落花生二苯乙烯類對HL-60細胞株的影響

Abstract

二苯乙烯類 (stilbenoids)為植物抵抗黴菌或病蟲害的天然抗生素，許多研究報告指出，二苯乙烯類具有抗氧化、抗發炎、防癌及抗癌等生理活性。本論文研究純化自花生仁的二苯乙烯類，包括resveratrol (RSV)、arachindin-1 (Ara-1)、arachindin-3 (Ara-3)及isopentadienylresveratrol (IPD)的抗癌活性，以HL-60血癌細胞株當作實驗模型，研究中發現，RSV、Ara-1及Ara-3可抑制HL-60細胞株的生長，其中，Ara-1在較低的濃度就可以抑制細胞生長 (EC50為4.2 μM)。以Ara-1處理HL-60細胞，在短時間內可造成細胞粒線體膜電位的下降、caspases的活化、DNA斷裂以及細胞週期改變。Ara-3處理HL-60細胞則是觀察到其細胞膜完整性的改變、細胞粒線體膜電位的下降，以及caspases的活化。綜合以上結果，Ara-1及Ara-3處理HL-60細胞皆可以引發細胞走向凋亡，而對正常不增生的周邊血單核球細胞則無影響，因此具有成為抗癌藥物的潛力。由於體外試驗Ara-1可抑制Topoisomerase II的活性，但對HL-60與HL-60/MX2 (Topoisomerase II缺乏的HL-60突變株)的毒性沒有差異，推測Ara-1造成細胞走向凋亡並非透過抑制Topoisomerase II。但仍可由以上結果顯示，Ara-1及Ara-3可能具有抗癌的潛力。

Stilbenoids are phytoalexins produced by plants under attack by pathogens such as fungi. Previous sutdies have demonstrated that stilbenoids have bioactivities such as anti-oxidation, anti-inflammation, cancer chemoprevention and anti-carcinogenic effect. In this study, resveratrol (RSV), arachidin-1 (Ara-1), arachidin-3 (Ara-3), and isopentadienylresveratrol (IPD) were isolated from peanuts. RSV, Ara-1 and Ara-3 display cytotoxic effect on HL-60, and Ara-1 is the most toxic. Further study showed that Ara-1 treatment on HL-60 cells caused loss of mitochondrial membrane potential (MMP), caspases activation, and changes in cell cycle distribution. Ara-3 treatment on HL-60 cells caused loss of MMP and cell membrane integrity as well as caspases activation. These results suggested that Ara-1 and Ara-3 are potential anticancer agents that induced cancer cell apoptosis. Ara-1 and RSV are cytotoxic to proliferating cells, HL-60, but did not affect on nonproliferating human peripheral blood mononuclear cells. Furthermore, Ara-1 was found to inhibit the activity of topoisomerase II in vitro, but showed no significant difference in cytotoxicity between HL-60 and Topo II defective HL-60/MX2 cells. Topoisomerase II inhibition may not be involved in the mechanisms of apoptosis induction by Ara-1 in HL-60 cells. These results indicate that Ara-1 and Ara-3 are potential anti-cancer agents.