title: Purification of innate immunostimulant from green tea using a silkworm muscle contraction assay.
abstract: A polysaccharide was purified from a hot water extract of green tea leaves by measuring the immunostimulatory activity in silkworm larvae. Nuclear magnetic resonance and chemical analysis of acid hydrolysates revealed that the purified substance possessed a backbone containing polygalacturonic acids with methyl ester residues. Treatment with β-glucanase attenuated the muscle contraction activity of the purified sample, suggesting that the β-glucan structure, probably as a branched form, was required for its activity. The purified fraction stimulated the production of interleukin-6 by mouse peritoneal macrophages. These results suggest that measuring immunostimulation in silkworm larvae is useful for evaluating innate immunostimulants from various sources.
authors.affiliation: Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Dhital
authors.forename: H
authors.initials: H
authors.lastname: Hamamoto
authors.forename: M
authors.initials: M
authors.lastname: Urai
authors.forename: K
authors.initials: K
authors.lastname: Ishii
authors.forename: K
authors.initials: K
authors.lastname: Sekimizu