Secondary metabolism responses in two Pisum sativum L. cultivars cultivated under Fe deficiency conditions

The present study was carried out to investigate the Fe deficiency effect on the secondary metabolism  responses in two Pisum sativum cultivars characterized by different tolerance to Fe deficiency. Previous study  investigating the physiological responses to Fe deficiency in these two pea cultivars showed that Kelvedon was  more tolerant than Lincoln. Both cultivars were grown in the absence or presence of Fe with the addition of bicarbonate for twelve days. Higher concentrations of phenols and flavonoids were observed in Fe-deficient  tissues of both cultivars; however, the increase was greater in the tolerant cultivar than in the susceptible  one. The activity of shikimate pathway enzymes tested was more enhanced in the tolerant cultivar. In  addition, lipid peroxidation and H2O2 concentrations were more increased in the susceptible cultivar when  compared with the tolerant one. Peroxidase activity was increased in the tolerant cultivar grown under  bicarbonate supply, while a considerable diminution was observed in the susceptible one, suggesting the  involvement of this antioxidant enzyme in the tolerance of pea to Fe deficiency. The lignifying peroxidases  activity was more decreased in Lincoln than in Kelvedon, especially in the presence of bicarbonate. Our data  suggest that the tolerance of Kelvedon was related to its ability to modulate the phenolic metabolism pathway and to enhance the antioxidant potentials.Key words: Iron deficiency, bicarbonate, phenolic metabolism, antioxidative enzymes, Pisum sativum

Essential oil composition and variability of Artemisia herba-alba Asso. Growing in Tunisia: Comparison and chemometric investigation of different plant organs

This study was conceived to investigate the composition of four essential oils (EOs) extracted by hydrodistillation from four parts (leaves, stems, leaves/stems, roots) of Artemisia herba-alba growing wild in the Center of Tunisia. For this, Artemisia herba-alba aerial and roots parts were shade dried with ventilation at room temperature. Then, plant different parts were cut into small pieces and subjected to hydrodistillation using a Clevenger-type apparatus. The gas chromatography (GC) analyses were accomplished with a HP-5890 Series II instrument. The main results showed a total of 152 compounds detected and identified by GC and GC-MS and accounting for 91.3-99.7% of the whole oil. The four oils were characterized by the predominance of monoterpene derivatives (68.2-99.5%) and the major volatile constituent was a-thujone (18.2-45.5%). Qualitative and quantitative differences between the four essential oils have been noted for some compounds. The main compounds of leaves essential oil were α-Thujone (45.5%), β-Thujone (11.4%), trans-sabinyl acetate (10.1%), 1,8-Cineole (7.4%) and camphor (6.8%). a-Thujone (27.5%) was also the main compound in the essential oil of leaves/stems, followed by camphor (22.9%), 1,8-cineole (8.3%), β-thujone (8.2%) and camphene (5.6%). The essential oil of stems was dominated by a-Thujone (28%) followed by β-Thujone (11.4%) and chrysantenone (11%). In the essential oil of roots, a-thujone was less represented (18.2%), followed by camphor (14.6%) and curcumen-15-al (14.3%). It is important to mention that curcumen-15-al has been reported for the first time in Artemisia herba-alba oil Our results revealed avariability in the chemical composition and the yield of the EOs from Artemisia herba-alba. Moreover, curcumen-15-al is a new chemotype first found in Artemisia herba-alba from Tunisia

Effect of drought on safflower natural dyes and their biological activities

Drought is the main abiotic constraint that affects crop species behaviour regarding biochemical responses. The current study was conducted to examine the effect of water deficit on growth, phenolic and carotenoid contents as well as the antioxidant and antimicrobial activities of two Carthamus tinctorius varieties (Jawhara and 104) flowers. Hence, plants were treated with different levels of water deficit: control (100 %), moderate water deficit (50 %) and severe water deficit (25 %). Obtained results showed that plant growth was significantly (p < 0.05) reduced under 50 %. Drought increased flower phenolic acids contents especially gallic acid where they increased significantly (p < 0.05) by 2.73 fold (104) and by 2.87 fold (Jawhara) with respect to controls under 50 %. However, the amounts of this major compound were reduced at 25 % by 9.66 % (104) and 3.83 % (Jawhara). Similar to phenolic compounds, total carotenoid content was at its highest level especially for Jawhar a with an increase by 35.19 % at 50 %. On the other hands, C. tinctorius flowers extracts exhibited high antiradical activity as compared to BHT. A gradual increase by 35.29 % (Jawhara) and 33.33 % (104) especially under 25 % was observed. Moreover, under 50 %, the antimicrobial activity increased significantly (p < 0.05) by 30 % and 10.05 % against Aspergillus carbonarus and Pseudomonas aerogenosa, respectively. Taken together, our findings suggest that C. tinctorius could be a raw material for production of natural dyes under moderate salinity conditions

