International MS/PhD Program in Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan.
Liver Center, Ulaanbaatar 14230, Mongolia.
Molecules. 2021 Feb 25;26(5):1217. doi: 10.3390/molecules26051217.
The Mongolian rhubarb- L. -and L. -a Taiwanese local rhubarb belonging to the family of -are principal therapeutic materials in integrative medicine due to their rich quantities of bioactive compounds; however, their phytochemical and antioxidant properties, and anti-cancer activity is poorly investigated. Furthermore, the phytochemical characteristics of both species may be affected by their different geographical distribution and climatic variance. The current study aimed to compare with extracts in different polarity solvents (n-hexane, ethyl acetate, acetone, ethanol, and water) for their phytochemical contents including the total phenolic content (TPC), total anthraquinone content (TAC), total flavonoid content (TFC), antioxidant and free radical scavenging capacities, and anticancer ability on the HepG2 cell. Except for the n-hexane extract, all of the extracts had considerably higher TPCs than extracts, ranging from 8.39 to 11.16 mg gallic acid equivalent (GAE) per gram of dry weight, and the TPCs of each extract were also significantly correlated with their antioxidant capacities by ABTS, DPPH, and FRAP assays ( < 0.05). Moreover, there was no remarkable association between the antioxidant capacities and either TACs or TFCs in both the and extracts. Besides, high-performance liquid chromatography (HPLC) analysis revealed that both the and extracts contained chrysophanol, emodin, and physcion, and those bioactive compounds were relatively higher in the n-hexane solvent extracts. Additionally, we observed different levels of dose-dependent cytotoxic effects in all the extracts by cell viability assay. Notably, the ethanol extract of had a compelling cytotoxic effect with the lowest half-maximum inhibition concentration (IC50-171.94 ± 6.56 µg/mL at 48 h) among the extracts than the ethanol extract of . Interestingly, the ethanol extract of but not significantly induced apoptosis in the human liver cancer cell line, HepG2, with a distinct pattern in caspase-3 activation, resulting in increased PARP cleavage and DNA damage. In summary, Mongolian Rhubarb, , showed more phytochemical contents, as well as a higher antioxidant capacity and apoptotic effect to HepG2 than RC; thus, it can be exploited for the proper source of natural antioxidants and liver cancer treatment in further investigation.
大黄- 和 台湾大黄- 属于蓼科植物，由于其富含生物活性化合物，是综合医学的主要治疗材料；然而，它们的植物化学和抗氧化特性以及抗癌活性研究甚少。此外，这两个物种的植物化学特征可能受到其不同的地理分布和气候差异的影响。本研究旨在比较 和 不同极性溶剂（正己烷、乙酸乙酯、丙酮、乙醇和水）提取物的植物化学含量，包括总酚含量（TPC）、总蒽醌含量（TAC）、总黄酮含量（TFC）、抗氧化和自由基清除能力以及对 HepG2 细胞的抗癌能力。除正己烷提取物外，所有 提取物的 TPC 均显著高于 提取物，范围为 8.39 至 11.16 毫克没食子酸当量（GAE）/克干重，并且每种提取物的 TPC 也与其通过 ABTS、DPPH 和 FRAP 测定的抗氧化能力显著相关（<0.05）。此外，在 和 提取物中，抗氧化能力与 TAC 或 TFC 之间均无显著相关性。此外，高效液相色谱（HPLC）分析表明， 和 提取物均含有大黄素、大黄素和大黄素，这些生物活性化合物在正己烷溶剂提取物中相对较高。此外，通过细胞活力测定，我们观察到所有提取物均存在不同程度的剂量依赖性细胞毒性作用。值得注意的是，与 提取物的乙醇提取物相比， 的乙醇提取物在 HepG2 人肝癌细胞系中具有更强的细胞毒性作用，其半数最大抑制浓度（IC50-171.94±6.56µg/mL，48 小时）最低。有趣的是，只有 的乙醇提取物而不是 的乙醇提取物在人肝癌细胞系 HepG2 中显著诱导细胞凋亡，并且 caspase-3 激活模式明显，导致 PARP 裂解和 DNA 损伤增加。总之，大黄- 和 台湾大黄- 比 RC 具有更高的植物化学含量、更强的抗氧化能力和促凋亡作用，可进一步研究其作为天然抗氧化剂和肝癌治疗的合适来源。
