Objective: To observe the clinical effects of Garlicin on unstable angina pectoris (UAP) and explore how the Garlicin’s effects vary among syndromes as defined by traditional Chinese medicine (TCM).Methods: Fifty-five patients with UAP were randomly divided into the Garlicin group (34 patients) and the control group (21 patients). Each patient was classified according to TCM Syndrome Differentiation as having Cold Syndrome type

Heat Syndrome type

severe blood stasis (SBS) type

and mild blood stasis (MBS) type of UAP. Garlicin 60 mg or nitroglycerin 5 mg was given to the two groups respectively by intravenous drip for 10 days as one therapeutic course. The curative effect was evaluated by symptomatic changes and electrocardiogram. The effective rates as well as indexes such as blood lipid

lipoprotein

apolipoprotein

and granule membrane protein-140 (GMP-140) were compared between groups and types.Results: Garlicin and nitroglycerin group did not differ significantly in effective rate

while that of Garlicin group was higher for the Cold Syndrome type than that of Heat Syndrome type (P < 0. 01). The high density lipoprotein/low density lipoprotein ratio and apolipoprotein A-I level rose markedly in the former type (P < 0.05)

while an opposite trend was seen in the Heat Syndrome type. Garlicin was more effective in the SBS type than that in the MBS type

and it markedly decreased GMP-140 in the MBS type.Conclusions: Garlicin is effective in UAP

especially the Cold Syndrome and SBS types. Its mechanism may involve improving blood lipid levels and inhibiting platelet activation.