Context: More than 500 Centaurea species compose the Asteraceae family, and most of the recent studies made on the species of this genus proved their pharmacological potential, especially to treat chronic illnesses. Aims: To evaluate for the first time the antioxidant, anti-inflammatory, neuroprotective and anti-microbial properties of the n-butanol (n-BuOH) and ethyl acetate (EA) extracts of the aerial part of Centaurea tougourensis. Methods: The antioxidant activity was determined by ABTS, galvinoxyl radical, phenanthroline, and reducing power assays, while the anti-inflammatory effects were assessed by heat-induced hemolysis and egg albumin denaturation assays. The neuroprotective activity was assessed against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) and the anti-microbial activity by the agar disk diffusion method. Results: Both extracts possess a great antioxidant capacity, but it was considered higher in the n-BuOH extract with respective IC50 values of 8.04 ± 0.21 μg/mL in ABTS assay and 4.25 ± 0.6 μg/mL in GOR assay, while the A0.50 values were 4.46 ± 0.55 μg/mL in phenanthroline assay and 11.16 ± 0.64 μg/mL in reducing power assay. The n-BuOH extract also showed a remarkable anti-inflammatory activity with an EC50 of 120.81 ± 0.2 μg/mL in egg albumin denaturation assay and 154.15 ± 0.14 μg/mL in heat-induced hemolysis assay. The neuroprotective activity of the n-BuOH extract was very strong in both AChE and BChE inhibitory assays with respective IC50 values of 9.8 ± 0.62 μg/mL and 173.53 ± 0.04 μg/mL. EA extract was more active on microbial strains. Conclusions: These encouraging results showed once again the pharmacological potential of Centaurea species.

Nowadays, plants bioactive compounds are considered as a new source of therapy, especially for the elaboration process of more effective drugs. 80% of the actual drug substances are purely natural and originate from plants, representing a new hope, especially for the treatment of chronic illnesses. The aim of this study is to characterize the phytochemical composition of C. tougourensis via gas chromatography-mass spectrometry (GC-MS) approach. This method allowed the identification of 45 compounds in the n-butanol extract (n-BuOH), in which 12 compounds were in majority, namely; 2H-Furo [2,3-b] indole, 3,3a,8,8atetrahydro-2,3-dimethyl- (16.12%), Benz [c] pyran-1,3-dione, 4,4-dimethyl- (14.87%), Octadecanoic acid,9-oxo-, methyl ester (9.69%), Hydromorphone (7.94%), Acetamide, N-[3-[2-(2,3-dihydro-3-hydroxy-2-oxo-3-indolyl)-1-oxoethyl]p (6.14%), 2,6-Di-n-propyl-4-(2-furyl)pyridine (6.11%), Norhydrocodone (5.98%), Anthracene, 1,2,3,4,5,6,7,8-octahydro- (4.72%), 2,4,6-Trimethylbenzonitrile, N-oxide (4.47%), 3-O-Methyl-d-glucose (2.94%), 3,5-Diethyl-4-(2-furyl) pyridine (2.75%) and 3H-Pyrrolo [3,2-f] quinoline, 5-methoxy-1,2,7,9-tetramethyl- (2.30%). Concerning the ethyl acetate (EA) extract; 23 compounds were identified, in which 13 compounds were in majority, namely; [Bi-1,4-cyclohexadien-1-yl]-3,3,′6,6′-tetrone, 4,4′-dihydroxy-2,2,′5,5′-tetramethyl- (27.31%), Thiosulfuric acid, S-(2-aminoethyl) ester (15.07%), 2-Pentadecanone, 6,10,14-trimethyl- (8.91%), 3-Methyl-4-(phenylthio)-2-prop-2-enyl-2,5-dihydrothiophene 1,1-dioxide (7.12%), Tetrapentacontane, 1,54-dibromo- (5.74%), Heptacos-1-ene (5.03%), Propionic acid, 3-iodo-, tetradecyl ester (4.92%), 2-Methyl-E-7-octadecene (4.68%), 7,8-Epoxylanostan-11-ol, 3-acetoxy- (3.65%), 4-Fluoro-1-methyl-5-carboxylic acid, ethyl(ester) (3.15%), Tetrapentacontane, 1,54-dibromo- (2.79%), Undec-10-ynoic acid, tetradecyl ester (2.77%), 3,7,11,15-Tetramethyl-2-hexadecen-1-ol (2.72%).

