To obtain the subject suppressant by including alnusenol and multiflorenol as active ingredients.

This suppressant is obtained by including alnusenol represented by formula I and/or multiflorenol represented by formula II as active ingredients. Furthermore, one or more kinds of isomultiflorenyl acetate represented by formula III, 5-gluten-3β-yl acetate represented by formula IV, spinasterol represented by formula V and ergosterol peroxide represented by formula VI are preferably included. The above active ingredients are obtained as four kinds of triterpenes and two kinds of sterols by defatting a dried material of Benincasa cerifera Savi produced in China with hexane, then extracting the defatted material with methanol under heating, providing a methanol extracted essence, then treating the resultant essence by a column chromatography, removing saccharides and amino acids as a water eluting part, subsequently affording an essence of a methanol eluting part and separating and purifying the resultant essence.