Biol. Pharm. Bull. 28(1) 176—180 (2005)

tributed all over the world. Although they are not commonly included in the diet of developed countries, they do in fact contain a rich array of nutritional components including vitamins, proteins, amino acids and trace elements such as zinc, selenium and manganese. In addition, ants have been used as medicine, owing to their special active substances such as citral (C10H16O), citionella terpene, ATP, histamine, growth hormone, testosterone and superoxide dismutase (SOD) etc. Of the many kinds of ants that has been used (e.g., Polyrhachis vicina ROGER, Polyrhachis lamellide SMITH, Formica Fusca L., Formica Sanguinea LATR, F. Rufa L, and Oecophylla Smaragdina FABR etc.), the black ant, Polyrhachis vicina ROGER has been extensively studied, showing that it possesses many pharmacological properties, such as reducing inflammation, relieving pain, retarding aging, reducing stress, reversing tumor growth, protecting liver, decreasing blood glucose, modulating immunological function and enhancing gonadal function, and has been used to treat various diseases such as arthritis, hepatitis and neurosis etc. in China for long years. Unfortunately, little is known about the pharmacological activities of other kinds of medicinal ants. Another species in the Polyrhachis genus, P. lamellidens SMITH, which is widely distributed in the mainland of China, Hong Kong, Taiwan, Japan and Korea, has been used for the treatment of inflammatory diseases including arthritis and hepatitis for centuries in China. However, there are almost no reports about its pharmacological activity and chemical constituents. We previously undertook chemical studies on the constituents of P. lamellidens and have isolated and structurally identified a disaccharide trehalose and two novel aliphatic polyketide lactones from its ethanol extract. In this paper, for the purpose of providing pharmacological evidence for its clinical use and of promoting further use of the rich resources of Chinese medicinal ants, we investigated the analgesic and anti-inflammatory effects of the ethanol extract of P. lamellidens SMITH and the fractions obtained by solvent partition of its total extract.