Authors:P. Apáti, K. Szentmihályi, P. Vinkler, É. Szőke, and Á. Kéry
Solidago canadensis L., (Asteraceae) has been used in European phytotherapy as a urological and antiphlogistical remedy for centuries. The behaviour of dissolution of mineral elements into different tinctures and aqueous extracts obtained from Solidaginis herba was investigated in connection with their quercetin glycoside and organic acid amount. Commonly applied aqueous and alcoholic extracts were analysed for Al, As, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Li, Mg, Mn, Mo, Na, P, Pb, S, Ti, V and Zn content. The concentrations of the minerals examined were determined by inductively coupled plasma emission spectrometry (ICP-OES). Determination of the flavonoids in solidaginis herba and extracts was carried out by a spectrophotometric method, as required by the German Pharmacopoea. For the study of the flavonoid composition of crude drug, the HPLC technique was applied. To determine the relative nutrient contribution of these pharmaceuticals to the diet, data obtained were combined with flavonoid content particulars, then a comparison with U.S Recommended Dietary Allowances (RDA) was made. For evaluation of the phytotherapeutic relevance, k/Na ratio was also calculated. It has been found that the pharmaceuticals examined are important sources of potassium, chromium, manganese, calcium, magnesium, phosphorus and lower sources of iron and zinc, assuming a daily intake of 1-2 l aqueous extracts as recommended for urological diseases. Flavonoid content of the different Solidaginis herba extracts ranged from 62.4 mg l-1 to 305.2 mg l-1.