Model Organisms and Traditional Chinese Medicine Syndrome Models

Table 1

Summary of TCM syndrome models.

Types	Examples	Characteristics	Application
TCM etiology and pathogenesis
Four diagnostic methods	Red tongue model induced by long-term heat drugs treatment; [17]; Thin white greasy tongue fur treated with alcohol, overeating, and eating disorders [18]	Advantage: Under the guidance of TCM theory; Simulating the TCM clinical etiology and pathogenesis; Symptoms are similar to human; Much closer to the TCM syndrome model; Disadvantage: Single intervention factor; TCM syndromes are separated from diseases; Difficult to control the TCM pathogenic factors and TCM syndrome model it causes; Without specific and accurate pathological changes; Lacking stability and poor repeatability	The theory of etiology and pathogenesis of TCM study; TCM therapeutics study
Eight-principle	Heat syndrome induced with excessive exercise after oral administration of heat drugs [19]
Qi-Blood-Liquid-Fluid pattern; identification	Qi-deficiency model induced by starvation [20]; Blood-deficiency syndrome treated with ^60CO 𝛾-ray radiation or cyclophosphamide [21]
Viscera syndrome types	Heart-Blood-Stasis syndrome induced by coronary artery ligation or continuous injection with isoprenaline [22, 23]; Spleen-deficient syndrome induced with low-protein diet and lapactic herbs or subcutaneous injection of reserpine [24]; Liver-Qi depression model established by bandaging or irritating animals [26–28]; Kidney deficiency syndrome induced by excessive adrenocortical hormone [5]
Based on Western medicine etiology and pathology	Stomach ache induced by formalin or salicylic acid (p.o.) [25]; Spleen asthenia syndrome treated with reserpine [24]; Blood-Stasis syndrome induced by ameroid constriction of a coronary artery [26];	Advantage: Specific and accurate pathological changes; Indicators are objective, standardized and can be quantified; Highly reproducible; Easy to establish; Disadvantage: Without clinical etiology evidence; Lacking relationship with TCM theory; Inappropriate tongue and pulse presentations	Pathology study; Mechanism of drug effect on disease model; Herb screening
Integrated with traditional Chinese and Western medicine	Heart-Blood-Stasis syndrome model basis on type 2 diabetic animals supplemented with prednisolone and adrenaline injection [27]; Congealing-Cold with Blood-Stasis syndrome model treated with adrenaline injection plus ice-water bath [28]	Advantage: Combine disease and TCM syndrome on the same animal model; Basis on stable and reliable disease model; Highly reproducible; Discussing the relationship between pathophysiology of disease and characteristics of TCM syndrome; Combining TCM theory and experimental method with macrocosm and microcosm unifies in an animal model; To diagnose a disease first then to identify the TCM syndromes; Disadvantage: Application limitations; Affected by environment, species of animal and animal individual differences	Pharmacodynamics study; Mechanism of drug effect on disease model; A link between TCM theory and clinic; Essential of Zheng study
Genetically engineered animals	Phlegm-Stasis syndrome (ApoE gene knockout mouse) [29]; Chan-syndrome (Knockout mice of Nurrl gene); [30]; Yin-deficiency and Blood-Stasis syndrome in diabetes (db/db mutant mouse); [31]; Arthromyodynia (Bi-syndrome) (Abb knockout/transgenic HLA-DR4 mice) [32]	Advantage: Stabilization; High fidelity; Hereditary; High consistency with human disease; Disadvantage: Limited categories (only mouse); Expensive; Difficult technology and complicated methods;	Pharmacodynamics study; Mechanism of drug effect on disease model; Drug screening; Pathogenesis study of hereditary disease, immunodeficiency disease, tumor, TCM syndrome animal model of insufficient natural endowment;