Anemarrhena asphodeloides is known to suppress inflammation and lower various fevers. To determine the active component of A. asphodeloides, ethanol (EtOH) extract of A. asphodeloides rhizomes was fractionized. The compounds isolated from the dichloromethane (CH2Cl2) soluble fraction were identified as 4 '-O-methylnyasol (1), nyasol (2), 3 ''-methoxynyasol (3), 3 ''-hydroxy-4 ''-methoxy-4 ''-dehydroxynyasol (4), 4-hydroxybenzaldehyde (5), and 4-hydroxyacetophenone (6). The four norlignans (1-4) potently inhibited the release of beta-hexosaminidase from immunoglobulin E (IgE)/dinitrophenol-conjugated bovine serum albumin (DNP-BSA)-treated rat basophilic leukemia (RBL)-2H3 and A23187 plus phorbol 12-myristate 13-acetate co-treated isolated rat primary mast cells, as markers of degranulation and histamine release. The intraperitoneal treatment with the EtOH extract significantly suppressed the fetal reaction, and serum histamine release induced by compound 48/80 in mice. These results suggest that the four active norlignan compounds and the EtOH extract of A. asphodeloides may have potential to be developed as medicines for the treatment of allergies by inhibiting the activation of mast cells. (C) 2016 Elsevier Masson SAS. All rights reserved.