Study Of Safety Evaluation Of Chinese Patent Medicines Containing Cinnabar With In Vitro Digestion Method

Flame atomic absorption spectrometric method (FAAS) for determination of mercury in cinnabar containing-Chinese Patent Medicines(CPMs) was developed and total mercury contents in some common CPMs containing cinnabar were successfully analyzed by using FAAS in the paper. Mercury bioaccessibility from CPMs containing cinnabar was estimated by measuring the soluble or dialyzable mercury fraction resulting from in vitro digestion method of CPMs containing cinnabar. In addition, the effects of phytochemical-rich food on bioaccessiblity of mercury in CPMs containing cinnabar were investigated under in vitro digestion. Taking into consideration mercury levels, intakes of CPMs and ongoing research in clinical surveying of mercury, the potential health risk of mercury for some common CPMs containing cinnabar was assessed. The results showed as follows:(1) CPMs samples (FuFangLuHuiJiaoNang capsule, TianWangBuXin Wan pill, BoZiYangXin pill, Xiaoerzhibao pill, RenDan pill, ZiXue powder and ErKeQiLiSan powder) were digested by HNO3-H2SO4-HClO4 digested acidic and the closed-pressurized system. The working condition of Flame Atomic Absorption Spectrophotometer (lamp current, burner height, acetylene flow rate, etc.) was optimized. At last, high pressure digestion-atomic absorption spectrometry was developed. The mercury content in FuFangLuHuiJiaoNang capsule was determined (11.62±0.3%) with the above method and t test showed that the result is in consistent with previously reported results (11.68±0.4%). Thus the developed method (high pressure digestion-atomic absorption spectrometry) meets the demands of analysis procedure. The concentrations of mercury in eight common CPMs were in the range of 2.99-116.23 mg·g-1, that means the mercury contents in all samples were thousands of times higher than the Food Standards (Hg≤1.0 mg·kg-1) and Medicinal Plants and preparation industry standards (Hg≤0.2 mg·kg-1).(2) In vitro digestion method was adopted to simulate the conditions of gastric compartment and intestinal compartment, before the soluble and dialysate fractions were collected and quantified by the means of HG-AFS. Firstly, cold vapor atomic fluorescence spectrometry (CV-AFS) and hydride generation atomic fluorescence spectrometry (HG-AFS) were compared in methodology. For ZYG-Ⅱintelligent cold atomic fluorescence, linear range of 0-2.0 ng·mL-1 was obtained, while linear range of 0-20.0ng·mL-1 for AFS-820 double channel atomic fluorescence spectrometer, and there was little difference in the detection limit between them. Thus AFS was selected for its wider linear range. Moreover the bioaccessibility data are very different following in vitro dissolution and in vitro digestion dialysis,0.33%-2.65% for the former and 0.0038%-0.0117% for the latter, with mercury bioavailability of 85.60% and 23.09% from HgCl. Compared with in vitro solubility procedure, In vitro digestion and dialysis can not only simulate physiological pH, but also reflect the passive diffusion process in the intestinal compartment, therefore data could be more convincing under in vitro digestion and dialysis.(3) Mercury bioaccessibility were measured following a simulated digestion of CPMs with added phytochemical-rich food treatments (black tea, green tea, a large soy milk, oat thick paste, thick corn syrup, orange juice). The result showed that all the phytochemical-rich food treatments reduced mercury bioaccessibility to some extent, with black tea (1-13%,17-22%), big soy milk (5-12%,21-29%) and green tea (1.7-18.4%,21.6-30%) having the most significant reduction of mercury bioaccessibility.(4) One risk assessment models (PTWIs evaluation model) was proposed to evaluate the potential risk of CPMs. For PTWIs evaluation model, daily bioaccessible mercury from TongRenAnSshengwan pill is just above the limit value, while the other five kinds of CPMs are one to two orders of magnitude less than the threshold value; Referring to mercury poisoning dose model proposed by Pangjingtuan, the maximal bioaccessible mercury is very close to the threshold value, while the other five kinds of CPMs are 1 to 2 orders of magnitude less than the threshold value. The two safety evaluation models reach the same conclusion that short-term oral administration of CPMs containing cinnabar poses little risk to human health.