Immunomodulatory effect of Linalool (Lin) against CCl4 -induced hepatotoxicity and oxidative damage in rats.

The current study explored the hepatoprotective and immunomodulatory effects of Linalool (Lin) against carbon tetrachloride (CCl4 )-induced toxicity in mice. Four study groups (n = 8 each) were used: (1) a negative control group and (2) a toxicity control group (single dose of CCl4 administered on day 14 as 1 mL/kg of CCL4 in 1% olive oil). Intraperitoneally (i.p.)), and two experimental groups where mice were treated with either (3) Lin (25 mg/kg b.w., orally, daily for 15 days) or (4) pretreated with Lin (25 mg/kg b.w., orally, daily for 14 days) and intoxicated with CCl4 (1 mL/kg of CCL4 in 1% olive oil. i.p.) on day 14. The levels of the anti-inflammatory cytokine interleukin 10 (IL-10), the proinflammatory cytokines TNF-α, IL-6, and TGF-1ß, and the histopathology of the liver were assessed. According to our findings, IL-10 concentrations were significantly increased in Lin-treated groups, while other cytokine levels were marked by a considerable decrease in the toxicity model group (CCl4 -treated group). Histopathological examinations of liver tissues showed that the Lin-treated groups had an almost normal structure. The current findings showed that Lin could inhibit CCl4 -induced liver injury in mice, which warrants further investigation of Lin as a potential protective and therapeutic agent against hepatotoxicity.

Antioxidant and hepatoprotective effects of novel heteropolysaccharide isolated from Lobularia maritima on CCl4-induced liver injury in rats.

The aim of the present study was to investigate the extraction and the characterization of a novel heteropolysaccharide from Tunisian halophyte Lobularia maritima (LmPS). We were also interested in its antioxidant, anti-inflammatory, and hepatoprotective effects on carbon tetrachloride (CCl4)-induced liver injury in rats. LmPS physicochemical properties were evaluated by thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), thermogravimetric analysis (TGA), and UV absorption. According to TLC and HPLC results, LmPS was a heteropolysaccharide composed of glucose, galactose, and xylose. Its molecular weight was 130.62 kDa. This heteropolysaccharide was characterized by a significant antioxidant potential and was efficient against oxidative stress and CCL4-induced hepatotoxicity in rat Wistar models (n = 8) treated with a single dose of LmPS 250 mg/kg of body weight. This was evidenced by a significant increase in serum marker enzymes specially aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH). The cytokines released after stimulation of rats with LmPS showed high anti-inflammatory profiles with an increased rate of interleukine-10 (IL-10) with 0.03 pg/mL compared to animals treated only with CCl4. On the contrary, we noticed a decrease of the other cytokines (tumor necrosis factor α: TNF-α, interleukine-6: IL-6, transforming growth factor beta 1: TGF-ß1) with average concentration values of <0.2, 0.1, and 0.04 pg/mL, respectively. Besides, histopathological examinations revealed that CCl4 causes acute liver damage, characterized by extensive hepatocellular necrosis, vacuolization, and inflammatory cell infiltration, as well as DNA fragmentation. LmPS administration at a dose of 250 mg/kg resulted in a significant hepatoprotection, evidenced by a reduction of CCl4-induced oxidative damage for all tested markers. These findings eagerly confirmed that LmPS was effective in the protection against CCl4-induced hepatotoxicity and genotoxicity. It, therefore, suggested a potential therapeutic use of this polysaccharide as an alternative medicine for patients with acute liver diseases.

Thiamine Demonstrates Bio-Preservative and Anti-Microbial Effects in Minced Beef Meat Storage and Lipopolysaccharide (LPS)-Stimulated RAW 264.7 Macrophages.

This study assessed the anti-inflammatory effect of thiamine (TA) in lipopolysaccharide-stimulated RAW264.7 cells and also assessed the preservative properties of TA in minced beef. TA demonstrated a concentration-dependent antimicrobial effect on microbial contaminants. Inhibition zones and MIC from the effect of TA on the tested bacterial strains were respectively within the ranges 15−20 mm and 62.5−700 µg/mL. TA significantly (p < 0.05) decreased all the pro-inflammatory factors [(nitric oxide (NO), prostaglandin E2 (PGE2), TNF-α, IL-6, IL-1ß, and nuclear factor-κB (NF-κB)] monitored relative to LPS-stimulated RAW264.7 cells. TA inhibited the expression of both iNOS and COX-2. In minced beef flesh, the growth of Listeria monocytogenes was inhibited by TA. TA improved physicochemical and microbiological parameters of stored minced beef meat compared to control. Principal component analyses and heat maps elucidate the quality of the tested meats.

