| The research was carried out on the6medicinal materials, which are, Radix Panacis Quinquefolii, Radix Astragali, Radix et Rhizoma Glycyrrhizae, Radix Paeoniae Alba, Radix et Rhizoma Salviae Miltiorrhizae and Flos Lonicerae Japonicae, they have heavy metals limited standards in Pharmacopoeia of People’s Republic of China. The research was presented to discuss the health hazards of heavy metals and establish proper limited standards of heavy metals, which included:1) Investigate the dissolution rate of heavy metals in decoction pieces of6medicinal materials and powder of Radix et Rhizoma Salviae Miltiorrhizae by decocting.2) Study the dissolution rate of heavy metals in the powder of6medicinal materials by simulating the digestion of gastro-intestinal fluid.3) According to the particularities of traditional Chinese medicines in using process, the proper limited standards of heavy metals in medicinal materials were calculated by previous research results, literature statistical data, Target hazard quotients (THQ) and Provisional Tolerable Weekly Intake (PTWI), which were given by USEPA and WHO respectively.4) Based on the Soil Environmental Quality Standards (SEQS) of China, Salvia. Miltiorrhiza was chosen as experimental material to be cultivated in the soil which was added cadmium (Cd) to simulate the different level of soil in SEQS. The examination of the effect of Cd on the growth, physiological signs, accumulation of secondary metabolites and Cd content in S. Miltiorrhiza was carried out.Results:1. The medicinal materials were decocted twice depending on its property in terms of the references. After the microwave or wet digestion, the content of heavy metals in the medicinal materials and decoction solution was detected by ICP-MS. The dissolution rate of Cu, As, Hg was between1.97%～22.14%,0～70.02%,3.36%～31.17%respectively while the dissolution rate of Pb and cd was0. The dissolution rate of Cu and Hg in Radix Paeoniae Alba was low. Pb and Cd dissolved out from the decoction solution of powder of Radix et Rhizoma Salviae Miltiorrhizae. The dissolution rate of heavy metal was modified on the basis of literature data, as the rate of Cu, Pb, As, Cd and Hg was taken80%of the maximum of the dissolution rate, and then got35%,40%,80%,55%and70%respectively.2. After the digestion of powder of6medicinal materials in the simulated gastro-intestinal fluid, the digestive juice was digested by wet digestion. And the heavy content was detected by ICP-MS. The dissolution rate of Cu, Pb, As, Cd, Hg was between29.41%～82.18%,11.08%～52.84%,55.83%～75.19%,12.08%～81.42%,0～22.76%respectively. Based on the reference, the dissolution rate of Cu, Pb, As, Cd and Hg was modified to80%,70%,75%,80%and60%separately.3. According to the particularities of traditional Chinese medicines in using process, the proper limited standards of heavy metals in medicinal materials were established on the basis of previous research results, literature statistical data, Target hazard quotients (THQ) and Provisional Tolerable Weekly Intake (PTWI) which were given by USEPA and WHO respectively. The calculation of the proper limited standards of Cu, Pb, As, Cd and Hg was57mg·kg-1,6mg·kg-1,3mg·kg-1,1.5mg·kg-1and1mg·kg-1respectively, which were higher than the standards given by Pharmacopoeia of People’s Republic of China. The data of heavy metals content in various medicinal materials from different habitats was collected from the references, which was used to calculate the exceeding rate on the basis of the calculation of the proper limited standards. There were817,857,913,801,648samples of Cu, Pb, As, Cd and Hg respectively, and the exceeding rate was2.583%,9.568%,6.572%,4.494%and1.852%separately, which was lower than10%overall.4. Based on the Soil Environmental Quality Standards (SEQS) of China, Salvia. Miltiorrhiza was chosen as experimental material to be cultivated in the soil, which was added cadmium (Cd) to simulate the different level of soil in SEQS. The examination of the effect of Cd on the growth, physiological signs, accumulation of secondary metabolites and Cd content in S. Miltiorrhiza was carried out. The promotion and inhibition effects of different Cd concentrations changed over time. The promotion effect was observed in the lower Cd concentrations groups at the early stage of treatment. Besides, the inhibition effects appeared in the higher Cd concentrations groups during the later stage of the treatment. The variation