Immunological impact of Ricinus communis leaves extract on isolated human peripheral blood mononuclear cells

Background: Plants are the source of many important drugs. Ricinus communis is utilized as a traditional folkloric remedy for the treatment of a wide extend of diseases around the world. Large number of phytochemicals such as alkaloids, terpenes, and phenolic compounds that have an established anticancer, antimicrobial, and immunological impact presence in many plant families. Objective: The aim of the present study was to investigate the immunological impact of R. communis leaves extract on human immune response using isolated human peripheral blood mononuclear cells (PBMNC). Materials and Methods: Cells were isolated using the gradient centrifugation method and treated with R. communis leaves extract at different concentrations, and then, the cytotoxic effect was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and the immunologic effect was estimated by measuring the cytokine levels via the enzyme-linked immunosorbent assay technique. Results: Plant extract showed a low cytotoxic effect on PBMNC at therapeutic doses and high doses (1000 µg/mL) used. Plant extract caused a significant reduction in the levels of interleukin (IL)-4 and IL-17 at higher doses and increased IFN-ɣ at both doses used. Conclusion: R. communis leaves extract appears to be safe for medical uses and has immunomodulatory effects.