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Evidence-Based Complementary and Alternative Medicine
Volume 2016, Article ID 5357689, 8 pages
Research Article

Essential Oils from Ugandan Medicinal Plants: In Vitro Cytotoxicity and Effects on IL-1β-Induced Proinflammatory Mediators by Human Gingival Fibroblasts

1Department of Dentistry, School of Health Sciences, College of Health Sciences, Makerere University, P.O. Box 7072, Kampala, Uganda
2Department of Medical Microbiology, School of Biomedical Sciences, College of Health Sciences, Makerere University, P.O. Box 7072, Kampala, Uganda
3Department of Dental Medicine, Unit of Periodontology, Karolinska Institutet, P.O. Box 4064, 141 04 Huddinge, Sweden
4Ecological Chemistry Group, Department of Chemistry, School of Chemical Science and Engineering, Royal Institute of Technology, 100 44 Stockholm, Sweden
5Mbarara University of Science and Technology, P.O. Box 1410, Mbarara, Uganda

Received 23 June 2016; Accepted 18 September 2016

Academic Editor: José L. Ríos

Copyright © 2016 Francis Ocheng et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The study investigated cytotoxicity of essential oils from four medicinal plants (Bidens pilosa, Ocimum gratissimum, Cymbopogon nardus, and Zanthoxylum chalybeum) on human gingival fibroblasts and their effects on proinflammatory mediators’ secretion. Cytotoxicity of essential oils was investigated using 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay. Effects of essential oils at subcytotoxicity concentrations on interleukin- (IL-) 6, IL-8, and prostaglandin E2 (PGE2) secretions by gingival fibroblasts treated with IL-1β (300 pg/mL) were evaluated by ELISA and EIA. IC50 values of the essential oils ranged from 26 μg/mL to 50 μg/mL. Baseline and IL-1β-induced secretion of PGE2 was inhibited by treatment with essential oil from O. gratissimum. Essential oils from B. pilosa and C. nardus had synergistic effects with IL-1β on PGE2 seceretion. In conclusion, the study suggests that essential oil from O. gratissimum decreases gingival fibroblasts secretion of PGE2, while essential oils from B. pilosa and C. nardus increase PGE2 secretion. Essential oil from Z. chalybeum was the most cytotoxic, while oil from C. nardus was the least cytotoxic. Although the clinical significance of these findings remains to be determined, it may be suggested that essential oil from O. gratissimum, applied at subcytotoxicity concentrations, could reduce the participation of gingival fibroblasts in the gingival inflammation and tissue destruction associated with periodontitis.