## 1 Introduction  
The use of medicinal herbs in disease treatment has been known since the beginning of civilization. These plants are also basic sources of nutritionally important chemical compounds. In general, medicinal plants are plants that, depending on their specific properties, are used in the treatment or as preventive measures for many diseases. The modern, busy lifestyle increases the risk of the development of many diseases caused by free radicals [1]. Plants used in traditional medicine are rich in various antioxidants, such as polyphenols, carotenoids, tocopherols, glutathione, ascorbic acid, and enzymeswith antioxidant activity, which help the body in the fight against dangerous oxidative damage [2; 3; 4; 5; 6]. Approximately 500 medicinal plants that exert pharmacological effects are known in Europe. The annual increase in the consumption of these plants ranges from 8 to 9%, with Europe being the biggest consumer. The food, cosmetic, pharmaceutical, and chemical industries are the main contributors to global consumption growth. The range of specific applications of medicinal plants is broad [7; 8; 9].  
The recently observed trend to use medicinal plants not only in traditional medicine but also in the food, pharmaceutical and cosmetic industries as well as modern gastronomy is a result of their sensory and biological value. This value comes from polyphenols that are found only in the plant kingdom. A number of substances contained in plants have proven effects on mental and physical conditions [10; 11; 12]. The most widespread way of administration is in the form of infusions [13]. In medicine, herbs find unlimited use because of their application in the treatment of many diseases, such as diseases of the digestive system, respiratory and urinary tracts, colds, skin problems, etc. They also have a positive effect on metabolism and are characterized by excellent detoxifying, anti-inflammatory and antibacterial properties, and many other therapeutic effects [14]. Considering their antioxidant and antimicrobial effects, such plants can be used in food preservation and for increasing the biological value of food. The increase in synthetically produced drugs and the associated increased occurrence of adverse side effects and intoxications has led to more and more therapists reaching for original plant drugs [2]. Plants contain a large number of natural chemicals or phytochemicals that interact with the active ingredient and help prevent side effects [15; 16]. Treatment with synthetic drugs often involves the use of one concentrated component, which may result in the need for other pharmaceuticals that work against its adverse effects [17].  
In the Slovak Republic, medicinal plants are paid outstanding attention. Collection, evaluation, reproduction and preservation of the gene pool of medicinal plants are of high priority, with 156 samples of medicinal plants deposited in the Gene Bank of the Slovak Republic in Piest'any. Of this number, 115 are in the active collection, 30 in the basic collection, and 11 in the field collection [18].  
The aim of this study was to determine the antioxidant activity (DPPH and phosphophospholybdenum method), polyphenols content (total polyphenols, flavonoids, and phenolic acids), mineral compounds composition (Cu, Zn, Mn, Fe, Cr, Ni, Co, Pb and Cd), and antimicrobial activity (with disc diffusion method) of medicinal herbs traditionally used in the Slovak Republic. The tested species and their specific parts were: _Primula veris_ L.--flowers, _Urtica dioica_ L.--leaves, _Ribes nigrum_ L.--leaves, _Fragaria vesca_ L.--leaves, _Mentha piperita_ L.--leaves, _Thymus serpyllum_ L.--flowering herbs, _Salvia officinalis_ L.--leaves, _Potentilla anserina_ L.--leaves, _Equisetum arrense_ L.--leaves, _Melissa officinalis_ L.--leaves, _Rosa canina_ L.--fruits, _Calendula officinalis_ L.--flowers, _Matricia chamomilla_ L.--flowers, _Achillea millefolium_ L.--flowering herbs, _Tropaeolum majus_ L.--seeds, _Plantago lancelata_ L.--leaves.