Atractylenolide I is a sesquiterpene that has been found in the rhizomes of A. macrocephala and has diverse biological activities, including anti-inflammatory, anti-angiogenic, anti-tumor, and antidepressant properties. It inhibits LPS-induced increases in TNF-α and nitric oxide (NO) production, as well as inducible nitric oxide synthase (iNOS) activity, in murine peritoneal macrophages (IC50s = 23.1, 41, and 67.3 μM, respectively). Atractylenolide I reduces pouch fluid weight, inflammatory cell count, granuloma weight, and vascular index (ID50s = 24.18, 19.46, 14.44, and 15.15 mg/kg, respectively) in a mouse air pouch granuloma model induced by Freund''s complete adjuvant (FCA). It also reduces the number of microvessels in the air pouch wall by 58.27% when administered at a dose of 20 mg/kg and reduces the blood levels of TNF-α, IL-1β, IL-6, VEGF, placenta growth factor (PlGF), and bFGF in a dose-dependent manner in a mouse model of FCA-induced granuloma. Atractylenolide I inhibits the growth of T-24, 5637, RT4, and 253J bladder cancer cells in vitro (IC50s = 12.8-63.7 μM) and reduces tumor growth in T-24 and 253J mouse xenograft models in a dose-dependent manner. In a mouse model of depression induced by chronic unpredictable mild stress, atractylenolide I reverses stress-induced decreases in hippocampal levels of serotonin (5-HT; ) and norepinephrine and reduces immobility time in the forced swim and tail suspension tests in a dose-dependent manner, indicating antidepressant-like activity.
