- 學位論文
苦蘵抗黑色素瘤及抗血小板活性之研究
Anti-melanoma and Anti-platelet Activities of Physalis angulata
摘要
苦蘵（Physalis angulata）為茄科草本植物，具有抗菌及抗發炎效果，也發現對人類腫瘤細胞株有細胞毒性的反應，苦蘵萃取物中具有多種成分，包含physalins及withangulatin A，亦是被報導具有細胞毒性。 目前已知發炎反應與癌症及血栓形成有密切關係，因此，如何運用抗發炎之作用以控制或治療癌症及血栓正逐漸成為一種新的策略。 黑色素瘤是皮膚癌中致死率較高，且可以迅速轉移的癌症之ㄧ。然而，目前可用於治療黑色素瘤的化學治療劑仍有限，本研究結果得知physalin B可對抗黑色素瘤細胞(A375, A2058)的效果（IC 50值低於4.6 μg/ml），其作用機制很可能是以細胞凋亡的方式進行，以西方墨點法發現3 μg/ml physalin B在刺激2小時後，A375癌細胞的NOXA蛋白質被誘導表現，隨後Bax及caspase-3在缺少tumor necrosis factor-related apoptosis inducing ligand (Apo2L/TRAIL) 的A375細胞中亦被誘導。這些結果表明，physalin B能夠誘導A375細胞凋亡是經由粒線體的通路。且實驗結果也證實physalin B不影響正常的纖維母細胞及心肌細胞。因此，physalin B具有潛力作為治療惡性黑色素瘤的化療藥物。 目前已知發炎對於血栓的形成是重要的危險因子，然而physalin B在血小板功能的影響尚不清楚。本研究針對physalin B對於抑制血小板活化和血栓形成的影響進行研究。實驗結果表明，10 μM physalin B能干擾花生四烯酸途徑抑制人類血小板的活化及阻斷P2Y12的活化受體，亦具有抗血小板功能但不影響血漿凝固因子的作用。此外，在80 μM physalin B可以降低TNF-?捋冗仈HP-1細胞附著內皮細胞粘附力。這些結果證實，physalin B的抗血栓形成活性來自於它的抗血小板和抗炎作用。
並列摘要
Physalis angulate of the family Solanaceae possesses antibacterial and anti-inflammatory effects, and exhibits cytotoxicity in human tumor cell lines. P. angulate extract contains numerous components, such as physalins which are cytotoxic compounds. Extant research has shown that inflammatory responses are highly correlated with cancer and thrombus formation. Thus, employing anti-inflammatory mechanisms to control or treat cancer and thrombus has become an emerging strategy. Among the various types of skin cancer, melanoma shows a higher death rate and rapid metastasis. Nevertheless, few chemotherapeutic agents are available for treating melanoma. The present study shows that the toxic mechanism of physalin B, which is used for fighting melanoma cells (A375, A2058; IC 50 < 4.6 μg/ml), takes effect through apoptosis. Western blot analysis indicated that NOXA expression was induced after 2 hour of stimulation with 3 μg/ml physalin B. Subsequently, Bax and caspase-3 were also induced in the A375 cell line, which lacks tumor necrosis factor (TNF)-related apoptosis-inducing ligand (Apo2L/TRAIL). These results indicate that physalin B induces the apoptosis of A375 through the mitochondrial channel. The experiment results also confirm that physalin B does not affect fibroblast and myoblast cells. Therefore, physalin B is potentially a suitable chemotherapeutic agent for treating malignant melanoma. Research confirms that inflammation is a significant risk factor for thrombosis formation; however, few studies have addressed the influence of physalin B on platelet function. The present study examined the influence of physalin B on inhibiting platelet activation and thrombosis formation. The results indicate that 10 μM physalin B can inhibit human platelet activation through an arachidonic acid pathway and block the activation of P2Y12 receptors. Physalin B also exhibits an antiplatelet function without affecting the function of plasma coagulation factors. In addition, 80 μM physalin B can reduce the adhesion between TNF-??-induced THP-1 and endothelial cells. The results further confirm that the antithrombotic activity of physalin B originates from its anti-platelet and anti-inflammatory effects.