Rhizoma coptidis as a Potential Treatment Agent for Type 2 Diabetes Mellitus and the Underlying Mechanisms: A Review

Abstract

Diabetes mellitus, especially type 2 diabetes mellitus (T2DM), has become a significant public health burden. Rhizoma coptidis (RC), known as Huang Lian, is widely used for treating diabetes in China. The bioactive compounds of RC, especially alkaloids, have the potential to suppress T2DM-induced lesions, including diabetic vascular dysfunction, diabetic heart disease, diabetic hyperlipidemia, diabetic nephropathy, diabetic encephalopathy, diabetic osteopathy, diabetic enteropathy, and diabetic retinopathy. This review summarizes the effects of RC and its bioactive compounds on T2DM and T2DM complications. Less research has been conducted on non-alkaloid fractions of RC, which may exert synergistic action with alkaloids. Moreover, we summarized the pharmacokinetic properties and structure-activity relationships of RC on T2DM with reference to extant literature and showed clearly that RC has potential therapeutic effect on T2DM.

Keywords: Huang Lian; Rhizoma coptidis; complications; ethnopharmacology; type 2 diabetes mellitus.

Figure 1

Appearance of Coptis chinensis Franch., Coptis deltoidea C. Y. Cheng et Hsiao and Coptis teeta Wall, and the structures of bioactive anti-T2DM components of RC.

Figure 2

Mechanisms involved in the regulation of glycometabolism in T2DM by RC. ↓ indicates inhibition/reduction, while ↑ indicates increase/promotion. The up or down direction of arrows reflects the promotion or suppression of the first signal in the signaling pathway.

Figure 3

Mechanisms of RC on diabetic vascular dysfunction and diabetic heart disease. —• with different colors indicate inhibition/reduction while → with different colors indicate increase/promotion. Arrows of different colors depict different references, and when the results of mechanism research overlap, just randomly select one of the colors. BBR represents berberine.

Figure 4

Mechanisms of RC on diabetic nephropathy. —• with different colors indicate inhibition/reduction while → with different colors indicate increase/promotion. Arrows of different colors depict different references, and when the results of mechanism research overlap, just randomly select one of the colors. BBR, Cop, and Jat represent berberine, coptisine, and jatrorrhizine.

Figure 5

Mechanisms of RC on diabetic encephalopathy. —• with different colors indicate inhibition/reduction while → with different colors indicate increase/promotion. Arrows of different colors depict different references, and when the results of mechanism research overlap, just randomly select one of the colors. BBR and Pal represent berberine and palmatine.

Figure 6

(A) Mechanisms of RC on diabetic osteoporosis; (B) mechanisms of RC on diabetic retinopathy; (C) mechanisms of RC on diabetic enteropathy. —• with different colors indicate inhibition/reduction while → with different colors indicate increase/promotion. Arrows of different colors depict different references, and when the results of mechanism research overlap, just randomly select one of the colors. BBR and Brb represent berberine and berberrubine.