The phytochemical study of Eleutherococcus senticosus (Rupr. & Maxim) leaves in hydroponics and soil culture

Abstract

Background: In the medical field Eleutherococcus senticosus (Rupr. & Maxim) (E. senticosus) or Siberian ginseng is known as a natural adaptogen and immunomodulator. All parts of E. senticosus: roots, stems, leaves, and berries, have medicinal properties. In medicine, E. senticosus is used to treat depression, Alzheimer's and Parkinson’s diseases, cardiovascular diseases, cerebral ischemia, and diabetes. The adaptogenic properties of the plant are related to its rich composition of biologically active compounds (phenylpropanoids, eleuterosides, flavonoids, phenolic acids, anthocyanins, vitamins, etc.). E. senticosus activates the body’s protection mechanisms, directly affecting tissue metabolism. It increases mental and physical performance, immunity, and protects from stress, making its use important in sports medicine and the military. The use of E. senticosus in food and dietary supplements has become popular in recent years, whereas some studies suggest that its potential benefits are the reduction of stress and enhancement of immune system function. Objective: To study the content of the main biologically active compounds of medicinal raw material (leaves) of E. senticosus, cultivated in outdoor hydroponics and soil conditions during different stages of growth and development. Methods: The spectrophotometric method was used to determine the content of total phenols, flavonoids, phenolic acids and eleutherosides in a 70 % water-alcohol extract from E. senticosus dry leaves at different phases of vegetation period. The spectra were recorded using an Agilent Cary 60 UV-Vis spectrophotometer. Moreover, the content of extractive substances was determined, and the content of vitamin C, and β-carotene in fresh leaves (State Pharmacopoeia 2015). Results: The results of our study showed that levels of phenolic compounds in the leaves of E. senticosus obtained in hydroponics and soil culture are the highest during the flowering phase (August-September). It was observed that during the flowering period, the content of total phenols, phenolic acids, and eleutherosides was 1.3 times higher, and flavonoids - 1.2 times higher compared to the vegetative phase. It is worth noting that the content of vitamin “C”, β-carotene and extractives was also higher during the flowering period. Hydroponic plants had higher content of vitamin “C”, β-carotene, and extractives, respectively by 1.4, 1.2 and 1.2 times compared to soil plants. This could be due to several factors such as the optimal content of nutrients (N=200 mg/L, P=65 mg/L, K=350 mg/L), and the high content of oxygen in the hydroponic system. Conclusion: According to the results of a phytochemical study of E. senticosus leaves grown in outdoor hydroponics and soil culture in the Ararat Valley, the highest content of biologically active compounds (eleutherosides, phenols, phenolic acids, vitamins) is recorded in hydroponic plants in the flowering period. In general, the research has practical importance, since the E. senticosus plants grown in hydroponic conditions can be a rich source for the production of natural food and dietary supplements.