Induction of antiparasite activity by pine cone lignin-related substances.

Pretreatment with two distinct lignin-related antitumor substances extracted from pine cone of Pinus parviflora Sieb. et Zucc. protected infant mice from Hymenolepis nana (Cestoda) infection. Subcutaneous administration of these fractions (10 mg/kg) to 1 week old mice evoked strong protective immunity against oral infection by Hymenolepis nana eggs. Significant antiparasite effects were also induced in 4 week old mice by intraperitoneal or oral administration of these fractions. These fractions had more potent antiparasite activity than pine cone extracts with lower antitumor and antiviral activity, and various polysaccharides derived from plants and bacteria.