Purpose: To determine the anti-inflammatory and anti-ulcer properties of the aerial parts of Centaurea tougourensis Boiss. & Reut. Methods: The effects of n-butanol (n-BuOH) extract of the aerial part of Centaurea tougourensis on carrageenan-induced paw edema and ethanol-induced gastric mucosal damage were determined at 2 doses (200 and 400 mg/kg, po) in a mouse model. For each test, the animals were randomly divided into negative and positive control groups, as well as extract-treated groups. The mice were observed for any sign of inflammation for a period of 24h. Results: Reduction of paw edema by C. tougourensis extract was highly significant (p < 0.001) at a dose of 400 mg/kg 24 h after carrageenan injection, with 55.26 % inhibition, followed very closely by 53.15 % inhibition at the dose of 200 mg/kg; indomethacin group showed an inhibition of 60 %. Histological examination supported the inhibition results. A significant reduction in inflammation by the extract at a dose of 400 mg/kg was also observed. No sign of ulcer was observed with C. tougourensis at the two doses (200 and 400 mg/kg). The total polyphenol content of the n-BuOH extract was 85.44 цg gallic acid equivalent/mg of extract. Tannins were the most abundant fraction (51.87 цg tannic acid equivalent/mg of extract), followed by flavonoids (25.55 цg quercetin equivalent/mg of extract). Conclusion: The results indicate that C. tougourensis may have potential beneficial effects in the treatment of diseases associated with inflammation and pain, besides its protective effect on the gastrointestinal tract.

The effect of three doses of UV-C radiation (1, 3 and 6 kJ m−2) on conservation potential after harvest of the Deglet-Nour date for five months of storage at 10 °C was studied. Contents of water, total sugar, carotenoids, proteins, total polyphenols, flavonoids and condensed tannins, as well as browning index, enzyme activities of polyphenoloxidase and peroxidase and antioxidant capacity of samples were monitored during storage using standard methods. Doses 1 and 6 kJ m−2 significantly slowed the water loss of samples until the second month of storage, with 17.68% and 16.02% of loss compared to control (31.45%). In the second month of storage, a significant increase in carotenoids was also observed for doses 1 and 6 kJ m−2, with values of 4.17 and 4.02 mg kg−1 versus the control (3.45 mg kg−1), which resulted in deceleration in carotenoid degradation. A gradual decrease in total sugar content was noted for all samples; it was slower within irradiated ones at the second month, where the slowing down of sugar consumption was significantly favored in the samples irradiated at 1 and 6 kJ m−2, which was marked by decreases of 4.98% and 4.57% versus 8.96% in the control. Protein content of irradiated samples (3 and 6 kJ m−2) increased at the third month, giving 1.70 and 2.41 g kg−1 compared to 1.29 g kg−1 for the control. An important decrease in enzymatic activity of polyphenoloxidase was detected, in addition to a fluctuation in peroxidase during storage. The browning index was lower in the irradiated sample until the fourth month of storage, where the result was more significant. An increase in the content of condensed tannins was detected, especially during the two first months, and while the significant increase in the content of flavonoids was read at the last month, it was detected from the first month for polyphenols. This was more significant for the highest dose, were the content reached 0.537 g kg−1 versus 0.288 g kg−1 in control at the first month. A dose-dependent increase in antiradical activity was noted during the last months of storage, while the increase in iron-reducing power was detected at the first month. UV-C delayed installation of Deglet-Nour browning and enriched it with antioxidants.

Summary Introduction Traditional medicine has an important place in human history and this since antiquity. Indeed, during Egyptian and Chinese civilization era, many detailed manuscripts, describing the therapeutic effect of plants, were found which suggest that folk medicine is the basis of the actual medicine. Objective To investigate the phytochemical and pharmacological properties of the n-butanol (n-BuOH) and ethyl acetate (EA) extracts of the aerial part of Centaurea tougourensis. Methods The phytochemical evaluation was done based on HPLC-DAD approach. The antioxidant activity was determined by DPPH and cupric ion reducing antioxidant capacity (CUPRAC), while the hemostatic effect was performed using plasma recalcification time (PRT) method. The antidiabetic capacity was investigated by alpha-amylase inhibition assay and the photoprotective test was evaluated by the measurement of sun protection factor (SPF). Results 13 phenolic compounds were identified in both extracts of C. tougourensis. These extracts showed antioxidant, haemostatic, antidiabetic and photoprotective properties with a dose-dependent manner. Amounts of n-BuOH activities were found higher, with a respective IC50 value of 0.72±0.07 μg/ml in DPPH assay, an A0.50 value lower than 3.125 μg/ml in CUPRAC assay besides a shortening rate percentage of coagulation (86.71%) in haemostatic assay, a moderate inhibition effect on alpha amylase activity with an IC50 value of (711.5±0.03 μg/ml) and a maximum sun protection factor of (56.035). These results were mostly found highly significant (p<0.001) when compared to respective standards. Conclusion This study demonstrated some pharmacological effects of C. tougourensis which suggests that our plant could be a good candidate to treat some illnesses related to oxidative stress, bleeding or skin cancer.