Study On The Mechanism And Prevention Of Aflatoxin In Polygala Tenuifolia Willd.

ObjectiveThrough the detection of aflatoxin in the Polygala tenuifolia medicinal material in the main production areas of China,the mechanism of aflatoxin production in the Polygala medicinal material was explored.In addition,through the research on the inhibitory effect of crude extracts of three lichen herbs such as Alectoria asiatica Du Rietz,Cladonia gracilis(L.)Willd.and Alectoria virens Tayl.on the growth of aflatoxin and its inhibitory effect on the production of aflatoxin in Polygala medicinal materials.It provides data reference for the quality evaluation of Polygala medicinal materials and the prevention and treatment of aflatoxin in Polygala medicinal materials.Methods(1)A total of 37 batches of Polygala medicinal materials from two major regions in Shaanxi Province and Shanxi Province were collected for aflatoxin B1,B2,G1,and G2 detection.The detection method,refer to the 2015 edition of the Pharmacopoeia of the "People’s Republic of China",for determination of aflatoxin(General Rule 2351).(2)The aflatoxin test was performed on the environmental soil in which Polygala plants are grown,the stems,leaves,seeds,fresh Polygala roots,and Polygala roots treated under 60 ℃ blast-dried Polygala and sweating conditions to determine sources of aflatoxin production in Polygala medicinal materials.(3)Alectoria asiatica Du Rietz,Cladonia gracilis(L.)Willd.and Alectoria virens Tayl.were subjected to absolute ethanol extraction and water extraction,respectively,and different concentrations of extracts were added to the comprehensive PDA medium.Aspergillus flavus spores were inoculated into the comprehensive PDA medium and cultured at 28 ℃.After 3 days,observe the growth of Aspergillus flavus,and measure the size of the growth circle of Aspergillus flavus by cross measurement.(4)After storage of Alectoria asiatica Du Rietz,Cladonia gracilis(L.)Willd.and Alectoria virens Tayl.with Polygala medicinal materials at room temperature for a month at a ratio of 1: 1,the aflatoxin content was measured to determine the effects of three lichen medicinal materials on the production of aflatoxin in Polygala medicinal materials.Results(1)Based on the detection of aflatoxin B1,B2,G1,and G2 on 37 batches of Polygala medicinal materials in two main producing regions of Shaanxi Province and ShanxiProvince,it was found that there were varying degrees of aflatoxin contamination in 37 batches of Polygala medicinal materials.The most carcinogenic aflatoxin B1 was detected in all Polygala medicinal materials.According to the 2015 edition of the Pharmacopoeia of the "People’s Republic of China",aflatoxin B1 content in Polygala medicinal materials should not exceed 5 μg / kg,The total content of aflatoxin B1,B2,G1 and G2 should not exceed 10 μg / kg.Of the 37 batches of Polygala medicinal materials samples,20 batches of aflatoxin B1 exceeded the standard,and 14 batches of aflatoxin B1,B2,G1,and G2 exceeded the standard.(2)The detection of aflatoxin B1,B2,G1,and G2 on the soil,Polygala seeds,stems,leaves,fresh Polygala roots,and Polygala roots treated under 60℃ blast-dried Polygala and sweating conditions,it is concluded that Polygala does not produce aflatoxin during its own growth,and no aflatoxin is produced in Polygala medicinal materials processed by blast-dried at 60 ℃.Higher levels of aflatoxin B1、B2、G1、G2 are detected in Polygala medicinal materials under sweating conditions.(3)Through experiments on the inhibition of Aspergillus flavus by crude extracts of Alectoria asiatica Du Rietz,Cladonia gracilis(L.)Willd.and Alectoria virens Tayl.it was found that the three lichen extracts had a certain inhibitory effect on the growth of Aspergillus flavus,and their absolute ethanol extracts’ effect on Aspergillus flavus is higher than that of the water extract,and the higher the concentration of the extract,the better the effect of inhibiting the growth of Aspergillus flavus.When the concentration of absolute ethanol extract was 3200 mg / L,the antibacterial rates of Alectoria asiatica Du Rietz,Cladonia gracilis(L.)Willd.and Alectoria virens Tayl.reached the highest values,which were 26.91%,18.33%,and 28.07%,respectively.(4)Alectoria asiatica Du Rietz,Alectoria virens Tayl.and Cladonia gracilis(L.)Willd.were stored with Polygala medicinal materials at room temperature for a month at a 1: 1mass ratio.After testing the aflatoxin content,Alectoria asiatica Du Rietz had the highest inhibition rate of aflatoxin B1 in Polygala,Which is 43.4%;Alectoria virens Tayl.has the highest inhibition rate of aflatoxin G1 in Polygala medicinal materials,which is 78.6%;Polygala medicinal materials were stored together with Alectoria asiatica Du Rietz and Alectoria virens Tayl.respectively,no aflatoxin G2 and B2 were detected;After Polygala storage with Cladonia gracilis(L.)Willd.aflatoxin B2 was detected,but aflatoxin G2 was not detected.ConclusionThe results of the detection of aflatoxin in Polygala medicinal materials in the two main producing areas of Shaanxi Province and Shanxi Province indicated that there is a serious problem of aflatoxin contamination in Polygala medicinal materials in the currentmarket.This not only affects the quality of Polygala medicinal materials,but also the safety of drug used by people has caused great hidden dangers;Polygala medicinal materials should be dried in time after harvesting to quickly remove moisture,and should not be piled up to avoid fresh Polygala medicinal materials due to self-heating,resulting in aflatoxin pollution;Alectoria asiatica Du Rietz,Alectoria virens Tayl.and Cladonia gracilis(L.)Willd.have an inhibitory effect on the growth of Aspergillus flavus,can reduce the production of aflatoxin in Polygala medicinal materials.It has important research significance for solving the problem of wasting resources caused by aflatoxin in Polygala medicinal materials.