Toxicological Assessment Of Liposoluble Tea Polyphenols

Tea polyphenols with phenolic hydroxyl structure, which determined its strong antioxidant activity, have been used as a natural antioxidant. This structure, however, led to its high water-solubility and poor lipid-solubility, which limit its practical application in the grease system. It is necessary to modify the molecular structure of tea polyphenols to increase its lipid-solubility; this can be able to extend its applied range under the condition of non-sacrifice of the outstanding biological and physiological activities. The point is the modified tea polyphenols is still safe or not, thus toxicological assessment of liposoluble tea polyphenols (LTP) was investigated in this thesis. The main research results were as follows:1. The acute oral toxicity study of LTP was evaluated to reveal the median lethal dose (LD50). The results showed that the LD50value of female mice was6.81g/kg, the95%confidence interval was4.41-10.5g/kg. While the LD50value of male mice was3.69g/kg, the95%confidence interval was2.27-5.99g/kg. According to the acute toxicity grading, this result indicated LTP was a low-toxic substance.2. To evaluate the mutagenicity of LTP, three genetic toxicity tests were selected, i.e., Ames test, bone marrow cell micronucleus test and sperm abnormality test in mice. Ames test confirmed that LTP has no mutagenic effect on salmonella typhimurium. In other words, Ames test is negative. Bone marrow cell micronucleus test is also negative with the dosage of experimental conditions. Sperm abnormality test showed that LTP has no reproductive cell toxicity. All the results of three genetic toxicity tests were negative, which indicated there’s no significant genetic toxicity of LTP.3. Thirty-day-feeding study by administering different doses of LTP investigated the no-observed-adverse-effect-level (NOAEL) and the potential target organs. The results also showed negative. There was no significant influence on the body weight gain, food utility ratio, hemogram index, blood biochemical index and the ratio organic weight to the body weight of the rats between the test group and the control group. There were no obviously harmful changes on the main visceral organs of the rats by observation of vivisection and tissue dissection. Results obtained in this study showed that LTP had no adverse effect in rats and no short-term side effects. It can be concluded that the non-toxic side effects dose of LTP would be high than the test dose.The relevant toxicological tests of LTP showed that there were no significant side effects and adverse reaction of LTP. From these results, LTP also was a safe material. Therefore, LTP can be used as food additive and it had broad development and application prospect.