Banat′s Journal of Biotechnology Contact: web: http://www.bjbabe.ro, e-mail: [email protected] Medicinal plants as sources of selenium and natural antioxidants DOI: 10.7904/2068–4738–XI(22)–48 Nadezhda GOLUBKINA1*, Vladimir LAPCHENKO2, Lubov RYFF3, Helene LAPCHENKO2, Tatiana NAUMENKO3, Natalia BAGRIKOVA3, Katherine KRAINUK3, Olga KOSHELEVA4, Gianluca CARUSO5 1 Federal Scientific Center of Vegetable Production, Selectsionnaya str. 14, VNIISSOK, Odintsovo district,Moscow region 143072 RUSSIA 2Federal Research Centre «A.O. Kovalevsky Institute for Biology of the Southern Seas of RAS» Branch «T.I. Vyazemsky Karadag Scientific Station — Nature Reserve of RAS», Nauki Street, 24, Kurortnoe, Feodosia, Republic of Crimea, RUSSIA 3Nikitsky Botanical Gardens, Nikita Yalta, 298648, Republic of Crimea, Yalta, RUSSIA 4Institute of Nutrition and Biotechnology, Ustinski pr, 2/14 109240 Moscow, RUSSIA 5Department of Agricultural Sciences, University of Naples Federico II, 80055 Portici (Naples) ITALY *Corresponding author: [email protected]; tel: +7–903–118–50–30 Abstract. The beneficial synergism between selenium (Se) and other antioxidants on human health stimulates the search of new medicinal plants with high antioxidant activity (AOA) and Se accumulation levels. Using fluorimetric method of Se analysis and titrimetric method of total AOA determination monitoring was achieved of 53 species of herbs, 24 species of deciduous and evergreen trees and shrubs and 11 species of conifers grown on the Southern and South–Eastern coast of the Crimean peninsular. Two new Se–hyperaccumulators were indicated among deciduous trees: Tamarix ramosissima and Paliurus spina–christi with leaves Se content 6236 and 1800 µg.kg–1 d.w. respectively. Among herbs 5 new hyperaccumulators were revealed: Artemisia draсunculus cv. Izumrudny, Anthemis tranzscheliana, Cota tinxtoria, Astragalus arnacantha and Limonium gerberi with Se accumulation levels of 23460, 9479, 960, 4110, and 1926 µg.kg–1 d.w. respectively. Medians of Se levels reached 97 µg.kg–1 for conifers, 86.5 µg.kg–1–for deciduous plants and 61 µg.kg–1 – for herbs with the appropriate AOA values: 67, 70. and 49.3 mg–GAE.g–1 d.w. respectively. Tamarix was the only plant with both Se hyperaccumulation abilities and high AOA level (212 mg–GAE.g–1 d.w). High AOA (188–256 mg–GAE.g–1 d.w) and relatively high Se levels (193–236 µg.kg–1) were demonstrated for Pistacia atlantica and Cotinus coggygria. Keyword: Selenium; antioxidant activity; deciduous evergreen trees and shrubs; conifers; herbs. Introduction important source of antioxidants for Antioxidants are an important group human beings, effectively blocking the of compounds capable to protect human oxidation processes and neutralizing free organism from many diseases, suitable radicals [PATEL CHIRAG et al., 2013]. Special for production of food additives and attention is paid to the role of plants inhibiting oxidation processes. Several antioxidants in cancer prevention groups of phenolics (anthocyanins, [GHOLAMIAN–DEHKORDI et al., 2017]. tannins, flavonones, resveratrol, ellagic Utilization in food, pharmaceutical acid) are already used in industry as and cosmetic industry, wide possibilities nutriceutics and/or functional food in medicine utilization form the basis of products [ESPIN et al., 2007; LOURENÇO et al., 2019]. constantly growing interest in search of Despite antioxidant properties, these new natural sources of antioxidants [HUANG compounds demonstrate wide spectrum et al., 2005; LOURENÇO et al., 2019]. of biological activity, including anti– In addition to plants secondary allergic, anti–inflammation, antithrombotic, metabolites important for human health, cardio–protective, anticarcinogenic and the elemental composition of plants is vasodilator effect [PANICKAR, 2013, AKINYEMI et al., also of great interest, as it is known to 2018]. All medicinal plants compose an affect plants biological activity. In this 48 Available on-line at http://www.bjbabe.ro Banat′s Journal of Biotechnology 2020, XI(22) respect, special attention is paid to regarding the plants ability to selenium known to demonstrate powerful hyperaccumulate Se and the question antioxidant properties, immune– needs special investigations. Up to date, modulating effect, being a part of few studies devoted to the search of enzymes with antioxidant activity, selenium hyperaccumulators with high including triiodothyronine deiodinases antioxidant activity have been achieved [SHARIFI-RAD J et al., 2010; OKLO et al., 2017]. [ZOTEK et al., 2019]. Se deficiency is widespread in the The aim of the present investigation world increasing risks of cardiovascular was to monitor medicinal plants in the and oncological diseases, disturbances in absence of significant anthropogenic