Potential antidiabetic and antioxidant activities of a heliangolide sesquiterpene lactone isolated from Helianthus annuus L. leaves

Abstract

<jats:title>Abstract</jats:title><jats:p>Heliangolide is a naturally occurring sesquiterpene lactone and its derivatives are biologically active compounds present in most medicinal plants. This study evaluated the antioxidant and antidiabetic properties of a heliangolide sesquiterpene lactone isolated from <jats:italic>Helianthus annuus</jats:italic> L. leaves. The heliangolide sesquiterpene lactone was isolated through a combination of solvent-solvent partitioning, column chromatography, thin layer chromatography and high-performance liquid chromatography techniques. The antioxidant activity of the compound was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and nitric oxide radical scavenging assays while the antidiabetic effects were investigated in alloxan-induced diabetic rats. The heliangolide derivative at the concentration of 954.2 µmol L<jats:sup>−1</jats:sup> showed 23.7 % DPPH and 26 % nitric oxide radical inhibitions compared with 96.6 and 50.9 %, resp., displayed by the controls (2,271.2 µmol L<jats:sup>−1</jats:sup>). It also reduced the fasting blood glucose (FBG) levels in a time-dependent manner. The highest activity was recorded within 6 h post-treatment at 0.2 mmol kg<jats:sup>−1</jats:sup> bm. The heliangolide derivative exhibited significant (<jats:italic>p</jats:italic> &lt; 0.05) antioxidant and antidiabetic properties and provides a basis for further development of constituents of <jats:italic>Helianthus annuus</jats:italic> leaves for the management of such diseases.</jats:p>

Sunflower (Helianthus annuus L.) Plants at Various Growth Stages Subjected to Extraction—Comparison of the Antioxidant Activity and Phenolic Profile

“…The abovementioned correlations indicate the main role of phenolic compounds in the antioxidant activity of the extracts of the aerial parts of sunflowers at all growth stages. In the sunflower seeds and leaves, non-phenolic antioxidants have also been determined, including tocopherols and volatile compounds [27,45]. However, their presence in the extracts, in our study, was limited by the extraction conditions: the polar solvent and high temperature of the process.…”

“…Recent information about the secondary metabolites of sunflower leaves has been provided as a result of metabolomic studies, in which compounds from three chemical groups, including hydroxycinnamoylquinates, methyl-flavonoids and sesquiterpenoids, were detected [25,26]. Onoja et al [27] found that a sesquiterpene lactone, isolated from H. annuus leaves, had antidiabetic and antioxidant properties, but, to the best of our knowledge, the total antioxidant potential of sunflower leaves has not yet been estimated.…”

The potential role of sesquiterpene lactones isolated from medicinal plants in the treatment of the metabolic syndrome – A review

“… Compound Class Plant source Biological effects Mechanisms implicated Refs. 1 Enhydrin Melampolide Smallanthus sonchifolius Hypoglycemic ( in vivo ) Post-prandial glucose levels (↓) Inhibition of α-glucosidase Genta et al., 2010 ; Serra-Barcellona et al., 2017 2 Polymatin A Melampolide Smallanthus macroscyphus Hypoglycemic ( in vivo ) Post-prandial glucose levels (↓) Serra-Barcellona et al., 2014 3 20-dehydroeucannabinolide Heliangolide Helianthus annuus Antidiabetic ( in vivo ) Antioxidant ( in vitro ) Fasting blood glucose level (↓) DPPH radical and NO scavenging activities Onoja et al., 2020 4 Eremanthin Guaianolide Costus speciosus Hypoglycemic, and hypolipidemic ( in vivo ) Antioxidant ( in vivo ) Blood glucose levels (↓), HbA1c (↓), plasma insulin (↑), tissue glycogen (↑) TC, TG and LDL-C (↓); HDL-C (↑) TBARS levels (↓), GSH (↑), SOD, CAT and GPx (↑) in brain, liver, heart, kidney, and pancreas Eliza et al., 2009a , 2009b , 2010 5 Costunolide Germacrolide Costus speciosus 6 Alantolactone Eudesmanolide Inula helenium Antiinflammatory-associated to glucose intolerance and IR ( in vitro ) Antiinflamatory- obesity-induced IR ( in vitro ) Attenuates lipid accumulation ( in vitro ) Antiinflamatory- associated to diabetic nephropathy ( in vivo ) STAT3 inhibitor. Inhibition of the TLR4 gene expression.…”

“…1 ). ( Onoja et al., 2020 ). Heliangolide SLns represent an isomeric form of germacranolides with a cyclodecadiene skeleton and double bonds at C1=C10 and C4=C5, which stereochemical configurations are trans, cis respectively ( Sülsen and Martino, 2018 ).…”

“…Heliangolide SLns represent an isomeric form of germacranolides with a cyclodecadiene skeleton and double bonds at C1=C10 and C4=C5, which stereochemical configurations are trans, cis respectively ( Sülsen and Martino, 2018 ). The heliangolide 3 reduced the fasting blood glucose level at dose of 0.2 mmol/kg in alloxan-induced diabetic rats ( Onoja et al., 2020 ). The authors suggested that this sesquiterpene lactone might have reducing effects in glucose absorption based on the heliangolide derivative structure, which presents an intact exo -methylene-γ-lactone group.…”