水果真的能保護大腦：科學告訴你為什麼
阿茲海默症（Alzheimer's disease）是一種逐漸侵蝕記憶力與思考力的退化性疾病。科學研究指出，體內自由基對細胞的不斷攻擊，會引發「氧化壓力（oxidative stress）」，導致細胞受損甚至死亡，這與阿茲海默症的發生密切相關。因此，想要守護腦力與記憶，如何降低氧化壓力就顯得格外重要。
水果多酚與神經保護：
香蕉、柳橙與蘋果等富含「多酚」化合物的水果，堪稱強力的天然抗氧化神器。研究結果顯示，這些多酚能有效提升 PC12 細胞在過氧化氫（H2O2）所引發的氧化壓力下之存活率，並降低乳酸去氫酶（LDH）的釋放，進一步保護細胞膜完整度。蘋果萃取物在眾多水果中表現最突出，緊接著是香蕉與柳橙。這些發現不僅再次驗證了多酚的抗氧化魔力，也提醒我們，日常生活中多吃富含抗氧化成分的水果，能有效降低阿茲海默症等神經退化性疾病的風險。
![Inhibition effect of LDH release of fruit phenolics on H2O2-induced membrane damage in PC12 cells. PC12 cells were pretreated for 10 min with various concentrations. The cells were treated with H2O2 (400 μM) for 2 h. LDH activity in culture supernatants was measured with a colorimetric LDH assay kit. Basal and total LDH activities were determined in intact cells and cell solubilized with 0.2% Triton X-100, respectively, and LDH release was calculated as [(sample LDH − basal LDH) / (total LDH − basal LDH)]× 100 (%). Quercetin (60 μM) was applied as positive control. All data are presented as the means ± SD (n= 3) and values obtained from 3 separate cultures. Statistical analysis indicated that the influence of the compounds used had significant effect on H2O2-induced membrane toxicity (LDH release) (P < 0.05).](https://images.vocus.cc/2ea60420-4546-4599-a165-1ca39e7386c9.gif)
Inhibition effect of LDH release of fruit phenolics on H2O2-induced membrane damage in PC12 cells. PC12 cells were pretreated for 10 min with various concentrations. The cells were treated with H2O2 (400 μM) for 2 h. LDH activity in culture supernatants was measured with a colorimetric LDH assay kit. Basal and total LDH activities were determined in intact cells and cell solubilized with 0.2% Triton X-100, respectively, and LDH release was calculated as [(sample LDH − basal LDH) / (total LDH − basal LDH)]× 100 (%). Quercetin (60 μM) was applied as positive control. All data are presented as the means ± SD (n= 3) and values obtained from 3 separate cultures. Statistical analysis indicated that the influence of the compounds used had significant effect on H2O2-induced membrane toxicity (LDH release) (P < 0.05).
Preventive effects of fruit phenolics on H2O2-induced membrane damage in PC12 cells. PC12 cells were plated at low density in 24-well plate. Cells were incubated with the phenolics for 10 min before the addition of 400 μM H2O2. Cultures were observed after additional 2 h, and trypan blue exclusion staining was performed. Quercetin (60 μM) was applied as positive control. Data are presented as mean ± SD for 1 representative triplicate determination and are expressed as the percent survival compared to the corresponding controls (P < 0.05).
圖表解讀：
- 圖 2： 以乳酸去氫酶（LDH）的釋放量來衡量細胞膜受損程度。數據顯示，在不同濃度的蘋果、香蕉、柳橙萃取物皆能顯著抑制 LDH 釋放；而且果萃濃度越高，保護效果越明顯。
- 圖 3： 透過 Trypan blue 排除測試，評估相同氧化壓力條件下細胞的整體存活率。結果顯示，蘋果萃取物的護腦效果最強，香蕉與柳橙也同樣展現令人矚目的保護力，同樣呈現劑量依賴性。
值得注意的是，圖 2 與圖 3 分別聚焦在細胞健康的兩個層面：前者關注細胞膜完整性，後者則總覽細胞存活狀況，兩者皆證實了水果多酚的神奇抗氧化效益。
關於 Trypan blue 排除測試：
這種方法能根據細胞膜是否完好來區分活細胞與死亡細胞。若存活率高，代表細胞仍然健康；反之，若存活率低，就意味著可能遭受氧化壓力或其他因素導致的嚴重損傷。
日常防護小撇步：
每天一杯我們的「牧牧現打果汁」，以新鮮香蕉、木瓜或蘋果製作，不只能讓你享受天然果香，更能為你的大腦提供抗氧化的多酚，減少自由基對神經細胞的威脅。簡單補充，即能替腦力健康加分，讓你在忙碌生活中得到更多保護與能量！
研究文章:
https://ift.onlinelibrary.wiley.com/doi/full/10.1111/j.1750-3841.2007.00632.x
