Acupuncture enhances warm kidney and spleen granules efficacy in diabetic diarrhea through synergistic p300/CBP inhibition and Nrf2/HO-1 pathway activation.

Diabetic diarrhea (DD), affecting ∼20% of diabetic patients, lacks effective pharmacological treatment. This study investigates Warm Kidney and Spleen Granules (WKSG) combined with acupuncture for treating DD, focusing on p300/CBP-H3K27ac pathway and antioxidant/inflammatory signaling mechanisms. Male Wistar rats with HFD/STZ-induced DD received WKSG (1 g/day, 14 days), acupuncture (daily for 4 weeks; seven acupoints), or combined therapy over 35 days. Additional diabetic rats and high-glucose-stimulated Caco-2 cells were used for mechanistic validation of p300/CBP pathway involvement through p300 overexpression/silencing and pharmacological activation with CTPB. Clinical parameters such as body weight, fasting blood glucose, defecation frequency, and fecal moisture content were assessed weekly. Intestinal permeability was evaluated via transepithelial electrical resistance (TEER) and in vivo FITC-dextran permeability. Tight junction proteins (ZO-1/occludin), oxidative stress markers (ROS/MDA/SOD/GSH), p300/CBP-H3K27ac expression, Nrf2/HO-1 activation, NF-κB phosphorylation, and inflammatory cytokines (TNF-α/IL-6) were measured by Western blotting, qPCR, and ELISA. Mechanistic causality was established using p300 overexpression (oe-p300) and silencing (si-p300) lentiviral vectors in both animals and high-glucose-stimulated Caco-2 intestinal epithelial cells. Epithelial apoptosis was assessed by flow cytometry. STZ-treatment elevated colonic p300/CBP-H3K27ac, oxidative stress, inflammatory cytokines, and intestinal permeability while reducing body weight, tight junction proteins, and antioxidant enzymes. WKSG suppressed p300/CBP-HAT activity, reduced ROS/MDA, restored SOD/GSH, activated Nrf2/HO-1, inhibited NF-κB and TNF-α/IL-6, and restored barrier function; these effects were reversed by p300 overexpression. In Caco-2 cells, WKSG suppressed p300/CBP-mediated H3K27ac acetylation. Combined acupuncture and WKSG synergistically enhanced all parameters beyond monotherapy, reducing apoptosis rates further. Overall, WKSG ameliorates DD through p300/CBP inhibition, activating Nrf2/HO-1 antioxidant defense and suppressing NF-κB-mediated inflammation. Acupuncture synergistically amplifies efficacy, establishing mechanistic rationale for integrated therapy in DD management.