Institute for Medical Research and Occupational Health, Zagreb, Croatia.
University of Zagreb Faculty of Food Technology and Biotechnology, Zagreb, Croatia.
Arh Hig Rada Toksikol. 2022 Jul 7;73(2):158-168. doi: 10.2478/aiht-2022-73-3653.
Strawberry tree ( L.) honey (STH), also known as "bitter honey", is a traditional medicine widely used in the Mediterranean area. Regardless of geographical origin, it usually has a very high content of phenolic compounds and strong antioxidant capacity. Yet, little is still known about the effects of STH, its phenolic extract (STHE), and its main bioactive compound - homogentisic acid (HGA) - at the cell level. The aim of this study was to estimate total phenolic content, DPPH radical scavenging activity, and ferric reducing antioxidant power of STH made in Croatia and investigate cytotoxic and pro-oxidative effects of STH, STHE and HGA on three human cell lines: tongue squamous cell carcinoma (CAL 27), hepatocellular carcinoma (HepG2), and epithelial colorectal adenocarcinoma cells (Caco-2) cells. These substances were tested at four concentrations (0.5-5× average human daily intake of STH) and over 30 min and 1 and 2 h. Croatian STH had a total phenolic content of 1.67 g gallic acid equivalents (GAE) per kg of honey, DPPH radical scavenging activity of 2.96 mmol Trolox equivalents (TE) per kg of honey, and ferric reducing antioxidant power (FRAP) of 13.5 mmol Fe per kg of honey. Our results show no clear and consistent time- or concentration-dependent cytotoxicity in any of the cell lines. ROS levels in all the three cell types at almost all exposure times were not significantly higher than control. The most important observation is that the tested substances have low cytotoxicity and high biocompatibility, regardless of concentration, which is a good starting point for further research of their biological effects in other models.
树莓蜜（L.），又称“苦蜜”，是一种在地中海地区广泛使用的传统药物。无论其地理来源如何，它通常都含有非常高的酚类化合物含量和强大的抗氧化能力。然而，目前对于树莓蜜、其酚类提取物（STHE）及其主要生物活性化合物 - 原儿茶酸（HGA）在细胞水平上的作用知之甚少。本研究旨在评估克罗地亚生产的树莓蜜的总酚含量、DPPH 自由基清除活性和铁还原抗氧化能力，并研究树莓蜜、STHE 和 HGA 对三种人类细胞系（舌鳞癌细胞（CAL 27）、肝癌细胞（HepG2）和上皮结肠直肠腺癌细胞（Caco-2））的细胞毒性和促氧化作用。这些物质在四个浓度（0.5-5×树莓蜜的平均人类每日摄入量）下进行测试，时间为 30 分钟以上以及 1 小时和 2 小时。克罗地亚树莓蜜的总酚含量为每公斤蜂蜜 1.67 克没食子酸当量（GAE），DPPH 自由基清除活性为每公斤蜂蜜 2.96 毫摩尔 Trolox 当量（TE），铁还原抗氧化能力（FRAP）为每公斤蜂蜜 13.5 毫摩尔铁。我们的结果表明，在任何细胞系中都没有明显且一致的时间或浓度依赖性细胞毒性。在几乎所有暴露时间点，所有三种细胞类型的 ROS 水平均不比对照高。最重要的观察结果是，无论浓度如何，测试物质的细胞毒性低且生物相容性高，这是进一步研究其在其他模型中的生物学效应的良好起点。
