Pholidota chinensis Lindl alleviates diabetic kidney disease by restoring mitochondrial dynamics and promoting mitophagy

ETHNOPHARMACOLOGICAL RELEVANCE: Pholidota chinensis Lindl. (P. chinensis), a traditional medicinal plant, exhibits notable antioxidant, anti-inflammatory, and antidiabetic properties. In Traditional Chinese Medicine, its pseudobulbs are applied for treating cough, bronchitis, diabetes, and diabetic kidney disease (DKD). The potential mechanism through which P. chinensis alleviates DKD requires further investigation. AIM OF THE STUDY: This investigation was designed to evaluate the potential of P. chinensis to optimize mitochondrial function via the dual regulation of dynamic remodeling and mitophagic flux within DKD models. MATERIALS AND METHODS: A DKD animal model was induced through unilateral nephrectomy and streptozotocin administration. Various parameters were evaluated, such as renal function, histopathology, inflammatory and fibrotic markers, and proteins related to mitochondrial fission-fusion balance and mitophagy. In vitro, AGEs-treated HK-2 cell model was employed to assess autophagic flux and mitochondrial function via adenoviral mCherry-GFP-LC3B transduction, JC-1 assay, together with measurements of ROS and ATP production. RESULTS: P. chinensis showed clear renoprotective effects in DKD rats, mainly by alleviating renal inflammation and fibrotic changes. Treatment was associated with improved mitochondrial dynamics, characterized by increased expression of mitochondrial fusion-related proteins (Mfn1, Opa1) and reduced levels of fission-related proteins (Drp1, Fis1). Meanwhile, a pronounced activation of mitophagy was observed, evidenced by increased levels of core regulators involved in the PINK1/Parkin pathway and autophagosome formation, along with reduced p62 accumulation. In vitro, P. chinensis exerted antioxidative effects by enhancing SOD activity while reducing MDA levels. It also facilitated autophagy activation and autophagosome-lysosome fusion, leading to improved mitochondrial membrane potential, reduced ROS production, and increased ATP generation. CONCLUSION: Overall, P. chinensis improves mitochondrial quality control by promoting fusion, reactivating mitophagy, and enhancing autophagic flux, thereby facilitating mitochondrial clearance and contributing to the attenuation of kidney injury and the slowing of DKD progression.