The study in cockscomb mineral composition

Cockscomb (Сelosia cristata (L.) Kuntze) is grown in Ukraine mostly as a decorative plant. According to literature, it contains phenolic, terpenic, steroid, and nitrogen-containing compounds, showing a large range of biological activity. The aim of the work was to study qualitative composition and determination of quantitative content of mineral elements in cockscomb roots, stems, leaves, flowers, and seeds. Materials and methods. The mineral composition of cockscomb raw material was studied by atomic absorption spectroscopy. Results. In cockscomb roots, stems, leaves, flowers, and seeds 19 mineral elements were identified and determined. The bulk of mineral elements was accumulated in cockscomb leaves – 11580.54 ± 289.51 μg/100 g. In all samples of the herb potassium dominated within the limits of 1125.00 ± 28.12 μg/100 g to 7000.00 ± 175.00 μg/100 g. Prevailing microelements were iron in plant roots and seeds (210.00 ± 5.25 μg/100 g and 81.00 ± 2.02 μg/100 g respectively), aluminum in leaves and flowers (215.00 ± 2.25 μg/100 g and 44.00 ± 1.10 μg/100 g respectively), zinc in stems (5.70 ± 0.14 μg/100 g). Besides, such microelements as zinc (53.00 ± 1.33 μg/100 g) and strontium (21.20 ± 0.53 μg/100 g) were mostly accumulated in roots, manganese (27.00 ± 0.68 μg/100 g) in leaves, copper (2.00 ± 0.05 μg/100 g) in flowers. The content of heavy metals was within the limits stipulated in Ukrainian Pharmacopoeia. Conclusions. The obtained results will be used in the standardization of cockscomb raw material and in the development of medicines on the basis of this raw material.

