Karim Hosni

Physiological changes, phenolic content and antioxidant activity of Salvia officinalis L. grown under saline conditions.

BACKGROUND Hydroponic culture was used to investigate the effect of NaCl concentrations on the growth, nutrient uptake, phenolic content and antioxidant activity of Salvia officinalis L. leaves. The antioxidant capacity of the methanolic extract of S. officinalis was evaluated by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging test and β-carotene-linoleic acid bleaching assay. Physiological and biochemical parameters of S. officinalis were assessed after 4 weeks of salt treatment with 0, 25, 50, 75 and 100 mmol L(-1) NaCl. RESULTS Plant growth exhibited a reduction of 61% at 100 mmol L(-1) NaCl. Assessment of Na(+), K(+) and Ca(2+) and water contents of shoots and roots showed that S. officinalis is able to regulate Na(+) concentration by active compartmentation in vacuoles. Salvia officinalis phenolics were increased in response to salinity at the threshold of 75 mmol L(-1) NaCl. This herb was also found to be able to achieve important DPPH(•) quenching activity and to inhibit the β-carotene-linoleic acid bleaching notably enhanced by salt treatment. It is interesting to highlight the correlation between the phenolic and antioxidant activity, suggesting the involvement of these compounds in this activity. CONCLUSION Salvia officinalis treated with 75 mmol L(-1) NaCl constitutes a potential source for production of secondary metabolites useful in several applications.

Myrtle berry seed aqueous extract inhibits human neutrophil myeloperoxidase in vitro and attenuates acetic acid-induced ulcerative colitis in rats

We aimed in the present study to investigate the protective effect of a myrtle (Myrtus communis L.) berry seed aqueous extract (MBSAE) on acetic acid (AA)-induced colitis in rats as well as the mechanism implicated in this coli-protection. The use of the LC/MS technique allowed us to identify 18 phenolic compounds in the MBSAE. Secondly, we found that the MBSAE inhibited the luminol-amplified chemiluminescence of resting neutrophils and N-formyl-methionylleucyl-phenylalanine (fMLF) or phorbolmyristate acetate (PMA) stimulated neutrophils in a dose-dependent manner. The MBSAE had no effect on superoxide anions, but it inhibited H2O2 production in the cell free system stimulated with horseradish peroxidase (HRPO) and MPO release from the neutrophils. In vivo, the pre-treatment of rats with sulfasalazine (100 mg kg−1) and the MBSAE (25, 50, and 100 mg kg−1) significantly reduced AA-induced colonic mucosa lesions as well as histopathological changes. The MBSAE counteracted AA-induced lipid peroxidation and the depletion of the activity of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). We also found that the myrtle extract inhibited the increase of the plasma scavenging activity (PSA) and preserved the content of non-enzymatic antioxidants such as sulfhydryl groups (–SH) and reduced glutathione (GSH). More importantly, acetic acid administration increased colonic hydrogen peroxide (H2O2), free iron and calcium levels, while the MBSAE pre-treatment reversed all intracellular mediator perturbations. In conclusion, our data suggests that the MBSAE exerted a potential protective effect against AA-induced injury and oxidative stress in the rat colon. This coli-protection might be related in part to its antioxidant and ROS scavenging activities or by negatively regulating Fenton reaction components such as H2O2 and free iron, which are known to lead to cytotoxicity mediated by intracellular calcium deregulation.

Protective effect of Artemisia campestris extract against aspirin-induced gastric lesions and oxidative stress in rat

The present study aims at evaluating the antiulcer and antioxidant effect of Artemisia campestris aqueous extract (ACAE) as well as the mechanism of action involved in such gastroprotection. The use of LC/MS allowed the identification of 11 phenolic compounds and the colorimetric analysis demonstrated that the ACAE exhibited an important in vitro antioxidant activity. We first showed that in vivo ACAE protected against macroscopic and histological changes induced by aspirin in stomach mucosa. Aspirin administration was accompanied by an oxidative stress status assessed by an increase in malondialdehyde (MDA) level, a decrease in the content of sulfhydryl –(SH) groups and a depletion of antioxidant enzyme activities such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). Pre-treatment with ACAE protected against aspirin-induced gastric oxidative stress. More importantly, aspirin administration increased plasma and tissue hydrogen peroxide (H2O2), free iron and calcium levels, while the ACAE pre-treatment reversed all the effects of aspirin-induced intracellular mediators. In conclusion, we suggest that Artemisia campestris aqueous extract has potent antiulcer and antioxidant properties. This gastroprotection offered by ACAE might be related partly to the safety of sulfhydryl group as well as its opposite effect on some intracellular mediators such as hydrogen peroxide, free iron and calcium.

Composition of garlic essential oil (Allium sativum L.) as influenced by drying method

Air-, oven- and freeze-dried garlic bulbs were hydrodistilled and the resulting essential oils were analyzed by gas chromatography (GC) and GC/mass spectrometry (GC/MS). The highest yields were 0.6 and 0.5% (w/w) for freeze- and oven-dried samples, respectively. The essential oils were characterized by a high amount of sulfur compounds (84.3–98.9%) with diallyl trisulfide (37.3–45.9%), diallyl disulfide (17.5–35.6%) and methyl allyl trisulfide (7.7–10.4%) being the major components. Remarkable qualitative and quantitative differences between the investigated oils owing to the drying procedure were found and a set of marker components was established to differentiate between them.

