Yousefi Z, Mirsanei Z, Bitaraf FS, Mahdavi S, Mirzaii M, Jafari R. Dose-dependent effects of oleuropein administration on regulatory T-cells in patients with rheumatoid arthritis: An in vitro approach.
Int J Immunopathol Pharmacol 2022;
36:3946320221086084. [PMID:
35410513 PMCID:
PMC9008820 DOI:
10.1177/03946320221086084]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Introduction:
Rheumatoid arthritis (RA) is an autoimmune disease that is identified with
chronic inflammation and progressive destruction of the joints. The
defective activity of regulatory T cells (Tregs) plays a crucial role in RA
development. Oleuropein (OLEU) is the most common polyphenolic compound in
olive leaf extracts with numerous pharmacological activities. In this study,
the potential effects of OLEU in shifting CD4+ T cells toward
Tregs are evaluated in patients with RA.
Methods
32 healthy controls (HC) and 45 RA patients were included in two groups. The
immunoturbidometric technique was used to measure serum levels of c-reactive
protein (CRP) and rheumatoid factor (RF). Isolated CD4+ T cells
from peripheral blood mononuclear cells (PBMCs) of HC and RA patients were
cultured with appropriate concentrations of OLEU. The cytotoxicity effects
of OLEU were determined using the MTT assay at 24, 48, and 72 h. The
percentage of CD4+CD25 + FoxP3 regulatory T lymphocytes (Tregs)
and the expressions of IL-10 and TGF-β were evaluated by flow cytometry and
immunoassay techniques after treatment of cells with different
concentrations of OLEU for 24 h. The serum levels of RF and CRP in patients
with RA were 11.8 ± 5.32 IU/ml and 6.36 ± 5.82 mg/l, respectively.
Results
OLEU had a dose-dependent effect on the CD4+ T cells via
increasing the frequency of CD4+CD25 + FoxP3 Tregs
(p = 0.0001). Moreover, it induced the production of
IL-10 (p = 0.0001) and TGF-β (p < 0.01)
in both HC and RA patients.
Conclusion
The findings of this study suggest that OLEU may have immunomodulatory
effects by inducing Tregs, and it might help in developing a novel nutrition
strategy for management of autoimmune diseases such as RA.
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