Mineral elements are important in the provision of a human organism's normal function. Such mineral elements as sodium and potassium are present in interstitial liquors, they support homeostasis, normalize arterial pressure. Abnormally low po tassium concentration in blood plasma leads to hypokalemia and osteoporosis, increases risks of a stroke [1][2][3]. Sodium deficit causes hyponatremia which may lead to renal and cardiac disease, provokes cerebral edema with correspon ding neurological consequences [1]. Calcium participates in nerve impulse transmissions, it is a structural component of conjunctive tissue and ensures bone strength [1,3]. Copper, iron, manganese, selenium, and zinc are hormone and enzyme cofactors, participating in numerous biochemical reactions in organism [3,4].
Copper controls free radical reactions and lipid perox idation processes. Copper deficit affects the antioxidant system which leads to an increase of active oxygen forms level, damage of lipids, proteins, and DNA, provokes liver fatty degeneration, and favors high cholesterol concentra tion in blood plasma [1,2]. Cobalt and iodine participate in red blood cell formation [4]. Iron as a component of hemoglobin and cytochromes supports cell respiration [3]. Molybdenum activates antioxidant enzymes [4]. Copper, selenium, and zinc control humoral immunity and increase organism resistivity [4]. Iodine deficit leads to goiter, irreversible mental deficiency, reproductive insufficiency [1,5]. As the human organism is unable to produce mineral elements, they must be introduced with food or replenished by taking medicines [1,4].
On a par with this, in the evaluation of medicinal herbs equally important is the content of heavy metals. Such elements as lead, cobalt, mercury, arsenic, cadmium, etc., may accumulate in body tissues, and their excess leads to intoxication with severe consequences. Under chronic intoxication with mercury compounds, we witness mental disorders, encephalopathy, vision and hearing disorders, tremor, tachycardia, nephrosis, and gastroenteritis [3,6,7]. Cadmium excess in organisms leads to osteoporosis, anemia, hypertension, nephropathy, cardiopathy, liver lesions. Toxic lead doses hinder hemopoiesis processes, cause anemia, nephropathy, encephalopathy [3,6,7]. Arsenic compounds affect the nervous system, hemolyzed red cells, and cause severe forms of cardiac, renal, and hepatic insufficiency [6,7]. Besides, cadmium and lead ions displace calcium, iron, copper, zinc, and magnesium ions from biological structures, such as hemoglobin and enzymes, thus destroy ing hemopoiesis, affecting nervous, cardiovascular, and locomotor systems [8].
Therefore, the content of heavy metals in medici nal herbs and in food products is strictly limited by the  [9,10].
Genus Celosia (Сelosia cristata L.) belongs to the Ama ranthaceae family (Amaranthaceae L.) and includes about 60 species which are popular at all continents for landscape decoration, whereas in West Africa, North America, China, Indonesia, India they are cultivated as food plants [1,11,12]. Their name means "fiery, lurid" and corresponds to the pe culiar shape and bright coloring of inflorescences [13,14]. The study in cockscomb mineral composition as a subspecies of quail grass [11,15], whereas others rank it as a separate species [1,12,13].
In cockscomb flowers from India, six mineral elements were identified. According to this study, in cockscomb flowers potassium content (520.40 ± 1.12 mg/100 g) was almost four times higher than that of calcium (128.68 ± 1.53 mg/100 g) and 6.8 times higher than that of magnesium (76.40 ± 0.52 mg/100 g). The content of sodium, zinc, and iron never exceeded 10 mg/100 g [12]. The study in mineral compo sition of quail grass leaves, stems, and flowers from India ascertained potassium (30.55-37.66 mg/g) and sodium (0.52-1.06 mg/g) content in those parts of the herb to be very close. Magnesium content (67.18 mg/g) was twice higher in leaves than in stems and flowers. Calcium content was almost identical in quail grass leaves and stems (79.70-86.60 mg/kg) and 5 times lower in flowers, whereas all samples of this raw material contained less than 0.52 mg/kg iron, zinc, and copper [19].
African samples of quail grass and wheat celosia showed as much as 178-242 mg/100 g calcium in leaves. Nevertheless, data on other elements substantially differ. Thus, leaves of wheat celosia contained 659 mg/100 g potassium, whereas those of quail grass contained 5 times less. Magnesium (463 mg/100 g) and phosphorus (102 mg/100 g) grossly pre vailed in wheat celosia leaves. Quail grass leaves contained sodium (71.32 mg/100 g) and iron (15.25 mg/100 g) almost three times more than those of wheat celosia. Content of copper, zinc, and manganese in these plants never exceeded 8 mg/100 g [1]. Other Indian authors determined the content of macro and microelements in quail grass herb before, during, and after blossoming. Potassium prevailed in all samples with in the range of 5995 to 10340 mg/100 g. Calcium was concen trated in those samples within the limits 1365-1540 mg/100 g. The content of magnesium (755-765 mg/100 g) and phos phorus (645-845 mg/100 g) was almost identical. It should be noted that potassium, calcium, phosphorus, and copper (1.70 mg/100 g) mostly accumulated in quail grass herb before blossoming, the maximum content of magnesium, zinc (12.30 mg/100 g) and iron (21.30 mg/100 g) was during blossoming, sodium (65.00 mg/100 g), and manganese (7.65 mg/100 g) mostly accumulated after blossoming [18]. The chemical composition of plant bioactive substances is known to differ depending on the climatic conditions and vegetation area. Therefore, it is necessary to study the mineral composition of cockscomb grown in Ukraine.

Aim
The aim of the work was to study qualitative composition and determination of quantitative content of mineral elements in cockscomb roots, stems, leaves, flowers, and seeds.

Materials and methods
We used air-dried milled roots, stems, leaves, flowers, and seeds of cockscomb collected in the Kharkiv Region, Ukraine in 2019-2020 for the mineral composition study. Mineral composition of cockscomb raw material was studied by atomic absorption spectroscopy according to the method de scribed in general article 2.0.1 "Atomic absorption spectros copy" of Ukrainian Pharmacopoeia [20]. The research was performed on the basis on A. B. Blank Analytical Chemistry Department, Institute of Monocrystals, National Academy of Sciences of Ukraine, under the guidance of Junior Scientist Olena Hryshyna.
Charred at muffle furnace and treated with dilute sulfuric acid a sample of raw material (about 2 g) was evaporated from graphite electrodes at intermittent current intensity. Arc discharge of this current was 16 A, the exposition was 60 sec [20]. Spectra were generated at IBC28 unit at pressure 0.04 MPa and flame temperature 2250 °С [20]. Spectra were registered at DFS8 spectrograph with grating 600 grooves/mm and a threelens slit lighting system. The intensity of obtained spectra was measured with MF-1 microphotometer with firing phase 60 °C, spectrograph slit width being 0.015 mm. The firing impulse frequency was 100 discharges per second at spectrum range 230 nm to 347 nm [20].
Copper was dissolved in nitric acid, whereas all other elements were analyzed using chemically pure reagents and double-purified water. For all elements line and background, blackening differences were calculated (S = S l+bg -S bg ) for sample (S sam ) and graduating standard (S GS ) spectra. On the basis of these results, we have built a graduation plot in coordinates: average background (S) and background (S GS ) blackening average value -logarithm of element content in graduation standard (lg С), where C is expressed as a percent of basis [20].
The content of mineral elements in ashes (а, %) was found from the plot. Element content in raw material (Х, %) was calculated by the formula: ISSN 2306-8094 The study in cockscomb mineral composition Х = a × m 1 , m where m 1 -ash mass, g; m -raw material (dry) mass, g; a -element content in ash, % [20].

