What question did this study set out to answer?

This research aims to investigate how nobiletin affects oxidative stress and endothelial dysfunction in obese mice.

May 16, 2026Open Access

Nobiletin Protects Endothelial Function in High-Fat Diet-Induced Obese Mice Through Activation of 5′ Adenosine Monophosphate-Activated Protein Kinase

Key Points

This research aims to investigate how nobiletin affects oxidative stress and endothelial dysfunction in obese mice.
Male C57BL/6J mice were divided into HFD and normal chow groups and treated with nobiletin (50 mg/kg/day) or vehicle for 8 weeks.
Vasoreactivity was measured using a wire myograph, and primary rat aortic endothelial cells were isolated for in vitro analysis.
Protein expressions were evaluated by Western blot to assess oxidative stress markers and signaling pathways.
Nobiletin co-treatment restored impaired nitric oxide generation and endothelium-dependent relaxations induced by high glucose in RAECs.
In DIO mice, nobiletin administration partially reversed body weight increase, elevated blood pressure, and oxidative stress in aortas.
AMPK/eNOS and Nrf2/HO-1 pathways were activated by nobiletin, leading to improved endothelial function.

Abstract

Background/Objectives: Nobiletin, one of the main components of citrus peel, exhibits potent antioxidant, anti-inflammatory, and metabolic regulatory properties. However, its effect on obesity-associated vasculopathay remains unknown. We aim to investigate the effect of nobiletin in ameliorating oxidative stress and endothelial dysfunction induced by a high-fat diet (HFD). Methods: Male C57BL/6J mice were fed a HFD (60 kcal% fat) or normal chow for four months and orally administered with vehicle or nobiletin (50 mg/kg/day) for 8 weeks. Vasoreactivity in aortas was measured on a wire myograph. Primary rat aortic endothelial cells (RAECs) were isolated from Sprague-Dawley rats for in vitro study. Protein expressions were detected by Western blot. Superoxide production was determined by fluorescence imaging. Results: Exposure to high glucose increased the phosphorylation of JNK (Tyr185) and decreased the protein expressions of Nrf2 and HO-1, as well as downregulated the phosphorylation of AMPK and eNOS (Ser1177) in RAECs. This led to reduced nitric oxide (NO) generation and elevation of oxidative stress. High glucose induction also impaired the endothelium-dependent relaxations (EDRs) in murine aortas. These high glucose-induced impairments were restored by co-treatment of nobiletin (1 μM or 10 μM) whereas effects of nobiletin were abolished by AMPK inhibitor Compound C. The DIO-induced diabetic animal model showed increased body weight and blood pressure, imbalance of glucolipid metabolism, impaired EDRs, and elevated oxidative stress in aortas. AMPK/eNOS and Nrf2/HO-1 pathways were downregulated in aortas from DIO mice. Oral administration of nobiletin could at least partially reverse the above damage. Conclusions: Nobiletin ameliorates endothelial dysfunction by reducing oxidative stress and enhancing NO bioavailability upon activation of AMPK/eNOS and Nrf2/HO-1 pathways in obese diabetic mice.

Nobiletin Protects Endothelial Function in High-Fat Diet-Induced Obese Mice Through Activation of 5′ Adenosine Monophosphate-Activated Protein Kinase

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Abstract

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