Anti‐Obesity Effects of <scp><i>Leuconostoc mesenteroides</i></scp> 4‐Fermented Lemon Peel Filtrate on <scp>HFD</scp>‐Induced Obese Mice via <scp>NFκB</scp>/ <scp>PPAR</scp>‐γ Pathway

Obesity is a major health problem associated with Type 2 diabetes, non-alcohol fatty liver disease (NAFLD), and atherosclerosis. Functional lactic acid bacteria-fermented products have been reported to have potential anti-obese effect. The present results revealed that <i>Leuconostoc mesenteroides</i> 4 (LMSS4)-fermented lemon peel filtrate slowed down the increase of body weight, and decreased liver and epididymal fat indices; it also decreased serum levels of TC (total cholesterol), TG (triglyceride), LDL-C (low-density lipoprotein cholesterol), ALT (alanine transaminase), AST (aspartate transaminase), and AKP (alkaline phosphatase), TNF-α (tumor necrosis factor-α), IFN-γ (interferon gamma), IL-1β (interleukin-1β), IL-6 (interleukin-6), and IL-10 (interleukin-10), increased the levels of HDL-C (high-density lipoprotein cholesterol), IL-4 (interleukin-4), and IL-10 (interleukin-10). Furthermore, the mRNA expression of NFκB-p65 (nuclear factor-κB p65), PPAR-γ (eroxisome proliferator-activated receptor γ), TNF-α, IL-1β, leptin, SREBP-1c (sterol regulatory element binding protein-1c), FAS (fatty acid synthase), and CEBP/α (CCAAT/enhancer binding protein α) were down-regulated, while the expression of IL-4, IκB-α (inhibitory subunit of NF Kappa B alpha), and IL-10 were upregulated after the mice were treated with LMSS4-fermented lemon filtrate; the filtrate also downregulated the protein expression of NFκB-p65 and PPAR-γ but increased the expression of IκB-α. The HPLC results found that rutin and hesperidin were the predominant constituents in both the unfermented and LMSS4-fermented lemon filtrates among the 15 constituents analyzed. In addition, chlorogenic acid, umbelliferone, byakangelicin, and oxypeucedanin hydrate were increased in the fermented lemon filtrate, in which chlorogenic acid showed the highest increase rate (83.51%). In conclusion, the anti-obesity effect of LMSS 4-fermented lemon peel filtrate was mediated via the regulation of the NFκB/PPAR-γ signaling pathway. These results could provide an experimental basis for developing new functional lemon beverages for obesity intervention.