Effect of Flavoring with Rosemary, Lemon and Orange on the Quality, Composition and Biological Properties of Olive Oil: Comparative Study of Extraction Processes.

The goal of this work was to investigate the impact of the flavoring of some aromatic plants/spices, including rosemary (R), lemon (L) and orange (O) at the concentration of 5% and 35% (w/w) added by 2 methods (conventional maceration and direct flavoring), on quality attributes, chemical changes and oxidative stability of extra virgin olive oil (EVOO). Six flavored oils were obtained (EVOO + O, O + O, EVOO + R, O + R, EVOO + L and O + L). The physicochemical parameters (water content, refractive index, acidity and peroxide value, extinction coefficient, fatty acids, volatile aroma profiles, Rancimat test, phenols and pigments composition) of the flavored oils were investigated. Based on the results obtained, it was observed that flavoring with a conventional process provided increased oxidative stability to the flavored oils, especially with rosemary (19.38 ± 0.26 h), compared to that of unflavored oil. The volatile profiles of the different flavored oils revealed the presence of 34 compounds with the dominance of Limonene. The fatty acid composition showed an abundance of mono-unsaturated fatty acids followed by poly-unsaturated ones. Moreover, a high antioxidant activity, a significant peripheral analgesic effect (77.7% of writhing inhibition) and an interesting gastroprotective action (96.59% of ulcer inhibition) have been observed for the rosemary-flavored oil. Indeed, the flavored olive oils of this study could be used as new functional foods, leading to new customers and further markets.

Chemical characterization and nutritional quality investigations of healthy extra virgin olive oil flavored with chili pepper.

The production of extra virgin olive oil (EVOO) flavored with diverse spices, herbs, fruits, and vegetables or natural aromas is believed to provide advantageous properties considering either the high nutritional value or biological activity in addition to the flavoring and industrial aspects. The biological activities including antioxidant and antimicrobial properties of Tunisian EVOO obtained from "Chemlali" variety and mixed with chili pepper were investigated. Molecular analyses, including the detection of twelve olive-infecting viruses and Pseudomonas savastanoi pv savastanoi, were performed to ensure that the samples were obtained from healthy olive trees and EVOO quality was not affected. Quality parameters like free acidity, peroxide number, oxidative stability, and specific absorption at K232 nm and K270 nm were also investigated and no significant variation was revealed. The content of minor compounds such as chlorophylls, carotenoids, and total phenols showed minor changes. However, the profiles of the volatile compounds showed remarkable differences, which appeared to be the main factor for the observed variability in consumer acceptance. The results showed for the first time high quantities of polyphenols and ortho-diphenols. Four colorimetric methods were used for the determination of the antioxidant activity, namely DPPH, ABTS, FRAP, and ß-carotene test. Compared to the control, a higher level of antioxidant activity was observed for the flavored EVOO. Furthermore, significant results were obtained in the antimicrobial tests. The quality parameters of the mixture showed no alteration compared to the control. Finally, all the measurements and the chemical characterization gave a scientific basis for food technology innovation of new food products.

Antioxidant, antimicrobial and phytotoxic activities of Rhaponticum acaule DC essential oil

The in-vitro antioxidant activity of Rhaponticum acaule essential oil (RaEO) was evaluated using ß-carotene/linoleic acid bleaching, chelating activity, and lipid peroxidation inhibition (TBARS) assays. The antimicrobial activity of RaEO was assessed by disc diffusion and microdilution methods against 8 bacteria and 4 yeast. Finally, the allelopathic activity of RaEO on the seed germination and the shoot and root elongation of lettuce (Lactuca sativa L.) seedlings were investigated. According to our results, the RaEO exhibited significant antioxidant activity, similar to those of standards (BHT and ascorbic acid) with IC50 values of 0.042 and 0.045 mg/mL obtained by ß-carotene bleaching and TBARS assays, respectively. On the other hand, despite its interesting ferrous chelating activity, RaEO possesses moderate IC50 value (0.35 mg/mL) as compared with that of EDTA (0.015 mg/mL). RaEO exhibited a strong antimicrobial activity against all the tested microorganisms, with IZ, MIC and MBC values being in the range of 7.67 ± 0.58 to 13.33 ± 0.58 mm, 1.25 to 5.00 and 5.00 to 10.00 mg/mL, respectively. The results reveled also that RaEO inhibited the shoot and root growth of Lactuca sativa L. seedlings. Our data suggested that the RaEO had pharmaceutical benefits and could be used as a potential natural herbicide resource

Biological Activities Evaluation of Enantiopure Isoxazolidine Derivatives: In Vitro, In Vivo and In Silico Studies.

