Consumption of Saturated Fatty Acids‐Rich Lard Benefits Recovery of Experimental Arthritis by Activating PPAR‐γ

• Published in: Molecular nutrition & food research 2023-01, Vol.67 (2), p.e2200429-n/a
• Main Authors: Wang, Rui, Ji, Cong‐Lan, Feng, Dan‐Dan, Wu, Yi‐Jin, Li, Yan, Olatunji, Opeyemi Joshua, Yu, Li‐Jun, Zuo, Jian
• Format: Article
• Language: English
• Subjects: Animal models; Animals; Arthritis; Arthritis, Experimental - drug therapy; Arthritis, Experimental - pathology; Body weight; Collagen; Colorimetry; Consumption; Cytokines; Cytokines - metabolism; diet; energy metabolism; Enzyme-linked immunosorbent assay; Fatty Acids; Flow cytometry; food research; Gene expression; Glycolysis; histology; Immunoblotting; Inflammation; lard; Metabolites; Mice; Monocytes; NF-kappa B - metabolism; Peroxisome proliferator-activated receptors; PPAR gamma - genetics; PPAR gamma - metabolism; PPAR‐γ; Rats; Rats, Sprague-Dawley; Recovery; Reporter gene; reporter genes; Rheumatoid arthritis; TLR4; TLR4 protein; Toll-like receptors
• ISSN: 1613-4125; 1613-4133
• DOI: 10.1002/mnfr.202200429

Scope This study investigates the impacts of lard and related fatty acids intake on rheumatoid arthritis (RA) animal models. Method and results Collagen‐induced arthritis (CIA) and adjuvant‐induced arthritis (AIA) are induced in SD rats and C57 BL/6 mice respectively, which are fed by lard‐rich diet (LRD) for 42 days with intake restriction or not. AIA SD rats are treated by representative fatty acids for 30 days. Body weight, arthritis score, and metabolic profile are periodically recorded. Monocyte distribution, cytokine/metabolites levels, gene expression, and tissue damages are investigated by flow cytometry, ELISA, colorimetry, PCR, and histological methods. After being treated by fatty acids in vitro, THP‐1 monocytes and the corresponding medium are collected for ELISA, PCR, immunoblotting, and reporter gene assays. Irrespective of intake amounts, LRD decreases inflammatory cytokines and inhibits glycolysis in all rheumatic rodents. Furthermore, it alters monocyte distribution and promotes PPAR‐γ expression in AIA mice. Overall evidences show that both saturated (SF) and unsaturated fatty acids (USF) from lard can attenuate inflammation by activating PPAR‐γ. Silencing PPAR‐γ abrogates their anti‐inflammatory effects in vitro. Besides, SF can stimulate TLR4/NF‐κB pathway. Conclusion Lard consumption is beneficial for active inflammatory arthritis recovery. Even SF can activate PPAR‐γ and consequently attenuate inflammation. Fat consumption is believed to be harmful for health, but this claim is questionable in the context of rheumatoid arthritis. The study reveals that lard‐rich diet attenuated experimental arthritis in rodents, when blood lipids are reduced, and lard‐derived unsaturated fatty acids show potentials in suppressing different factors‐induced inflammation in monocytes. It suggests that supplement of certain lipids is beneficial for anti‐rheumatic therapies.