Protective Effects Assessment of Combined Extracts from Periplaneta americana Residues and Cybister chinensis Motschulsky on Feline Renal Cells: In Vitro Evidence Related to Inflammation, Oxidative Stress, and Fibrosis

With the rising prevalence of feline kidney diseases, effective preventive and therapeutic strategies are urgently needed. This study evaluated the effects of Cybister chinensis extracts (CCME) and Periplaneta americana residue extracts (PAE) on inflammation-associated, oxidative stress-related, and fibrosis-related responses in Crandell-Rees Feline Kidney (CRFK) cells. Using MTT assays, flow cytometry, and qPCR, we assessed cytoprotection in models of lipopolysaccharide (LPS)-, hydrogen peroxide (H2O2)-, and palmitic acid (PA)-induced injury. Preliminary HPLC fingerprint analysis of three batches of a combined extract from Periplaneta americana residues and Cybister chinensis Motschulsky (CPCE) revealed similar chromatographic profiles, indicating good batch-to-batch consistency. Within non-cytotoxic ranges, CPCE increased cell viability and reduced apoptosis in injured CRFK cells. Anti-inflammatory effects were evidenced by significant downregulation of TNF-α and IL-6 mRNA. Potential antioxidant-related effects were suggested by decreased expression of oxidative stress–responsive genes SOD1, CAT, and GSTP1. In the PA model, anti-fibrotic potential was supported by reduced TGFB1 expression, accompanied by improvements in inflammatory and oxidative stress markers, and by decreased levels of fibrosis-associated markers α-SMA, COL I, and HCB III. These findings suggest that CPCE exerts cytoprotective effects in vitro, potentially through modulation of inflammation, oxidative stress, and fibrosis.