Solidago virga-urea L. is a valuable medicinal plant that has anti-inflammatory, antimicrobial, antispasmodic, diuretic and analgesic effects. S. virga-urea L a perennial rhizomatous plant with a height of 25-100 cm belonging to the Asteraceae family has a wide distribution throughout Europe, the temperate regions of Asia and North-West Africa. Its distribution in Iran is limited to the forest and open pasture areas of Golestan, Mazandaran and Gilan provinces. Herbal medicines containing S. virga-urea have been used for centuries to treat urinary tract diseases. These drugs have anti-inflammatory, antimicrobial, diuretic, antispasmodic and sedative effects and are used to treat inflammation, infection, prevent the formation of kidney stones and help to remove urinary stones in a safe and secure manner. This study explores the effect of types of organs and growth stages on phytochemical compounds and active substances of S. virga-urea.
Materials and methods
In order to evaluate the phenolic and flavonoid compositions in different organs extract (rosette leaf, stem leaf and flower) and also in extracts obtained from different growth stages (before bloom, first bloom, full bloom and after bloom) of S. virga-urea L.'Phasa F type', two separate experiments were conducted in the form of a randomized complete block design with three replications. S. virga-urea var. 'Phasa F type' seeds were obtained from Pharmasaat CO. (Germany). The experiment carried out in the Research Institute of Plants and Medicinal Raw Materials of Shahid Beheshti University of Tehran in 2019. In the first part of the research, different organs of the plant, including rosette leaves, stem leaves, and flowers were harvested at the full flowering stage. In the second part, sampling was done at four different phenological stages (before bloom, first bloom, full bloom, and after bloom), from the flowering branch of the plant. The samples were dried under shade and room temperature conditions. In order to extract phenolic and flavonoid compounds, 200 mg of dry plant samples were powdered, and then 10 ml of methanol was added to the sample and placed in an ultrasonic bath at room temperature for 30 minutes. Phytochemical properties including total phenol content, total flavonoids and leiocarposide content were measured by Folin–Ciocalteu, Aluminum Chloride method and high performance liquid chromatographic analysis, respectively.
The results showed that among different organs, the highest amount of total phenol (29.36 mg GAE.g-1 dry weight) was in flowers; flavonoids (8.63 mg RUT. g-1 dry weight) in rosette leaves; and leiocarposide (5.17 mg.g-1 dry weight) in stem leaves. Due to medicinal importance of the studied compounds, all three organs (rosette leaves, stem leaves, and flowers) can be used depending on the needs of the pharmaceutical and food industries. Among the growth stages, the highest phenol (28.84 mg GAE.g-1 dry weight) and total flavonoids (7.95 mg RUT. g-1 dry weight) were obtained in the full bloom stage, while the highest amount of leiocarposide (9.65 mg.g-1 dry matter) obtained before blooming. According to the findings, it is recommended to harvest the flowering branches at the full flowering stage to obtain the maximum levels of total phenol and flavonoid, and at the early flowering stage to obtain the highest levels of leiocarposide.
The content of phenol, flavonoid and leiocarposide were varied in different organs and developmental stages. Therefore, it is concluded that the amount of active ingredients in this plant are never fixed and depends completely on environmental and soil factors, organ type, genetic diversity and plant phenology. According to the results obtained from this study, the best organ and harvest time for having high amounts of total phenol, total flavonoids or leiocarposide can be chosen based on pharmaceutical and food industries requirements, in the climatic conditions of Tehran.