Antiproliferative activity of various Uncaria tomentosa preparations on HL-60 promyelocytic leukemia cells

The woody Amazonian vine Uncaria tomentosa (cat’s claw) has been recently more and more popular all over the world as an immunomodulatory, antiinflammatory and anti-cancer remedy. This study investigates anti-proliferative potency of several cat’s claw preparations with different quantitative and qualitative alkaloid contents on HL-60 acute promyelocytic human cells by applying trypan blue exclusion and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction assay (MTT). By standardization and statistical comparison of the obtained results pteropodine and isomitraphylline are indicated to be most suitable for standardization of medical cat’s claw preparations.

B/W
– Uncaria tomentosa bark extracted in water at 37°C, B/50E
– bark extracted in 50% ethanol at 37°C, B/96E
– bark extracted in 96% ethanol at 37°C, B/W – bark extracted in boiling water, B/E – bark extracted in boiling ethanol, B/S – bark alkaloid-rich preparation, L/E – leaves extracted in boiling ethenol.