Evaluation of herbs as potential alternatives for bear bile and rhino horn used in traditional Chinese medicines : chemical and biological analysis

Abstract

There is currently an unsustainable rate of exploitation of certain species of plants and animals for use in traditional medicines. Bear bile and rhino horn are derived from endangered species and are traditionally combined with medicinal herbs as anti-bacterial and anti-inflammatory agents. This study was designed to assess herbs for use as possible alternatives for these two products. Herbs were selected based on their traditional use as antiinflammatory and anti-bacterial agents. Chemical methods were used to confirm the plant species of the herbs and to measure concentrations of metals and pesticide residues as a means for assessing their quality. Antibacterial activities were determined using a direct bioautography technique. Anti-inflammatory activities of the herb extracts and isolated compounds were ascertained using an in vitro nuclear factor kappaB (NF-KB) activity, as assessed by IL-6 luciferase gene reporter assay. A novel assay was developed to estimate drug-herb interactions by measuring the effects of selected herbs and drugs on the production of eicosatrienoic acids from hepatic cytochrome P450 (CYP450) metabolism of arachidonic acid. In addition, CYP3A4 enzyme assays were conducted. The pesticide residue and heavy metal concentrations of the tested herbs was found not to exceed the existing legally permitted concentrations in foodstuffs, but the rhino horn sample contained elevated levels of Cd, Pb, Hg and Zn. Rhino horn was not found to be an effective anti-bacterial or anti-inflammatory agent In the assays used in this study. Seventeen herbs demonstrated anti-bacterial activity. Also, nine herbs demonstrated inhibitory NF-KB activity. Preliminary results indicate that co-administration of Scutel/aria baicalensis, Salvia miltiorrhiza, Rehmann/a glutinosa or Coptidis Rhizoma with drugs metabolised by CYP3A4, could lead to possible drug-herb interactions. Based on the Information obtained in these studies nine herbs are proposed as alternatives to rhino horn; eight herbs and two Kampo medicines are proposed as alternatives to bear bile.EThOS - Electronic Theses Online ServiceGBUnited Kingdo