Neuroprotective effects of oleuropein on retina photoreceptors cells primary culture and olive leaf extract and oleuropein inhibitory effects on aldose reductase in a diabetic model: Meriones shawi.

Aldose reductase (AR) is an enzyme implicated in the development of diabetes complications among them diabetic retinopathy. Erythrocyte AR activity was measured in control and diabetic Meriones shawi, a type-2 diabetic model. We noticed an increase of AR activity in diabetic Meriones by comparison to controls. Olive leaf aqueous extract and oleuropein were tested for their inhibitory potential on AR activity. Both exerted a partial in-vitro inhibition effect which was higher with the olive leaf extract. The ex-vivo protective effect of oleuropein was tested in photoreceptors rod and Mcône retinal cells of Meriones shawi in hyperglycaemic conditions. Mixed retinal cells were cultured at 25 mM glucose for 5 days and treated with oleuropein. Cell viability was assessed using MTT test and trypan blue exclusion dye. Rod and Mcône Photoreceptors were characterised by immuno-cytochemistry. Oleuropein protected retinal cells against the toxic effect of glucose by improving the viability of photoreceptors.

Lobularia maritima leave extract, a nutraceutical agent with antioxidant activity, protects against CCl4-induced liver injury in mice.

Lobularia maritima (Alyssum maritimum, Brassicaceae), commonly known as sweet alyssum, is an annual ornamental halophyte widely spread along the Tunisian seashore. Lobularia maritima leaf ethanol extract was tested in an experimental model of hepatotoxicity induced by carbon tetrachloride (CCl4). L. maritima extract was found to possess in vitro antioxidant activity by scavenging the DPPH radical (IC50= 45 µg/mL), reducing/chelating iron ions and inhibiting liver lipid peroxidation induced by FeSO4. The levels of total phenolics and flavonoids were 175 ± 2.66 mg GAE/g, and 35 ± 2.88 mg QE/g respectively. Moreover, HPLC analysis revealed six compounds, namely gallic, salicylic, ellagic and ferulic acids as well as catechin and quercetin. A mice model of acute liver injury was successfully established after a single intraperitoneal injection of CCl4, as evidenced by histological analysis, Masson trichrome and Sirius red staining. Compared with the CCl4 intoxicated group, the L. maritima treatment resulted to reduce the liver serum marker enzymes, lipid peroxidation and increased the activities of antioxidant enzymes with further amelioration in the oxidative stress. The present findings discover the therapeutic potentials of L. maritima empowered with promising natural leads for the treatment of oxidative stress associated health disorders by attenuating free radicals, inhibiting lipid peroxidation, and upregulating the tissue-specific antioxidant enzymes.

Novel non-specific lipid-transfer protein (TdLTP4) isolated from durum wheat: Antimicrobial activities and anti-inflammatory properties in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages.

Lipid transfer proteins (LTP) are members of the family of pathogenesis-related proteins (PR-14) that play a key role in plant defense mechanisms. In this study, a novel gene TdLTP4 encoding an antifungal protein from wheat (cv. Om Rabiaa) was cloned, overexpressed in Escherichia coli BL-21 (DE3) and enriched using ammonium sulfate fractionation. The TdLTP4 fusion protein was then tested against a panel of pathogens, food-borne and spoilage bacteria and fungi in order to evaluate the antimicrobial properties. TdLTP4 was applied to 0.5 µg/mL LPS-induced RAW 264.7 macrophages in vitro at different concentrations (5, 10, 20, 50 and 100 µg/mL). Levels of nitric oxide (NO), pro-inflammatory cytokines interleukin (IL)-1ß (IL-1 ß), interleukin (IL)-6 (IL-6), tumor necrosis factor (TNF-α) and anti-inflammatory cytokine IL-10 in the supernatant fraction were measured using enzyme-linked immunosorbent assay (ELISA). Expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) were detected via Western blot. The inhibition zones and minimal inhibitory concentration (MIC) values of bacterial strains were in the range of 14-26 mm and 62.5-250 µg/mL, respectively. Moreover, a remarkable activity against several fungal strains was revealed. TdLTP4 (5-100 µg/mL) decreased the production of NO (IC50 = 4.32 µg/mL), IL-6 (IC50 = 11.52 µg/mL), IL-1ß (IC50 = 7.87 µg/mL) and TNF-α (IC50 = 8.66 µg/mL) by lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. TdLTP4 could modulate the macrophages inflammatory mode by causing reduction in iNOS and COX-2. According to these findings, TdLTP4 fusion protein could be used as natural anti-inflammatory and antimicrobial agent in food preservation and human health.

