Mechanism of Astragali radix combined with Salviae miltiorrhizae Radix et Rhizoma in alleviating diabetic nephropathy: Focus on the AGEs/RAGE/MAPK signaling Pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Both Astragali radix (Huangqi) and Salviae miltiorrhizae Radix et Rhizoma (Danshen) were first documented in Shennong Bencaojing (Shennong's Classic of Materia Medica), a foundational text of traditional Chinese medicine (TCM). Historically and in contemporary practice, these herbs are frequently combined to enhance therapeutic efficacy. According to TCM theory, this herb pair exerts the effects of replenishing qi, nourishing blood, promoting diuresis to alleviate edema, and activating blood circulation to resolve stasis-effects that align with the "qi deficiency and blood stasis" syndrome type of diabetic nephropathy (DN). Therefore, Astragali radix and Salviae miltiorrhizae Radix et Rhizoma are widely used clinically for treating DN and have demonstrated favorable therapeutic outcomes in the management of this condition. Furthermore, modern research has also indicated that compound preparations combining Astragali radix and Salviae miltiorrhizae Radix et Rhizoma exhibit efficacy in improving DN.

AIM OF THE STUDY: This study aims to verify the pharmacodynamic effect and mechanism of action of Astragali radix combined with Salviae miltiorrhizae Radix et Rhizoma (ARSMR) in streptozotocin (STZ)-induced diabetic nephropathy (DN) rat models fed a high-sugar/high-fat diet.

MATERIALS AND

METHODS

First, the chemical components of ARSMR were characterized using ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MS). Subsequently, a rat model of DN was established via STZ injection coupled with a high-sugar/high-fat diet. Following ARSMR treatment, we assessed blood glucose levels, renal function parameters, blood lipid profiles, and oxidative stress markers in the rats. Renal and hepatic pathological changes were also examined histologically. Next, network pharmacology and molecular docking analyses were employed to predict potential signaling pathways and therapeutic targets of ARSMR for DN. Finally, these predictions were experimentally validated using reverse transcription quantitative polymerase chain reaction (RT-qPCR), Western blotting (WB), and immunohistochemistry (IHC) to elucidate the molecular mechanism underlying ARSMR's efficacy against DN.

RESULTS

UHPLC-MS analysis identified 71 compounds in ARSMR, with Quercetin, Tanshinone IIA, Tanshinone IIB, and Formononetin as primary constituents. In STZ/high-fat/high-sugar diet-induced DN rats, ARSMR treatment significantly restored body weight, reduced blood glucose and lipid levels, improved renal function, attenuated oxidative stress, and reversed renal/hepatic histopathological damage, accompanied by decreased renal fibronectin expression. Network pharmacology and molecular docking predicted the AGEs-RAGE and MAPK signaling pathways as key mechanistic targets, demonstrating strong binding between ARSMR components and core proteins. Experimental validation via RT-qPCR, WB, and IHC confirmed ARSMR inhibits the AGEs/RAGE/MAPK pathway activation and renal apoptosis, elucidating its mechanism for ameliorating DN.

CONCLUSION

These research findings indicate that ARSMR can significantly downregulate the levels of blood glucose and blood lipids in DN rat models induced by STZ combined with a high-sugar and high-fat diet, and ameliorate the damage to the kidneys and liver of DN rats. The potential mechanism of ARSMR in treating DN mainly relies on the regulation of the AGEs/RAGE/MAPK signaling pathway.