Drugs with the efficacy of modifying rheological properties of blood, blood
vessels and their interactions are denoted by "hemorheologicals". Drugs of
anti-hyperviscosemia, anti-coagulants, anti-platelet drugs, anti-thromboti
cs, vasodilators, endothelial cell protectors and anti-arthrosclerosis shou
ld be considered as hemorheologicals due to the actions in keeping blood fl
uidity and in maintaining normal vascular functions. The studies in hemorhe
ology indicate that a tendency of hyperviscosity, hypercoagulation and bein
g prone to thrombosis is prevalent in the elderly. Hemorheologicals are imp
ortance for and aging and life-threatening diseases. Blood stasis syndrome
is a common pathological syndrome in the elderly. In traditional Chinese me
dicine, the treatment for the syndrome is by herbs which activates blood ci
rculation to remove blood stasis. The herbs have the efficacy of improving
hemorheological events. Therefore, the herbs are the source for developing
hemorheologicals. Ligustrazine isolated from Chuangxiong is an example. It
showed significant inhibition on shear induced platelet aggregation and on
platelet intracellular calcium demonstrated by laser confocal microscope.