Activities of ethanol-extract of red ginger (Zingiber officinale var. Rubrum) on Completed Freund's Adjuvant-induced arthritis in mice

Background: Red ginger has been known to have anti-inflammatory and analgesic potency. Objective: This study aimed to analyse the ethanolic extract of red ginger (EERG) in mice's arthritis model induced by Completed Freund’s Adjuvant (CFA). Method: Red ginger was extracted using ethanol 96%. Arthritis mice (n = 25) were injected with CFA i.p., and sham mice (n = 5) were injected with normal saline. On day seven, mice were divided into six groups: sham, CFA, gabapentin 100 mg/kg BW, and EERG (dose 200; 400; 600 mg/kg BW). Treatments were administered orally once a day for seven days. Latency time and plantar thickness were measured on days zero, one, three, five, seven, eight, ten, twelve, and fourteen. On day 15, the mice were sacrificed, and the blood and spinal cords were collected. The haematology profiles were determined. Result: The EERG significantly prolonged the latency time towards thermal stimulus and decreased plantar thickness in arthritis mice, the same as gabapentin which served as the control. The EERG also reduced the number of leukocytes, lymphocytes, and neutrophils, and improved the morphology of the spinal cord's dorsal horn of arthritis mice. Conclusion: The EERG of 400 mg/kg BW significantly affects arthritis-induced hyperalgesia.