Health risk assessment of arsenic in Realgar and NiuHuangJieDu Tablets based on pharmacokinetic study

Abstract

NiuHuangJieDu Tablets (NHJDT), a popular realgar (As4S4) containing patented traditional Chinese medicine (TCM), is widely used in the treatment of acute tonsillitis, pharyngitis, periodontitis and mouth ulcer. However, arsenic is considered as one of the most toxic elements, leading to growing concerns about the quality and safety of realgar-containing TCMs recently. In this study, health risk assessment of arsenic in realgar and NHJDT was conducted through oral administration of both substances to rats with single and multiple doses, respectively. The total blood arsenic concentration was used as the health risk indicator and determined by hydride generation-atomic fluorescence spectrometry after modified Kjeldahl digestion, and then applied to the pharmacokinetic study. For single oral dose study in rats, the low, medium, and high doses of realgar and NHJDT were set equivalent to 1, 5 and 20 times the human therapeutic dose (1.3 mg realgar/kg), respectively. Multiple doses were given at low and high dose levels every 12 h for seven consecutive days, respectively. Significant differences in the total blood arsenic pharmacokinetic profiles were observed between the corresponding realgar and NHJDT groups. These results indicated that NHJDT significantly reduced the total blood arsenic exposure present in realgar, and the detoxification mechanism might be attributed to herb–herb interactions in NHJDT. However, the accumulation of blood total arsenic was significant due to the long elimination half-life and high accumulation index in both realgar and NHJDT groups. Therefore, the potential health risk of arsenic caused by the administration of realgar-containing TCMs should be taken into account for excessive or long-term medication. Precautions should be taken for the clinical application of realgar-containing TCMs.