Table 4.

Summary of the antihyperglycemic effects of Rhizoma Coptidis extracts, Rhizoma Coptidis-dominant couplet medicines, or Chinese patent drug and the relevant mechanisms [78–89].

Drug	Effects	Experimental model	Mechanism of actions
Rhizoma Coptidis decoction	Antihyperglycemic effects	Rat brain homogenate	Inhibited pancreatic lipid peroxidation [78]
	Reverse insulin resistance	Rat model with metabolic syndrome	Reversed insulin resistance, reduced visceral fat, and upregulated the expression of p-AMPK-A protein [79]
Water extracts of Rhizoma Coptidis	Reverse insulin resistance	3T3-L1 preadipocytes	Increased glucose uptake in preadipocytes [80]
Rhizoma Coptidis coupled with Panax Ginseng	Enhance insulin sensitivity	Type 2 diabetic rats	Lowered TNF-α levels, prevented TNF-α from inhibiting the expression of GLUT4 in fat and muscle cells, improved autophosphorylation of insulin receptor, inhibited second messenger activation, and promoted lipolysis [81]
	Reverse insulin resistance and regulate glucose and lipid metabolism	Type 2 diabetic rats	Reduced lipotoxicity [81]
	Antihyperglycemic effects	Type 2 diabetic rats	Activated PPAR-γ, slowed the release of FFA, enhanced the sensitivity of skeletal muscles and the liver to insulin, reduced the exportation of glycogen, and promoted the uptake of glucose in skeletal muscles [81]
	Reverse insulin resistance	Type 2 diabetic rats	Regulated FBG, INS, FFA, and TNF-α levels and improved insulin resistance [82]
	Enhance insulin sensitivity	Type 2 diabetic rats	Regulated lipid metabolism and reversed lipotoxicity [83]
A combination of Rhizoma Coptidis, Astragalus Mongholicus, and Solomonseal Rhizome	Vascular-protective	Wistar rats	Increased erythrocyte SOD activity and decreased serum MDA level, thereby reducing free radical damages in the hyperglycemic state [84]
Sanhuang compound (a mixture of Rhizoma Coptidis, Radix Astragali, and Radix Rehmanniae)	Antihyperglycemic and hypolipidemic effects	Type 2 diabetic rats	Protected and repaired pancreas, enhanced insulin secretion and glycogenesis, and inhibited gluconeogenesis [85]
Rhizoma Coptidis coupled with dried Rehmannia root	Reverse insulin resistance	Type 2 diabetic rats	Decreased the levels of inflammatory cytokine to improve insulin resistance and inhibited apoptosis of islet cells to protect islet β-cells [86]
Jinlian Jiangtang capsules	Antihyperglycemic effects	Kunming mice	Promoted insulin release and glucose uptake and improved β-cell functioning [87]
Jinqi Jiangtang tablets	Reverse insulin resistance and antihyperglycemic effects	Wistar rats	Inhibited resistin gene expression [88]
	Antihyperglycemic effects	3T3-L1 cells and KK-Ay mice	Activated the AMPK signaling pathway [89]

MDA: malondialdehyde.