Rhaponticum acaule (L) DC essential oil: chemical composition, in vitro antioxidant and enzyme inhibition properties

Abstract

Backgroundα-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.MethodsThe 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.ResultsThe 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.ConclusionThe results revealed that the RaEO is a new promising potential source of antioxidant compounds, endowed with good practical applications for human health.

Fatty Acid and Phytosterol Composition, and Biological Activities of Lycium ruthenicum Murr. Seed Oil

“…Mosbah et al. () have previously reported that rhaponticum acaule (L) DC essential oil had pancreatic lipase inhibitory activity with IC 50 ranging between 20.9 and 25.9 mg/mL. Zhang and Lu () have also reported that petroleum ether extract from Cleistocalyx operculatus flower buds show high pancreatic lipase inhibitory activity with IC 50 of 38.65 μg/mL.…”

Therapeutic Potential of β-Caryophyllene: A Dietary Cannabinoid in Diabetes and Associated Complications

“…var. pungens [ 89 ], Rhaponticum acaule (L.) DC [ 90 ], Acacia mollissima and Acacia cyclops [ 91 ] and Neolitsea kedahense Gamble [ 92 ] and Senna podocarpa (Guill. and Perr.)…”

“…[ 93 ] containing BCP as a major constituent have shown α-glucosidase inhibitory activity. The essential oils obtained from the seeds, flowers, leaves, and/or stems of these plants characterized to contain BCP as one of the major components and attributed to display potent free radical scavenging, xanthine oxidase inhibition, metal chelating, and antioxidant activities, in addition to inhibition of α-glucosidase [ 90 ]. These plants rich in BCP were suggested useful in T2DM, obesity, and hyperlipidemia in many studies [ 90 ].…”

“…BCP present in numerous plants such as Ferulago nodosa (L.) Boiss. [ 98 ], Rhaponticum acaule (L.) DC [ 90 ], Artemisia annua [ 99 ], Ocimum kilimandscharicum [ 100 ], Pinus massoniana L. [ 101 ] has been attributed to exert lipase inhibitory activity. One of the important lipase inhibitors used clinically in obesity and T2DM prevention is orlistat reported to display numerous side effects like alteration in liver enzymes, fecal urgency and incontinence, and steatorrhea.…”

Selected essential oils and their mechanisms for therapeutic use against public health disorders. An overview

“…Compared to positive control tetrahydrolipstatin (IC 50 0.16 mg/mL), RAEO was less potent. These promising results, especially α-glucosidase inhibition, make RAEO interesting as a treatment of metabolic disorders like type 2 diabetes [59].…”