Additive renal protective effects between arctigenin and puerarin in diabetic kidney disease.

Recent studies have shown that the combined use of renin angiotensin system inhibitor, SGLT2 inhibitors and/or mineralocorticoid receptor antagonist provides additional renal protection for patients with diabetic kidney disease (DKD). Similarly, in traditional Chinese medicine, the synergistic application of multiple herbs often brings more significant therapeutic effects. However, the synergistic or additive mechanisms of traditional Chinese medicine in combination therapy are not fully understood. In our previous studies, we show that arctigenin (ATG), a major component of Fructus Arctii, attenuates proteinuria and renal injury in diabetic mice by activating PP2A, and puerarin (a class of known isoflavones) can also reduce proteinuria and renal injury in diabetic mice via activation of Sirt1. Here, we further explored the potential additive renal protection of these two compounds in diabetic mice. Research has found that ATG and puerarin have a synergistic effect in reducing albuminuria in db/db mice. Mechanistically, we found that ATG reduced NF-κB p65 phosphorylation likely through activation of PP2A while puerarin reduced p65 acetylation via Sirt1 activation. Therefore, ATG and puerarin have additive inhibitory effects on the NF-κB activation, which is a key inflammatory pathway in DKD. RNA-sequencing analysis revealed distinct pathways activated by ATG and puerarin in the diabetic kidney, which may provide an additional mechanism for their additive effects in DKD. Our study suggests that ATG and puerarin could be a new combination therapy for DKD and reveals its underlined mechanisms.