Background and purpose: Saffron (Crocus sativus) is a medicinal plant with anti-inflammatory effects. Macrophages are major cells that participate in inflammatory and immunity responses. The present study was performed to investigate the immunomodulatory effects of hydro-alcoholic extract of Saffron on rat peritoneal macrophages.
Materials and methods: This experimental study was conducted in two groups of male rats; an experimental and a control group. The animals in treatment group received hydro-alcoholic extract of Saffron for 4 constitutive weeks (400 mg/kg- daily, orally). The control rats received the same volume of distilled water. At the end of the study, macrophages were isolated from peritoneal cavity of rats and challenged with opsonized yeast. Then, the macrophages were evaluated for the rate of respiratory burst, nitric oxide production, and cytokine production using nitro-blue tetrazolium reduction assay, Griess test, and ELISA, respectively.
Results: The results of stimulation of macrophages showed a significant decrease in respiratory burst (P<0.001) and nitric oxide production (P<0.01) in macrophages isolated from treatment groups compared to that in control rats. Nevertheless, the results of phagocytosis assay and vitality did not show any significant differences between macrophages in controls and treatment group. Moreover, Saffron caused a significant increase in production of anti-inflammatory IL-10 by macrophages isolated from treatment group (P<0.01). The level of pro-inflammatory IL-12 did not alter significantly. But, the IL-12 to IL-10 ratio decreased significantly (P<0.01).
Conclusion: It seems that Saffron is a natural source to intervene the damages caused by inflammatory macrophages in immunopathological conditions.