Ethnopharmacological relevance: The whole plant, roots and stems of Ephedra gerardiana (Family Ephedraceae) have long been used as a folk remedy to treat rheumatism and painful joints in Northern Areas of Pakistan.

Aim of the study: The purpose of study was to observe the preventive efficacy of Ephedra gerardiana (EG) aerial parts in treating rheumatoid arthritis using Freund's complete adjuvant (FCA) induced arthritis in rat model and to determine its possible mechanism of action.

Material and methods: Arthritis was induced in Sprague Dawley rats by immunization with 0.1 ml FCA in left footpad. EG aqueous ethanolic extract (30:70) and its aqueous, n-butanol and ethyl acetate fractions at 200 mg/kg were orally administered from day 0, 30 min prior to adjuvant injection and sustained for 28 days. Paw volume/diameter, arthritic score, body weight, and hematological (WBC, RBC, ESR, Hb and Platelet count) and biochemical (AST, ALT, ALP, urea, creatinine, CRP and RF) parameters were observed. The mRNA expression levels of COX-2, IL-1β, IL-6, NF-kB, TNF-α, IL-4 and IL-10 were measured by real time reverse transcription polymerase chain reaction (RT-PCR) while, PGE2 and TNF-α levels in serum samples were measured by Enzyme linked immunosorbent assay (ELISA). Moreover, radiographs of hind paws and histological changes in ankle joint were analyzed in adjuvant injected rats. In addition, anti-oxidant activity of plant extract and fractions was also evaluated using DPPH and reducing power assays. Also, preliminary phytochemistry and total phenolic and flavonoid contents were investigated in most active fraction (aqueous fraction).

Results: EG extract and fractions (notably aqueous fraction) significantly suppressed paw swelling and arthritic score, prevented cachexia and remarkably ameliorated hematological and biochemical changes. Furthermore, the overproduction of PGE2, COX-2, IL-1β, IL-6, NF-kB and TNF-α were remarkably attenuated in all EG treated rats, however, IL-4 and 10 were markedly increased. The radiographic and histopathologic improvement in joint architecture was also observed in EG treated rats. Piroxicam, used as reference drug, also significantly suppressed arthritis. Additionally, plant exhibited notable anti-oxidant activity and phytochemical analysis revealed the presence of alkaloids, flavonoids, phenols, tannins, saponins and glycosides.

Conclusion: These results indicate that EG extract and fractions significantly attenuated adjuvant arthritis in rats by decreasing the levels of aforementioned pro-inflammatory and increasing the levels of anti-inflammatory mediators. This suggests that Ephedra gerardiana aerial parts might be used as a therapeutic agent for treating human arthritis.