Synthesis and preclinical pharmacological evaluation of a novel ~(99m)Tc-shikonin as a potential tumor imaging agent

摘要

Shikonin was isolated from Ratanjot pigment then the obtained shikonin was well characterized. This study is aimed to optimize radiolabeling yield of shikonin with ~(99m)Tc with respect to factors that affect the reaction conditions such as shikonin amount, SnCl _2?2H _2O amount, reaction time and pH of the reaction mixture. In vitro stability of the radiolabeled complex was checked and it was found to be stable for up to 6 h. Biodistribution studies showed that, ~(99m)Tc-shikonin accumulate in tumor sites with higher T/NT than other currently available ~(99m)Tc(CO) _3-VIP, ~(99m)Tc-nitroimidazole analogues and ~(99m)Tc-polyamine analogues indicating that shikonin deliver ~(99m)Tc to the tumor sites with a percentage sufficient for imaging and can overcome many drawbacks of other radiopharmaceuticals used for tumor imaging.c