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The aim of this work is to investigate the chemical composition, antioxidant, and antimicrobial activities of Tunisian Thymus vulgaris essential oil (TVEO). DPPH, superoxide anion, reducing power, chelating effect on ferrous ions and β-Carotene assays have been employed to determine the antioxidant potential of TVEO. In contrast, 24 reference bacterial strains and 16 fungal strains have been used for the assessment of the antimicrobial activity. Results revealed that TVEO has as carvacrol (67.33%) chemotype, it was equipped with an important antioxidant capacity that is better (P

This study was carried out to evaluate the effect of extraction methods (direct maceration (DM) and successive maceration (SM)) and solvents (dichloromethane (DCM), ethyl acetate (EAc), butanol (Bu...

Five Oudneya Africana (OA) leaves extracts were screened for their total phenolic (TPC), total flavonoid (TFC), condensed tannins (CTC) content, as well as their antioxidant capacity. The highest amount of TPC (661.66 ± 0.08 mg GAE/g), TFC (344.68 ± 0.44 mg QE/g) and TCT (90.18 ± 0.49 mg CE/g) was recorded to ethanol, acetone, and dichloromethane extracts, respectively. For 2,2-diphenyl-1-picrylhydrazyl (DPPH) (22.00 ± 0.03 µg/mL) and Reducing Power Assay (FRAP) (269.00 ± 0.01µg/mL) assays, ethanol extract showed the potent activity, while with ABTS test, acetone extract was the most active (761.15 ± 0.09 µg/mL). HPLC-MS analysis of acetonic and ethanolic extracts reveals the predominance of quinic acid, chlorogenic acid, 4-O-caffeoylquinic acid, and rutin compounds. The addition effect evaluation of OA extracts in beef burger preservation demonstrates the powerful effect (p < 0.05) of acetonic and ethanolic ones (0.03%) to inhibit lipids oxidation during storage for 10 days, given by the lowest increase in Thiobarbituric Acid-reactive Substances (TBARS) values as compared to the (−) control with a significant difference between free thiols values. In addition, these two extracts appear to be effective (p < 0.05) for pH stability, color, and sensory parameters as compared to (+) and (−) controls and aqueous extract. Hamburger odour was considered as a dependent variable in multiple linear regression analysis, where the models results showed that physicochemical parameters determine more burger odour than sensorial ones.

Essential oils (EO) from fresh and dry aerial parts of Pituranthos chloranthus (Benth.) Hook and Pituranthos tortuosus (Coss.) Maire were isolated by hydrodistillation and analyzed by GC/MS. The main constituents of the EO obtained from fresh herb of P. chloranthus were found to be α-pinene, sabinene, cis-ocimene and myrcene. In dry biomass, a significant increase of the content of some compounds such as α-phellandrene, △,3-carene and β-phellandrene characterized the oil. Minor changes in the chemical composition of the P. tortuosus EOs obtained from fresh or dry herbs and the major constituents were found to be sabinene and myrcene with equilibrate amounts of α-pinene, p-cymene, cis-ocimene, limonene, trans-β-ocimene, γ-terpinene and cis-verbenol. The paper disc diffusion method was used to evaluate the antibacterial activity and results showed an important inhibitory effect of oils obtained from fresh herb against most tested bacteria.

This study was conceived to examine the antimicrobial and antioxidant activities of four essential oil types extracted by hydrodistillation from the aerial parts of Artemisia herba-alba cultivated in southern Tunisia. The chemical composition was investigated using both capillary GC and GC/MS techniques. β-thujone, α-thujone, α-thujone/β-thujone and 1,8-cineole/camphor/α-thujone/β-thujone were respectively, the major components of these oil types. The antimicrobial activity of different oils was tested using the diffusion method and by determining the inhibition zone. The results showed that all examined oil types had great potential of antimicrobial activity against strains. In addition, antioxidant capacity was assessed by different in vitro tests and weak activity was found for these A. herba-alba oils.

The essential oils extracted by Clavenger apparatus from leaves of Rosmarinus officinalis cultivated in different areas in Djerba (Island in the southern of Tunisia) were evaluated for their chemical composition (GC and GC-MS methods), antioxidant (DPPH method) and antibacterial activities (agar-well diffusion method). GC-MS analysis revealed the presence of three chemotypes of oils: 1,8-cineole, 1,8-cineole/camphor/α-pinene/camphene and 1,8-cineole/camphor/α-pinene/ verbenone/borneol which was not previously detected in Tunisian Rosmarinus officinalis. The three chemtypes exhibited moderate antioxidant activity with an IC50 ranged from 4.186 mg/ml for chemotype I to 7.298 for chemotype II and showed strong to moderate antibacterial activity against the six bacterial strains tested with a MIC ranged from 0.156 to 1.25 mg/mL (Chemotype I and chemotype II) and from 1.25 to 5 mg/mL (chemotype III). This study showed that the essential oil extracted from Rosmarinus officinalis cultivated in Djerba ha...

