Evaluation on Analgesic and Anti-Inflammatory Activities of Total Flavonoids from Juniperus sabina

The leaves of Juniperus sabina (Cupressaceae) are used in traditional Uygur medicine for the treatment of rheumatism and arthritic pain. This study aimed to investigate the analgesic and anti-inflammatory effects of total flavonoids from leaves of Juniperus sabina (JSTF) on rodents. The anti-inflammatory activity was investigated using the carrageenan, egg albumin, or histamine-induced rat paw edema as well as xylene-induced ear edema, capillary permeability, and cotton pellet granuloma while the antinociceptive activity was evaluated using the mouse writhing, formalin, and hot-plate tests. JSTF (125, 250, 500 mg/kg) significantly inhibited xylene-induced ear edema in mice (inhibition ratio as 16.22%, 40.67%, and 51.78%, respectively) and also significantly ameliorated acetic acid increased vascular permeability in mice (inhibition ratio as 11.63%, 32.56%, and 53.49%, respectively). JSTF (250 and 500 mg/kg) gave significant reduction of carrageenin-induced paw oedema at the interval of 1 h and 5 h. Administration of JSTF (500 mg/kg) caused a significant anti-inflammatory effect against oedema induced by egg albumin or histamine at the interval of 0.5 h and 4 h, and both which induced the paw oedema were also inhibited by JSTF (250 mg/kg) at a point in 1, 2, or 3 h after the inflammation. Furthermore, JSTF (125, 250, and 500 mg/kg) produced time-course increase in pain threshold in hot-plate test also. JSTF produced concentration-dependent inhibition on cyclooxygenase-2 (COX-2) or 5-lipoxygenase (5-LO) activities in vitro, and their IC(50) values were 31.92 and 129.26 μg/mL, respectively. Moreover, JSTF significantly caused a significant dose-dependent inhibition on acetic acid induced writhing response in mice (inhibition ratio as 23.27%, 36.91%, and 50.76%, respectively). JSTF also significantly ameliorated formalin-induced pain in mice in the late phase on dose-dependent way. These results confirms the clinical use of J. sabina for treatment of rheumatoid arthritis in ethnomedicine, and its effective mechanism will be further studied in the future.