Justicia procumbens Attenuates Obesity-induced Metabolic Disorders by Regulating NF-kB-mediated Adipose Tissue Inflammation

Abstract

Obesity has become a major public health concern, affecting more than a billion people worldwide. It is associated with low grade of chronic inflammation, which contribute to related metabolic diseases. It has been reported that some plants and their bioactive compounds possess anti-inflammatory activity associated with lipid metabolism. Justicia procumbens, an edible medicinal plant native to Northeast Asia including Korea, is reported to exert antioxidant, anti-inflammatory, and antibacterial properties. However, its effects on obesity and its related metabolic dysfunctions remain unreported. This study aimed to investigate anti-obesity and anti-inflammatory effects of J. procumbens ethanol extract in vitro and in vivo. J. procumbens markedly reduced lipid accumulation in a dose-dependent manner, accompanied by diminution of adipogenic and lipogenic markers including CEBPa, PPARg, SREBP-1, and FAS in 3T3-L1 cells. In high-fat diet (HFD) fed obese mice, daily oral administration of J. procumbens (200 mg·kg-1) for nine weeks significantly lowered body weight and body fat mass across different fat depots while improving plasma lipid profile. J. procumbens also mitigated adipose tissue inflammation by reducing macrophage infiltration and down-regulating pro-inflammatory mediators in white adipose tissue. Notably, J. procumbens treatment enhanced insulin sensitivity, as indicated by reduced plasma insulin levels and HOMA-IR. An in vitro study using adipocyte-conditioned medium (ad-CM)-treated Raw264.7 macrophages showed also reduced nitric oxide production and decreased expression of pro-inflammatory cytokines in macrophages via inhibiting NF-kβ signaling, which demonstrated that J. procumbens effectively suppressed inflammatory responses in adipose tissue. These findings suggest that J. procumbens may serve as potential therapeutic agent for obesity and its associated metabolic complications by modulating lipid metabolism and adipose tissue inflammation.