trends of the content of Chl a, Chl b, TChl, carotenoid and Chl a/b in the control and Cd concentrations groups were similar, which increased constantly during the treatment. These results indicated that the S. Miltiorrhiza was immature when they were transplanted into the experimental soil. So, the chlorophyll kept synthesizing while the leaves of S. Miltiorrhiza were growing during the treatment. In addition, the high Cd concentration group exhibited a promotion effect on the photosynthesis slightly on the basis of chlorophyll fluorescence data. The Cd content in the underground parts of the control group was closed to the limited standards given by Pharmacopoeia of People’s Republic of China at the fourth month. Furthermore, the Cd content in the some parts of the0.4mg·kg-1Cd concentration exceeded the standards in the third and fourth month. The experimental soil of the control and0.4mg·kg-1Cd concentration represented the First and Second grades clean soil in SEQS. After being grown in the clean soil for four months, the Cd content in the underground parts of S. Miltiorrhiza was higher than the limited standards. The accumulation of water-soluble constituents in the overground parts was later than in the underground parts. There were no significant differences observed in the content of constituents in Cd concentrations groups showed insignificant differences from the control group over the treatment time, but the slightly promotion effect of high Cd concentration on the accumulation of constituents was observed at the fourth month.Conclusion:The heavy metals content in the medicinal materials was not the amount that taken by the human beings. The dissolution rates of Pb and cd were0. It might due to the poor water solubility of lead and cadmium salt which led to the no dissolution of Pb and Cd in the decoction pieces. The dissolution rate of Cu and Hg in Radix Paeoniae Alba was low. It can be caused by the peeling and poaching in the decoction pieces preparation procedure. Pb and Cd dissolved out from the decoction solution of powder of Radix et Rhizoma Salviae Miltiorrhizae. This might be caused by the powdering procedure which increased the contact area of medicinal materials and water by cell wall disruption. The dissolution rate was quite different under the various medications forms. The dissolution rate of heavy metals in powder was higher than in the decoction pieces because of the acidic simulated gastric fluid and the increasing contact area of powder. The dissolution rate of heavy metal in the simulated gastric fluid was higher than in simulated intestinal liquid. This may be induced by the acidic condition of simulated gastric fluid. Also, the dissolution rate of heavy metals was obviously different in6medicinal materials. The content of heavy metals in the medicinal materials, which was richer relatively can cause a higher dissolution rate, just like Pb. Owing to the low Hg content in the medicinal materials, many samples didn’t dissolve any Hg into the digestive juice. Comparing to the previous experimental results, the dissolution rate of heavy metals in powder was higher than in the decoction pieces on account of the acidic simulated gastric fluid and the increasing contact area of powder. And this can be the main reason for the powder ration less than the decoction ration. Based on the previous research result, the proper limited standards were proposed for Cu, Pb, As, Cd and Hg was57mg·kg-1,6mg·kg-1,3mg·kg-1,1.5mg·kg-1and1mg·kg-1separately.The Cd treatment in the experimental made no obvious harm to the growth and physiology of S. Miltiorrhiza, while the high Cd concentration promoted the growth slightly. The slightly promotion effect of high Cd concentration on the accumulation of constituents was observed at the fourth month. After being grown in the clean soil for four months, the Cd content in the underground parts of S. Miltiorrhiza was higher than the limited standards. It demonstrated that S. Miltiorrhiza had enrichment effect of Cd, which might cause the standards-exceeding of S. Miltiorrhiza easily. It demonstrated that S. Miltiorrhiza had enrichment effect of Cd, which might cause the standards-exceeding of S. Miltiorrhiza easily.The innovations in the dissertation as below:The research was carried out on the basis of different medications and risk assessment of heavy metals, which are given by US EPA and WHO. |
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