EFFECTS OF OLIVE DRYING AND STORAGE ON THE OXIDATIVE STATUS, AROMA, CHLOROPHYLL AND FATTY ACIDS COMPOSITION OF OLIVE OIL

Objective: In this study, we thoroughly investigate the effect of drying and storage of olives from four Tunisian cultivars (Chetoui, Chemlali, Oueslati and Picholine) on the final composition of olive oil.Methods: Olives were dried using three different methods: ambient air, infrared radiation and oven heating. Oven-dried olives were stored during six months. Extraction was conducted using a soxhlet apparatus. Its quality was assessed by analyzing the fatty acid and aroma composition on one hand, and on the other hand by evaluating the total chlorophyll content and measuring specific extinctions at 232 and 270 nm.Results: The main results show that air dried fruits (Chetoui cultivar) gave the most pigmented oil (3.32 ppm of total chlorophylls) followed by oven dried olives (1.12 ppm), whereas infra-red dried olives had the least amount of chlorophylls (0.98 ppm). Furthermore, the highest amount of total aroma was found in oven dried fruits whereas the lowest one characterized infrared dried olives. Fatty acid composition of our oils wasn't affected by drying techniques. Also, oven dried and stored olives showed an insignificant change in chlorophyll contents and aroma composition (Chetoui variety), coupled with a decreased level of total fatty acid amount as of the third month of preservation.Conclusion: Drying techniques and storage affected aroma compounds, while oil oxidation, chlorophyll and fatty acid composition were unaffected. A better control for drying and storage should be developed to insure a better quality of olive oil. A comparison should be done between the current study and salt and dried olive preservation in order to offer hypertensive patients fruits with preserved nutritional values and the peculiar delicate flavour characteristic of olive oilÂ

EFFECT OF DROUGHT ON SAFFLOWER NATURAL DYES AND THEIR BIOLOGICAL ACTIVITIES

ABSTRACT Drought is the main abiotic constraint that affects crop species behaviour regarding biochemical responses. The current study was conducted to examine the effect of water deficit on growth, phenolic and carotenoid contents as well as the antioxidant and antimicrobial activities of two Carthamus tinctorius varieties (Jawhara and 104) flowers. Hence, plants were treated with different levels of water deficit: control (100 %), moderate water deficit (50 %) and severe water deficit (25 %). Obtained results showed that plant growth was significantly (p &lt; 0.05) reduced under 50 %. Drought increased flower phenolic acids contents especially gallic acid where they increased significantly (p &lt; 0.05) by 2.73 fold (104) and by 2.87 fold (Jawhara) with respect to controls under 50 %. However, the amounts of this major compound were reduced at 25 % by 9.66 % (104) and 3.83 % (Jawhara). Similar to phenolic compounds, total carotenoid content was at its highest level especially for Jawhara with an increase by 35.19 % at 50 %. On the other hands, C. tinctorius flowers extracts exhibited high antiradical activity as compared to BHT. A gradual increase by 35.29 % (Jawhara) and 33.33 % (104) especially under 25 % was observed. Moreover, under 50 %, the antimicrobial activity increased significantly (p &lt; 0.05) by 30 % and 10.05 % against Aspergillus carbonarus and Pseudomonas aerogenosa, respectively. Taken together, our findings suggest that C. tinctorius could be a raw material for production of natural dyes under moderate salinity conditions

An Overview of the Potential of Medicinal Plants Used in the Development of Nutraceuticals for the Management of Diabetes Mellitus: Proposed Biological Mechanisms

Diabetes mellitus (DM) is a chronic metabolic disorder in which the pancreas does not produce enough insulin or the body cannot effectively use it. The prevalence of diabetes is increasing steadily, making it a global public health problem. Several serious complications are associated with this disease. There are a number of different classes of antidiabetic medications. Interestingly, traditional medicine can also be used for the development of novel classes of hypoglycemic therapeutics. This article summarizes an update of the potential of various important medicinal plants used in the development of nutraceuticals for the management of diabetes mellitus, and a proposal of their biological mechanisms

Essential Oils’ Chemical Characterization and Investigation of Some Biological Activities: A Critical Review

