Inhibitory effect of Angelica sinensis extract in the presence of 2-hydroxypropyl-β-cyclodextrin

Angelica sinensis (AS) is a traditional Chinese medicinal herb. Its ethanolic extract contains active ingredients, such as ferulic acid, ligustilide, and butylidenephthalide, which are hydrophobic and have inhibitory effects on hepatoma cells. To increase the aqueous solubility/dispersibility of AS extract and study the consequent inhibitory effect on hepatoma cells, the ethanolic extract of AS was complexed with 2-hydroxypropyl-β-cyclodextrin (HP-β-CD), a cyclic oligosaccharide that has a hydrophilic outer surface and a hydrophobic central cavity. The AS–HP-β-CD complex (weight ratio of AS extract: HP-β-CD = 1:5) was prepared and characterized. The effect of complexing the AS extract with HP-β-CD on Hep3B cell growth was investigated by analyzing cytotoxicity. Our results showed that cytotoxicity inhibition of AS–HP-β-CD complex was up to 94% and higher than that of AS extract (about 68%). These observations suggested that the use of HP-β-CD to stabilize AS extract in aqueous solution was possible for herbal medicine application.