Antioxidative Stress and Anti-Inflammatory Activity of Fucoidan Nanoparticles against Nephropathy of Streptozotocin-Induced Diabetes in Rats

Oxidative stress and inflammation have been shown to interact and have the role of importance in causing diabetic nephropathy complications. Fucoidan has a strong antioxidant and anti-inflammation effect, so the aim of this research was to evaluate the antioxidative stress and anti-inflammatory effect of fucoidan nanoparticles against nephropathy of streptozotocin-induced diabetes in rats. Fucoidan nanoparticles are characterized using dynamic light scattering (DLS) and scanning electron microscope (SEM). The rats were randomized into the control group (were given with aquadest), streptozotocin group (were injected with streptozotocin at a dose of 55 mg/kg BW i.p.), and fucoidan nanoparticle group (were given orally with fucoidan at doses 75, 150, and 300 mg/kg BW and then injected streptozotocin at a dose of 55 mg/kg BW i.p.). The blood was taken to evaluate the level of blood urea nitrogen (BUN) and creatinine. The kidney tissues were collected to measure malondialdehyde (MDA), interleukin-6 (IL-6), and tumor necrosis factor α (TNF-α) by ELISA; superoxide dismutase (SOD), and glutathione peroxidase (GPx) by immunohistochemical staining and histological observation by Hematoxylin & Eosin (H&E) staining. The DLS demonstrated that the fucoidan nanoparticle size was 330.6 ± 58.8 nm, and the SEM showed an irregular shape with a rough surface image. The administration of streptozotocin significantly increased BUN, creatinine, MDA, IL-6, and TNF-α levels, whereas expression of SOD and GPx decreased as compared with the control group (p < 0.05). The administration of fucoidan nanoparticles only at a dose of 300 mg/kg BW significantly decreases BUN, creatinine, MDA, IL-6, and TNF-α levels. However, fucoidan nanoparticles at a dose of 300 mg/kg BW significantly increase SOD and GPx expression as compared with the streptozotocin group (p < 0.05). The administration of streptozotocin caused the loss of normal kidney cell structure and necrosis, while treatment with fucoidan nanoparticles improved renal cell necrosis. It can be concluded that fucoidan nanoparticles are promising agents in terms of the protection afforded against streptozotocin-induced nephropathy through antioxidative stress by decreasing MDA and increasing SOD and GPx and through anti-inflammatory effect by decreasing levels of IL-6 and TNF-α.