Fucoidan and 16:8 intermittent fasting attenuate oxidative stress and cavernosal remodeling in an STZ/NA-induced type 2 diabetic rat model

Abstract

Objective: Type 2 diabetes mellitus (T2DM) induces erectile dysfunction (ED) via oxidative stress and structural remodeling of the corpus cavernosum (CC). This study investigated the protective effects of fucoidan and intermittent fasting (IF), alone and in combination, on cavernosal impairment in a T2DM rat model. Materials and Methods: Male Sprague-Dawley rats were assigned to Control, Diabetic (streptozotocin [STZ]/nicotinamide [NA]- induced), Diabetic+Fucoidan (DF), Diabetic+IF (DIF), and Diabetic+Fucoidan+IF (DFIF) groups. After a 4-week intervention, cavernosal function was assessed using an organ bath assay. Oxidative stress was evaluated using superoxide dismutase (SOD) activity and luminol/lucigenin chemiluminescence. Structural changes were analyzed using hematoxylin and eosin (H&E), Masson’s trichrome, and endothelial nitric oxide synthase (eNOS)/alpha-smooth muscle actin (α-SMA) immunohistochemistry. Results: Type 2 diabetes mellitus induced significant trabecular disorganization and increased collagen deposition (p<0.05). The DFIF group showed a reduction in lucigenin-derived superoxide signals (p=0.0302) and the greatest increase in SOD activity (p=0.0064). Histologically, DFIF significantly preserved the cavernosal architecture and sinusoidal area compared to the diabetic group (p=0.0091). While α-SMA expression improved mainly in the fucoidan-treated groups, eNOS levels remained below control values. Functional outcomes showed favorable trends but did not reach statistical significance. Conclusion: The combined DFIF regimen provides broad protection against cavernosal oxidative stress and fibrotic remodeling, suggesting its potential value as a non-pharmacological adjunct for diabetic ED.

Keywords

• Diabetic erectile dysfunction
• Fucoidan
• Intermittent fasting
• Oxidative stress
• Corpus cavernosum
• Combined effect

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