Phenolic Compound, Antioxidant, Antibacterial, and In Silico Studies of Extracts from the Aerial Parts of Lactuca saligna L.

Medicinal plants are considered a major source for discovering novel effective drugs. To our knowledge, no studies have reported the chemical composition and biological activities of Moroccan Lactuca saligna extracts. In this context, this study aims to characterize the polyphenolic compounds distributed in hydro-methanolic extracts of L. saligna and evaluate their antioxidant and antibacterial activities; in addition, in silico analysis based on molecular docking and ADMET was performed to predict the antibacterial activity of the identified phenolic compounds. Our results showed the identification of 29 among 30 detected phenolic compounds with an abundance of dicaffeoyltartaric acid, luteolin 7-glucoronide, 3,5-di-O-caffeoylquinic acid, and 5-caffeoylquinic acid with 472.77, 224.30, 196.79, and 171.74 mg/kg of dried extract, respectively. Additionally, antioxidant activity assessed by DPPH scavenging activity, ferric reducing antioxidant power (FRAP) assay, and ferrous ion-chelating (FIC) assay showed interesting antioxidant activity. Moreover, the results showed remarkable antibacterial activity against Escherichia coli, Salmonella typhimurium, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus, and Listeria monocytogenes with minimum inhibitory concentrations between 1.30 ± 0.31 and 10.41 ± 0.23 mg/mL. Furthermore, in silico analysis identified three compounds, including Apigenin 7-O-glucuronide, Quercetin-3-O-glucuronide, and 3-p-Coumaroylquinic acid as potent candidates for developing new antibacterial agents with acceptable pharmacokinetic properties. Hence, L. saligna can be considered a source of phytochemical compounds with remarkable activities, while further in vitro and in vivo studies are required to explore the main biological activities of this plant.

HPLC-PDA/ESI-MS Analysis of Phenolic Compounds and Bioactivities of the Ethanolic Extract from Flowers of Moroccan Anacyclus clavatus.

In this work, polyphenols were extracted from Anacylus clavatus flowers using a hydroethanolic solvent, and the obtained extract was studied for its total phenol and flavonoid contents and evaluated for its antioxidant and antibacterial capacities. The contents of total phenols and flavonoids were measured by employing gallic acid and quercetin as references, respectively, and the phenolic composition analysis was conducted using high-performance liquid chromatography combined with a photodiode array and electrospray ionization mass spectrometry (HPLC-PDA/ESI-MS). The antioxidant capacity of the extracts was tested using a potassium ferric reducing antioxidant power (PFRAP) assay, and the antibacterial activity assay was carried out against Gram-negative bacteria (Escherichia coli and Salmonella typhimirium) and Gram-positive bacteria (Staphyloccocus aureus and Listeria monocytogenes) using the broth microdilution assay. The phenolic and flavonoid contents of the extracts equaled 9.53 ± 0.48 mg GAE/g dm and 1.31 ± 0.06 mg QE/g dm, respectively. The chromatographic analysis of the phenolic profile detected 26 phenolic compounds belonging to phenolic acids, flavones and flavonols, and with the caffeoylquinic acid derivatives being the major phenolic compounds present in 12 isomers. Only one organic compound, viz. citric acid, was found. The extracts exhibited interesting antioxidant activity. Bacteriostatic activity towards Escherichia coli and bactericidal activity against Salmonella typhimirium, Staphyloccocus aureus and Listeria monocytogenes were determined. This study revealed that Anacyclus clavatus flower extracts contain phenolic compounds with interesting bioactivities.

Chemical Composition, Antifungal and Anti-Biofilm Activities of Volatile Fractions of Convolvulus althaeoides L. Roots from Tunisia.

