Determination of Nettle Leaves Extracts Antioxidant Activity by Various Methods

Abstract

Introduction . Recently, much attention has been paid in the literature to the primary assessment of the pharmacological effect of various drugs using in vivo and in vitro tests. Great interest in determining the antioxidant activity ( АА ) of drugs, including herbal remedies, medicinal plant materials and their biologically active substances (BAS). It is known that such an officinal medicinal plant, like dioica nettle, is rich in natural antioxidants ( АО ) in its phytochemical composition: flavonoids, carotenoids, ascorbic acid, etc. In some publications, there is information about the АА of nettle leaves and preparations based on it. However, information on the comparative characteristics of the use of various methods for determining the АА of this type of medicinal plant material and the results obtained are not found in the scientific literature. Aim . The aim of this work was a comparative determination of the АА of medicinal plant raw materials of nettle dioica by various methods. Materials and methods . The object of the study was the finished crushed raw material of dioica nettle leaves (Folia Urticae) in filter bags produced by a domestic manufacturer. AA of water and water-alcohol extracts was determined titrimetrically according to the method developed by T. V. Maksimova with co-authors; the ability to inhibit the autooxidation of adrenaline in vitro. The Paramecium caudatum cell culture was also used as a biological model to determine the АА of aqueous extracts from the studied raw material on a living cell. The determination of the qualitative and quantitative composition of phenolic AO was determined by HPLC-DMD-MS. Results and discussion . The total АА of water and water-alcohol extracts from dioica nettle leaves was determined using various techniques recommended in the literature. The effect of the extractant polarity on the value of АА was investigated and an inversely proportional relationship was revealed. It was found that the highest content of АО in the extraction is observed when using 96% ethanol as an extractant. Evaluation of the АА of the test object by the biological method was carried out in accordance with the values of the index of biological activity. HPLC-DMD-MS analysis of water-methanol extraction from nettle leaves showed the presence of 17 substances - representatives of the group of phenolic compounds. Conclusion . Using four independent methods, the prospects of using dioica nettle leaves and preparations based on it as a source of AO are shown. The data obtained undoubtedly open up new possibilities for the use of a long-known plant and confirm the feasibility and prospects of its use for obtaining new dosage forms.