Phythochemical analysis of Uncaria products commercially available in Hungary

In the last few decades the number of products containing Asian, South-American and African plants has been steadily increasing on the European market. A significant proportion of these products contain plants which have not been widely studied and are not integrated in the evidence based phytotherapy. Proposed indications often lack sufficient scientific evidence and in many cases are not in line with the original traditional application of the plant.

Uncaria tomentosa (Willd.) DC. (Rubiaceae) is a scrambling liana indigenous in South America. The stem bark of the plant is traditionally used to treat asthma, fever, infections and dermatological disorders. Preclinical investigations revealed antiproliferative, immune stimulating and anti-inflammatory activities [1]. The latter effect, attributed to the pentacyclic oxindole alkaloids of the stem bark, is the base of the application of U. tomentosa in the symptomatic treatment of arthritis [2]. However, therapeutic recommendations of Uncaria containing products often go far beyond this indication.

The aim of our investigation was to compare the therapeutic indications proposed with those supported by scientific evidence, and to analyze the alkaloid compositions of some U. tomentosa containing products available on the Hungarian market. The indications of the products registered as herbal medicinal products are in good accordance with the current scientific evidence, however, some products were claimed to have anticancer and anti-HIV effects. The majority of the analyzed products contains the dried bark of the plant. Qualitative and quantitative analysis of the oxindole alkaloids in the products was carried out by HPLC and TLC-densitometry. Total amounts of oxindole alkaloids and the percentage of each alkaloid shows unusually large variation among the products. The alkaloid quantities measured often deviate considerably from those declared on the products.

References: 1. WHO monographs on selected medical plants Volume 2. World Health Organization (2007) Switzerland.

3. Mur, E. et al. (2002) Journal of Rheumatology 29:678–681.