COMPONENTS SCREENING FROM CURCUMA LONGA LINN. AND THEIR BIOAFFINITY PROPERTY ON HUMAN UMBILICAL VEIN ENDOTHELIAL CELLS BY CELL MEMBRANE CHROMATOGRAPHY

Abstract

Curcuma longa Linn. (CLL) is widely used as a traditional herbal medicine for the prevention of diabetic vascular complications, but the potential active compounds and its bioaffinity property to cells remain obscure. In this study, cell membrane chromatography (CMC) was used to screen the active components binding to human umbilical vein endothelial cells (HUVECs). Demethoxycurcumin and curcumin in CLL were identified as two cells-binding compounds. MTT and acridine orange-ethidium bromide (AO-EB) results demonstrated demethoxycurcumin and curcumin had protection activity on advanced glycation end products (AGEs)-induced HUVECs damage, including increasing cell viability and reducing apoptosis. CMC was also used to determine the bioaffinity property of these compounds to cells. The dissociation equilibrium constants (Kd) of demethoxycurcumin and curcumin were 3.173 ± 0.46 and 3.088 ± 0.51 nM. Maximum binding capacities (Bmax) were 22.61 ± 3.74 and 24.39 ± 2.11 fmol · mg⁻¹ protein. The IC₅₀ of demethoxycurcumin and curcumin were (2.50 ± 0.16) and (1.59 ± 0.28) × 10⁻⁷ M, respectively. Our results indicated that demethoxycurcumin and curcumin were the potential active compounds in CLL for the prevention of diabetic vascular complications, and CMC provided a rapid and efficient method for screening potential active components in traditional Chinese medicines against diabetic vascular complications.

Keywords:

• bioaffinity
• cell membrane chromatography
• Curcuma longa Linn.
• curcumin
• demethoxycurcumin
• diabetic vascular complications

ACKNOWLEDGMENT

The authors gratefully thank the financial support of Natural Science Foundation of Shaanxi Province (No.2012JM4013) and Leading Talent Foundation of Jiangsu Chinese Medicine (2006).

Jiping Liu and Liang Feng contributed equally to the work.