reproductive function and brain activity interferences in the territories of Nature [GUPTA, GUPTA, 2016]. Especially important is Reserves of the Southern and South– the fact that synergistic interactions Eastern Crimean coast using Se and AOA between natural antioxidants including Se parameters. [SONAM, GULERIA, 2017; GOLUBKINA, PAPAZYAN, 2006] decrease the requirement of doses of Material and methods different drugs in combination thus Sample collection and preparation reducing the side effects caused by the Samples of plant leaves were high concentrations of a single drug. gathered at the end of May– beginning of Most of agricultural crops and herbs June 2017–2018 in the territory of are not Se accumulators and the only way Karadag Nature Reserve (44o56’10’’с.ш.; to get products with high Se and 35o14’00’’в.д.), Martyan Cape Nature antioxidants content is biofortification. Se Reserve and Nikitsky Botanical Garden hyperaccumulators among plants are (N 44°30.725; Е 34°14.089), and Ayu– rather rare and, as a rule, are grown on Dag protected area (N 44.55831503; E soils rich with selenium [PILON–SMITS, 2019; 34.33527650) (Figure 1). WHITE, 2016]. Overall, there are a few data Figure 1. Plants sampling sites: 1– Nikitsky Botanical Garden, 2–Martian cape, 3–Ayu– Dag, 4–Karadag Among deciduous and evergreen Asphodelaceae, Boraginaceae, Brassicaceae, trees and shrubs 23 plant species were Hypericaceae, Capparidaceae, investigated, belonging to 12 families: Caryophyllaceae, Lamiaceae, Ephedraceae, Anacardiaceae, Cornaceae, Fabaceae, Euphorbiaceae, Papaveraceae, Rosaceae, Elaeagnaceae, Fagaceae, Myrtaceae, Paeoniacea, Plumbaginaceae, Polygonaceae, Ranunculaceae, Solanaceae, and Urticaceae. Moraceae, Oleaceae, Rhamnaceae, Status and nomenclature of taxa Rosaceae, Tamaricaceae, and Vitaceae. are presented according to modern Among conifers 11 evergreens international databases. The 2013 Plant species were studied. And among List, 2020 Catalogue of Life and IPNI. herbaceous species we investigated 54 Samples of leaves were cut with taxa (including 3 cultivars of the same plastic knife and dried at room species) belonging to 20 families: temperature to constant weight without Asparagaceae, Asteraceae, Fabaceae, direct sunlight. Dried samples were 49 Banat′s Journal of Biotechnology Contact: web: http://www.bjbabe.ro, e-mail: [email protected] homogenized and the resulting powders popular in modern biochemical were kept in hermetically closed laboratories [KASOTE et al., 2019]. polyethylene bags without direct sunlight. Selenium was analyzed using the Extraction of antioxidants was micro fluorimetric method previously achieved using 70 % ethanol. Half gram described for tissues and biological fluids of dry leaves powder were mixed with 15 [ALFTHAN, 1984]. The method includes wet mL of 70 % ethanol, heated at 80 оС digestion of dried homogenized samples during one hour and cooled to room via heating with a mixture of nitric–chloral temperature. Mixtures were quantitatively acids, subsequent reduction of selenate transferred to volumetric flasks and the (Se+6) to selenite (Se+4) with a solution of volume was adjusted to 25 mL with 70 % 6 N HCl, and formation of a complex ethanol and samples were filtered through (piazoselenol) between Se+4 and 2,3– a pleated filter. Despite the fact that each diaminonaphtalene. The calculation of Se biological object requires a special concentration was achieved by recording selection of optimal conditions for piazoselenol fluorescence values in antioxidants extraction [XU et al., 2017], 70 % hexane at 519 nm λ emission and 376 nm ethanol is used most frequently which λ excitation. Each determination was allows to simplify the process of performed in triplicate. The precision of monitoring. the results were verified using in each Antioxidant activity (AOA) of determination a reference standard– medicinal plants leaves was assessed lyophilized cabbage with Se concentration using a redox titration method [GOLUBKINA et of 150 μg·kg−1. al., 2020] via titration of 0.01 N KMnO4 Statistical analysis solution with ethanolic extracts of dry Data were processed by analysis of samples. The reduction of KMnO4 to variance and mean separations were colorless Mn+2 in this process reflects the performed through the Duncan multiple quantity of antioxidants dissolvable in range test, with reference to 0.05 70% ethanol. The values were expressed probability level, using SPSS software –1 in mg gallic acid equivalents (GAE) g version 21. d.w. The KMnO4 acidic solution has been successfully used earlier for the Results and discussion determination of the Ocimum basilicum Literature data indicate several antioxidant potential [SRIVASTAVA et al., 2015] plant orders and families where Se and the antioxidant capacity