Salicylic acid and H2O2 seed priming alleviates Fe deficiency through the modulation of growth, root acidification capacity and photosynthetic performance in Sulla carnosa.

Iron (Fe) is one of the essential nutrients for plant growth which is involved in several physiological functions. Hence, there are intensive efforts to improve plant tolerance to Fe deficiency, by genotypic screening and by the use of adapted physiological tools. The intend of the current study was to explore the seed priming effect with salicylic acid (SA 0.25 mM) and hydrogen peroxide (H2O2 20 mM), either separately applied or combined, on plant growth, nutritional elements status (Fe and potassium K), root acidification and photosynthetic activity in two S. carnosa cultivars (Sidi Khlif and Kalbia) with different tolerance to such constraint. Under unprimed conditions, Fe deficiency decreased plant growth, chlorophyll concentration, in addition to Fe and K contents. Moreover, it affected the photosynthetic activity by inhibiting the net CO2 assimilation rate and increasing the transpiration rate of both cultivars, following a reduced water use efficiency. The changes above described were much less pronounced in Sidi Khlif than in Kalbia. The stomatal conductance increased in Fe-deficient leaves of both cultivars, suggesting that the photosynthesis impairment should be attributed to non-stomatal factors. Interestingly, priming seeds with both agents significantly improved the growth performance and the rhizosphere acidification of deficient S. carnosa plants. However, the D + SA + H2O2 treatment had the most beneficial effect on S. carnosa plant growth. The degree of this stimulation may vary depending on the cultivar, the tissue and the priming agent applied. This could be owing to the photosynthetic performance modulation, leading to more efficient nutrient uptake.

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.

Essential oil from halophyte Lobularia maritima: protective effects against CCl4-induced hepatic oxidative damage in rats and inhibition of the production of proinflammatory gene expression by lipopolysaccharide-stimulated RAW 264.7 macrophages.

The present study evaluates the chemical profiling of the essential oil of a halophyte, L. maritima (LmEO), and its protective potential against CCl4-induced oxidative stress in rats. Forty compounds have been identified in LmEO. The major components are α-pinene (3.51%), benzyl alcohol (8.65%), linalool (22.43%), pulegone (3.33%), 1-phenyl butanone (7.33%), globulol (4.32%), γ-terpinene (6.15%), terpinen-4-ol (4.31%), α-terpineol (3.9%), ledol (3.59%), epi-α-cadinol (3.05%) and α-cadinol (4.91%). In comparison with the CCl4-intoxicated group, LmEO treatment resulted in decreased liver serum marker enzymes, decreased lipid peroxidation and increased antioxidant enzyme levels, with overall further amelioration of oxidative stress. The administration of LmEO to CCl4-treated rats at a dose of 250 mg kg-1 body weight significantly reduced the toxic effects and the oxidative stress on the liver, thus validating the traditional medicinal claim of this plant. Moreover, the anti-inflammatory activity of LmEO was evaluated in lipopolysaccharide-stimulated murine RAW 264.7 cells. Our oil could modulate the inflammatory mode of the macrophages by causing reduction in iNOS and COX2 enzymes as well as in IL-1ß, IL-6, and TNF-α cytokine levels. These findings suggest that LmEO exerts anti-inflammatory effects by regulating the expression of inflammatory cytokines.

Astaxanthin inhibits aldose reductase activity in Psammomys obesus, a model of type 2 diabetes and diabetic retinopathy.

