補充綠藻對C57BL/6J小鼠攝食維生素B12缺乏飼料的影響

The effect of Chlorella sorokiniana supplementation on C57BL/6J mice fed with vitamin B12-deficient diets

許韻韻(Victoria Yun-Yun Khor)

指導教授 ： 林璧鳳

國立臺灣大學/生命科學院/生化科技學系/碩士(2020年)

https://doi.org/10.6342/NTU202003734

摘要

綠藻 (chlorella) 是一種單細胞微藻，為目前熟知的保健營養品，具有抗氧化、降血糖、血脂，調節免疫等功能。綠藻含有豐富的營養素，但對於綠藻内的維生素B12，是否為具活性在人體可利用的形式，目前還有爭議。因此，本研究利用動物實驗探討在B12降低的情況下，補充綠藻 (Chlorella sorokiniana) 是否可以改善B12缺乏引起的代謝異常情況。實驗包括實驗一：給予13，21週齡C57BL/6J小鼠AIN-93 (ctrl組) 與B12缺乏飼料15週，後將缺乏組分爲B12缺乏組 (dB12) 和綠藻組 (dB12Ch)，餵食28週。實驗二，重複實驗一但小鼠週齡與餵食時間不同。小鼠於9-13週齡開始實驗，餵食AIN-93與B12缺乏飼料17週後，補充綠藻餵食16週。實驗三，給予8週齡C57BL/6J小鼠ctrl組與B12缺乏飼料12週後，分爲B12缺乏組 (dB12) ，1% 綠藻組 (dB12Ch1) 和5% 綠藻組 (dB12Ch5)，補充綠藻餵食10週。定期採血，測血糖、血脂和血膽固醇，犧牲後採集性腺脂肪、皮下脂肪、腎周脂肪等測得體脂肪百分率，並測肝臟、腎臟、尿液及糞便的B12含量，和分析脾臟探討補充綠藻對餵予維生素B12缺乏的全身性免疫影響。結果顯示，綠藻可顯著降低血糖、血膽固醇、肝臟膽固醇與三酸甘油酯，也能顯著增加糞便内膽固醇與三酸甘油酯的含量，改善脂質代謝狀況。另外，綠藻也可顯著提高IL-10並降低TNF-α，可能具有免疫調節作用。綠藻的補充顯著增加肝臟與腎臟内維生素B12含量，表示綠藻内的維生素B12可被吸收並儲存於小鼠體内，可作為素食者的維生素B12食物來源。

關鍵字

素食 ； 維生素B12缺乏 ； 綠藻 ； 脂質代謝 ； 免疫

並列摘要

Chlorella is a single-celled microalgae. It is a well-known health supplementation. Chlorella is rich in nutrients, but it is still debatable whether vitamin B12 in Chlorella is an active form which can be used in human body. In this study, we used animal model to investigate whether supplementation of Chlorella sorokiniana can improve metabolic abnormalities caused by B12 deficiency. Experiments included Experiment 1: 13-21-week-old C57BL/6J mice were fed with AIN-93 and B12-deficient diet for 15 weeks, deficient group were divided into B12 deficient group (dB12) and chlorella supplement group (dB12Ch), fed for 28 weeks. Experiment 2: repeat experiment 1, but difference in ages and feeding periods. 9-13-week-old C57BL/6J mice, fed with AIN-93 and B12 deficiency diet for 17 weeks, supplemented with Chlorella for 16 weeks. In Experiment 3, 8-week-old C57BL/6J mice fed AIN-93 and B12-deficient diet for 12 weeks, were divided into B12-deficient group (dB12), 1% chlorella group (dB12Ch1) or 5% chlorella group (dB12Ch5), and fed for 10 weeks. Blood samplings were carried out regularly. Gonadal white adipose tissue, Inguinal white adipose tissue, Retroperitoneal white adipose tissue and Brown adipose tissue were collected after sacrificing to measure the percentage of body fat. The content of B12 in liver, kidney, urine, feces and the spleen were investigated as well as the effect of chlorella on the systemic immunity of vitamin B12 deficiency. The results showed Chlorella can significantly reduce blood sugar, blood cholesterol, liver cholesterol and triglycerides, partially due to significant increase of cholesterol and triglycerides in feces. In addition, Chlorella supplement obviously increase IL-10 and reduce TNF-α, which may have immunomodulatory effects. The vitamin B12 content in the liver and kidney were significantly elevated after supplement of Chlorella, indicating that vitamin B12 in Chlorella can be absorbed and stored in mice. It suggest that Chlorella may be the source of vitamin B12 for vegans.

並列關鍵字

Vegans ； vitamin B12 deficiency ； Chlorella sorokiniana ； lipid metabolism ； immunology

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