Anti-inflammatory activity studies on the stems and roots of Jasminum lanceolarium Roxb

Jasminum lanceolarium Roxb is an important traditional Chinese medicine. Its stems and roots have been used for the treatment of rheumatism and fever while the leaves are used as an anti-inflammatory agent to relieve pain. In order to support its traditional Chinese medicinal uses, five animal models were designed and the anti-inflammatory and analgesic properties of the 70% EtOH-H2O extracts of J. lanceolarium (EJL) were investigated. Meanwhile, biochemical parameters such as cyclooxygenase-2 (COX-2), 5-lipoxygenase (5-LOX) in blood serum of rats exposed to acute (carrageenan) inflammation model were evaluated. At doses of 400 mg/kg, EJL exhibited higher anti-inflammation effect than that of indomethacin and better analgesic activity than that of aspirin (P<0.001). Furthermore, eleven isolated compounds including six lignanoids (1, 2, 6, 7, 8, and 11) and five iridoids (3, 4, 5, 9, and 10) were isolated from the active extracts and showed significant anti-inflammatory activities with the IC50 values of 1.76-5.22 mg/mL, respectively, when testing their inhibitory effects on phospholipase A2 in vitro. The results demonstrated that the possible anti-inflammatory mechanisms might be attributed to inhibit the hydrolysis of membrane phospholipids, production on both COX-2 and 5-LOX, and then finally inhibit the release of prostaglandins (PGs), which suggested that EJL had a non-selective inhibitory effect on the release or actions of these mediators, and might be a dual LOX-COX inhibitor for the treatment of inflammation from the natural resource. The studies on the animals and the inflammatory mediators, along with the bioactive compounds presumed that the existences of iridoids and lignanoids could be response for their bioactivities of the whole plants.