川陳皮素與橘紅素抑制七種腫瘤細胞及人類B型肝炎病毒表面抗原之作用

The Inhibition Effects of Nobiletin and Tangeretin on Seven Kinds of Tumor Cells and Hepatitis B Surface Antigen

川陳皮素(nobiletin)與橘紅素(tangeretin)為多甲氧基黃酮類 (Polymethoxylated Flavones；PMF)化合物，具有許多生物活性。本論文以體外細胞培養模式，探討二者抑制肝癌、乳癌、肺癌、胃癌、大腸癌、腦癌及血癌等七種人類腫瘤細胞之作用，MTT assay測試結果顯示，對胃癌細胞(AGS)、腦癌細胞(U87)及肺癌細胞(H2981)無抑制作用；乳癌細胞(MCF-7)及肝癌細胞(HepG2)具有輕度抑制作用；大腸癌細胞(Colo201)具有中度抑制作用；血癌細胞(U937)具有強度抑制作用，川陳皮素處理24小時IC50為8.6 ± 0.6μg/mL、處理48小時IC50為7.2 ± 2.0μg/mL；橘紅素處理24小時IC50為26.7 ± 0.9μg/mL、處理48小時IC50為14.3 ± 1.6μg/mL，二者均具有時間與濃度依賴性。細胞凋亡藉由ELISA kit測定，顯示二者均具有誘導肝癌、乳癌、大腸癌及血癌細胞凋亡之活性，且細胞毒殺作用顯示最強的血癌細胞，其被誘導細胞凋亡活性也最強。更進一步利用2.2.15作為野生型HBV產生之病毒株，M33作為肝安能抗藥性突變株，進行抗人類B型肝炎病毒活性之探討，結果顯示，川陳皮素與橘紅素對B型肝炎野生型病毒株，無細胞毒性下，對表面抗原具有顯著抑制作用；對e抗原無抑制作用；對肝安能抗藥性突變株，無顯著細胞毒性下，對表面抗原具有顯著抑制作用；對e抗原無抑制作用。

Nobiletin and tangeretin are two pure compounds belonging to Polymethoxylated Flavones, PMF, with many bioactivities. The goal of this study is to explore their anti-tumor effects on 7 kinds of tumor cells (i.e., hepatoma, breast cancer, lung cancer, gastric cancer, colon cancer, brain cancer and leukemia). MTT assay data showed that nobiletin and tangeretin have no effects on gastric cancer cells (AGS), brain cancer cells (U87) or lung cancer cells (H2981); slight inhibition on brest cancer cells (MCF-7) and hepatoma cancer cells (HepG2), intermediate effect on colon cancer cells (Colo201); but showed strong inhibition on leukemia cell line (U937) (i.e., IC50 = 8.6 ± 0.6 μg/mL at 24 hours and IC50 = 7.2 ± 2.0 μg/mL at 48 hours for nobiletin; IC50 = 26.7 ± 0.9 μg/mL at 24 hours and IC50 = 14.3 ± 1.6 μg/mL at 48 hours for tangeretin) in a time and concentration-dependent manner. Moreover, by analyzing the DNA apoptosis with ELISA method, we found that both nobiletin and tangeretin indeed induced apoptosis on HepG2, MCF-7, Colo201 and U937 cells. Moreover, the leukemia cell line (U937) which shows the most cytotoxicity effects also depicts the most apoptosis intensity as induced by nobiletin and tangeretin. Finally, by using wild-type hepatitis B virus producing cell line (2.2.15) and lamivudine-resistant mutant virus producing cell line (M33) to evaluate the anti-HBV effects of nobiletin and tangeretin under doses with non-cytotoxicity to both cell lines, both nobiletin and tangeretin have significantly reduced the HBsAg secretion, albeit no effects to e antigen secretion.