Qinghai Key Laboratory of Tibetan Medicine Pharmacology and Safety Evaluation, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xinning Road 23, Xining, Qinghai, 810008, China.
University of Chinese Academy of Sciences, Beijing, 100047, China.
Biol Trace Elem Res. 2018 Aug;184(2):536-545. doi: 10.1007/s12011-017-1185-x. Epub 2017 Nov 12.
Zuotai, also named as "gTso thal", a known Tibetan medicinal mixture containing insoluble cubic crystal mercuric sulfide (β-HgS), has been used to treat diseases with long history. The mercury release ratio from Zuotai in gastrointestinal environment is one determinant factor for its bioavailability and biological effect. However, the information is still scarce now. Therefore, the study was designed to investigate the effect of sulfhydryl biomolecules [L-cysteine (Cys) and glutathione (GSH)] and pH on mercury dissociation from Zuotai, β-HgS, and hexagonal crystal mercuric sulfide (α-HgS) in artificial gastrointestinal juices or pure water with a 1:100 solid-liquid ratio. And, the digestion and peristalsis of gastrointestinal tract were simulated in vitro. The results showed the following trend for the mercury release ratio of Zuotai, artificial gastric juice > artificial intestinal juice > pure water, whereas the trend for β-HgS and α-HgS was as follows, artificial intestinal fluid > artificial gastric fluid > pure water. The mercury release ratios of Zuotai, β-HgS, and α-HgS significantly increased in artificial intestinal juice containing L-Cys or GSH compared to those without sulfhydryl biomolecules in the juice. However, in contrast to the results observed for β-HgS and α-HgS, the mercury release ratio of Zuotai was reduced remarkably in pure water and artificial gastric juice with Cys or GSH. And, we found that strong acidic or strong alkaline environments promoted the dissociation of mercury from Zuotai, β-HgS, and α-HgS. Taken together, current findings may contribute to other studies regarding clinical safety and bioavailability of the traditional drug Zuotai containing β-HgS.
坐台，也称为“gTso thal”，是一种已知的藏药混合物，含有不溶性立方晶状硫化汞（β-HgS），用于治疗疾病已有悠久的历史。在胃肠道环境中，从坐台释放的汞释放率是其生物利用度和生物效应的一个决定因素。然而，目前的信息仍然很少。因此，本研究旨在探讨巯基生物分子[L-半胱氨酸（Cys）和谷胱甘肽（GSH）]和 pH 值对 1：100 固液比下坐台、β-HgS 和六方晶状硫化汞（α-HgS）在人工胃肠液或纯水中的汞解离的影响，并模拟了胃肠道的消化和蠕动。结果表明，坐台的汞释放率趋势为人工胃液>人工肠液>纯水，而β-HgS 和α-HgS 的趋势为人工肠液>人工胃液>纯水。与不含巯基生物分子的人工肠液相比，含 L-Cys 或 GSH 的人工肠液中坐台、β-HgS 和α-HgS 的汞释放率显著增加。然而，与β-HgS 和α-HgS 的结果相反，在含 Cys 或 GSH 的纯水和人工胃液中，坐台的汞释放率显著降低。此外，我们发现强酸或强碱性环境促进了坐台、β-HgS 和α-HgS 中汞的解离。综上所述，目前的研究结果可能有助于其他关于含β-HgS 的传统药物坐台的临床安全性和生物利用度的研究。
