Objective:Brown sumac extract may reduce rheumatoid arthritis (RA) inflammation due to its anti-inflammatory and antioxidant properties. This study tested freeze-dried sumac extract in a RA model.
Materials and methods: Sumac extract's effects were evaluated in healthy and RA induced Wistar rats. Healthy rats received 0, 100, 200, or 400 mg/kg of the extract orally for one month. RA was induced by injecting Freund's adjuvant, followed by the same extract doses from day 7 to 25 post-induction, after the arthritis index exceeded one.
Results:The extract contained 179.45 ± 3.12 mg/g total phenolics (gallic acid equivalents) and a FRAP antioxidant activity of 101.9 ± 0.98 mmol Trolox equivalents/100 g. HPLC results determined the gallic acid content of the extract to be 58.38 mg/ml.In healthy rats, the extract increased serum TAC dose-dependently, without affecting RBC, WBC, Hemoglobin (Hb) and hematocrit (Hct) levels . In RA rats, disease progression was reduced with treatment, especially at 200 and 400 mg/kg, with the latter showing the lowest arthritis index. Extract at 200/400 mg/kg improved anemia, normalizing WBC and elevating RBC, Hb, and Hct. TAC levels were restored dose-dependently. The serum levels of C-reactive protein, nitric oxide, and myeloperoxidase decreased with increasing extract dosage, particularly at 200/400 mg/kg. Sumac extract led to a reduction in the mRNA ratios of RORγt/T-bet, RORγt/GATA-3, RORγt/FoxP3, T-bet/GATA-3, and T-bet/FoxP3, while concurrently increasing the ratio of GATA-3/FoxP3 in the joints of RA rats.
Conclusion: Sumac extract may mitigate inflammatory effects and aid in managing RA.