School of Pharmacy, South African Herbal Science and Medicines Institute (SAHSMI), University of the Western Cape, Private Bag X17, Bellville, 7535, South Africa
Dube, A., School of Pharmacy, South African Herbal Science and Medicines Institute (SAHSMI), University of the Western Cape, Private Bag X17, Bellville, 7535, South Africa; Manthata, L.N., School of Pharmacy, South African Herbal Science and Medicines Institute (SAHSMI), University of the Western Cape, Private Bag X17, Bellville, 7535, South Africa; Syce, J.A., School of Pharmacy, South African Herbal Science and Medicines Institute (SAHSMI), University of the Western Cape, Private Bag X17, Bellville, 7535, South Africa
Herbal materials are known to present significant challenges with regard to designing credible placebos. This study intended to demonstrate the possibility of designing placebo material for crude herbals and used Artemisia afra, a popular traditional herbal medicine in South Africa, as a model. To produce the placebo, step-wise solvent extractions were conducted on the plant leaves and the process was monitored spectrophotometrically and using high performance liquid chromatography (HPLC) with diode array detection. The odour and taste between the placebo and A. afra was matched by inclusion of linalool and sodium saccharin, respectively. The muscle relaxant activity of the placebo was evaluated using an isolated guinea-pig tracheal muscle preparation. The UV absorbance of the extracts and the HPLC chromatograms, showed that most of the phytochemical constituents had been removed and the placebo closely resembled the A. afra leaves. The EC50 of the placebo and the leaves were 4846.00 and 68.49 mg/mL, respectively, which showed that not only did the A. afra leaves possess muscle relaxant activity, but that the placebo did not possess any significant activity compared with the A. afra leaves (p value 0.0001). These results demonstrated that it is possible to design credible, pharmacologically inert placebo material for crude herbals. Copyright © 2007 John Wiley & Sons, Ltd.
herbaceous agent; placebo; plant medicinal product; animal experiment; animal tissue; Artemisia; article; controlled study; diode; female; guinea pig; high performance liquid chromatography; male; muscle relaxation; nonhuman; odor; plant leaf; solvent extraction; South Africa; spectrophotometer; taste; trachea muscle; ultraviolet radiation; Animals; Artemisia; Chromatography, High Pressure Liquid; Drug Evaluation, Preclinical; Guinea Pigs; Medicine, Herbal; Muscle Contraction; Muscle, Smooth; Odors; Placebos; Plant Preparations; Taste; Trachea; Artemisia afra; Cavia