Abstract
Noni (Morinda citrifolia L.) juice is increasingly recognized for its potential health-promoting properties. In this research, the bioactive compounds and physiological effects of commercial noni juice products in Korea were assessed. Noni juice was found to contain high levels of total phenolics (6.39 ± 1.45 mg gallic acid equivalents (GAE)/g) and proanthocyanidins (8.64 ± 6.20 mg catechin equivalents (CE)/g). Furthermore, it exhibited potent antioxidant activities, with 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activities of 44.03 ± 14.88% and 55.91 ± 2.62%, respectively, which exceeded those reported for common fruit juices such as apple, orange, and blueberry. Additionally, noni juice reduced lipid accumulation by 5.92% and reactive oxygen species (ROS) levels by 7.23% in 3T3-L1 adipocytes; improved fusion index to 81.44% and restored myotube diameter by 37.24% in dexamethasone-induced C2C12 cells; and suppressed LPS-induced nitric oxide (NO) production. These results suggested that noni juice has anti-inflammatory, anti-obesity, anti-muscle atrophy, and antioxidant properties, supporting its potential as a functional health beverage.