| Abstract: | 40年來癌症已高居台灣十大死因首位。癌症的治療除了切除原位癌之外，化學治療為全身性且較常使用的治療手段。但是，癌症化學治療藥劑對正常細胞易引起毒性，造成多種不良症狀，進而影響身體機能，嚴重降低患者生活品質。順鉑(cis-diamminedichloroplatinum II, cisplatin)是一種常用於癌症治療之藥物，透過抑制 DNA 合成和誘發細胞凋亡等機制而有效抑制腫瘤生長，但經常導致嚴重的腎臟毒性、神經問題以及嚴重的噁心和嘔吐等諸多副作用。近年許多研究證實，植物化學物質(phytochemicals)可透過抗氧化、抗發炎等作用而改善癌藥副作用。迷迭香酸(rosmarinic acid)為酚酸類化合物的一種，具有抗氧化(antioxidation)和抗發炎(antiinflammation)的能力，也證實具有抗癌(anticancer)作用，甚至在近年的研究中更證實可減輕癌症第一線用藥唐黴素(doxorubicin)誘發心肌細胞凋亡的毒性、神經毒性以及睪丸傷害等。但，迷迭香酸是否可減輕順鉑或者其他癌藥引起的副作用及其機制仍需探討。因此，本研究擬探討迷迭香酸對減少順鉑引起腎臟細胞毒性的可能效用和機制。結果發現，順鉑(20-50μM)會造成正常腎細胞NRK-52E存活率下降，並引起p53介導的細胞凋亡(apoptosis)路徑蛋白的改變，包括上調p53和caspase-3蛋白表現，並使抗凋亡指標蛋白Bcl-2下降，可能是順鉑造成正常腎臟細胞死亡的分子機制。在預培養迷迭香酸(1-50μM)的情況下，順鉑降低細胞存活率的作用有減少的趨勢，且迷迭香酸的預處理也抑制順鉑所引起的p53凋亡路徑相關蛋白的改變。此外，在本試驗的條件下，順鉑並沒有增加脂質過氧化(lipid peroxidation)、胞內活性氧(reactive oxygen species, ROS)和胞外一氧化氮(nitric oxide, NO)含量。綜合以上結果，在正常腎臟細胞中，順鉑會透過活化p53介導的細胞凋亡訊息路徑導致細胞死亡，而迷迭香酸的預處理可以有效阻斷該路徑，而減少順鉑對細胞造成的傷害。因此，本研究證實迷迭香酸具有改善順鉑引起腎毒性的潛力。
Between 1982 to 2021, cancer has been a leading cause of death in Taiwan. Most patients are already at an advanced stage at the time the diagnosis is confirmed. The primary choice of treatment is chemotherapy. However, cytotoxicity and resistance to chemotherapeutic agents are major limitations to its clinical use. Further, these effects reduce their therapeutic effect and often result in a myriad of undesirable symptoms that affect physical functioning and the quality of life. Cisplatin, an anticancer drug widely used to treat various types of cancers, exerts chemotherapeutic effects by cross-linking DNA and interfering in the transcription and replication processes to trigger cell death. However, cisplatin induces several side effects, such as nephrotoxicity, neurotoxicity, and severe nausea and vomiting, limiting their clinical application. Many studies have demonstrated that phytochemicals can ameliorate chemotherapy-induced side effects through their antioxidative and anti-inflammatory functions. Rosmarinic acid is a phenolic acid compound that exerts antioxidant and anti-inflammatory activities in vitro and in vivo and has been proven to have anticancer effect. Rosmarinic acid can reduce first-line cancer drug doxorubicin-induced cardiotoxicity, neurotoxicity and testicular damage. Further, rosmarinic acid can attenuate cisplatin or other cancer drug-induced side effects; however, the mechanisms of its effects still need to be verified. Thus, in this study, we assessed the effects and mechanisms of rosmarinic acid on attenuating cisplatin-induced renal cytotoxicity. After incubation with different concentrations of rosmarinic acid (1–50 μM) for 24 h, we determined cell viability, lipid peroxidation, reactive oxygen species (ROS) levels, nitric oxide (NO) levels, and p53-dependent apoptosis-related protein levels in a cisplatin-induced cytotoxic model in NRK-52E normal kidney cells. We showed that cisplatin (20–50 μM) decreases cell viability, induces changes in the p53-mediated apoptosis pathway proteins, including upregulating p53 and caspase-3 protein expression, and decreases the levels of the anti-apoptotic indicator protein Bcl-2, which may be the molecular mechanism of cisplatin-induced cell death. After incubation with different concentrations of rosmarinic acid (1–50 μM), the cytotoxicity and regulation of p53-dependent apoptosis-related protein levels induced by cisplatin was restored. Furthermore, cisplatin did not increase lipid peroxidation and levels of intracellular ROS and extracellular NO under the conditions of this study. Based on the above results, in normal kidney cells, cisplatin can lead to cell death by activating the p53-mediated apoptotic signaling pathway, and pretreatment with rosmarinic acid can effectively block this pathway and reduce the cytotoxic effect of cisplatin. We conclude that rosmarinic acid has the potential to ameliorate cisplatin-induced nephrotoxicity. |
