Summary: | 碩士 === 國立宜蘭大學 === 生物技術與動物科學系 === 104 === Lung cancer remains one of the most deadly cancers in the world. Nonsmall-cell lung cancer (NSCLC) exhibits highly resistance to surgical resection, radiotherapy, chemotherapy and targeted therapy. A complementary strategy is cancer chemoprevention, using natural, synthetic or biological agents to inhibit progression of cancer or render the patients more resistance to carcinogens. Recently, studies show that many fruits, plants and medical herbs are rich of compounds that possess a wide range of functional properties including anti-inflammatory, antioxidant and anticarcinogenic actions, which is a potential chemopreventive agents. Vernonia amygdalina (VA), a perennial shrub belongs to the Asteraceae family and widespread in the Africa tropics, south America and southeast Asia. VA leaves have been used as treatment for diabetes, gastrointestinal tract problems, liver disease and others. Reports also show that VA extracts was a potent inhibitor of human breast cancer cell MCF-7, imply anti-cancer effects in vitro. In this study, we investigated the anti-inflammatory effect of four VA extracts [dry leaves-methanol (DM), dry leaves-water (DWF), fresh leaves-methanol (FM) and fresh leaves-water extract (FWF)] using NO assay, both extract exhibited anti-inflammatory activity to Raw 264.7 after LPS stimulation. In MTT assay, DM extract show higher cytotoxicity (IC50 = 47.77 μg/ml) against human lung cancer cell A549 compared to DWF, FM and FWF extract. After DM extract treatment, the expression of Bcl-XL had declined significantly, while the expression of pERK and pAKT declined in dose and time-dependent manner. On the other hand, we observed cell shrinkage in A549 using confocal microscopy, revealed DM extract may induces apoptosis in A549. Flow cytometric analysis demonstrated that DM extrat treatment could significantly increase sub G1 population in IC50 and IC75. In wound healing assay, DM extract inhibits cell migration of A549 in IC10 and IC25. Meanwhile, the expression of E-cadherin and HLJ-1 increased significantly, and the expression of Vimentin declined significantly in IC25.Our study demonstrates the potential applications of VA as chemopreventive agent for lung cancer.
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