title: Medicinal plants used as excipients in the history in Ghanaian herbal medicine.
abstract: BACKGROUND
  The present study was carried out to investigate the traditional use, pharmacology and active compounds of four plants commonly used as excipients in herbal medicine in Ghana.
  
  
  METHODS
  A comprehensive literature search was conducted to gain knowledge about the traditional use, pharmacology and active compounds of the four plant excipients. The broth dilution antibacterial assay and the DPPH radical scavenging antioxidant assay were used to evaluate the antibacterial and antioxidant activity of the plants, respectively. Ethanol, warm water and cold water extracts were prepared from the dried seeds/fruits of Aframomum melegueta, Piper guineense, Xylopia aethiopica and Monodora myristica, and tested in the assays.
  
  
  RESULTS
  A. melegueta and P. guineense seemed to act as pharmacoenhancers, since they have been shown to inhibit specific CYP-enzymes. A. melegueta could act as an antioxidant to preserve herbal preparations. None of the plant excipients had antibacterial activity against the bacteria tested in this study. Compounds with an aromatic or pungent smell had been identified in all the plant excipients. An explanation for the use of the plants as excipients could rely on their taste properties.
  
  
  CONCLUSIONS
  The present study suggests that there may be more than one simple explanation for the use of these four plants as excipients. Plausible explanations have been proven to be: (1) a way to increase the effect of the medicine, (2) a way to make the medicine more palatable or (3) a way to preserve the activity of the medicinal preparation over time.
authors.affiliation: Department of Drug Design and Pharmacology, Universitetsparken 2, 2100 Copenhagen, Denmark.
authors.forename: Sara Holm
authors.initials: SH
authors.lastname: Freiesleben
authors.affiliation: Department of Drug Design and Pharmacology, Universitetsparken 2, 2100 Copenhagen, Denmark; Museum of Natural Medicine, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark.
authors.forename: Jens
authors.initials: J
authors.lastname: Soelberg
authors.affiliation: Department of Drug Design and Pharmacology, Universitetsparken 2, 2100 Copenhagen, Denmark. Electronic address: anna.jager@sund.ku.dk.
authors.forename: Anna K
authors.initials: AK
authors.lastname: Jäger
mesh_terms: D001419:Bacteria / Q000187:drug effects; D065607:Cytochrome P-450 Enzyme Inhibitors / Q000494:pharmacology; D005079:Excipients / Q000737:chemistry*; D016166:Free Radical Scavengers / Q000494:pharmacology; D005638:Fruit / Q000737:chemistry; D005869:Ghana; D029001:Herbal Medicine; D006801:Humans; D016488:Medicine, African Traditional; D008826:Microbial Sensitivity Tests; D010936:Plant Extracts / Q000494:pharmacology; D010946:Plants, Medicinal / Q000737:chemistry*; D011310:Preservatives, Pharmaceutical; D012639:Seeds / Q000737:chemistry; D013649:Taste / Q000187:drug effects
chemical_list: D065607:Cytochrome P-450 Enzyme Inhibitors; D005079:Excipients; D016166:Free Radical Scavengers; D010936:Plant Extracts; D011310:Preservatives, Pharmaceutical
keywords: Aframomum melegueta; Antioxidant; Monodora myristica; Piper guineense; Plant excipients; Xylopia aethiopica