3 research outputs found
Rhaponticum acaule (L) DC essential oil: chemical composition, in vitro antioxidant and enzyme inhibition properties
Background: α-glucosidase is a therapeutic target for diabetes mellitus (DM) and α-glucosidase inhibitors play a
vital role in the treatments for the disease. Furthermore, xanthine oxidase (XO) is a key enzyme that catalyzes
hypoxanthine and xanthine to uric acid which at high levels can lead to hyperuricemia which is an important cause
of gout. Pancreatic lipase (PL) secreted into the duodenum plays a key role in the digestion and absorption of fats.
For its importance in lipid digestion, PL represents an attractive target for obesity prevention.
Methods: The flowers essential oil of Rhaponticum acaule (L) DC (R. acaule) was characterized using gas
chromatography-mass spectrometry (GC-MS). The antioxidant activities of R. acaule essential oil (RaEO) were also
determined using 2,2’-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), reducing power,
phosphomolybdenum, and DNA nicking assays. The inhibitory power of RaEO against α-glucosidase, xanthine
oxidase and pancreatic lipase was evaluated. Enzyme kinetic studies using Michaelis-Menten and the derived
Lineweaver-Burk (LB) plots were performed to understand the possible mechanism of inhibition exercised by the
components of this essential oil.
Results: The result revealed the presence of 26 compounds (97.4%). The main constituents include germacrene D
(49.2%), methyl eugenol (8.3%), (E)-β-ionone (6.2%), β-caryophyllene (5.7%), (E,E)-α-farnesene (4.2%),
bicyclogermacrene (4.1%) and (Z)-α-bisabolene (3.7%). The kinetic inhibition study showed that the essential oil
demonstrated a strong α-glucosidase inhibiton and it was a mixed inhibitor. On the other hand, our results
evidenced that this oil exhibited important xanthine oxidase inhibitory effect, behaving as a non-competitive
inhibitor. The essential oil inhibited the turkey pancreatic lipase, with maximum inhibition of 80% achieved at
2 mg/mL. Furthermore, the inhibition of turkey pancreatic lipase by RaEO was an irreversible one.
Conclusion: The results revealed that the RaEO is a new promising potential source of antioxidant compounds,
endowed with good practical applications for human health.
Keywords: α-glucosidase, Antioxidant activity, Chemical composition, Pancreatic lipase inhibition, Rhaponticum
acaule essential oil, Xanthine oxidase