高糖環境下INS-1細胞添加香瓜茄水萃物之影響

細胞長期處於高血糖環境下易有氧化損傷，並會促使過多葡萄糖走向多元醇路徑代謝。當β細胞因長時間培養於高糖下，會有失去功能、數目減少、萎縮及死亡等情形。香瓜茄為澎湖地區的特有植物，本實驗室先前已發現香瓜茄對第2型糖尿病小鼠具延緩併發症病程之作用，故本研究將以細胞模式，模擬動物模式中之第2型糖尿鼠，探討高糖所誘發之氧化壓力對大鼠胰島細胞(INS-1 cells)的影響，並觀察香瓜茄水萃物是否可改善高糖所造成的氧化傷害。實驗將INS-1 cells分別培養於控制組(control)、低糖組(2.8mM glucose)、高糖組(16.7mM glucose)、低糖-0.5%香瓜茄組(2.8mM glucose＋0.5%香瓜茄水萃物)、高糖-0.5%香瓜茄組(16.7mM glucose＋0.5%香瓜茄水萃物)、低糖-0.75%香瓜茄組(2.8mM glucose＋0.75%香瓜茄水萃物)、高糖-0.75%香瓜茄組(16.7mM glucose＋0.75%香瓜茄水萃物)連續三天，於第四天收集細胞樣本分析。結果顯示不同劑量的香瓜茄水萃物在高糖環境下可幫助細胞恢復胰島素的分泌能力至正常狀態，增加細胞之存活率、降低細胞凋亡、脂質過氧化物及多元醇路徑中關鍵酵素Aldose reductase mRNA的表現量與其終產物Fructose量。因此推論INS-1 cells在高糖所誘發之氧化壓力下，添加香瓜茄可減少細胞死亡及降低細胞走向多元醇路徑而達到保護的作用，改善高糖所帶帶來的氧化傷害。

Solanum muricatum Ait (Pepino) is a popular vegetable in Penghu. Our previous study indicated that Pepino intake attenuated diabetic complication in BALB/c mice. The present study was designed to investigate the effects of an aqueous extract from Pepino against high glucose induced oxidative pressures in INS-1 cells. INS-1 cells were cultured under control, low glucose (2.8mM glucose), high glucose (16.7mM glucose), low glucose plus 0.5% aqueous extract from Pepino (AEP) (2.8mM glucose+0.5%AEP), high glucose plus 0.5％AEP (16.7mM glucose+0.5％AEP), low glucose plus 0.75％AEP (2.8mM glucose+0.75％AEP), high glucose plus 0.75％AEP (16.7mM glucose+0.75％AEP) for 3 consecutive days. Results showed that aqueous extract from Pepino recovered the ability of cell to secret insulin to normal states. Furthermore, these treatments increases cell viability, declined cell apoptosis, decreased malondialdehyde production and mRNA expression of aldose reductase, as well as fructose level. These results suggest that pepino could protect INS-1 cells against high glucose induced oxidative stress and polyol pathway activation.