This review covers literature data summarizing, on one hand, the chemistry of essential oils and, on the other hand, their most important activities. Essential oils, which are complex mixtures of volatile compounds particularly abundant in aromatic plants, are mainly composed of terpenes biogenerated by the mevalonate pathway. These volatile molecules include monoterpenes (hydrocarbon and oxygenated monoterpens), and also sesquiterpenes (hydrocarbon and oxygenated sesquiterpens). Furthermore, they contain phenolic compounds, which are derived via the shikimate pathway. Thanks to their chemical composition, essential oils possess numerous biological activities (antioxidant, anti-inflammatory, antimicrobial, etc…) of great interest in food and cosmetic industries, as well as in the human health field

Assessing the potential and safety of Myrtus communis flower essential oils as efficient natural preservatives against Listeria monocytogenes growth in minced beef under refrigeration

In this research, the chemical composition and biological properties of Tunisian Myrtus communis (McEO) flowers were investigated. The antibacterial effect of McEO toward some bacteria was assessed, alone and in combination with nisin. The major components of McEO were α-pinene, 1,8-cineol, limonene, and linalool. McEO exhibited cytotoxicity toward HepG2 and MCF-7 cell lines. The microbiological data showed that Gram-positive bacteria were more susceptible to McEO. McEO had a bactericidal effect against L. monocytogenes. McEO is able to prevent lipid oxidation, microbial development at noncytotoxic concentrations, when used alone or in combination with nisin. It can improve sensory attributes within acceptable limits and improve the conservation of shelf life of minced beef meat during the 4°C storage period. The most potent preservative effect was obtained with the mixture: 0.8% McEO with 500 IU/g of nisin. This combination may be a good alternative for the development of natural preservatives

Chemical Composition, Antioxidant Potential, and Antibacterial Activity of Essential Oil Cones of Tunisian Cupressus sempervirens

The extraction yield of the essential oil (EO) extracted by hydrodistillation from the cones of Tunisian Cupressus sempervirens L. was of 0.518%. The chemical composition was analyzed by GC-MS. Results showed that this essential oil was mainly composed of monoterpene hydrocarbons (65%) with α-pinene as the major constituent (47.51%). Its antioxidant activity was ascertained by evaluating the total antioxidant capacity and also by evaluating its inhibitory effect against DPPH and ABTS radicals. In addition, it showed a strong antioxidant power against the DPPH (IC50 = 151 µg/mL) and ABTS (IC50 = 176.454 µg/mL) radicals scavenging. Moreover, its antibacterial activity was tested against different species of pathogenic bacteria (three Gram-positive and eight Gram-negative bacteria). The bacterial strains susceptible to the evaluated oil were Bacillus subtilis, Escherichia coli, Klebsiella oxytoca, Morganella morganii, Shigella, and Vibrio cholerae

The Influence of Organs on Biochemical Properties of Tunisian <i>Thuja occidentalis</i> Essential Oils

In this study, the chemical composition and biological activities of the essential oil (EO) extracts (from leaves and cones) of the Tunisian Thuja occidentalis were evaluated. The composition of the leaf EO extract was more complex than that of the cones. The major components of the leaf EO extract were &#945;-Pinene (34.4%), cedrol (13.17%), and &#946;-Phellandrene (8.04%), while the composition of the cone EO extract was characterized by the predominance of &#945;-Pinene (58.55%) and 3-Carene (24.08%). All EO extracts showed much better antioxidant activity than Trolox against 2, 2&#8242;-diphenyl-1-picryl hydrazyl (DPPH) radical scavenging, but EOs extracted from leaves exhibited the highest total antioxidant activity. All EOs showed strong antibacterial and antifungal activities against nine tested foodborne microorganisms (Bacillus cereus American Type Culture Collection (ATCC) 1247, Listeria monocytogenes ATCC 7644, Staphylococcus aureus ATCC 29213, Aeromonas hydrophila EI, Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 27853, Salmonella typhimurium NCTC 6017, Aspergillus flavus (foodborne isolate), and Aspergillus niger CTM 10099. The highest antimicrobial activities by disk diffusion assay were recorded for the EOs extracted from leaves, while no difference in potency was marked between leaf and cone EO extracts by the agar dilution method. The most potent antimicrobial activity was recorded among fungi. This study confirms the strong antimicrobial and antioxidant potential of EO extracts from the Tunisian T. occidentalis (from the Sidi Bou Said site), highlighting its potential as a natural preservative against foodborne pathogens, particularly against E. coli and S. typhimurium