da Rosa H S, Salgueiro A C F, Colpo A Z C, Paula F R, Mendez A S L, Folmer V
Laboratório de Bioquímica e Toxicologia de Produtos Naturais e Sintéticos, Universidade Federal do Pampa, Uruguaiana, RS, Brasil.
Laboratório de Desenvolvimento e Controle de Qualidade em Medicamentos, Universidade Federal do Pampa, Uruguaiana, RS, Brasil.
Braz J Med Biol Res. 2016 Jul 11;49(8). doi: 10.1590/1414-431X20165282.
Sida tuberculata (Malvaceae) is a medicinal plant traditionally used in Brazil as an antimicrobial and anti-inflammatory agent. Here, we aimed to investigate the different extractive techniques on phytochemical parameters, as well as to evaluate the toxicity and antioxidant capacity of S. tuberculata extracts using in silico and in vitro models. Therefore, in order to determine the dry residue content and the main compound 20-hydroxyecdysone (20E) concentration, extracts from leaves and roots were prepared testing ethanol and water in different proportions. Extracts were then assessed by Artemia salina lethality test, and toxicity prediction of 20E was estimated. Antioxidant activity was performed by DPPH and ABTS radical scavenger assays, ferric reducing power assay, nitrogen derivative scavenger, deoxyribose degradation, and TBARS assays. HPLC evaluation detected 20E as main compound in leaves and roots. Percolation method showed the highest concentrations of 20E (0.134 and 0.096 mg/mL of extract for leaves and roots, respectively). All crude extracts presented low toxic potential on A. salina (LD50 >1000 µg/mL). The computational evaluation of 20E showed a low toxicity prediction. For in vitro antioxidant tests, hydroethanolic extracts of leaves were most effective compared to roots. In addition, hydroethanolic extracts presented a higher IC50 antioxidant than aqueous extracts. TBARS formation was prevented by leaves hydroethanolic extract from 0.015 and 0.03 mg/mL and for roots from 0.03 and 0.3 mg/mL on egg yolk and rat tissue, respectively (P<0.05). These findings suggest that S. tuberculata extracts are a considerable source of ecdysteroids and possesses a significant antioxidant property with low toxic potential.
刺蒴麻（锦葵科）是一种药用植物，在巴西传统上用作抗菌和抗炎剂。在此，我们旨在研究不同提取技术对植物化学参数的影响，并使用计算机模拟和体外模型评估刺蒴麻提取物的毒性和抗氧化能力。因此，为了确定干残渣含量和主要化合物20-羟基蜕皮酮（20E）的浓度，制备了叶和根的提取物，测试了不同比例的乙醇和水。然后通过卤虫致死试验评估提取物，并估计20E的毒性预测。通过DPPH和ABTS自由基清除试验、铁还原能力试验、氮衍生物清除试验、脱氧核糖降解试验和TBARS试验进行抗氧化活性测定。HPLC评估检测到20E是叶和根中的主要化合物。渗漉法显示20E的浓度最高（叶和根提取物分别为0.134和0.096 mg/mL）。所有粗提物对卤虫的毒性潜力都很低（LD50>1000 µg/mL）。20E的计算评估显示毒性预测较低。对于体外抗氧化试验，叶的水乙醇提取物比根的提取物最有效。此外，水乙醇提取物的抗氧化IC50高于水提取物。叶的水乙醇提取物在蛋黄和大鼠组织中分别从0.015和0.03 mg/mL以及根从0.03和0.3 mg/mL开始阻止TBARS的形成（P<0.05）。这些发现表明，刺蒴麻提取物是蜕皮甾体的重要来源，具有显著的抗氧化特性且毒性潜力低。
