory reaction was significantly alleviated in positive control group and various TF-SB groups. As compared with model control group, LC3-II/LC3-I was significantly increased, while NLRP3/caspase-1/IL-1βand IL-18 protein expressions were significantly decreased in positive control group and TF-SB groups. Serum IL-1β and IL-18 levels in model control group were found higher than those in control group (P<0.001), but they were significantly lowered in positive control group and TF-SB groups (P<0.05, P<0.01 or P<0.001). Taken together, total flavonoids in S. barbata could effectively alter the tumor growth micro-environment by inhibiting the expression of NLRP3 inflammasome, and its anti-tumor effect may be associated with the induction of tumor cell autophagy.endprint