第一部分:利用Dabsylation及高效液相層析系統分析茶的茶胺酸及伽瑪胺基丁酸含量;第二部分:龍葵葉子水萃物促使AU565乳癌細胞進行自噬作用

Abstract

Part I Dabsyl chloride (dimethylaminoazobenzene sulfonyl chloride), a useful chromophoric labeling reagent for amino acids and amines, was developed in our laboratory in 1975. Although several methods have been developed to determine various types of amino acids, a quick and easy method of determining theanine, GABA and other amino acids has not been developed in one HPLC system. Here, we analyze the free amino acid contents of theanine and GABA in different teas (green tea, black tea, oolong tea, Pu-erh tea, GABA tea, and luobuma tea) with a dabsylation and reverse phase high performance liquid chromatography (HPLC) system coupled with a detector at 425nm absorbance. In this system, our data suggests that different teas may be recognized by their various theanine contents. The high theanine content of high mountain tea was observed in both green tea and oolong tea. Furthermore, the raw (natural fermented) Pu-erh tea contained more theanine than ripe (wet fermented) Pu-erh tea. And the GABA contents in normal teas were significantly lower than that in Luobuma tea and GABA tea. Part II Solanum nigrum Linn belong to Solanaceae is a plant widely grows in south Asia and has been used in traditional folk medicine. It is believed to have many biology activities including antipyretic, diuretic, anti-cancer, and hepatoprotective effect. However, the exactally mechanism of such effects needed further research. In our lab, we used the water extract of Solanum nigrum Linn leaf (SN leaf) to compare the response of different cells, including liver cancer, breast cancer, and fibroblast. The results showed that AU565 bresat cancer cells were more sensitive to the extract. SN leaf induced autophagy but not apoptosis in AU565. The induced autophagy seemed not related to Akt or AMPK pathway, but the exactly mechanism was still unknown. Low dose ( 100 μg/ml) of SN leaf could inhibit the level of p-Akt and cause the cell death. These confirmed that Akt is the key survival factor for AU565, and the using of SN leaf for the treatment of AU565 related cancers were needed further evaluation.