Departamento de Química, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Campus UFSM, Santa Maria, RS, Brazil.
Lipids Health Dis. 2013 Feb 8;12:12. doi: 10.1186/1476-511X-12-12.
Previous experimental investigations have suggested that guaraná (Paullinia cupana Kunth, supplied by EMBRAPA Oriental) consumption is associated with a lower prevalence of cardiovascular metabolic diseases and has positive effects on lipid metabolism, mainly related to low density lipoprotein (LDL) levels. As LDL oxidation is an important initial event in the development of atherosclerosis, we performed in vitro and in vivo studies to observe the potential effects of guaraná on LDL and serum oxidation.
The in vivo protocol was performed using blood samples from 42 healthy elderly subjects who habitually ingested guaraná (GI) or never ingested guaraná (NG). The formation of conjugated dienes (CDs) was analyzed from serum samples. The in vitro protocols were performed using LDL obtained from 3 healthy, non-fasted, normolipidemic voluntary donors who did not habitually ingest guaraná in their diets. The LDL samples were exposed to 5 different guaraná concentrations (0.05, 0.1, 0.5, 1, and 5 μg/mL).
GI subjects demonstrated lower LDL oxidation than did NG subjects (reduction of 27%, p < 0.0014), independent of other variables. In the GI group the total polyphenols was positively associated with LDL levels. Also, guaraná demonstrated a high antioxidant activity in vitro, mainly at concentrations of 1 and 5 μg/mL, demonstrated by suppression of CDs and TBARS productions, tryptophan destruction and high TRAP activity.
Guaraná, similar to other foods rich in caffeine and catechins such as green tea, has some effect on LDL oxidation that could partially explain the protective effects of this food in cardiometabolic diseases.
先前的实验研究表明，瓜拉那（Paullinia cupana Kunth，由 EMBRAPA Oriental 提供）的消费与心血管代谢疾病的患病率较低有关，并且对脂质代谢有积极影响，主要与低密度脂蛋白（LDL）水平有关。由于 LDL 氧化是动脉粥样硬化发展的重要初始事件，我们进行了体外和体内研究，以观察瓜拉那对 LDL 和血清氧化的潜在影响。
体内研究方案使用 42 名习惯性摄入瓜拉那（GI）或从不摄入瓜拉那（NG）的健康老年受试者的血液样本进行。分析血清样本中的共轭二烯（CDs）形成。体外方案使用来自 3 名健康、非空腹、正常血脂志愿者的 LDL 进行，这些志愿者的饮食中从不习惯摄入瓜拉那。将 LDL 样本暴露于 5 种不同的瓜拉那浓度（0.05、0.1、0.5、1 和 5 μg/mL）。
GI 组的 LDL 氧化程度低于 NG 组（降低 27%，p<0.0014），与其他变量无关。在 GI 组中，总多酚与 LDL 水平呈正相关。此外，瓜拉那在体外具有很高的抗氧化活性，主要在 1 和 5 μg/mL 的浓度下，通过抑制 CDs 和 TBARS 的产生、色氨酸的破坏和高 TRAP 活性来证明。
瓜拉那与其他富含咖啡因和儿茶素的食物（如绿茶）相似，对 LDL 氧化有一定的影响，这可能部分解释了这种食物对心血管代谢疾病的保护作用。
