Biological activity of new flavonoid from Hieracium pilosella L.

Abstract

Hieracium pilosella L. (Asteraceae) is a well-known plant used in ethno-medicine as its inflorescences are particularly rich in beneficial polyphenolics. This research aimed to elucidate the structure of a new flavone glycoside isolated from the inflorescences of Hieracium pilosella and evaluate its antioxidant, antimicrobial and antiproliferative activities. The chromatographic methods were successfully applied to isolate the new flavonoid. Its structure was determined by subsequent UV, NMR and MS experiments and identified as isoetin 4′-O-β-D-glucopyranoside. Free radical scavenging capacity was examined by measuring the scavenging activity of the new isoetin derivative on 2,2-diphenyl-1-picrylhydrazyl (DPPH). The compound was also screened for spectrum of antimicrobial activity using the agar well diffusion method. Minimum inhibitory concentration (MIC) for Pseudomonas aeruginosa ATCC 9027 was performed by the micro-dilution broth method. The antiproliferative effect of tested glycoside was assessed in two human tumor cell lines derived from lung (A549) and colon (HT-29) carcinoma and cell proliferation was determined by means of MTT method. The tested compound showed high antiradical activity, reducing the DPPH? with EC50 7.9 μM (3.7 µg/ml) and exhibited narrow antimicrobial spectrum among tested microorganisms. The compound was active against Pseudomonas aeruginosa ATCC 9027 (MIC 125 μg/ml) which is prone to causing infections that are difficult to treat due to it developing extremely rapid antibiotic resistance. In the antiproliferative studies, cell proliferation of the colon (HT-29) carcinoma cell line was significantly decreased after exposure to the compound. The results indicate that isoetin 4′-O-β-D-glucopyranoside possesses antioxidant capacity and very promising antibacterial activity and could have uses as an effective antipseudomonal agent as well a antiproliferative agent.

Hieracium waldsteinii (Asteraceae) and Onosma stellulata (Boraginaceae) as a Source of Antioxidant and Antimicrobial Agents

“…In addition, for any of the mentioned endemics there are no data about potential application as a source of different antimicrobial and antitumor agents. Since the plants from Hieracium and Onosma genera are a well‐known source of different antioxidants, [4,10,19,11–18] enzyme inhibitors, [11,13–20] anti‐diabetic, [16,21] antiproliferative [10] antimicrobial [2,10] as well as antitumor [21,22] agents, the current study aimed to achieve the following:…”

“…In addition, for any of the mentioned endemics there are no data about potential application as a source of different antimicrobial and antitumor agents. Since the plants from Hieracium and Onosma genera are a well-known source of different antioxidants, [4,10,19,[11][12][13][14][15][16][17][18] enzyme inhibitors, [11,13 -20] anti-diabetic, [16,21] antiproliferative [10] antimicrobial [2,10] as well as antitumor [21,22] agents, the current study aimed to achieve the following: a) to determine a general phytochemical profile of above-ground parts (stem, leaf and flower) of H. waldsteinii and O. stellulata by determining the total phenolic, flavonoid and pigment (carotenoid, chlorophyll A and B) content as well as the content of soluble sugars and starch; b) to determine a detailed phenolic profile of the above-mentioned endemic species via HPLC MS-MS analysis; c) to determine antioxidant properties using four different assays including DPPH * and ABTS * + scavenging tests as well as in vitro phosphomolybdenum total antioxidant capacity (TAC) and ferric reducing power (FRP) tests; d) to evaluate possible antimicrobial activity of examined extracts against several bacteria and fungi; e) to approach possible application of extracted H. waldsteinii and O. stellulata bioactive compounds as antitumor agents.…”

Ethnopharmacology, phytochemistry, and bioactivities of Hieracium L. and Pilosella Hill (Cichorieae, Asteraceae) species

“…In addition, in case of the DPPH assay the results were altered to IC 50 if synonyms of this value were stated. In only on case the authors investigated the antioxidant capacity of a single compound, isoetin 4 ′ -O-β-D-glucopyranoside, isolated from the flowering heads of P. officinarum (Gawrońska-Grzywacz et al, 2011). In the remaining studies, crude extracts of different polarity of 39 plant species were investigated, revealing a broad range of antioxidant activity.…”

Hieracium pilosella L. – a new adventive species for the flora of the Tian Shan (Kazakhstan)

“…Объясняется это быстрым разрастанием его из-за интенсивного вегетативного размножения с помощью надземных столонов. Именно по этой причине данный вид широко распространился по всему миру за пределами своего естественного ареала -в Северную и Южную Америку, Тасманию и Новую Зеландию, куда был интродуцирован как декоративное растение или занесен с семенами сельскохозяйственных культур (Webb et al, 1988;Rudman, Goninon, 2002;Gawrońska-Grzywacz et al, 2011;Cipriotti et al, 2012;USDA-NRCS, 2016). На этих континентах и островах H. pilosella рассматривается как агрессивный инвазивный вид, наносящий урон аборигенной флоре и сельскому хозяйству (Grundy, 1989;Wilson et al, 1997;Rudman, Goninon, 2002;USDA-NRCS, 2016).…”

“…В Европе H. pilosella считается лекарственным растением и приводится в британской, французской травяной фармакопеях и в польской этномедицине как традиционное лекарственное средство (Gawrońska-Grzywacz et al, 2011;Assessment report on ..., 2014;Borisova-Jan et al, 2017). Имеются также сведения об использовании его аборигенами Северной Америки (Frey, Meyers, 2010).…”