Vitamin D and canagliflozin combination alleviates Parkinson's disease in rats through modulation of RAC1/NF-κB/Nrf2 interaction.

Objective: Oxidative stress and neuroinflammation are crucial factors in the pathogenesis of Parkinson's disease (PD). Vitamin D (Vit D) and canagliflozin (CAN) are known to have anti-inflammatory and antioxidant properties. Together, they target key molecular pathways involved in PD, including oxidative stress and neuroinflammation, specifically, the small GTPase protein (RAC1)/nuclear factor-kappa B (NF-κB)/nuclear factor erythroid 2-related factor 2 (Nrf2) signaling, which regulates brain's oxidative stress and inflammation. This study investigates the effects of Vit D and CAN alone and in combination in a rat model of PD.

Materials and methods: Fifty male Wistar rats were assigned to five groups (n = 10), including control, rotenone (ROT), Vit D + ROT, CAN + ROT, and Vit D + CAN + ROT. We assessed weight changes, brain weight, neurobehavioral functions, biochemical markers, and immunohistopathology of brain tissues.

Results: The results showed that Vit D treatment was more effective than CAN in alleviating PD symptoms, with the combination of Vit D and CAN offering the best therapeutic outcome. This combination therapy significantly improved serum Vit D, striatal dopamine (DA) levels, antioxidant status (reduced glutathione (GSH) and catalase (CAT), reduced oxidative stress (malondialdehyde (MDA)), and ameliorated inflammation (tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), and interleukin 10 (IL-10)). Additionally, the combination therapy modulated the expression of RAC1, NF-κB, Nrf2, vitamin D receptors (VDR), and vitamin D-binding protein (DBP) and immunoexpression of tyrosine hydroxylase (TH), and α-synuclein (α-SYN).

Conclusion: These findings suggest that Vit D and CAN synergistically modulate the RAC1/NF-κB/Nrf2 pathway, leading to improved neuroprotection in PD.