Analysis of Mauby Bark and its preparations

ABSTRACT

Mauby Bark, obtained from the plant Colubrina elliptica, is used in the West Indies for medicinal purposes including the treatment of diabetes. It is also sold in small amounts in Afro Caribbean markets in London and an extract of the bark is incorporated into several soft drinks available in the UK which have a reputation as tonics. In common with many such materials, there are no standards for ensuring that the correct bark is sold or used to make commercial preparations. The bark is reported to contain peptide alkaloids and triterpene glycosides but it is not known whether these chemical constituents are responsible for any biological effect. Samples of Mauby bark were obtained from Dominica, Barbados and a sample of authentic Mauby bark from the reference collection of medicinal plants at King's College London. The samples showed no differences in their botanical structure but some differences when examined chromatographically. This underlines the need to standardize herbal material not only botanically but also on the basis of chemical content since chemical variation can be reflected in variation between batches of bark and preparations. As a test for antidiabetic activity, the effect of extracts of the barks on hexokinase was investigated. An increase in activity would lower glucose levels and thus be beneficial in diabetic patients. No such effect was noted. (AU)