Cytotoxicity of epigallocatechin-3-gallate to LNCaP cells in the presence of Cu2+

Abstract

Epigallocatechin-3-gallate (EGCG) has shown remarkably anti-cancer activity, with its bioactivity being related to reactive conditions, such as pH and metal ions. The present study investigated the degradation of EGCG and its effect on prostate cancer cell in the presence of Cu 2+. EGCG was incubated with prostate cancer cells, LNCaP, pretreated with or without Cu 2+ . EGCG in F-12 medium was quantified using HPLC and the viability of cells was assessed by gel electrophoresis, flow cytometry, and electron microscope. The results of HPLC showed that EGCG degraded completely within 12 h in F-12 medium with or without Cu 2+. Gel electrophoresis and flow cytometry did not detect apoptosis of LNCaP cells when they were incubated with EGCG. Electron microscopy examination revealed that EGCG-Cu 2+ complex led to damage of cytoplasm membrane in LNCaP cells. It was speculated that not EGCG, but its oxide and complex with Cu 2+ , are the bioactive components responsible for its cytotoxicity to LNCaP prostate cancer cells.

Structural changes of oviduct of freshwater shrimp, Macrobrachium nipponense (Decapoda, Palaemonidae), during spawning

“…The structure of oviduct wall of M. nipponense is similar to that found in other shrimp (Macrobrachium carcinus, Macrobrachium rosebergii) (Deng, 2000;Yu and Lu, 2005), but is different from that of crabs (Decapoda, Braclyrora) and Isopoda (Hartnoll, 1968;Hryniewiecka-Szyfter and Tyczewska, 1992;Jensen et al, 1996).…”

“…The oviduct of shrimp, M. carcinus or M. rosebergii, is also composed of a thin layer of connective tissue and a layer of columnar epithelial cells (Deng, 2000;Yu and Lu, 2005). While the oviduct of the Dungeness crab, Cancer magister, is composed of a layer of columnar epithelium cell with a thin chitin lining, and the gonoduct wall is composed of three layers: the columnar epithelium, chitin, and connective tissue (Jensen et al, 1996).…”

“…The lateral pouch epithelial cells of the oviduct of the fairy shrimp Streptocephalus dichotomus (Munuswamy and Subramoniam, 1985), of the follicle duct wall of Triops cancriformis (Trentini and Scanabissi, 1982), and of the oviduct wall of M. carcinus (Deng, 2000), M. rosebergii (Yu and Lu, 2005) and M. nipponense consists of secretory cells. While the lateral pouch epithelial cells of the oviduct of fairy shrimp S. dichotomus form a layer of flattened to cylindrical cells surrounded by a single layer of longitudinal muscle cells and some circular muscles lie at regular intervals (Munuswamy and Subramoniam, 1985).…”

Epigallocatechin-3-gallate affects the growth of LNCaP cells via membrane fluidity and distribution of cellular zinc

“…Recently, several reports have focused on the interactions of catechin with metal ions (Reznichenko et al, 2006;Yu et al, 2005;Hayakawa et al, 2004;Chen et al, 2007). Catechin induces redox reactions or chelates with metal ions, especially transitional metal ions, which lead to bioactivity changes of catechin.…”

“…In view of this, it is important to know the interaction between EGCG and Zn 2+ and how their interaction modifies the risk of prostate cancer. Our previous studies revealed that biological activities of EGCG are altered in the presence of Zn 2+ , Cu 2+ , and Cd 2+ , and the results rely on (1) the relative concentrations of EGCG and metal ions, and (2) the order of their additions that might have led to the formation of complexes between EGCG and metal ions, which could lead to changes in the generation of free radicals within the cells (Yu et al, 2005;Chen et al, 2007). Nevertheless, there is little information available in literature about the interactions between EGCG and metal ions, especially with regard to their action on cell membrane of prostate cancer cells.…”