Seedlings of Artemisia herba-alba Asso collected from Kirchaou area were transplanted in an experimental garden near the Institut des Regions Arides of Medenine (Tunisia). During three years, the aerial parts were harvested (three levels of cutting, 25%, 50%, and 75% of the plant), at full blossom and during the vegetative stage. The essential oil was isolated by hydrodistillation and its chemical composition was determined by GC (RI) and 13C-NMR. With respect to the quantity of vegetable material and the yield of hydrodistillation, it appears that the best results were obtained for plants cut at 50% of their height and during the full blossom. The chemical composition of the essential oil was dominated by b-thujone, a-thujone, 1,8-cineole, camphor and trans-sabinyl acetate, irrespective of the level of cutting and the period of harvest. It remains similar to htat of plants growing wild in the same area.

SUMMARYArtemisia herba-alba Asso has been successfully cultivated in the Tunisian arid zone. However, information regarding the effects of the harvest frequency on its biomass and essential oil yields is very limited. In this study, the effects of three different frequencies of harvesting the upper half of the A. herba-alba plant tuft were compared. The harvest treatments were: harvesting the same individual plants at the flowering stage annually; harvesting the same individual plants at the full vegetative growth stage annually and harvesting the same individual plants every six months. Statistical analyses indicated that all properties studied were affected by the harvest frequency. Essential oil yield, depended both on the dry biomass and its essential oil content, and was significantly higher from plants harvested annually at the flowering stage than the other two treatments. The composition of the β- and α-thujone-rich oils did not vary throughout the experimental period.

This study investigated the chemical composition and evaluated the antioxidant, antimicrobial, cytotoxic and anti-acetylcholinesterase properties of Tunisian Origanum majorana essential oil. The findings showed that the oil exhibited high activity, particularly in terms of reducing power and β-Carotene bleaching, inducing higher IC50 values than BHT. The oil showed an important antimicrobial activity against 25 bacterial and fungal strains. In fact, the IZ, MIC and MBC values recorded for the bacterial strains were in the range of 8 ± 0-18.33 ± 0.57 mm, 0.097-3.125 and 0.39-6.25 mg/mL, respectively. The IZ, MIC and MFC values of the fungal strains varied between 11±0-28 ± 0 mm, 0.058-0.468 mg/mL and 0.234-1.875 mg/mL, respectively. A low cytotoxic effect was observed against cancer (Hep-2 and HT29) and continuous cell lineage (Vero), with CC50 values ranging from 13.73 to 85.63 mg/mL. The oil was also evaluated for anti-acetylcholinesterase effects, which showed that it exhibited significant activity with IC50 values reaching 150.33 ± 2.02 μg/mL.

The intraspecific chemical variability of essential oils (50 samples) isolated from the aerial parts of Artemisia herba-alba Asso growing wild in the arid zone of Southeastern Tunisia was investigated. Analysis by GC (RI) and GC/MS allowed the identification of 54 essential oil components. The main compounds were β-thujone and α-thujone, followed by 1,8-cineole, camphor, chrysanthenone, trans-sabinyl acetate, trans-pinocarveol, and borneol. Chemometric analysis (k-means clustering and PCA) led to the partitioning into three groups. The composition of two thirds of the samples was dominated by α-thujone or β-thujone. Therefore, it could be expected that wild plants of A. herba-alba randomly harvested in the area of Kirchaou and transplanted by local farmers for the cultivation in arid zones of Southern Tunisia produce an essential oil belonging to the α-thujone/β-thujone chemotype and containing also 1,8-cineole, camphor, and trans-sabinyl acetate at appreciable amounts.

Essential oil extracted by hydrodistillation from Tunisian variety of Cuminumcyminum was characterized by means of GC and GC-MS. Twenty-one components were identified and C. cyminum contained cuminlaldehyde (39.48%), gamma-terpinene (15.21%), O-cymene (11.82%), beta-pinene (11.13%), 2-caren-10-al (7.93%), trans-carveol (4.49%) and myrtenal (3.5%) as a major components. Moreover, C. cyminum oil exhibited higher antibacterial and antifungal activities with a high effectiveness against Vibrio spp. strains with a diameter of inhibition zones growth ranging from 11 to 23 mm and MIC and MBC values ranging from (0.078-0.31 mg/ml) to (0.31-1.25mg/ml), respectively. On the other hand, the cumin oil was investigated for its antioxidant activities using four different tests then compared with BHT. Results showed that cumin oil exhibit a higher activity in each antioxidant system with a special attention for beta-carotene bleaching test (IC(50): 20 microg/ml) and reducing power (EC(50): 11 microg/ml). In the light of these findings, we suggested that C. cyminum essential oil may be considered as an interesting source of antibacterial, antifungal and antioxidants components used as potent agents in food preservation and for therapeutic or nutraceutical industries.