愛玉子瘦果萃取物對降血糖與抗肥胖之功效研究

Abstract

愛玉子 (Ficus pumila L. var. awkeotsang) 為臺灣特有物種，儘管食用愛玉凍的歷史已有幾百年，但對於愛玉子相關的機能功效尚有許多研究空間。目前已有部分研究指出，服用可溶性膳食纖維，可減緩餐後血糖上升，也對降低膽固醇、降低血脂有顯著作用。由於許多文獻發現類黃酮及多酚化合物有助於增加胰島素敏感性、調節葡萄糖轉運蛋白 (GLUT) 對葡萄糖的運輸，因此値得探討愛玉凍 (愛玉子瘦果凝膠態萃取物) 與愛玉子瘦果非凝膠態萃取物對於抗糖尿病、抗肥胖的功效。 本研究使用60倍水量－60 μg/mL 鈣離子濃度為所有品系的統一製膠配方，進行體外模擬消化試驗。結果顯示三種品系的愛玉凍皆具有延緩澱粉水解的效果，膽固醇吸附力與葡萄糖相關的體外模擬試驗皆有相似的趨勢，野生種與紅九品系愛玉凍的表現較佳。愛玉子瘦果非凝膠態萃取物的部分，甲醇萃取物 (80M) 對糖解酵素的抑制能力大幅高於水萃物 (W)，抑制能力由高至低為紅九80M、苗二80M、野生種80M。抗氧化能力分析中，紅九80M的總多酚含量、類黃酮含量、還原力、DPPH (1,1-diphenyl-2-picryl-hydrazyl) 自由基清除力皆高於其他組別。 進一步將紅九80M與3T3-L1脂肪細胞於誘導分化時期共培養，從油紅O染色結果來看，紅九80M萃取物確實能抑制脂肪油滴形成。三酸甘油脂含量測定的結果也顯示能減少脂肪累積、降低分化程度，且預防組與治療組皆有抑制效果。若綜合顯微鏡觀察細胞形態變化、油紅染色結果、三酸甘油脂含量的結果，認為預防組200 μg/mL (p-200組) 應該為最具有抑制肥胖及改善高血糖病症之潛力的組別。根據紅九80M愛玉子瘦果非凝膠萃取物透過糖解酵素抑制能力分析與細胞實驗可知，該萃取物具有降血糖與抗肥胖的潛在功效。

Aiyuzi (Ficus pumila L. var. awkeotsang) is an endemic species in Taiwan. Although the history of consuming Aiyu Jelly has been hundreds of years, there are still less researchs for the functional effects related to F. pumila L. var. awkeotsang. At present, some studies have pointed out that taking soluble dietary fiber can slow down the rise of blood sugar after meals, and there has been a significant effect on lowering cholesterol and lowering blood lipids. Since many literatures have found that flavonoids and polyphenolic compounds help increasing insulin sensitivity, and are also related to regulation of glucose transport by gluclose transporter (GLUT). It is worth exploring Aiyu Jelly (Aiyuzi achene gel extract) and Aiyuzi achene non-gel extract about the effects of anti-diabetic and anti-obesity. In this study, 60 times the amount of water - 60 μg/mL calcium ion concentration was used as the unified jelly formula for all strains to conduct in vitro simulated digestion tests. In the in vitro starch decomposition test, it is obvious that the three strains of Aiyu Jelly have the effect of delaying the hydrolysis of starch. The in vitro simulation tests related to cholesterol adsorption and glucose have similar trends, and the wild species and Hongjiu strain Aiyu Jelly performed better. As for the part of Aiyuzi achene non-gel extract, methanol extract (80M) has a much higher inhibitory effect on glycolytic enzymes than water extract (W). The inhibitory ability from high to low is Hongjiu 80M, Miaoli No.2 80M, and Wild strain 80M. In the analysis of antioxidant capacity, the total polyphenolic compound content, flavonoid content, reducing power, and DPPH (1,1-diphenyl-2-picryl-hydrazyl) free radical scavenging ability of Hongjiu 80M are higher than other groups. Furthermore, Hongjiu 80M and 3T3-L1 adipocytes were co-cultured during the induction period. Judging from the results of Oil Red O staining, Hongjiu 80M extract can indeed inhibit the formation of fatty oil droplets. The result of determination of triglyceride content also shows that Hongjiu 80M extract can reduce the accumulation of fat, reduce the degree of differentiation, and both the prevention group and the treatment group have inhibitory effects. Based on microscope observation of cell morphology changes, Oil Red O staining results, triglyceride content results, the prevention group 200 μg/mL (p-200) should be the most effective group with potential to inhibit obesity and improve hyperglycemia. According to the analysis of glycolytic enzyme inhibition and cell experiments, the non-gel extract of Aiyuzi achene of the Hongjiu 80M shows the potential to lower blood sugar and prevent obesity.