Maslinic Acid Inhibits Cervical Intraepithelial Neoplasia by Suppressing Interleukin- 6 and Enhancing Apoptosis in a Mouse Model

Background: Cervical Intraepithelial Neoplasia (CIN) directly precedes cervical cancer, and elevated proinflammatory cytokine Interleukins (IL)-6 is implicated in CIN. Objective: As maslinic acid exhibits anti-IL-6 property, the present study sought to determine the effect of maslinic acid on CIN in vitro and in vivo using cell cultures and mouse CIN models, respectively. Methods: The dose-effect of maslinic acid on HeLa cells, a human cervical cancer cell line, was first evaluated, including cytotoxicity, IL-6 secretion, IL-6 receptor (IL-6R) expression, proliferation potential and apoptosis status. A mouse model of CIN was also established, which was then subjected to increasing doses of maslinic acid treatment, followed by assessment of serum IL-6 level, cervical expression of IL-6R, and the proliferation potential and apoptosis of cervical tissues. Results: Maslinic acid dose-dependently inhibited cell growth and proliferation potential, reduced IL-6 secretion, cervical expression of IL-6R and induced apoptosis of HeLa cells in vitro. In the CIN mouse model, serum IL-6 level and cervical expression of IL-6R were elevated, which could be repressed by maslinic acid administration dosedependently. Additionally, maslinic acid treatment in the CIN mice could also restore the otherwise increased proliferation potential and reduced apoptosis in the cervical tissues. Conclusion: Maslinic acid exhibits potent anti-IL-6 property in the CIN mouse model, and alleviates the diseaserelated abnormality in proliferation potential and apoptosis state of the cervical tissue cells, demonstrating its usefulness as a promising agent in treating CIN.