Serum metabolomics and 16S rRNA amplicon sequencing reveal the role of puerarin in alleviating bone loss aggravated by antidiabetic agent pioglitazone in type 2 diabetic mice.

ETHNOPHARMACOLOGICAL RELEVANCE

Pioglitazone (PIO) was an anti type 2 diabetes (T2D) agent but caused bone loss and bone marrow fat accumulation. Puerarin (PUE) was a natural component of herbal medicine extracted from Pueraria lobata (Willd.) Ohwi and reduced glycemia and improved bone mass as a supplementary drug. A combination of PIO and PUE might be good for maintaining bone mass and blood glucose.

AIM OF THE STUDY

We aimed to elucidate the potential correlation and underlying mechanisms of dietary supplement PUE in reducing side effects caused by PIO.

MATERIALS AND METHODS

In vitro, alkaline phosphatase (ALP) staining, alizarin S (ARS) staining and qRT-PCR were performed to detect the osteogenesis activity in MC3T3-E1 cells. In vivo, we established the T2D model by treating C57BL6/J mice with high-fat diets and streptozotocin (STZ). Micro-CT, hematoxylin and eosin (H&E) staining and tartrate-resistant acid phosphatase (TRAcP) staining were performed to observe the difference in skeletal phenotype. Serum metabolomics and 16S rRNA amplicon sequencing were applied to analyze the potential effect of the combination of PIO and PUE.

RESULTS

We showed that the PUE could increase ALP activity and mineralization nodes of MC3T3-E1 with PIO. PIO could aggravate bone loss but PUE alleviated the effect caused by PIO in T2D mice. PUE promoted alpha-linolenic acid metabolism and glycerophospholipid metabolism, and affected the alpha diversity of the gut microbiome by regulating the genera of Alloprevotella, Fusobacterium, Rodentibacter, etc. Correlation analysis indicated that sphingosine-1-phosphate, nonadecylic acid, and margaric acid were associated with the effect of PUE.

CONCLUSIONS

Taken together, we demonstrated that PIO combined with PUE was able to lower blood sugar levels without causing bone loss. The effect of PUE mainly correlated with the genua of Alloprevotella, Fusobacterium, Rodentibacter, and Alistipes. Also, alpha-linolenic acid metabolism and glycerophospholipid metabolism were major targets of PUE.