Medicinal plants offer imperative sources of innovative chemical substances with important potential therapeutic effects. Among them, the members of the genus Inula have been widely used in traditional medicine for the treatment of several diseases. The present study investigated the antioxidant (DPPH, ABTS and FRAP assays) and the in vitro anti-hyperglycemic potential of aerial parts of Inula viscosa (L.) Aiton (I. viscosa) extracts through the inhibition of digestive enzymes (α-amylase and α-glucosidase), responsible of the digestion of poly and oligosaccharides. The polyphenolic profile of the Inula viscosa (L.) Aiton EtOAc extract was also investigated using HPLC-DAD/ESI-MS analysis, whereas the volatile composition was elucidated by GC-MS. The chemical analysis resulted in the detection of twenty-one polyphenolic compounds, whereas the volatile profile highlighted the occurrence of forty-eight different compounds. Inula viscosa (L.) Aiton presented values as high as 87.2 ± 0.50 mg GAE/g and 78.6 ± 0.55mg CE/g, for gallic acid and catechin, respectively. The EtOAc extract exhibited the higher antioxidant activity compared to methanol and chloroform extracts in different tests with (IC50 = 0.6 ± 0.03 µg/mL; IC50 = 8.6 ± 0.08 µg/mL; 634.8 mg ± 1.45 AAE/g extract) in DPPH, ABTS and FRAP tests. Moreover, Inula viscosa (L.) Aiton leaves did show an important inhibitory effect against α-amylase and α-glucosidase. On the basis of the results achieved, such a species represents a promising traditional medicine, thanks to its remarkable content of functional bioactive compounds, thus opening new prospects for research and innovative phytopharmaceuticals developments.
The Moroccan flora is rich in medicinal plants that are commonly used in folk medicine for the treatment of various diseases. The present study was designed to investigate the total phenolic and flavonoid contents, as well as the antioxidant properties of leaves extracts from Globularia alypum L. colected from the Taza region in northeast Morocco. Additionally, the individual phenolics and volatiles of the extracts were also evaluated. The organic extracts of this plant were obtained by Soxhlet extraction using two different solvents, namely ethyl acetate and chloroform. The antioxidant capacity of leaves extracts was measured using DPPH, ABTS and FRAP assays; the phenolic profile was determined by HPLC-DAD/ESI-MS analysis, whereas the volatile composition was elucidated by GC-MS. The ethyl acetate extract analysis showed a total of 20 phenolic compounds and the determination of phenolic contents showed a significant value of 56.5 ± 0.61 µg GAE/mg of extract in comparison with the chloroform extract (18.9 ± 0.48 µg GAE/mg of extract). Also, the determination of the flavonoid contents revealed that the ethyl acetate extract contained the highest value (30.2 ± 0.55 µg CE/mg of extract) in comparison with the chloroform extract (18.0 ± 0.36 µg CE/mg of extract). Concerning the antioxidant properties, interesting values were attained for the ethyl acetate extract which exhibited higher antioxidant activity, namely IC50 = 12.3 ± 3.83 µg/mL and IC50 = 37.0 ± 2.45 µg/mL for the DPPH and ABTS assays, respectively, whereas a value of 531.1 ± 17.08 (mg AAE/g DW) was obtained for the FRAP assay. Concerning the volatile profile, a total of 73 compounds were positively detected and among them n-hexadecanoic acid (13.5%) was the most abundant one. The results achieved confirm the important role of this plant as a source of natural antioxidants.
The present work was designed to investigate the effects of different extraction processes, namely ultrasonic-assisted, supercritical fluid, microwave-assisted and Soxhlet applied to carob pods. The total phenolic quantification and the antioxidant activity were assessed by the means of rapid in vitro spectrophotometric assays; the phenolic profile was identified using ultra-high performance liquid chromatography coupled to mass spectrometry. The results revealed that the phenolic compounds and the antioxidant capacity varied significantly with the nature of the extraction process. The content of total phenolic compounds ranged from 11.55 to 34.38 mg GAE/g DW; the content of total flavonoids varied from 3.50 to 10.53 mg QE/g DW, and the content of condensed tannins fluctuated from 3.30 to 6.55 mg CE/ g DW. All extracts performed differently on antioxidant activity when determined by the DPPH assay producing a dose-dependent response, with IC50 extended from 11.33 to 6.07 µg/mL. HPLC analysis enabled the identification of nine compounds. As a function of the studied extraction methods, the phenolic compound contents were positively correlated with antioxidant activity.
3 November 2022 in Journal of Food Measurement and Characterization
Azadirachta indica , commonly known as neem or Mim in Chad, is recognized for its significant biological activities and is used for medicinal purposes. This study quantifies phenolic content, analyzes chemical composition via high-performance liquid chromatography–mass spectrometry, and evaluates the antioxidant activity of Mim leaf extracts with ethanol (ELE) and water (WLE). The analysis identified bioactive compounds with strong radical scavenging activity and conducted in silico studies by molecular docking with AutoDock Tools. Crystal structures were sourced from the Protein Data Bank, and the Swiss absorption, distribution, metabolism, and excretion platform analyzed the pharmacokinetic properties. Results indicated that WLE had a higher phenolic content (264.7 ± 0.03 µg gallic acid equivalent [GAE]/mg) compared to ELE (135.3 ± 0.05 µg GAE/mg). Flavonoid content was greater in ELE (138.33 ± 0.002 µg catechin equivalent [CE]/mg) than in WLE (83.38 ± 0.002 µg CE/mg). Major compounds identified through high-performance liquid chromatography coupled to mass spectrometry included diethyl phthalate in ELE (92.31%) and butylated hydroxytoluene (BHT) in WLE (28.12%). Antioxidant activities measured by 2,2-di-phenyl-1-picrylhydrazyl, 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid), and ferric-reducing power assays showed promising results for both extracts. BHT demonstrated a better affinity for glutathione reductase and lipoxygenases, while vanillin showed a strong affinity for cyclooxygenase. Most compounds exhibited high intestinal absorption and are not P-glycoprotein substrates, indicating potential for oral medication. Finally, Mim extracts contain diverse compounds that contribute to their notable antioxidant activity.