The antifungal drugs currently available and mostly used for the treatment of candidiasis exhibit the phenomena of toxicity and increasing resistance. In this context, plant materials might represent promising sources of antifungal agents. The aim of this study is to evaluate for the first time the chemical content of the volatile fractions (VFs) along with the antifungal and anti-biofilm of Convolvulus althaeoides L. roots. The chemical composition was determined by gas chromatography coupled to a flame ionization detector and mass spectrometry. In total, 73 and 86 chemical compounds were detected in the n-hexane (VF1) and chloroform (VF2) fractions, respectively. Analysis revealed the presence of four main compounds: n-hexadecenoic acid (29.77%), 4-vinyl guaiacol (12.2%), bis(2-ethylhexyl)-adipate (9.69%) and eicosane (3.98%) in the VF extracted by hexane (VF1). n-hexadecenoic acid (34.04%), benzyl alcohol (7.86%) and linoleic acid (7.30%) were the main compounds found in the VF extracted with chloroform (VF2). The antifungal minimum inhibitory concentrations (MICs) of the obtained fractions against Candida albicans, Candida glabrata and Candida tropicalis were determined by the micro-dilution technique and values against Candida spp. ranged from 0.87 to 3.5 mg/mL. The biofilm inhibitory concentrations (IBF) and sustained inhibition (BSI) assays on C. albicans, C. glabrata and C. tropicalis were also investigated. The VFs inhibited biofilm formation up to 0.87 mg/mL for C. albicans, up to 1.75 mg/mL against C. glabrata and up to 0.87 mg/mL against C. tropicalis. The obtained results highlighted the synergistic mechanism of the detected molecules in the prevention of candidosic biofilm formation.

Determination of the polyphenolic content of Ammodaucus leucotrichus Cosson and Durieu by liquid chromatography coupled with mass spectrometry and evaluation of the antioxidant and antiglycation properties.

Ammodaucus leucotrichus Cosson and Durieu, known as Sahara cumin, is a plant belonging to the Apiaceae family with a very strong smell of anise growing in the maritime sands in the countries of North Africa. The present work aims to study the polyphenolic profile of its seeds hydroalcoholic extract along with the determination of the antioxidant and antiglycation properties. The phytochemical screening revealed the presence of 16 compounds, out of which 15 have been detected in this extract for the first time. Luteolin-glucoside turned out to be the most abundant one (281.32 ± 0.34 mg/kg), followed by apigenin-hexoside (235.06 ± 0.29 mg/kg) and luteolin (202.41 ± 0.40 mg/kg). In terms of antioxidant activity, a half-maximal inhibitory concentration value as high as 0.39 ± 0.003 mg AAE/ml (w/v) was attained. Further, the antiglycation activity was determined to yield interesting results: at a concentration of 1.5 mg/ml, the extract showed an antiglycation activity (%I) of 61.86 compared to metformin as a positive control (%I = 84.01); on the other hand, increasing the concentration to 10 mg/ml, the inhibition activity switched to advanced glycation end products formation activation (%I = 41.71).

Dittrichia viscosa L. Leaves: A Valuable Source of Bioactive Compounds with Multiple Pharmacological Effects.

This work focused on the leaves of Dittrichia viscosa, a plant used in Mediterranean folk medicine. Compared to water extract, the methanolic extract had higher antioxidant effects. Moreover, this extract showed potent in vitro inhibitory activity against α-amylase and α-glucosidase and showed an interesting antiglycation effect. Additionally, the evaluation of the cytotoxic activity of the methanolic extract against two human breast cancer cell lines, MCF-7 and MDA-MB-468, was very promising, with no cytotoxicity towards normal cells (peripheral blood mononuclear cells (PBMCs). The antibacterial effect was also assessed and showed potent inhibitory activity against Proteus mirabilis and Bacillus subtilis. On the other hand, Dittrichia viscosa leaves were rich in macro-elements containing appropriate micro-elements and high levels of phenolics and flavonoids such as caffeic acid derivatives. Taken together, the results obtained in this study indicate that Dittrichia viscosa could constitute a valuable source of bioactive molecules and could be used either on the preventive side or for therapeutic applications without toxicity.

