Raw data: Mercury leaching ratio (μg/g) from Tibetan medicine Zuotai,β-HgS and α-HgS in pure water and artificial gastrointestinal juices containing Cys(or GSH) or not.

Zuotai, a known Tibetanmedicinal mixture containing insoluble cubic mercuric sulfide (β-HgS), has beenused to treat diseases with long history. The mercury leaching ratio from Zuotai ingastrointestinal environment is one determinant factor for its bioavailabilityand 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)] on mercury leaching from Zuotai,β-HgS, and α-HgS in artificial gastrointestinal juices or pure water.The artificial gastric juice and artificial intestinal juice were preparedaccording to the methods described in Chinese Pharmacopoeia (2010version). The following solutions were prepared: Cys in pure water (5.21g/L), GSH in pure water (13.21 g/L), Cys in artificial gastric juice (5.21g/L), GSH in artificial gastric juice (13.21 g/L), Cys in artificial intestinaljuice (5.21 g/L), and GSH in artificial intestinal juice (13.21 g/L). The molesof Cys and GSH in this study were 0.215 mmol—the same as that of β-HgS andα-HgS. A solid-liquid ratio of 1:100 was adopted in all leaching experiments.Digestion, peristalsis and emptying of drug in the gastrointestinal tract weresimulated in vitro. We detected the mercury released in solutionsusing Automatic Direct Mercury Analyzer. Leaching Ratio of Mercury(μg/g)=[Total Weight of Mercury Released (μg)]/[Total Weight of SubstanceTested (g)]The results showed the following trend forthe mercury leaching ratio of Zuotai: artificial gastric juice >artificial intestinal juice > pure water, whereas the trend for β-HgS andα-HgS was as follows: artificial intestinal fluid > artificial gastric fluid> pure water. The mercury leaching ratios of Zuotai, β-HgS, andα-HgS significantly increased in artificial intestinal juice containing L-Cysor GSH compared to that without sulfhydryl biomolecules in the juice. However,in pure water and artificial gastric juice with Cys or GSH, the mercuryleaching ratio of Zuotai reduced remarkably, in contrast tothe results observed for β-HgS and α-HgS.