Evaluating Food Additives Based on Organic and Inorganic Salts as Antifungal Agents against Monilinia fructigena and Maintaining Postharvest Quality of Apple Fruit.

A set of commonly used food additives was evaluated for their antifungal activity against the brown rot disease of fruits caused by the fungal pathogen Monilinia fructigena, which is one of the most economically important agents, causing important damage to pome fruits, such as pears and apples. The radial mycelial growth of the fungal pathogen was assessed in PDA amended with different concentrations (0.5, 2, 2.5, and 5%) of each additive. The results underlined that most of the additives displayed a significant inhibition of mycelial growth, with the extent of inhibition varying depending on the specific additive and concentration used. Five food additives showed high inhibition rates (above 88%), of which sodium bicarbonate, sodium carbonate, copper sulphate, and sodium hydroxide were the most effective, whereas ammonium carbonate, magnesium chlorite, and citric acid were the least effective. Interestingly, the coatings containing sodium bicarbonate, copper sulphate, and ammonium bicarbonate significantly reduced the incidence of brown rot disease in apples, but other additives were not effective, such as ammonium carbonate and magnesium sulphate. The anhydrous sodium sulphate used at a concentration of 2%, was found to be one of the least effective additives, with a reduction rate of 20%. Subsequently, food additives showing good growth inhibition rates and reduction in disease severity were then tested in semi-commercial trials at temperatures of 4 °C and 22 °C. The results indicated that these additives demonstrate effectiveness in controlling M. fructigena at specific concentrations, and lower temperatures (4 °C) can improve the efficiency of the control measures. In addition, the selected food additives exhibited significant antimicrobial activity against M. fructigena, suggesting their application as a promising alternative for managing brown rot disease in apple fruits.

Phytochemical Profile, Antioxidant, Antimicrobial, and Antidiabetic Activities of Ajuga iva (L.).

In Morocco, many applications in ethnomedicine on Ajuga iva (L.) have been recognized as able to treat various pathologies such as diabetes, stress, and microbial infections. The objective of this work is to carry out phytochemical, biological, and pharmacological investigations on the extracts of Ajuga iva leaves in order to confirm its therapeutic effects. The phytochemical screening carried out on the different extracts of Ajuga iva showed its richness in primary (lipids and proteins) and secondary metabolites (flavonoids, tannins, reducing compounds, oses, and holoside. The best contents of polyphenols, flavonoids, and tannins evaluated by spectrophotometric methods were found in the hydroethanolic extract (69.850 ± 2.783 mg EAG/g DE, 17.127 ± 0.474 mg EQ/g DE, 5.566 ± 0.000 mg EQC/g DE), respectively. Analysis of the chemical composition of the aqueous extract by LC/UV/MS revealed 32 polyphenolic compounds including ferulic acid (19.06%), quercetin (10.19%), coumaric acid (9.63%), and apigenin-7-(2-O-apiosylglucoside) (6.8%). The antioxidant activity of Ajuga iva extracts was evaluated by three methods (DPPH*, FRAP, CAT). The hydroethanolic extract recorded the strongest reducing power: DPPH* (IC50 = 59.92 ± 0.7 µg/mL), FRAP (EC50 = 196.85 ± 1.54 (µg/mL), and CAT (199.21 ± 0.37 mg EAG/gE). A strong correlation between phenolic compounds and antioxidant activities was confirmed by the determination of Pearson's coefficient. The antimicrobial activity of Ajuga iva studied by the microtiter method revealed potent antifungal and antibacterial qualities against Candida parapsilosis and Staphylococcus aureus BLACT. An in vivo oral glucose tolerance test (OGTT) using normal rats revealed that the antihyperglycemic action of the aqueous extract significantly reduced postprandial hyperglycaemia at (30 min, p < 0.01) and area under the curve (AUC glucose), p < 0.01. Similarly, the aqueous extract, tested on pancreatic α-amylase enzyme activity in vitro and in vivo significantly inhibited pancreatic α-amylase activity with IC50 = 1.52 ± 0.03 mg/mL. In conclusion, the extract from Ajuga iva could be a good source of bioactive molecules, which exhibit potent antioxidant and antimicrobial activity, as well as strong antidiabetic activity, for applications in the pharmaceutical industry.

Identification of Compounds of Crocus sativus by GC-MS and HPLC/UV-ESI-MS and Evaluation of Their Antioxidant, Antimicrobial, Anticoagulant, and Antidiabetic Properties.

