MAPK8 and Obesity: By activating the c-Jun N-terminal kinase (JNK) and nuclear factor-kappa B (NF-κB) signaling pathways, obesity increases the production of pro-inflammatory cytokines like TNF-α and IL-6.27 In our study, obese rats that were in the HFD and WD groups also developed higher levels of TNF-α and IL-6.