Medicinal plants concentrating selenium: Prospects of wider use

Abstract

The use of medicinal plants has a centuries-old history; however, nowadays they are also widely used, and there is a tendency to even wider applications. Their pharmacological activity is known to depend on their ability to synthesize various physiologically active compounds (PACs). However, in the latest decades, plants were also found to accumulate biologically important elements due to absorption from soil. These micronutrients are required for improving the micronutrient balance in humans, which prevents numerous diseases and pathological conditions. Such medicinal plants are sometimes viewed as potential sources of micronutrient. However, when used for disease treatment, the effects of these concentrated elements are often not taken into consideration, although these effect may be opposite to those of PACs. This study was aimed at finding plants concentrating selenium (Se) in which the Se effect is not coincident with that of PACs contained in the same preparations in order to created prerequisites for widening the range of the use of these species. The element composition of medicinal plants (~180 species) has been determined using the method of atomic absorption combined with spectrophotometric detection and Ermakov’s fluorometric method. Among these species, concentrators accumulating Se at high doses were detected. As evident from the table, the Se concentration in these plants ranged from 0.60 to 1.30 µ g/g, which exceeds significantly (6- to 13-fold) the average content of this element in plants growing in the same areas (clark). The consumption rate of Se is known to be low; it varies within the range 50‐250 µ g per day, the minimum consumption being 20‐30 µ g per day. At the same time, the Nonchernozem region and Central and Eastern Siberia, which constitute the most part of Russia, are characterized by low amounts of Se, which results in its deficiency in the soil‐plants‐animals‐humans biological cycle. Insufficient consumption of exogenous Se, in turn, induces imbalance of Se metabolism in humans, which leads to severe diseases, such as malignant tumors, cardiovascular diseases, immunodeficiency, atherosclerosis, and borderline pathological conditions. In these cases, Se preparations or corresponding additives are used for treatment; their effect is based on the antioxidant properties of this element and its involvement in peroxidation of lipids, corticosteroid and thyroid hormones, cholesterol, etc. [1‐ 10].