Antiproliferative Effect of Liposome Encapsulated PITC-2 on Cancer Cell Line ( U 937 , K 562 and HL 60 ) in Vitro

PITC-2, a new thiophene derivative was encapsulated in vitro in liposomes composed of phosphatidylcholine, cholesterol and PITC-2 at a molecular ratio of 9: 1: 1. Permeation studies were carried out with a Keshary-chien diffusion cell apparatus (with a capacity of 100 ml), using rat skin membrane as the diffusion barrier. In vitro studies showed that the liposome formulations provided an increasing drug release profile, up to 24 hrs. After 24 hrs it gradually decreased and followed a steady-state pattern up to 48 hrs. Ex vivo studies with excised rat skin revealed that liposome formulation was released and penetrated slowly into rat skin. This result is consistent with the fact that hydrophobic thiophene derivative is effective on the percutaneous absorption for sustained release dosage form. The anticancer property and cytotoxic effect of PITC-2, liposome-encapsulated PITC-2 and tissue cultured Pluchea indica root extract (TCPIRE) was compared against human leukemic cell lines U937, K562 and HL60. Liposome-encapsulated PITC-2 significantly inhibited the cell proliferation (in the case of U937 93.01%, K562 78% and HL60 89.525%) and showed a higher cytotoxic effect than free PITC-2 and tissue-cultured P. indica root extract (TCPIRE) in vitro. An MTT assay showed that the growth of metabolically active cells was inhibited by treatment with the drugs. Result revealed that liposome formulation of PITC-2 possesses potent antiproliferative activity in vitro. The PITC-2 liposome formulation can show great promise against leukemia in the future. _____________________________________________________________________________________________________________