Pesticide-poor concentrates of active components of plants are obtained in that in a first step plants or parts thereof, which may be charged in fresh or dried state, are extracted with at least one polar solvent at a measured pH-value in the range from 3.2 to 9.8 in such a way, that in the obtained primary extract are contained mainly the desired plant components, accompanied by undesired plant components, accompanying substances and pesticides, in a second step said primary extract is contacted with adsorber resin(s) in such a way, that on one hand the desired plant components are adsorbed thereon, and on the other hand the solution with the undesired plant components, the accompanying substances and pesticides are separated from the charged resin, in a third step the desired plant components are desorbed from said resin with at least one solvent, and in a fourth step the solvent(s) is (are) removed either partially or completely, and by this way a concentrate of active components is obtained. These concentrates of active components may be used in products of the pharma, cosmetic and food industry.

A purified extract from Harpagophytum procumbens and/or Harpagophytum zeyheri DENCE is obtainable by dissolving an aqueous and/or aqueous/alcoholic extract in water saturated with n-butanol, extracting with n-butanol saturated with water, and removing the n-butanol in vacuo. It may be used for the preparation of medicaments for the treatment of Asthma bronchiale, Colitis ulcerosa, Morbus Crohn, diseases of the rheumatic type, and indications in which an increase of the lipoxygenase level occurs either by medicaments, other substances or diseases.