The auditors invesuigalad the imfluence of green tea polyphenuls (GTPs) on the liver mitochondria permeability transition pore (PTP) opening through mitochondria swelling and change of miuochondria mem-brane potential. The data showed that GTPs had obvious prouective effecl on the Ca21-indued PTP opening in a dose-dependent manner deuected by mitochondria swelling. The results were obtained by rneasurring the change of miuochondria membrane pouential through Rh 123. Further experiments were conducted to examine the detailed influenee of GTPs on Ca21 import and export of mitochondria. The resulis showed thai GTPs had remarkably inhibitory effect on the C-2a21-induced Ca21 import in mitochondria; and that they oould accelerale Ca221-release from mitochondria. Our data provide an ahtemate interpretalion of the potent proleclive function of GTPs on cell against apoptosis.

Tea is one of the most popular beverages, consumed by over two thirds of the world's population; but the aluminum accumulation property of tea plant is becoming the focus of many researches because of aluminum's known adverse effect on human health. Investigation of the interactions of catechins with Al3+ showed that during the interaction of catechins with Al3+, the UV-vis spectrum of catechins was changed. Absorption of EGCG at 274 nm decreased and increased at 322nm; EC and C's at 278nm changed little. The ratio of Al3+to EGCG was 1:1 in pH 5.0 buffer solution; in pH 6.2 buffer solution, the ratio in the Al-EGCG complex was 1:1. Interestingly, while the ratio reached to over 2, after the complex of Al-EGCG started polymerization, the ratio in the polymer was 2:1. In pH 6.2 buffer solution, the complex behavior of C with Al3+ was the same as that of EGCG, with a little difference for EC. When the ratio of Al3+ to EC was<1, the complex in ratio was 1:2, but, the complex polymerized when the ratio of Al3+ to EC was>1. It was found that the ratio of Al3+ to EC in the polymer was 1:1. Polymerization of Al-catechin complexes might reduce aluminum absorption in the intestine. Kow value was also employed to study the properties of aluminum species in tea infusion (at gastric and intestine pH condition) and the effect of catechins and tea polyphenols on Kow in buffer solution. Results showed that Kow value rose much higher at the intestine pH than at the gastric pH. Tea polyphenols and catechins could greatly reduce aluminum Kow value in acetic buffer, indicating that these compounds may reduce aluminum absorption during tea intake.

线粒体是细胞内重要的细胞器，是生成ATP的主要场所。线粒体通透性改变孔道（PT孔道)的开放会引起线粒体许多功能的紊乱而导致细胞死亡。对茶多酚及其单体儿茶素对过氧化氢诱导的线粒体膨胀及膜电势变化过程中PT孔开放的影响进行了研究。验结果表明茶多酚及其儿茶素单体对PT孔开放的影响显著不同：茶多酚及其主要成分EGCG和ECG能够有效地抑制PT孔道的开放；CG，(+)2C 和EGC 却加速PT孔道的开放过程。从总体效果来看，茶多酚及其单体EGCG和ECG对线粒体的保护作用占主导地位。

The comparison of the protective effects of four components of "green tea polyphenols' (GTP)-(-)-epigallocatechin gallate, EGCG; (-)-epicatechin gallate, ECG; (-)epigallocatechin, EGC; and (-)epicatechin, EC-against iron-induced lipid peroxidation in synaptosomes showed that: (1) the inhibitory effects of those compounds on TBA reactive materials from lipid peroxidation decreased in the order of EGCG>ECG>EGC>EC; (2) the scavenging effects of those compounds on lipid free radicals produced by lipid peroxidation could be classified as follows: ECG>EGCG>EC>EGC. Furthermore, we investigated the iron-chelating activity and the free radical scavenging activity of those compounds as their protective mechanisms against lipid peroxidation in synaptosomes. As for the iron-chelating activity, the ratio of EGC, EGCG, ECG or EC to iron(Ⅲ) was 3:2, 2:1, 2:1 and 3:1, respectively. The hydroxyl radical (HO) scavenging activity of those compounds was investigated in a photolysis of the H2O2 system. It was found that their ability to scavenge hydroxyl radicals decreased in the order of ECG>EC>EGCG>>EGC. It was also found that they could scavenge lipid free radicals in the lecithin/lipoxidase system and their scavenging activity was classified as follows: ECG>EGCG>>EGC>EC. Moreover, we found that their antioxidant active positions were different from each other and the stability of the semiquinone free radicals produced by those compounds in NaOH solution decreased in the order of EGCG > ECG >> EC. The results indicated that the ability of those compounds to protect synaptosomes from the damage of lipid peroxidation initiated by Fe2+/Fe3+ was dependent not only on their iron-chelating activity and free-radical scavenging activity, but also on the stability of their semiquinone free radicals.

茶多酚（GTP）单体L-EGGG对香烟气相物质损伤鼠肺细胞膜的保护作用研究结果表明，L-EGGG能抑制香烟气相物质引发的脂质过氧化：用脂肪酸自旋标记物5-DOXYL和16-DOXYL标记鼠肺细胞膜，发现预先加入LEGCG可抑制气相烟引起的膜浅层流动性改变，并与L-EGGG的浓度呈量效关系。在0.001到0.1mg/mL浓度范围内，L-EGGG本身对膜的浅层没有影响，而能使膜深层的流动性略有增大。由试验推测，LEGGG的保护作用很可能是由于清除了气相烟中的自由基或脂质过氧化产生的脂类自由基。