Anti-arthritic Effects of Total Flavonoids from Juniperus sabina on Complete Freund's Adjuvant Induced Arthritis in Rats

CONTEXT: Twigs and leaves of Juniperus sabina L. have been traditionally used as the medicinal herb in China for the treatment of many ailments including rheumatoid arthritis (RA). AIMS: To confirm the therapeutic effect of total flavonoids from J. sabina (JSTF) on RA-induced by Complete Freund's Adjuvant (CFA) in rats. SETTINGS AND DESIGN: Wistar rats (200 ± 20 g) were immunized by intradermal injection of 0.1 mL of CFA into the right hind metatarsal footpad. JSTF was administered orally at the dose of 125,250 and 500 mg/kg on 14 days after the induction of adjuvant arthritis. Tripterygium glycoside (20 mg/kg) was used as a positive control. Paw swelling, arthritic score, body weight loss, serum cytokines, inflammatory mediators, and histological change were measured. RESULTS: We found that JSTF could ameliorate paw swelling of CFA rats, and significantly inhibit arthritic score (P < 0.05). The overproduction of tumor necrosis factor alpha and interleukin 1beta were remarkably suppressed in the serum of JSTF (125,500 mg/kg) treated rats (P < 0.05). Histopathological studies also showed a marked decrease of synovial inflammatory infiltration and synovial lining hyperplasia in the joints of JSTF-treated animals. Six flavonoids were isolated and from JSTF by various chromatographic methods and identified as follows: Catechin, quercitrin, isoquercitrin, isoscutellarein 7-O-β-D-xylopyranoside, isoscutellarein 7-O-β-D-xylopyranose-(1 → 3)-α-L-rhamnoside, and rutin. CONCLUSIONS: These results suggest the potential therapeutically effect of JSTF as an anti-arthritis agent toward CFA-induced arthritis in rats, and verified therapeutic applications of J. sabina on RA in folk medicine. SUMMARY: Twigs and leaves of Juniperus sabina L. have been traditionally used as the medicinal herb in China for the treatment of rheumatoid arthritis. JSTF could ameliorate paw swelling of CFA rats, and significantly inhibit arthritic score. Histopathological studies showed a marked decrease of synovial inflammatory infiltration and synovial lining hyperplasia in the joints of JSTF-treated animals. Six flavonoids were isolated and from JSTF including: Catechin, quercitrin, isoquercitrin, isoscutellarein 7-O-β-D-xylopyranoside, isoscutellarein 7-O-β-D-xylopyranose-(1 → 3)-α-L- rhamnoside, and rutin. Abbreviations used: JSTF: Total flavonoids from Juniperus sabina; CFA: Complete Freund's Adjuvant; TG: Tripterygium glycoside; TNF-α: Tumor necrosis factor alpha; IL-1β: Interleukin 1beta; IL-6: Interleukin 6; H and E: Hematoxylin and eosin.