title: Essential Oils from Ugandan Aromatic Medicinal Plants: Chemical Composition and Growth Inhibitory Effects on Oral Pathogens.
abstract: The study assessed the growth inhibitory effects of essential oils extracted from ten Ugandan medicinal plants (Bidens pilosa, Helichrysum odoratissimum, Vernonia amygdalina, Hoslundia opposita, Ocimum gratissimum, Cymbopogon citratus, Cymbopogon nardus, Teclea nobilis, Zanthoxylum chalybeum, and Lantana trifolia) used traditionally in the management of oral diseases against oral pathogens. Chemical compositions of the oils were explored by GC-MS. Inhibitory effects of the oils were assessed on periodontopathic Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans and cariogenic Streptococcus mutans and Lactobacillus acidophilus using broth dilution methods at concentrations of 1%, 0.1%, and 0.01%. The most sensitive organism was A. actinomycetemcomitans. Its growth was markedly inhibited by six of the oils at all the concentrations tested. Essential oil from C. nardus exhibited the highest activity with complete growth inhibition of A. actinomycetemcomitans and P. gingivalis at all the three concentrations tested, the major constituents in the oil being mainly oxygenated sesquiterpenes. Most of the oils exhibited limited effects on L. acidophilus. We conclude that essential oils from the studied plants show marked growth inhibitory effects on periodontopathic A. actinomycetemcomitans and P. gingivalis, moderate effects on cariogenic S. mutans, and the least effect on L. acidophilus. The present study constitutes a basis for further investigations and development of certain oils into alternative antiplaque agents.
authors.affiliation: Department of Dentistry, School of Health Sciences, College of Health Sciences, Makerere University, P.O. Box 7072, Kampala, Uganda ; Department of Medical Microbiology, School of Biomedical Sciences, College of Health Sciences, Makerere University, P.O. Box 7072, Kampala, Uganda ; Department of Dental Medicine, Unit of Periodontology, Karolinska Institutet, P.O. Box 4064, 141 04 Huddinge, Sweden.
authors.forename: Francis
authors.initials: F
authors.lastname: Ocheng
authors.affiliation: Department of Medical Microbiology, School of Biomedical Sciences, College of Health Sciences, Makerere University, P.O. Box 7072, Kampala, Uganda.
authors.forename: Freddie
authors.initials: F
authors.lastname: Bwanga
authors.affiliation: Department of Medical Microbiology, School of Biomedical Sciences, College of Health Sciences, Makerere University, P.O. Box 7072, Kampala, Uganda.
authors.forename: Moses
authors.initials: M
authors.lastname: Joloba
authors.affiliation: Department of Dental Medicine, Unit of Periodontology, Karolinska Institutet, P.O. Box 4064, 141 04 Huddinge, Sweden.
authors.forename: Abier
authors.initials: A
authors.lastname: Softrata
authors.affiliation: Ecological Chemistry Group, Department of Chemistry, School of Chemical Science and Engineering, KTH, Royal Institute of Technology, 100 44 Stockholm, Sweden ; Department of Chemistry, COMSATS Institute of Information Technology, Abbottabad 22060, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Azeem
authors.affiliation: Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, P.O. Box 280, 177 71 Stockholm, Sweden.
authors.forename: Katrin
authors.initials: K
authors.lastname: Pütsep
authors.affiliation: Ecological Chemistry Group, Department of Chemistry, School of Chemical Science and Engineering, KTH, Royal Institute of Technology, 100 44 Stockholm, Sweden.
authors.forename: Anna-Karin
authors.initials: AK
authors.lastname: Borg-Karlson
authors.affiliation: Department of Pharmacology and Therapeutics, School of Biomedical Sciences, College of Health Sciences, Makerere University, P.O. Box 7072, Kampala, Uganda.
authors.forename: Celestino
authors.initials: C
authors.lastname: Obua
authors.affiliation: Department of Dental Medicine, Unit of Periodontology, Karolinska Institutet, P.O. Box 4064, 141 04 Huddinge, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Gustafsson