Characterization of fructan from Chikuyo-Sekko-To, a Kampo prescription, and its antiherpetic activity in vitro and in vivo

A fructan (CSH1-1, Mw = 4.0 × 103) was isolated as an antiviral principle by combination of column chromatographies from Chikuyo-Sekko-To (CST), which is a traditional Japanese herbal (Kampo) medicine for infectious diseases. Chemical and spectroscopic analyses revealed that CSH1-1 was a highly branched fructan consisted of terminal (19.0%), 2,1- (61.9%), 2,6- (4.9%) and 1,2,6-linked β-d-Fruf residues (12.3%) with 1,6-linked β-d-Glcp residues (1.9%). CSH1-1 showed anti-herpes simplex virus type 2 (HSV-2) effects in vitro and in vivo. The polysaccharide had stimulating effects of nitric oxide production and induction of several cytokine mRNA expression including IL-1β, IL-6, IL-10 and TNF-α on RAW264.7 cells. From these results, a fructan from CST was suggested to be a candidate as an anti-HSV-2 agent.