In order to valorize the species Crocus sativus from Morocco and to prepare new products with high added value that can be used in the food and pharmaceutical industry, our interest was focused on the phytochemical characterization and the biological and pharmacological properties of the stigmas of this plant. For this purpose, the essential oil of this species, extracted by hydrodistillation and then analyzed by GC-MS, revealed a predominance of phorone (12.90%); (R)-(-)-2,2-dimethyl-1,3-dioxolane-4-methanol (11.65%); isopropyl palmitate (9.68%); dihydro-ß-ionone (8.62%); safranal (6.39%); trans-ß-ionone (4.81%); 4-keto-isophorone (4.72%); and 1-eicosanol (4.55%) as the major compounds. The extraction of phenolic compounds was performed by decoction and Soxhlet extraction. The results of the determination of flavonoids, total polyphenols, condensed tannins, and hydrolyzable tannins determined by spectrophotometric methods on aqueous and organic extracts have proved the richness of Crocus sativus in phenolic compounds. Chromatographic analysis by HPLC/UV-ESI-MS of Crocus sativus extracts revealed the presence of crocin, picrocrocin, crocetin, and safranal molecules specific to this species. The study of antioxidant activity by three methods (DPPH, FRAP, and total antioxidant capacity) has proved that C. sativus is a potential source of natural antioxidants. Antimicrobial activity of the aqueous extract (E0) was investigated by microdilution on a microplate. The results have revealed the efficacy of the aqueous extract against Acinetobacter baumannii and Shigella sp. with MIC ≤ 600 µg/mL and against Aspergillus niger, Candida kyfer, and Candida parapsilosis with MIC = 2500 µg/mL. Measurements of pro-thrombin time (PT) and activated partial thromboplastin time (aPTT) in citrated plasma obtained from routine healthy blood donors were used to determine the anticoagulant activity of aqueous extract (E0). The anticoagulant activity of the extract (E0) studied showed that this extract can significantly prolong the partial thromboplastin time (p < 0.001) with a 359 µg/mL concentration. The antihyperglycemic effect of aqueous extract was studied in albino Wistar rats. The aqueous extract (E0) showed strong in vitro inhibitory activity of α-amylase and α-glucosidase compared with acarbose. Thus, it very significantly inhibited postprandial hyperglycemia in albino Wistar rats. According to the demonstrated results, we can affirm the richness of Crocus sativus stigmas in bioactive molecules and its use in traditional medicine.

Phytochemistry and Biological Activities of Essential Oils from Six Aromatic Medicinal Plants with Cosmetic Properties.

In this work, the chemical composition and antioxidant and antimicrobial activities of the essential oils (EOs) of six species-Laurus nobilis, Chamaemelum nobile, Citrus aurantium, Pistacia lentiscus, Cedrus atlantica, and Rosa damascena-have been studied. Phytochemical screening of these plants revealed the presence of primary metabolites, namely, lipids, proteins, reducing sugars, and polysaccharides, and also secondary metabolites such as tannins, flavonoids, and mucilages. The essential oils were extracted by hydrodistillation in a Clevenger-type apparatus. The yields are between 0.06 and 4.78% (mL/100 g). The analysis of the chemical composition carried out by GC-MS showed the presence of 30 to 35 compounds and represent between 99.97% and 100% of the total composition of EOs, with a variation in the chemical composition detected at the level of the majority compounds between these species. Indeed, in the EO of Laurus nobilis, 1,8-cineole (36.58%) is the major component. In Chamaemelum nobile EO, the most abundant compound is angelylangelate (41.79%). The EO of Citrus aurantium is rich in linalool (29.01%). The EO of Pistacia lentiscus is dominated by 3-methylpentylangelate (27.83%). The main compound of Cedrus atlantica is ß-himachalene (40.19%), while the EO of Rosa damascenaa flowers is rich in n-nonadecane (44.89%). The analysis of the similarity between the EOs of the plants studied by ACH and ACP showed that the chemical composition of the EOs makes it possible to separate these plants into three groups: the first represented by Chamaemelum nobile, because it is rich in oxygenated monoterpenes, the second defined Cedrus atlantica and Rosa damascena, which are rich in sesquiterpenes, and the third gathers Pistacia lentiscus, Laurus nobilis and Citrus aurantium, which are composed of oxygenated sesquiterpenes and monoterpenes (these three species are very close). The study of the antioxidant activity showed that all the EOs tested have a high capacity for scavenging free radicals from DPPH. The EOs of Laurus nobilis and Pistacia lentiscus showed the highest activity, 76.84% and 71.53%, respectively, followed by Cedrus atlantica EO (62.38%) and Chamaemelum nobile (47.98%) then Citrus aurantium EO (14.70%). Antimicrobial activity EO was tested against eight bacterial strains and eight fungal strains; the results showed that EOs exhibit significant bactericidal and fungicidal activities against all the microorganisms tested, of which the MICs of the bacterial strains start with 5 mg/mL, while the MICs of the fungal strains are between 0.60 mg/mL and 5 mg/mL. Thus, these EOs rich in antimicrobial and antioxidant components can serve as a natural alternative; this confirms their use as additives in cosmetics.

