Study On Quality Of Cortex Moutan Affected By Soil Environment And Its Risk Assessment Of Heavy Metals

Cortex Moutan,the root bark of Paeonia ostii T.Hong et J.X.Zhang,is a famous traditional Chinese medicine.Cortex Moutan produced by Fenghuang Mountain in Tongling,Anhui Province is considered the best in quality.Soil factors play an important role in the growth and development of plants,and also have an important impact on the accumulation of secondary metabolites in medicinal plants,which affects the quality of the herbs.Tongling is a famous copper city with some copper mines or tailings.It is necessary to study the effect of soil environment in Tongling area on the quality of Cortex Moutan.In this research,three planting areas in Tongling were chosen to be investigated.The physical and chemical properties and elemental contents of the soil were analyzed.The inorganic elements,effective chemical composition and biological efficacy were determined to evaluate the quality of Cortex Moutan.Furthermore,soil factors affecting the quality of Cortex Moutan were also analyzed and studied.In addition,through the analysis of heavy metals in soil and cortex,the potential ecological risks of the soil and the health risks of the human via consumption of Cortex Moutan were assessed.Through research,main results were summed as follows:?1?Through the analysis of the physical and chemical properties of the soil in the genuine planting areas of Moutan in Tongling,it was concluded that the soil in planting area was acidic and soil physical and chemical properties and inorganic elements were different in these three areas.The soil fertility in the farmland area was the best and the contents of heavy metals Cu,Cd,Pb and Zn in soils in the tailings areas were significantly higher than those in the farmland.The pH value and organic matter content in soils were highly correlated with inorganic elements.Pb,Zn,Cu,Cd,Mg,and Na were the first principal components in the principal component analysis of inorganic elements in soils,which could be considered as the characteristic elements of the soil in the Cortex Moutan planting areas.?2?The content of inorganic elements in soils varied significantly in the three regions of Cortex Moutan planting area.Ca content in each region was the highest,the Cd content in farmland and hillside was the lowest,and the Co content in tailings was the lowest among these elements.According to the results of principal component analysis of elements in Moutan,it was considered that the characteristic elements of genuine Cortex Moutan were Zn,Pb,Cu and Cd.Physical and chemical properties,the content of inorganic elements in soil and the synergistic or antagonistic effect of the elements in the medicinal materials were the main factors that affected the absorption of inorganic elements by the herb.Soil pH values had a great influence on the absorption of Cu,Mg,Mn and Zn elements.And soil organic matter had significant effects on Fe,Na and P in Moutan.While total nitrogen,available potassium and available phosphorus in soils mainly affected absorption of nutrients from soils.The inorganic elements in soils had more influence than the physicochemical properties.Ten of the fifteen elements were affected by the relevant elements in the soil,and there were also synergistic or antagonistic interaction between elements in plants or between elements in soils and plants.?3?The contents of five effective ingredient such as gallic acid,catechin,paeoniflorin,benzoic acid and paeonol in Moutan were analyzed by high performance liquid chromatography.The order of five chemical components contents was paeonol>paeoniflorin>benzoic acid>gallic acid>catechin.Besides,paeonol content of all samples exceeded the standards of the Chinese National Pharmacopoeia.The content of paeonol in the tailing area was the highest while other four chemical components were highest in the medicinal plants from the farmland.Soil physical and chemical properties and inorganic elements could affect the accumulation of chemical constituents:electricity conductivity affected paeonol,paeoniflorin,gallic acid content;soil organic matter affected paeonol content;available potassium affected paeoniflorin and gallic acid content.The influence of soil elements on chemical composition was greater than the physical and chemical properties of soil.Among these factors,the characteristic elements of Cortex Moutan played an important role in the accumulation of chemical components:Cu improved the content of paeonol and paeoniflorin,what's more,Zn and Cd promoted the synthesis or transformation of paeonol.In addition,there were also promotion or inhibition effects between the chemical constituents in Moutan on accumulation of the paeonol.?4?Hepatoprotective effects of different concentrations of Cortex Moutan from the three areas were evaluated by the liver injury model caused by CCl₄ in mice.The results showed that Cortex Moutan in all three areas could enhance the liver resistance against CCl₄ toxicity,significantly reduce the activities of alanine aminotransferase?ALT?and aspartate aminotransferase?AST?,increase the activities of superoxide dismutase?SOD?,glutathione peroxidase?GSH-Px?and catalase?CAT?,and inhibit the over-expression of malondialdehyde?MDA?in liver tissue,suggesting the good prevent effect on liver injury.The normal dose of this traditional medicine in each area had the best effect on liver protection in mice,and the effects of high-concentration groups of medicine from farmland and hillside area were also significant,but as to the herbal medicine form tailing area,it had no liver-protecting effect.Comprehensive analysis of the changes of transaminase,various antioxidant enzymes and pathological sections showed that the hepatoprotective effects of Cortex Moutan in the farmland and hillside area were better than that of the tailings area.?5?Compared with the soil background value of the Tongling area,the heavy metal concentration?except Cr in the farmland?in the soil of P.ostii cultivating area exceeded the background value.Cr,Cu and Zn concentrations in soils of the three areas exceeded the national risk control standard for soil contamination of agricultural land,and Pb in the tailings area also exceeded this standard.Nemerow comprehensive pollution index analysis showed that the soils in different areas were polluted by Cd,Cu and Zn elements to different extents.Through the evaluation of the potential risk parameters of heavy metals,it was concluded that Cd was the element that could cause the extremely serious potential environmental risk of the soil.The accumulated potential environmental risks of the studied heavy metal elements in the soils were also the highest in the tailings area,followed by the hillside area and the lowest in the farmland area.?6?The concentration of heavy metals in Moutan from tailings area was higher than that in the other two areas,and Pb and Cd content exceeded the the national or international limits of heavy metal concentration in medicinal plants.Accumulation factor of Cd in Moutan from the tailing area was the highest in these three areas.The results of single-factor pollution index evaluation showed that the heavy metal pollution of Cortex Moutan collected from the farmland was safe,while it was slightly polluted by Cu in the medicine from hillside area,and was slightly polluted by Cd,Cu and Pb in that from the tailing area.The results of the health risk assessment showed that the amount of heavy metals that entered the human body through the consumption of Cortex Moutan was less than the average daily intake limit prescribed by the World Health Organization.Hazard quotient?HQ?for all heavy metals in all sites was under1,indicating that cortex in the three areas may not cause the non-carcinogenic health risk to human by consumption.Moreover,even if people take Cortex Moutan daily for the maximum recommended amount during the lifetime,Cr may cause a certain carcinogenic risk which was acceptable to the human.In the three collected areas,the health risk of the heavy metals was the lowest in the farmland area,followed by the hillside area,and the highest in the tailing area.Health risk of Pb in tailing area was mainly caused by the content of Pb,Cd and Cu in soils and the synergistic effect of Cr and Cu in the plants.While health risk of Cr was caused by Cr and Ni in soils and synergy of Pb in the plants.Besides,health risk of Cu was mainly due to the content of Cu and Zn in the soils and also synergy effect of Pb and Zn in the plants.