Data mining and frequency analysis for licorice as a "Two-Face" herb in Chinese Formulae based on Chinese Formulae Database.

Liquorice is the root of Glycyrrhiza uralensis Fisch. or Glycyrrhiza glabra L., Leguminosae. Licorice is described as 'National Venerable Master' in Chinese medicine and plays paradoxical roles, i.e. detoxification/strengthen efficacy and inducing/enhancing toxicity. Therefore, licorice was called "Two-Face" herb in this paper. The aim of this study is to discuss the paradoxical roles and the perspective usage of this "Two-Face" herb using data mining and frequency analysis. More than 96,000 prescriptions from Chinese Formulae Database were selected. The frequency and the prescription patterns were analyzed using Microsoft SQL Server 2000. Data mining methods (frequent itemsets) were used to analyze the regular patterns and compatibility laws of the constituent herbs in the selected prescriptions. The result showed that licorice (Radix glycyrrhizae) was the most frequently used herb in Chinese Formulae Database, other frequently used herbs including Radix Angelicae Sinensis (Dang gui), Radix et rhizoma ginseng (Ren shen), etc. Toxic herbs such as Radix aconiti lateralis praeparata (Fu zi), Rhizoma pinelliae (Ban xia) and Cinnabaris (Zhu sha) are top 3 herbs that most frequently used in combination with licorice. Radix et rhizoma ginseng (Ren shen), Poria (Fu ling), Radix Angelicae Sinensis (Dang gui) are top 3 nontoxic herbs that most frequently used in combination with licorice. Moreover, Licorice was seldom used with sargassum (Hai Zao), Herba Cirsii Japonici (Da Ji), Euphorbia kansui (Gan Sui) and Flos genkwa (Yuan Hua), which proved the description of contradictory effect of Radix glycyrrhizae and these herbs as recorded in Chinese medicine theory. This study showed the principle pattern of Chinese herbal drugs used in combination with licorice or not. The principle patterns and special compatibility laws reported here could be useful and instructive for scientific usage of licorice in clinic application. Further pharmacological and chemical researches are needed to evaluate the efficacy and the combination pattern of these Chinese herbs. The mechanism of the combination pattern of these prescriptions should also be investigated whether additive, synergistic or antagonistic effect exist using in vitro or in vivo models.