Phytochemical Profile, Antioxidant Activity, Anti-Hyperglycemic Effect and Toxicity Assessment of Ridolfia segetum (L.) Moris Extract.

The present work was designed to study the chemical composition, antioxidant, antihyperglycemic effect, and toxicity assessment of Ridolfia segetum (L.) Moris extract. The chemical composition was studied by use of high-performance liquid chromatography (HPLC). Antioxidant power was tested by use of DPPH and FRAP assays. The antihyperglycemic effect was tested by use of a glucose tolerance test, while toxicity assessment was done in vivo by use of Wistar rats for 14 days. Analysis of the extract by HPLC-UV revealed the presence of gallic acid, catechol, vanillic acid, catechin, tannic acid, rosmarinic acid, naringenin, and coumarin acid. The crude hydroethanolic extract possessed high levels of total phenols (15.6 ± 1.76 mg EAG/g), condensed tannins (383.49 mg ECat/g DM), and flavonoid (11.63 mg EQ/g). The findings showed that the studied extract possessed good antioxidant power with IC50 values equal to 550, 650, 700 µg/mL respectively for the decoction, the ethyl acetate fraction (F2M), and the ethyl acetate fraction (F2E). For the antioxidant activity by FRAP, the aqueous fraction (F3E) and the aqueous extract (F4) showed CE50 values of 0.33 mg/mL and 0.4 mg/mL, respectively. Glucose tolerance test analysis showed that R. segetum (L.) Moris decoction had a significant postprandial antihyperglycemic effect in normal Wistar rats. The results of the acute toxicity test showed that the decoction was not toxic even at 2 g/Kg. Pancreatic α-amylase activity was significantly inhibited in the presence of R. segetum (L.) Moris extract (IC50 = 0.133 ± 0.09 mg/mL). The outcome of the present work showed that R. segetum (L.) Moris is very rich in phenolic compounds with potent antioxidant and antihyperglycemic effects.

Phytochemical Analysis, Antimicrobial and Antioxidant Properties of Thymus zygis L. and Thymus willdenowii Boiss. Essential Oils.

Essential oils (EOs) are chemical products produced by odoriferous glands from a variety of plants. These essential oils have many health benefits: antiseptic, anti-inflammatory and antimicrobial activities. So due to these medicinal properties, the present study was designed to analyze essential oils of Thymus zygis L. and Thymus willdenowii Boiss. for their chemical composition and biological activities. These two thyme species were collected from the region of Ifrane, Middle Atlas of Morocco. The EO was obtained by hydrodistillation, and the yields were 5.25% for T. zygis and 3.00% for T. willdenowii. The chemical composition of the EOs was analyzed by gas chromatography coupled with mass spectrometry (GC-MS), and the results showed that T. zygis EO is dominated by carvacrol (52.5%), o-cymene (23.14%), and thymol (9.68%), while the EO of T. willdenowii contains germacrene D (16.51%), carvacrol (16.19%), and geranyl acetate (8.35%) as major compounds. The antioxidant activity assessed by Diphenylpicrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays revealed that both EOs have excellent antioxidant activities; by DPPH it resulted in IC50 = 6.13 ± 0.11 for T. zygis and 6.78 ± 0.3 µg/mL for T. willdenowii, while the one by FRAP yielded EC50 = 2.46 ± 0.01 (T. zygis) and 5.17 ± 0.2 (T. willdenowii) µg/mL. The antimicrobial activity of the two essential oils was evaluated against six bacterial strains and five fungal strains by the disk diffusion method to determine the Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC) and Minimum Fungicidal Concentration (MFC). The EOs revealed variable antimicrobial activities against the different tested microbial strains and showed strong antimicrobial activities, even against strains known as multi-resistant to antibiotics (Acinetobacter baumannii) at low concentrations (2 µL/mL). T. zygis EO showed the most powerful activity against all the studied bacteria, while that of T. willdenowii recorded moderate activity when tested against Shigella dysenteriae and Salmonella Typhi. With inhibition diameters that vary between 75 mm and 84 mm for concentrations of 2 µL/mL up to 12 µL/mL, S. aureus was shown to be the most sensitive to T. zygis EO. For the antifungal activity test, T. zygis EO showed the best inhibition diameters compared to T. willdenowii EO. These results showed that T. zygis EO has more powerful antioxidant and antimicrobial activities than T. willdenowii EO, therefore, we deduce that thyme EOs are excellent antioxidants, they have strong antimicrobial properties, and may in the future represent new sources of natural antiseptics that can be used in pharmaceutical and food industry.