2.3. Si Miao San Treatment

Concentrated granules of SMS, composed of Cortex Phellodendri Chinensis (Z002.701MK02), Rhizome Atractylodes (Z002.545MK02), Radix Achyranthis Bidentatae (Z002.585MK02), and Semen Coicis (Z002.955KR02), were purchased from Beijing Tcmages Pharmaceutical Co., Ltd. The Chinese herbs were extracted and concentrated to produce granules. The process was undertaken according to Good Manufacturing Practice (GMP) for Drugs (Chinese FDA, 2010 Version) to guarantee quality. The efficacy of 1 g of SMS granules was equal to that of 6 g of decoction pieces. On day 14, successfully modelled rats with arthritis scores over 4 were randomly allocated to 5 groups: the CIA, methotrexate (MTX), and SMS at low-dose (S-L), medium-dose (S-M), and high-dose (S-H) groups. SMS granules and MTX were dissolved in double distilled water and fully blended prior to use. The positive drug group was treated with MTX (2 mg/kg) once a week, and the SMS groups were administered corresponding doses of SMS granules (2.16, 4.31, and 8.63 g/kg) every day. Rats in the normal control (Con) and CIA groups were administered an equal volume (15 ml/kg) of double distilled water.

The animals were made comfortable until they were sacrificed with 2% pentobarbital on day 53. Blood, knee synovial tissues, and hind paw ankles were excised from the rats.