The Digestibility of Hibiscus sabdariffa L. Polyphenols Using an In Vitro Human Digestion Model and Evaluation of Their Antimicrobial Activity.

Hibiscus sabdariffa L. (H.s.) is a polyphenolic-rich plant commonly consumed either as a beverage or spice. The aim of the present study was to evaluate the in vitro digestibility of H.s. polyphenols using an in vitro model of digestion which simulates the human stomach and small intestine. The bioaccessible polyphenols released in the digested samples were analyzed by liquid chromatography coupled to photodiode array and mass spectrometry detection. H.s. anthocyanins (cyanidin-3-O-sambubioside and delphinidin-3-O-sambubioside) content drastically dropped during the digestion process from 2.91 ± 0.03 µg g-1 and 8.53 ± 0.08 µg g-1 (w/w) CG (Cyanidin-glucoside) in the raw extract, respectively, to 0.12 ± 0.01 µg g-1 0.12 ± 0.01 µg g-1 (w/w) CG at the end of duodenal digestion. Total polyphenols also have shown a decrease from 1192.65 ± 30.37 µg g-1 (w/w) in the raw extract to 282.24 ± 7.21 µg g-1 (w/w) by the end of gastric digestion, in contrast to their increase by the end of duodenal digestion 372.91 ± 3.97 µg g-1 (w/w). On the other hand, the decrease in certain compounds (e.g., caffeoylquinicandcoumaroylquinic acids) was observed during gastric digestion resulting in an increase of quinic acid in the duodenal aliquots, thus suggesting that this compound was derived from the degradation of the more complex hydroxycinnamic acids. H.s. extract also exhibited a bacteriostatic effect against Staphylococcus aureus ATCC 6538 (MIC of 2.5 mg mL-1) and a bactericidal effect against a food isolate of Listeria monocytogenes (MBC of 2.5 mg mL-1). The undigested polyphenols of H.s. in the upper gastrointestinal tract enters the colon, where they are metabolized by the gut microbiota. The present study results showed that resistance of H.s. polyphenols during gastrointestinal digestion might affect their uptake, resulting in a decrease in their digestibility.

Elucidation of Antioxidant Compounds in Moroccan Chamaerops humilis L. Fruits by GC-MS and HPLC-MS Techniques.

The aim of this study was to characterize the phytochemical content as well as the antioxidant ability of the Moroccan species Chamaerops humilis L. Besides crude ethanolic extract, two extracts obtained by sonication using two solvents with increased polarity, namely ethyl acetate (EtOAc) and methanol-water (MeOH-H2O) 80:20 (v/v), were investigated by both spectroscopy and chromatography methods. Between the two extracts, the MeOH-H2O one showed the highest total polyphenolic content equal to 32.7 ± 0.1 mg GAE/g DM with respect to the EtOAc extract (3.6 ± 0.5 mg GAE/g DM). Concerning the antioxidant activity of the two extracts, the EtOAc one yielded the highest value (1.9 ± 0.1 mg/mL) with respect to MeOH-H2O (0.4 ± 0.1 mg/mL). The C. humilisn-hexane fraction, analyzed by GC-MS, exhibited 69 compounds belonging to different chemical classes, with n-Hexadecanoic acid as a major compound (21.75%), whereas the polyphenolic profile, elucidated by HPLC-PDA/MS, led to the identification of a total of sixteen and thirteen different compounds in both EtOAc (major component: ferulic acid: 104.7 ± 2.52 µg/g) and MeOH-H2O extracts (major component: chlorogenic acid: 45.4 ± 1.59 µg/g), respectively. The attained results clearly highlight the potential of C. humilis as an important source of bioactive components, making it a valuable candidate to be advantageously added to the daily diet. Furthermore, this study provides the scientific basis for the exploitation of the Doum in the food, pharmaceutical and nutraceutical industries.

Phytochemical Investigation and Antioxidant Activity of Globularia alypum L.

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.