Effects of cement dust on volatile oil constituents and antioxidative metabolism of Aleppo pine ( Pinus halepensis ) needles

The effects of cement dust on the chemical composition of essential oil, lipid peroxidation and antioxidant enzyme activities of Aleppo pine (P. halepensis) needles were studied. Cement dust resulted in a significant decrease in the yield of essential oil with the effect being more pronounced in the close vicinity of the cement factory. A concomitant decrease in all components of the oil was observed and δ-2-carene, trans-carveol, trans-carvyl acetate, α-terpinyl acetate, β-copaene, (E,E)-α-farnesene, α-calacorene, α-cadinene, spathulenol, humulene oxide II, 8-epi-γ-eudesmol, Ί-muurolol, cubenol and ethyl hexadecanoate have been proposed as biological indicators of cement dust. Moreover, a redirection of the secondary metabolism toward the biosynthesis of monoterpenes has been evidenced. Malondialdehydes (MDA), a decomposition product of polyunsaturated fatty acids, often considered as a suitable biomarker for lipid peroxidation was induced in the needles exposed to cement dust. Similarly, a remarkable induction of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activities was noticed. The positive relationships were observed among activities of antioxidant enzymes, and between MDA content and activities of antioxidant enzymes, indicating the cooperative action of these antioxidant enzymes to cope with the oxidative stress induced by cement dust. The results obtained indicate that P. halepensis needles are useful bio-monitors of cement dust pollution.

Antidiarrhoeal, antimicrobial and antioxidant effects of myrtle berries (Myrtus communis L.) seeds extract

The present study was carried out to determine the antidiarrheal effects of myrtle (Myrtus communis L.) berries seeds aqueous extract (MBSAE) from Tunisia as well as the involvement of its antimicrobial and antioxidant properties in such protection.

Chemical Composition of the Essential Oils Obtained from the Leaves, Fruits and Stems of Salvia verbenaca L. from the Northeast Region of Tunisia

Abstract The variation in essential oil composition of Salvia verbenaca L. fruits, stems and leaves was determined by GC and GC/MS. Essential oil yields were 0.003%, 0.01% and 0.06% in the leaves, stems and fruits, respectively (dwt). Sixty-three components were identified in the fruit oil with β-caryophyllene (23.1%), caryophyllene oxide (15.9%), camphene (6.5%), α-humulene (5.6%) and viridiflorol (4.3%) as the most abundant components and sesquiterpenes hydrocarbons were the predominant class (35.1%). Forty-four constituents were detected in the stem oil which was rich in oxygenated monoterpenes (26.5%). Camphor (10.9%) and viridiflorol (10.3%) were found as the main constituents. In contrast to the other oils, the leaf oil was characterized by the occurrence of labdane type diterpenes (24.7%) in high amounts with epi-13-manool (13.7%) and manool (11.0%) as main compounds.

Volatile oil constituents of Rosa canina L.: Differences related to developmental stages and floral organs

Abstract The evolution of the volatile oils during three developmental stages of Rosa canina L. flowers and the repartition of the constituents of the oils among different floral parts were examined using high-resolution gas chromatography and gas chromatography–mass spectrometry. Numerous components belonging to different chemical classes suggesting the occurrence of different metabolic pathways were identified. The main component in all oil samples was 2-phenylethanol, and its content increased gradually during the floral development process. Irrespective of flowers developmental stage, hydrocarbons were found to be the main group components. A great qualitative and quantitative change of the essential oil composition among different floral parts was also revealed. The volatile oil compositions are discussed in relation to their defensive and pollinators attraction roles.

Responses of Nigella sativa L. to Zinc Excess: Focus on Germination, Growth, Yield and Yield Components, Lipid and Terpene Metabolism, and Total Phenolics and Antioxidant Activities

A comprehensive analysis of the responses of Nigella sativa L. to elevated zinc concentrations was assessed in pot experiments. Zn excess supply did not affect the germination but drastically reduced radicle elongation. A concentration-dependent reduction in all growth parameters, yield, and yield components was observed. With the increasing Zn concentrations, total lipid contents decreased and changes in fatty composition toward the production of saturated ones were underscored. Despite the reduction in the seeds essential oil yield, a redirection of the terpene metabolism toward the synthesis of oxygenated compounds has been evidenced. A significant increase in the total phenols and flavonoids contents concomitant with improved antioxidant activities has also been found. Collectively, these results highlight the possible use of N. sativa L. in phytoremediation applications, on the one hand, and that Zn excess could represent an excellent alternative to improve the nutritional attributes of this important species, on the other hand.

Volatile Oil Constituents of Rosa canina L.: Quality As Affected by the Distillation Method

The volatile oils of R. canina flowers were isolated by hydrodistillation (HD) and traditional dry distillation (DD) and analyzed by HRGC-FID and GC-MS. Compared to HD, DD at 50°C leads to the isolation of high quality oil which contains the highest content of oxygenated compounds (83%). The main components are the 2-phenethyl alcohol and eugenol. The percentage of the 2-phenethyl alcohol, a highly desirable component in rose oil, was significantly higher (58.4%) in DD extract when compared to that of HD one (13.6%). As temperature increased (100°C) during DD, the oil quality decreased. The most significant changes were observed in 2-phenethyl alcohol percentage (4.5%). Moreover, an increase of alkanes/alkenes and the production of furan derivatives were observed. So, DD at moderate temperature (50°C) seemed more suitable to improve the volatile oil quality and hence, to make more value of R. canina.