Jalil Abbe Maleyki Mhd, Ismail Amin, Pei Chong Pei, Hamid Muhajir, Kamaruddin Syed Hasbullah Syed
Department of Nutrition and Dietetics, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
J Agric Food Chem. 2008 Sep 10;56(17):7877-84. doi: 10.1021/jf8015915. Epub 2008 Aug 15.
In this present study, we investigated the effects of cocoa extract containing polyphenols and methylxanthines prepared from cocoa powder on the biochemical parameters of obese-diabetic (Ob-db) rats. Obese-diabetic (Ob-db) rats were developed using a high-fat diet (49% fat, 32% carbohydrate, and 19% protein from total energy, kcal) for 3 months, followed by a low dose (35 mg/kg body weight) streptozotocin (STZ) injection. Cocoa extract (600 mg/kg body weight/day) was given to the rats for 4 weeks. The results indicated that there were no significant differences in fasting plasma glucose and insulin level after 4 weeks of cocoa extract administration. Oral glucose tolerance test revealed that cocoa supplementation in Ob-db rats significantly (p < 0.05) reduced plasma glucose at 60 and 90 min compared to unsupplemented Ob-db rats. Plasma free fatty acid and oxidative stress biomarker (8-isoprostane) were significantly (p < 0.05) reduced after cocoa supplementation. Superoxide dismutase activity was enhanced in Ob-db compared to that in nonsupplemented rats. However, no change was observed in catalase activity. The results showed that cocoa supplementation had an effect on postprandial glucose control but not for long term (4 weeks). Moreover, cocoa supplementation could reduce circulating plasma free fatty acid and 8-isoprostane and may enhance the antioxidant defense system.
在本研究中，我们调查了由可可粉制备的含有多酚和甲基黄嘌呤的可可提取物对肥胖糖尿病（Ob-db）大鼠生化参数的影响。采用高脂饮食（总能量千卡中脂肪占49%、碳水化合物占32%、蛋白质占19%）喂养3个月，随后注射低剂量（35毫克/千克体重）链脲佐菌素（STZ）来培育肥胖糖尿病（Ob-db）大鼠。给大鼠喂食可可提取物（600毫克/千克体重/天），持续4周。结果表明，给予可可提取物4周后，空腹血糖和胰岛素水平无显著差异。口服葡萄糖耐量试验显示，与未补充可可提取物的Ob-db大鼠相比，补充可可提取物的Ob-db大鼠在60分钟和90分钟时血浆葡萄糖显著降低（p < 0.05）。补充可可提取物后，血浆游离脂肪酸和氧化应激生物标志物（8-异前列腺素）显著降低（p < 0.05）。与未补充的大鼠相比，Ob-db大鼠的超氧化物歧化酶活性增强。然而，过氧化氢酶活性未观察到变化。结果表明，补充可可提取物对餐后血糖控制有影响，但对长期（4周）血糖控制无影响。此外，补充可可提取物可降低循环血浆游离脂肪酸和8-异前列腺素，并可能增强抗氧化防御系统。
