A promising drug combination of mangiferin and glycyrrhizic acid ameliorates disease severity of rheumatoid arthritis by reversing the disturbance of thermogenesis and energy metabolism

Abstract

Background: Activation of immune system in rheumatoid arthritis (RA) consumes amount of energy, and the energy metabolic signals may be a potential target for RA therapy. Baihu-Guizhi decoction (BHGZD) achieves satisfactory therapeutic effects in RA in clinics by recovering the adjacent articular cartilage and bone destruction, and abnormal articular temperature. However, its pharmacological material basis and molecular mechanisms have not been fully elucidated.

Purpose: This study focused on exploring the potential acting mechanism of BHGZD against RA, and identifying its main bioactive compounds (BACs) of the combination of mangiferin and glycyrrhizic acid.

Methods: Key putative targets of BHGZD acting on adjuvant-induced arthritis (AIA)-M rats were screened by the transcriptomic profiling of the whole blood cells and synovium tissues collected from rats in normal control, AIA-M model and AIA-M-BHGZD treatment groups. Then, BACs of BHGZD against RA were identified using Ultra Performance Liquid Chromatography-Mass spectrum/Mass spectrum, molecular docking, surface plasmon resonance and pharmacokinetic analysis. In vivo experiments based on AIA-M rats and in vitro experiments based on 3T3-L1 preadipocytes were performed to verify the pharmacological effects of BACs against RA and the corresponding mechanisms.

Results: PKA-ADCY5-PPARγ-PGC 1α-UCP1-PRDM16 signal axis was demonstrated to be the candidate targets of BHGZD against RA and was involved in maintaining the balance of thermogenesis and energy metabolism, according to the transcriptional regulatory network analysis based on "herbs-putative targets-disease interaction network". Then, mangiferin from Rhizoma Anemarrhenae and glycyrrhizic acid from Radix Glycytthizae were identified as the main BACs of BHGZD against RA due to their highly accumulation in the blood in vivo, strong binding affinities with the two candidate targets of BHGZD against RA-ADCY5 and PPARγ, as well as the in vivo and in vitro strong regulation effects on energy metabolism disturbance.

Conclusions: These findings offer evidence that the combination of mangiferin and glycyrrhizic acid from BHGZD may be a promising candidate drug for RA therapy, and also provide an important reference for the development and modernization of traditional Chinese formulae.

Keywords: Baihu-Guizhi decoction; Glycyrrhizic acid; Main bioactive compounds; Mangiferin; Pharmacological mechanism; Rheumatoid arthritis.