Scientific Validation of Using Active Constituent as Research Focus in Traditional Chinese Medicine: Case Study of Pueraria lobata Intervention in Type 2 Diabetes

Abstract

Objectives: Traditional Chinese Medicine (TCM) is recognized for its complex composition and multiple therapeutic targets. However, current pharmacological research often concentrates on extracts or individual components. The former approach faces numerous challenges, whereas the latter oversimplifies and disregards the synergistic effects among TCM components. This study aims to investigate the scientific validity of focusing on the active constituent in TCM efficacy research, using Pueraria lobata (P. lobata) as a case study. Methods: Through spectrum-effect correlation analysis, network pharmacology, and molecular docking, five active ingredients of P. lobata were identified: puerarin, formononetin, tuberosin, 4',7-dihdroxy-3'-methoxyisoflavone, and Daidzein-4,7-diglucoside. These ingredients were combined to form an active constituent, which was subsequently tested in vitro and in vivo. Results: In in vitro, the active constituent exhibited superior effects in enhancing glucose consumption and glycogen synthesis compared to both the P. lobata extract and individual components. In vivo experiments demonstrated that medium and high doses of the active constituent were significantly more effective than P. lobata extract, with effects comparable to those of metformin in reducing blood sugar levels. Conclusions: The active constituent effectively improves T2DM by lowering blood glucose levels, promoting glycogen synthesis, and modulating glycolipid metabolism. Both in vitro and in vivo studies indicate that it outperformed the P. lobata extract and individual components. This study establishes the scientific validity and feasibility of utilizing the active constituent as the focus for investigating the efficacy of TCM, thereby offering novel insights and a new research paradigm for future TCM investigations.

Keywords: Pueraria lobata; active constituent; potential pharmacodynamic ingredients; type 2 diabetes.

Figure 1

Results of spectrum-effect correlation. (A) Total ions chromatogram of the blood components of P. lobata extract in rats; (B) Heat map of the correlation between the blood components of P. lobata and the serum indicators; (C) The correlation between the components of P. lobata and comprehensive evaluation indicator, the red line indicates a correlation of 0.70.

Figure 2

(A) The shared targets of P. lobata in the TCMSP and TCMID databases, along with differential genes associated with T2DM from the GeneCards, OMIM, and TTD datasets; (B) The compound-target network illustrating 12 candidate active ingredients and their 167 potential targets for P. lobata in T2DM; (C) The PPI network of genes involved in the treatment of T2DM with P. lobata; (D) Outcomes representing the top 16 significant targets within the PPI network as determined by CytoNCA.

Figure 3

(A) GO analysis for 167 protein targets in the treatment of T2DM with P. lobata; (B) KEGG pathway analysis involving 167 protein targets related to P. lobata therapy for T2DM.

Figure 4

Results of the molecular docking. (A) Heat map of the docking binding energy between 12 active compounds and five core targets; (B) Pattern diagram of molecular docking.

Figure 5

Cell viability in IR-HepG2 cells induced by INS. Puerarin (A), formononetin (B), tuberosin (C), Daidzein-4,7-diglucoside (D), 4′,7-dihdroxy-3′-methoxyisoflavone (E), P. lobata extract (F), and active constituent (G).

Figure 6

Beneficial effect curve of puerarin (A), formononetin (B), tuberosin (C), Daidzein-4,7-diglucoside (D), 4′,7-dihdroxy-3′-methoxyisoflavone (E), P. lobata extract (F), and active constituent (G); effect of P. lobata on glucose consumption (H) and glycogen levels (I) in IR-HepG2 cells. In comparison to the control group, ^## p < 0.01; when contrasted with the model group, * p < 0.05, ** p < 0.01.

Figure 7

Hypoglycemic effect of P. lobata extract and active constituent on STZ-induced T2DM mice. Food intake (A), water intake (B), FBG levels (C), and OGTT (D,E) of the mice treated with P. lobata extract and active constituent for 10 weeks. In comparison to the control group, ^## p < 0.01; when contrasted with the model group, ** p < 0.01.

Figure 8

Influence of P. lobata on insulin sensitivity in STZ-induced T2DM mice. (A) Levels of insulin in serum; (B) HOMA-IR values; (C) HOMA-β values; (D) Insulin tolerance test (ITT); (E) AUC for ITT. In comparison to the control group, ^## p < 0.01; when contrasted with the model group, ** p < 0.01.

Figure 9

Improvement of P. lobata extract and active constituent on biochemical indicators in STZ-induced T2DM mice. Levels of T-CHO (A), TG (B), LDL-C (C), HDL-C (D), GHb (E), and KB (F) in serum. In comparison to the control group, ^## p < 0.01; when contrasted with the model group, * p < 0.05, ** p < 0.01.

Figure 10

Histological evaluation of the effects of P. lobata extract and active constituent on liver and pancreas tissues in STZ-induced T2DM mice. In the results of H&E staining (A) and PAS staining (B) of liver (magnification, ×400), and H&E staining of pancreas (C) (magnification, ×100), a–g represent the Control group, Model group, Metformin (Met) group, PUE group, and AC groups (50, 100, 200 mg/kg).