芹素之抗肝癌及抗B型肝炎病毒研究

Anti-Hepatoma and Anti-Hepatitis B Virus Effects of Apigenin

林奕丞(I-Cheng Lin)

指導教授 ： 林俊清 ； 蔣連財

高雄醫學大學/藥學院/天然藥物研究所碩士班/碩士(2003年)

摘要

芹素 (Apigenin) 為一存在於許多植物中的天然化合物，是大車前草、銀杏等天然藥物的主成分之一。近年來許多研究發現芹素有抗發炎、抗病毒及抗癌等的體外實驗活性。其中抗癌活性方面，芹素對前列腺癌、血癌、甲狀腺癌等具有誘導細胞凋亡的效果；而抗病毒活性方面，芹素有抑制愛滋病毒(HIV-1) 的活性。為開發治療肝癌之天然物藥物資源，遂選定芹素進行體外細胞增生抑制活性效果測試，發現芹素在Hep G2、PLC/PRF/5和Hep 3B三種人類肝癌細胞株中，對Hep G2細胞的抑制效果最好，且對正常老鼠肝臟細胞的毒性小。另一方面，基於B型肝炎與肝癌存在著強烈的相關性，且芹素亦有抗病毒潛在活性，筆者們也以2.2.15細胞來探討芹素的抗B型肝炎病毒活性。
由於芹素對於Hep G2細胞株的增生抑制效果最好 (IC50 = 8.02 μg/ml)，於是以Hep G2進行細胞抑制作用之深入研究。DNA電泳結果發現，芹素能使Hep G2細胞的DNA呈現階梯狀分佈 (DNA ladder) ，證明芹素能造成Hep G2細胞凋亡。以流式細胞儀觀察細胞週期，發現芹素能使Hep G2細胞週期停在G2/M期。而芹素處理Hep G2細胞後，細胞內的p53、p21蛋白質皆有明顯增加的現象。在抗肝癌研究方面，芹素能選擇性地誘發人類肝癌細胞株Hep G2細胞凋亡，且使Hep G2細胞週期停止在G2/M期，而細胞週期停滯和凋亡則是經由p53和p21基因調控。
在抗B型肝炎的研究方面：由於2.2.15細胞會分泌B型肝炎表面抗原(HBsAg) 和可溶性抗原 (HBeAg)，所以用EIA kit測回收實驗後的培養基，結果顯示芹素能降低表面抗原和可溶性抗原的活性，而且芹素對兩種抗原的抑制活性均顯著地比對照藥物 (甘草素) 強。
芹素造成人類肝癌細胞Hep G2程序性死亡；且能抑制B型肝炎表面抗原與可溶性抗原，具抗肝癌與抗B型肝炎之活性，非常值得再深入探討其抗癌與抗病毒之作用機轉。

關鍵字

芹素

並列摘要

Apigenin, a naturally occurring flavone, widely presents in many medical plants. Numerous reports indicate that apigenin exhibits anti-inflammatory, antiviral and anticancer activities in vitro. In this study, I evaluated the antihepatoma and anti-hepatitis B virus effects of apigenin.
I found that apigenin expressed antiproliferation activity on different hepatoma cell lines. Statistic showed apigenin exhibiting the similar effect on Hep G2 as 5-FU (positive control) and its IC50 value was 8.02μg/ml. For future investigaion, I chose the human hepatoma Hep G2 cells to discern whether apigenin induced cellular apoptosis. DNA ladder and flow cytometric analysis showed that apigenin treatment resulted in induction of apoptosis and G2/M arrest in cell cycle. In addition, apigenin induced p53 expression and was accompanied by elevation of p21 expression that was associated with a cell cycle arrest in G2/M phase.
In the antiviral study, my results showed that secretions of HBsAg and HBeAg in 2.2.15 cells were inhibited by apigenin with higher selective indexes than positive control of glycyrrhizin. Thus I’ll be to explore another anti-HBV activities of apigenin, such as effect on HBV DNA replication. These results suggest that apigenin has potential for development as a therapeutical agent for hepatoma and hepatitis B virus infection. Additional studies are needed to clarify the mechanism of these biological activities.

並列關鍵字

Apigenin

參考文獻

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