Results
According to the results of the mineral composition study in all samples of cockscomb raw material, we identified and determined 6 macroelements (silicon, phosphorus, magnesium, calcium, sodium, and potassium), 8 microelements (iron, aluminum, manganese, nickel, molybdenum, copper, zinc, and strontium) and 5 heavy metals (lead, cobalt, cadmium, arsenic, and mercury). Qualitative composition and quantitative content of mineral elements in cockscomb raw material presented in Table 1.

Discussion
In the course of the research, we established that the bulk of mineral elements was accumulated in cockscomb leaves and roots that were 11580.54 ± 289.51 μg/100 g and 10513.52 ± 262.84 μg/100 g respectively. The total content of mineral elements in the stems (4578.53 ± 114.46 μg/100 g) of tested plant was almost 2.5 times lower than that in its leaves. Flowers (3851.60 ± 96.29 μg/100 g) of cockscomb contained 1.7 times more mineral elements than its seeds (2272.73 ± 56.82 μg/100 g). Total mineral content increased from seeds, flowers, and stems up to roots and leaves. Microelements in cockscomb roots, leaves, stems, and flowers possess only 1 % to 5 % of total mineral content, and only in seeds, it reached as much as 7 %.
Quantitative content of identified mineral elements gradually decreased in succession K > Ca > Mg > Si > P > Al >Na > Fe > Zn > Mn > Sr > Cu > Mo > Ni. A similar situation was observed in stems, roots, and seeds. The study in cockscomb mineral composition Nevertheless, in stems sodium prevailed over phosphorus and silicon, zinc over iron. In seeds and roots potassium, silicon, calcium, and magnesium dominated. In seeds phosphorus prevailed over aluminum, sodium, and zinc, whereas in roots it was vice versa. Besides, seeds contained much more nickel than copper and strontium. This distribution can be explained by the physiological feature of the plant. They can capability to accumulate individual macroand micronutrients in certain organs and tissues.
The highest content of macroelements was in cockscomb leaves that was 11215.00 ± 280.38 μg/100 g, that of mi croelements was in its roots (516.52 ± 12.91 μg/100 g). At the same time, the leaves of the tested plant contained total mi croelements almost 1,5 times less (365.54 ± 9.14 μg/100 g) than its roots.
Dominating microelements in cockscomb roots were iron and aluminum in almost identical amounts that was 210.00 ± 5.25 μg/100 g. Aluminum prevailed in leaves and flowers, iron prevailed in seeds. Aluminum contented in cockscomb leaves (215.00 ± 5.38 μg/100 g) was almost 5 times higher than in flowers (44.00 ± 1.10 μg/100 g). Cockscomb seeds contained 2.6 times less iron than their roots that was only 81.00 ± 2.02 μg/100 g.
The prevailing microelement in cockscomb stems was zinc to the amount of 5.70 ± 0.14 μg/100 g. Iron content in this part of the herb was somehow less that is 4.60 ± 0.12 μg/100 g. At the same time, the results of our experiment showed zinc accumulation most in roots (53.00 ± 1.33 μg/100 g). Identically high molybdenum con tent was found in cockscomb roots and leaves that is 0.21 ± 0.01 μg/100 g. Manganese content prevailed in leaves (27.00 ± 0.68 μg/100 g), copper content prevailed in flowers (2.00 ± 0.05 μg/100 g) and that of nickel prevailed in seeds of this plant (0.54 ± 001 μg/100 g).
The content of heavy metals in all tested samples of cockscomb raw material met the requirements of Ukrainian Pharmacopoeia never exceeding acceptable limits for me dicinal raw material.

Conclusions
1. According to this research in roots, leaves, stems, flowers, and seeds of cockscomb were identified and quantitatively determined 6 macroelements, 8 microelements, and 5 heavy metals by atomic absorption spectroscopy.
3. The content of heavy metals in cockscomb raw material met the requirements of Ukrainian Pharmacopoeia.
Prospects for further research. The obtained results will be used in the standardization of cockscomb raw material and in the development of medicines on the basis of this raw material.