β-Eudesmol in Rhizoma Atractylodis targets AVPR2 to inhibit the cAMP-AQP2 pathway and promote fluid metabolism

Background

Rhizoma Atractylodis, a classic dryness traditional Chinese medicine (TCM), demonstrates potent fluid metabolism–promoting properties. Previous studies have identified volatile oils as the primary active fraction of Rhizoma Atractylodis in regulating fluid metabolism, and β-eudesmol was predicted as the key component; however, the bioactivity of β-eudesmol has not been experimentally verified and the mechanism promotes fluid metabolism and causes dryness remains unclear.

Purpose

This study seeks to validate the dryness effect of β-eudesmol and elucidate its key mechanisms in regulating fluid metabolism to produce dryness effect.

Methods

This study used normal mice to compare the effects of Rhizoma Atractylodis volatile oil and β-eudesmol on fluid metabolism regulation. Transcriptomic analysis was used to predict the potential mechanisms by which β-eudesmol modulates fluid metabolism. Through molecular docking and cellular thermal shift assay (CETSA), preliminary identification of potential target mediating β-eudesmol's dryness effect was achieved. In vitro target validation was performed using TCMK-1 cells with plasmid transfection or siRNA interference. In vivo target validation was conducted in mice transfected with adeno-associated virus (AAV)

Results

β-Eudesmol significantly altered water intake, urine output, aquaporin 2 (AQP2) expression. Transcriptomic analysis revealed the cAMP-AQP2 pathway as the core component of the renal transcriptional regulatory network of β-eudesmol. Therefore, the inhibitory effect of β-eudesmol on the cAMP-AQP2 pathway was validated in mouse kidneys and TCMK-1 cells, and its targeted binding to the arginine vasopressin receptor 2 (AVPR2) was demonstrated via molecular docking and CETSA. However, after AVPR2 overexpression, the fluid metabolism–promoting effect of β-eudesmol decreased, and the dryness manifestations in mice were alleviated.

Conclusion

This study determined that β-udesmol is the key component for the dryness of Atractylodes macrocephalaelucidates the mechanism of moisture removal and diuresis by Rhizoma Atractylodis, providing a scientific basis for its clinical use to treat dampness-related conditions experimental evidence for reducing dryness and increasing. Moreover, it provides a new reference for theoretical research on the properties of TCM.