Influence of Extraction Techniques and Solvents on the Antioxidant and Biological Potential of Different Parts of Scorzonera undulata

Abstract

The genus Scorzonera has various medicinal values. Species belonging to this genus were traditionally used as drugs or in food. The current study aimed to determine the phytochemical composition, antioxidant activity, and biological properties of the tuber, leaf, and flower of Scorzonera undulata extracts, collected from the southwest of Tunisia. Phenolic compounds from the three parts were extracted using two solvents (water and ethanol) and two extraction techniques (maceration and ultrasound). The total phenolic content was measured by the Folin–Ciocalteu assay. Furthermore, the chemical composition of Scorzonera undulata extract was also investigated by the LC-ESI–MS method using phenolic acid and flavonoid standards. The variation of the extraction methods induced a variation in the real potentialities of the three parts in terms of bioactive molecules. However, the aerial part of S. undulata (leaves and flowers) showed, in general, the highest phenolic contents. Twenty-five volatile compounds have been detected by GC-MS in S. undulata extracts; among them, fourteen were identified before derivatization. The DPPH test showed that the aerial part of the plant has a higher antioxidant activity compared to the tuber (25.06% at 50 µg/mL for the leaf ethanolic extract obtained by ultrasound extraction). For most biological activities (anti-Xanthine, anti-inflammatory, and antidiabetic (alpha-amylase and alpha-glucosidase)), the aerial parts (flowers and leaves) of the plant showed the highest inhibition than tubers.

Phenolic Profiling, Antioxidant, and Antibacterial Activities of Selected Medicinal Plants from Tunisia

“…Quinic acid reached the highest amount in both decocted extract of M. arvensis (1606.232 mg/kg) and ultrasonic extract of H. tuberculatum (1694.662 mg/kg). Which was in accordance with data found by Benabderrahim et al., [16] Mahmoudi et al., [47] Ben Yakoub et al., [48] Gasmi et al., [23] as well as Idoudi et al [49] . In the same context, both hydroxycinnamic (caffeic acid, p‐ coumaric acid…), hydroxybenzoic acids (gallic acid, protocatechuic acid…) and their derivatives contributed to the overall health improvement.…”

“…The phenolic acid contents varied Quinic acid reached the highest amount in both decocted extract of M. arvensis (1606.232 mg/kg) and ultrasonic extract of H. tuberculatum (1694.662 mg/kg). Which was in accordance with data found by Benabderrahim et al, [16] Mahmoudi et al, [47] Ben Yakoub et al, [48] Gasmi et al, [23] as well as Idoudi et al [49] In the same context, both hydroxycinnamic (caffeic acid, pcoumaric acid…), hydroxybenzoic acids (gallic acid, protocatechuic acid…) and their derivatives contributed to the overall health improvement. According to their various therapeutic activities including antioxidant, anti-inflammatory, hypoglycemic, Alzheimer's disease and other brain dysfunctions, as well as prevention of cancer and cardiovascular diseases.…”

Chemical Composition, Antioxidant, and Anti-Diabetic Activities of Scorzonera phaeopappa Boiss

“…Idoudi et al (2023) tested the antidiabetic activity of the different parts (flowers, leaves, and tubers) of Scorzonera undulata using anti-alpha-glucosidase and anti-alphaamylase essays, using acarbose (50 µg/mL) as a reference. The results showed that the best inhibitory results of α-glucosidase were those of the aqueous flower extract obtained by ultrasound, with the percentage ranging from 0% to 9.77%, while for the α-amylase the inhibition percentage of the aqueous tuber extract obtained by maceration (50 µg/L) was the highest and ranged from 0% to 31.34% [15].…”

“…Medicinal plants and herbal extracts that are rich in polyphenols have been reported to demonstrate antioxidant and potential antidiabetic activities [12]. However, to the best of our knowledge, only a few recent studies have been conducted to determine the antidiabetic activity of any of the Scorzonera species [13][14][15][16][17], despite the fact that S. semicana DC has been used to treat diabetes mellitus in Turkish traditional medicine [18].…”