Background: Obesity is linked to reduced levels of adiponectin, an adipocyte-derived circulating protein, contributing to the development of inflammation, oxidative stress, and metabolic diseases. Strategies targeting increased production of adiponectin might be promising for preventing or improving metabolic risk factors and reducing obesity-associated metabolic disorders1,2,3. Anthocyanins are dietary bioactive compounds with antioxidant and anti-inflammatory properties4. Emerging evidence suggests that anthocyanins may increase adiponectin, which is interesting for research into novel therapies to improve inflammation and oxidative stress in obesity5,6,7. However, there is currently limited understanding of the link between the effects of anthocyanin on adiponectin in relation to inflammation and oxidative stress in obesity.
Methodology: A systematic literature review was conducted to evaluate the effects of anthocyanins on adiponectin, inflammation, and oxidative stress in obesity. The literature search was reported according to PRISMA guidelines8 and conducted by two researchers independently using the databases PubMed, ScienceDirect, Scopus, Web of Science, and MEDLINE The protocol for this systematic review was registered on PROSPERO (CRD42023425413).
Results: Preclinical studies (n=64), including in-vitro models of hypertrophied adipocytes (n=24) and rodent obesity-induced models (n=40), demonstrated an up-regulation of adiponectin (n=41) and SOD (n=8), and down-regulation of IL-6 (n=15), TNF-α (n=18), ROS (n=12), IL-1β (n=5), after treatment with different concentrations of anthocyanins. Clinical trials reported a significant increase in plasma adiponectin levels (n=3) and a decrease in pro-inflammatory cytokines, including TNF-α (n=4), IL-6 (n=2), and IL-10 (n=1), following supplementation with dietary anthocyanins at doses ranging from 102-165 mg/day.
Conclusions: Clinical and preclinical evidence suggests that supplementation with dietary anthocyanins may be an effective strategy for improving circulating adiponectin, and decreasing inflammatory and oxidative stress biomarkers. Targeting a high intake of anthocyanins may be beneficial for obesity and related disorders, however, further clinical trials are needed to confirm the effects and identify optimal doses and dietary sources.