A series of enantiopure isoxazolidines (3a-c) were synthesized by 1,3-dipolar cycloaddition between a (-)-menthone-derived nitrone and various terminal alkenes. The screened compounds were evaluated for their antioxidant activity by two in vitro antioxidant assays, including ß-carotene/linoleic acid bleaching, and inhibition of lipid peroxidation (thiobarbituric acid reactive species, TBARS). The results revealed that compound 3b (EC50 = 0.55 ± 0.09 mM) was the most potent antioxidant as compared to the standard drug (EC50 = 2.73 ± 0.07 mM) using the TBARS assay. Furthermore, the antimicrobial activity was assessed using disc diffusion and microdilution methods. Among the synthesized compounds, 3c was found to be the most potent antimicrobial agent as compared to the standard drug. Subsequently, the acute toxicity study has also been carried out for the newly synthesized compounds and the experimental studies revealed that all compounds were safe up to 500 mg/kg and no death of animals were recorded. The cytotoxicity of these compounds was assessed by the MTT cell proliferation assay against the continuous human cell lines HeLa and compound 3c (GI50 = 46.2 ± 1.2 µM) appeared to be more active than compound 3a (GI50 = 200 ± 2.8 µM) and 3b (GI50 = 1400 ± 7.8 µM). Interestingly, all tested compounds displayed a good α-amylase inhibitory activity in competitive manner with IC50 values ranging between 23.7 and 64.35 µM when compared to the standard drug acarbose (IC50 = 282.12 µM). In addition, molecular docking studies were performed to understand the possible binding and the interaction of the most active compounds to the α-amylase pocket.

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

BACKGROUND: α-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. METHODS: The 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. RESULTS: The result revealed the presence of 26 compounds (97.4%). The main constituents include germacrene D (49.2%), methyl eugenol (8.3%), (E)-ß-ionone (6.2%), ß-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. CONCLUSION: The results revealed that the RaEO is a new promising potential source of antioxidant compounds, endowed with good practical applications for human health.

Revalorization of wild Asparagus stipularis Forssk. as a traditional vegetable with nutritional and functional properties.

The nutritional values and phytochemical composition of young shoots of wild Asparagus stipularis Forssk. from Tunisia were determined in this study. The antioxidant (tested by four different in vitro assays) and antiproliferative properties (against human tumour cell lines) of aqueous and hydroalcoholic extracts of the young shoots were also investigated. The obtained results indicated that the young shoots are a potential source of valuable nutrients and dietary fiber, and their hydroalcoholic extract showed marked antioxidant and antiproliferative activities in all tested assays. The major phenolic compound, characterized by using a high-performance liquid chromatograph coupled with diode-array and mass spectrometer detectors, in both extracts was diferuloyl glycerol. Our results reinforce the interest in recovering the traditional culinary uses of this wild plant, with potential functional properties, which can be included in the modern diet as an alternative to the variety of vegetables normally used.

Hepatoprotective effect of Opuntia microdasys (Lehm.) Pfeiff flowers against diabetes type II induced in rats.

Opuntia sp. has long been used as a folk medicine to treat hepatitis and diabetes in Sicile (Italy). To extract the polyphenols from the flower of Opuntia microdasys Lehm. at post flowring stage and evaluate the antidiabetic activity in vitro and in vivo. The hepatoprotective activity of Opuntia microdasys aqueous flowers extract at post flowering stage (OFP) has been tested for their antidiabetic activity. On fructose-alloxan induced diabete in rat model, evaluating the inhibitory effects of OFP on some carbohydrate metabolizing enzymes, pancreatic α-amylase and intestinal α-glucosidase activities in vitro. The OFP extract showed inhibitory activity against α-glucosidase (IC50=0.17±0.012mg/ml) and α-amylase (IC50=2.55±0.41mg/ml). The inhibitory potential of OFP extract on these enzymes suggests a positive and probable role of this extract in the management and treatment of diabetes mellitus, particularly, for type 2. Oral administration of the OFP at 200mg/kg to diabetic male rats for 28days demonstrated a significant protective effect by lowering the levels of glucose (123.21±1.38mg/dL) and hepatic marker enzymes (AST, ALT, LDH, γ-GT, BT, PAL, TC, LDL-C, HDL-C and TG). OFP attenuated oxidative stress by decreasing the SOD, CAT, GPX activity and the levels of PC and MDA in the liver and restored the histological architecture of the rat liver. OFP has protective effects on the protection of liver, thereby reducing some of the causes of diabetes in experimental animals.

Characterisation of phenolic antioxidants in Scabiosa arenaria flowers by LC-ESI-MS/MS and NMR.

OBJECTIVES: This work describes the bioguided fractionation of the flower's ethyl acetate fraction of Scabiosa arenaria Forssk. (Dipsacaceae). METHODS: The identification of the pure compound isolated has been studied by mono-dimensional NMR experiments. The mixture of phenolic compounds was analysed by LC-ESI-MS/MS. The antioxidant activity has been evaluated by the 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay. KEY FINDINGS: The bioguided fractionation of the flower's ethyl acetate fraction of Scabiosa arenaria led to the isolation of a pure compound: luteolin. The mixture of three phenolic compounds was identified as: 1, 4-O-dicaffeoylquinic acid, apigenin 7-O-glucoside and luteolin-7-O-glucoside. Two of which are reported here for the first time in Scabiosa genus. Luteolin had the highest antioxidant activity with an IC50 value of 0.02 ± 0.007 mg/ml, followed by the three phenolic compounds with an IC50 value of 0.025 ± 0.008 mg/ml. CONCLUSIONS: The results of the present work indicate that S. arenaria flower's ethyl acetate extract could be used as natural antioxidant agents in food preservation and human health.