en Pharmacognosy Pharmacognosy Original Research Original Research <p><strong>Background: </strong>Portulaca oleracea, known as Purslane, is an annual growing herb with wide distribution around the world and traditionally used to manage several diseases. Different therapeutic properties as an anti-fever agent as well as anti-inflammatory and analgesic effects have been attributed to P. oleracea. The aim of this study was to investigate the effects of P. oleracea aerial extract on production of pro- and anti-inflammatory cytokines by human peripheral blood mononuclear cells (PBMCs).<br> <strong>&nbsp;&nbsp; Methods: </strong>Aerial parts of P. oleracea (stems and leaves) were collected and extracted by percolation using methanol. The optimal and non-cytotoxic dose of hydro-alcoholic extract for cell culture analysis was determined by MTT assay. To assess the anti-inflammatory effects of P. oleracea, PBMCs obtained from 12 normal volunteers were cultured in RPMI complete medium and co-treated with E. coli lipopolysaccharide (LPS) and P. oleracea hydro-alcoholic extract. Following 18-hour incubation, culture supernatants were harvested for measurement of secreted TNF-&alpha;, IL-6 and IL-10 by ELISA. Statistical analyses were performed using the SPSS v.20, and data analyzed by Kolmogorov-Smirnov, Mann-Whitney U, Kruskal-Wallis and post Hoc tests. P-values<0.05 were considered significant.<br> <strong>&nbsp;&nbsp; Results: </strong>The optimal non-cytotoxic concentration of P. oleracea aerial extract was defined as 100 &mu;g/ml based on MTT viability assay. P. oleracea hydro-alcoholic extract significantly decreased the concentration of both pro-inflammatory cytokines TNF-&alpha; and IL-6 in LPS-stimulated PBMCs (p<0.001 and p<0.001, respectively). However, the concentration of IL-10 as an anti-inflammatory cytokine, did not show any statistically&nbsp;significant change (p=0.390).<br> <strong>&nbsp;&nbsp; Conclusion:</strong> Our findings highlighted the potential anti-inflammatory properties of P. oleracea in herbal medicine. Future analysis on different constituents of total extract may confirm its therapeutic effects as a promising anti-inflammatory compound.<br> &nbsp;<br> &nbsp;</p> <p></p> Portulaca oleracea, Anti-inflammatory agent, Tumor necrosis factor-alpha, Interleukin-6, Interleukin-10 464 469 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-3397-1&slc_lang=en&sid=1 Esmaeil Allahmoradi s.allahmoradi69@gmail.com 200319475328460039839 200319475328460039839 No Student Research Committee, & Department of Immunology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran. Saeid Taghiloo saeid.taghiloo@yahoo.com 200319475328460039840 200319475328460039840 No Student Research Committee, & Department of Immunology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran. Versa Omrani-Nava versa.peace@gmail.com 200319475328460039841 200319475328460039841 No Student Research Committee, & Department of Immunology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran. Saeideh Sadat Shobeiri saeideshobeiri@gmail.com 200319475328460039842 200319475328460039842 No Student Research Committee, & Department of Immunology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran. Mohsen Tehrani drmtehrani@gmail.com 200319475328460039843 200319475328460039843 No Department of Immunology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran. Mohammad Ali Ebrahimzadeh Zadeh20@yahoo.com 200319475328460039844 200319475328460039844 No Student Research Committee, & Pharmaceutical Sciences Research Center, School of Pharmacy, Mazandaran University of Medical Sciences, Sari, Iran. Hossein Asgarian-Omran asgarianhossein@yahoo.com 200319475328460039845 200319475328460039845 Yes Department of Immunology, School of Medicine, & Immunogenetics Research Center, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran.