The effect of oral administration and topical application of black seed oil (Nigella Sativa) on pain, function and secrum indices of inflanmmation and oxidative stress in patients with knee osteoarthritis

Abstract

Knee osteoarthritis (OA) is a common degenerative musculoskeletal disease and recognized reason for disability around the world. It consumes a considerable amount of health system resources and budgets. Nigella sativa (N. Sativa) is a traditional herbal medication that has an extensive range of pharmacological properties, including antioxidant, immune-modulator, analgesic and anti-inflammatory. Considering these and increasing OA prevalence in our country this trial designed to investigate the effect of topical and oral application of N. Sativa oil in comparison with placebo in patients with knee OA. Methods: This was a double-blind randomized controlled trial conducted at two Physical Medicine and Rehabilitation outpatient centers in Tabriz, Iran. 45 patient with radiographic evidence of mild to moderate KOA enrolled in the study and randomly assigned (1:1:1) to receive oral N. Sativa oil (2.5 ml of N. Sativa oil twice a day) and applicant topical placebo oil or topical N. Sativa oil (2.5 ml of N.Sativa oil three times a day) and oral placebo oil or placebo for 6 weeks. The primary outcomes including pain and physical activity were measured with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), visual analogue scale (VAS), and timed up & go test (TUG) scores. The secondary outcome measures were WOMAC subscale (pain, stiffness, and limitations of physical function) scores and adverse events (AEs). Outcome measurements were taken at baseline and 6 weeks after starting interventions and receiving N.Sativa oil. Results: Totally 40 patients finalized the study. No serious AEs were specified. There were no significant differences between study groups concerning demographic, anthropometric, and clinical data at baseline. In 6th week measurements, VAS, WOMAC pain, WOMAC limitations of physical function and WOMAC total score improved significantly in the oral N. Sativa group and topical N. Sativa groups (all p-values<0.050). However, VAS and WOMAC pain improved more significantly only in the Topical N. Sativa group compared to the placebo group (p=0.005 and p=0.015). On the other hand, topical N. Sativa oil was more efficient than oral N. Sativa oil in improving WOMAC limitations of physical function and WOMAC total scores in patients after treatment (all p-values<0.05). There were no significant effects of topical and oral N. Sativa oil in comparison with placebo concerning WOMAC stiffness score and TUG in patients with KOA (all p-values>0.05). Among inflammatory factors, CRP and MDA reduced in oral N.Sativa group which was only significant for CRP factor (p-value<0.05).