Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, MG, Brazil.
Free Radic Res. 2012 Mar;46(3):329-38. doi: 10.3109/10715762.2012.656100. Epub 2012 Feb 6.
Annatto (Bixa orellana L.) contains a mixture of orange-yellowish pigments due to the presence of various carotenoids that have antioxidant effect. The immune system is especially vulnerable to oxidative damage because many immune cells, such as neutrophils, produce reactive oxygen and nitrogen species (ROS and RNS) as part of the body's defence mechanisms to destroy invading pathogens. It is well known that the function of neutrophils is altered in diabetes; one of the major functional changes in neutrophils in diabetes is the increased generation of extracellular superoxide via the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase system. The purpose of this study is to evaluate the production of ROS and nitric oxide (NO) as well as the expression of NADPH oxidase subunits, inducible nitric oxide (iNOS), superoxide dismutase (SOD) and catalase (CAT) in neutrophils from diabetic rats treated with annatto extract and β-carotene. Forty-eight female Fisher rats were distributed into six groups according to the treatment received. All animals were sacrificed 7 days after treatment, and the neutrophils were isolated using two gradients of different densities. The ROS and NO were quantified by a chemiluminescence and spectrophotometric assays, respectively. Analyses of gene expression were performed using quantitative real time polymerase chain reaction (qRT-PCR). The results show that treatment with annatto extract and β-carotene was able to decrease ROS production and the mRNA levels of p22(phox) and p47(phox) and increase the mRNA levels of SOD and CAT in neutrophils from diabetic rats. These data suggest that annatto extract and β-carotene exerts antioxidant effect via inhibition of expression of the NADPH oxidase subunits and increase expression/activity of antioxidant enzymes.
胭脂树（Bixa orellana L.）含有各种类胡萝卜素，呈现橙黄色调，具有抗氧化作用。免疫系统特别容易受到氧化损伤，因为许多免疫细胞，如中性粒细胞，会产生活性氧和氮物种（ROS 和 RNS），作为身体防御机制的一部分，以摧毁入侵的病原体。众所周知，中性粒细胞的功能在糖尿病中会发生改变；糖尿病中性粒细胞的主要功能变化之一是通过烟酰胺腺嘌呤二核苷酸磷酸（NADPH）氧化酶系统增加细胞外超氧化物的产生。本研究旨在评估糖尿病大鼠中性粒细胞中 ROS 和一氧化氮（NO）的产生以及 NADPH 氧化酶亚基、诱导型一氧化氮合酶（iNOS）、超氧化物歧化酶（SOD）和过氧化氢酶（CAT）的表达，这些中性粒细胞用胭脂树提取物和β-胡萝卜素处理。将 48 只雌性 Fisher 大鼠根据接受的治疗方案分为六组。所有动物在治疗后 7 天处死，使用两种不同密度的梯度分离中性粒细胞。通过化学发光和分光光度法分别定量测定 ROS 和 NO。使用实时定量聚合酶链反应（qRT-PCR）进行基因表达分析。结果表明，胭脂树提取物和β-胡萝卜素处理能够降低糖尿病大鼠中性粒细胞中 ROS 的产生和 p22(phox)和 p47(phox)的 mRNA 水平，并增加 SOD 和 CAT 的 mRNA 水平。这些数据表明，胭脂树提取物和β-胡萝卜素通过抑制 NADPH 氧化酶亚基的表达和增加抗氧化酶的表达/活性来发挥抗氧化作用。
