Worldwide, one of the drivers of substitution and adulteration is the cost of the natural resources (plants, animals, fungi) that are ingredients of traditional medicines. Relatively few studies have been done that link prices of traditional medicine ingredients to what drives changes in price, yet this is an important topic. Theoretically, prices have been widely considered as an economic indicator of resource scarcity. Rare, slow growing medicinal plants sell for high prices and common, less popular species for low prices. Price levels also influence the viability of farming vs. wild harvest (and incentives to overharvest high value species when tenure is weak). Prices can also influence the harvesting or buying behaviour of harvesters, traders or manufacturers. When prices are high, then there is a greater incentive to use cheaper substitute species or adulterants. As previous studies on herbal medicine ingredients have shown, adulteration applies in a wide variety of cases, including to some Traditional Chinese Medicine (TCM) species.
Tag: medicinal plant
Variation in Antimicrobial Activity of Warburgia ugandensis Extracts from Different Populations across the Kenyan Rift Valley
Warburgia ugandensis isa highly valuedmedicinal tree within East Africa which is over-exploited for its medicinal use among many communities. This species has its habitat encroached and this has led to a notable decrease in its population size to the level that warrant some conservation efforts. Information on diversity in its antimicrobial activity is also lacking. The aim of this study was to evaluate variation in antimicrobial activity of W. ugandensis leaf and stem bark extracts from different populations across the Kenyan Rift Valley. The plant materials were collected, dried at room temperature, milled into powder and sequentially extracted with dichloromethane (DCM) and methanol (MeOH). The antimicrobial activity tests against Staphylococcus aureus, Escherichia coli and Candida albicans were carried out using disk diffusion and ninety six well microtitre plate assays. Antimicrobial activities were qualitatively and quantitatively assessed by the presence or absence of inhibition zones and minimum inhibitory concentration values. The stem bark extracts displayed the highest antimicrobial activity compared to the leaf extracts, regardless of the extracting solvents. The DCM extracts exhibited stronger antimicrobial activity compared to MeOH extracts. Staphylococcus aureus and C. albicans were sensitive to the plant extracts while E. coli was resistant. This study revealed significant differences in antimicrobial activity between extracts of W. ugandensis from different plant parts and regions (P > 0.05). The knowledge on variations in antimicrobial activity is important in developing efficient conservation and utilisation strategies for the species through identification of suitable genotypes.