The Antioxidant Activity of Muntingia calabura L. Leaf Extract and its Effect in Acute Gout Arthritis Rat Model: Reactive Oxygen Species Modulation

Gout arthritis is an inflammatory joint condition caused by uric acid crystal accumulation. The inflammatory mechanism involves complex pathways that increase reactive oxygen species (ROS) levels. Muntingia calabura L. leaves contain bioactive compounds, such as phenolics, including flavonoids, which are known to reduce ROS production by mitigating pro-inflammatory signaling pathways. This study aimed to evaluate the phenolic content and effectiveness of Muntingia calabura L. leaves extract as an anti-inflammation and antioxidant agent in regulating ROS levels in Wistar rats with acute gout arthritis. Five groups of rats were used, which consisted of positive control, negative control, and treatment groups receiving the extract at doses of 50, 100, and 200 mg/kg BW. Folin-Ciocalteu assay revealed a high phenolic content of 26.12 ± 0.18%, with strong antioxidant activity (IC50 = 23.85 ± 0.16 µg/mL). In line with this, LC-MS-MS showed that flavonoids were the most predominant compounds in the extract. Meanwhile, the extract administration slightly reduced pain-induced monosodium urate (MSU) crystal injection. Interestingly, 50 mg/kg BW of the extract was identified as the most effective dose in reducing MSU-induced ROS production—even stronger than that of colchicine (p = 0.0049). This study highlighted the significant antioxidant activity of the extract due to its phenolic content, which markedly lowered ROS levels in the animal model.