Astaxanthin (ATX) is a marine carotenoid known for its powerful antioxidant and neuroprotective properties. In this study, we investigated the in vitro and in vivo potential inhibitory effect of ATX on the aldose reductase (AR) activity, a key enzyme in the polyol pathway responsible for the pathogenesis of diabetic complications including diabetic retinopathy (DR). The gerbil Psammomys obesus (P. ob.), an animal model for type 2 diabetes and DR has been used. The erythrocyte and retinal AR activity of P. ob. individuals were, respectively, assessed monthly and at the 7th month during a 7-month hypercaloric diet (HD) using a NADPH oxidation method. Meanwhile, the body weight and blood glucose of the gerbils were monitored. After 7 months, P. ob. individuals were fed with ATX (4.8 mg/kg of body weight) once a day for 1 week. The results showed that the HD-fed animals developed significant obesity and hyperglycemia in comparison with controls. Erythrocyte AR activity showed a progressive and significant increase in the HD-fed group compared with controls. Retinal AR activity was higher in the 7-month HD-fed group compared with controls. Erythrocyte AR activity was markedly decreased after ATX-treatment in vitro and in vivo. These findings suggested that ATX inhibited the erythrocyte AR activity and could be used for DR prevention and/or early treatment.

Chemical composition and hepatoprotective effect of essential oil from Myrtus communis L. flowers against CCL4-induced acute hepatotoxicity in rats.

Myrtus communis L. (Myrtle) is one of the most important aromatic and medicinal species from the Myrtaceae family. It is traditionally used as antiseptic, disinfectant drug and hypoglycemic agent. The aim of our study was to evaluate the protective effect of Myrtus communis essential oil (McEO) on CCl4-induced hepatotoxicity in rat. Thirty two adult Wistar rats were divided into 4 groups of 8 each: (1) a control group; (2) was given a single dose of CCl4 (1 mL kg-1 in 1% olive oil. ip) on the 14th day (3) were given during 15 days a daily i.p. injection of McEO at 250 mL kg-1 b.w (4) a group was pretreated with McEO and intoxicated with CCl4 on the 14th day. The major components of McEO are α-pinene (35.20%), 1,8-cineole (17%), linalool (6.17%) and limonene (8.94%) which accounted for 67.31% of the whole oil. The antioxidant activity of McEO was evaluated using DPPH scavenging ability, ß-carotene bleaching inhibition and hydroxyl radical-scavenging activity. Moreover, the effect of McEO (250 mg kg-1 body weight BW) administrated for 14 consecutive days was evaluated in wistar rat. Administration of a single dose of CCl4 caused hepatotoxicity as monitored by an increase in lipid peroxidation (thiobarbituric acid reactive substances) as well in protein carbonyl level but decreased in antioxidant markers in the liver tissue. The McEO pre-treatment significantly prevented the increased plasma levels of hepatic markers and lipid levels induced by CCl4 in rats. Furthermore, this fraction improved biochemical and histological parameters as compared to CCl4-treated group. Our results suggest that M. communis contains promising substances to counteract the CCl4 intoxication and which may be efficient in the prevention of hepatotoxicity complications.

Potential anti-inflammatory and antioxidant effects of Citrus aurantium essential oil against carbon tetrachloride-mediated hepatotoxicity: A biochemical, molecular and histopathological changes in adult rats.

The present study aimed (1) to investigate the chemical composition as well as the anti-inflammatory properties and in vitro antioxidant activity of Citrus aurantium peel essential oil (pEOCa) and (2) to evaluate its potential effect in vivo. The main results showed that the major components of pEOCa are Limonene and Linalool. Additionally, DPPH scavenging ability and ß-carotene bleaching inhibition tests confirmed the antioxidant capacity of pEOCa. Our oil reduced the production of NO by LPS-stimulated RAW264,7 macrophages in a concentration-dependent. This inhibition occurred at a transcriptional level. pEOCa in CCl4 treated rats alleviated hepatotoxicity as monitored by the improvement of hepatic oxidative stress biomarkers levels plasma biochemical parameters, and DNA molecule aspect. Furthermore, the mRNA gene expression of Cu-Zn SOD, CAT, and GPx increased under CCl4 + pEOCa exposure to reach the same value to the control. Similarly, antioxidant activities of these three enzymes changed in accordance with the mRNA levels. These results were confirmed by the histological results. It seems obvious that the treatment with pEOCa prevented liver damage induced by CCl4 , thus preventing the harmful effects of free radicals.

Antioxidant and hepato-preventive effect of Citrus aurantium extract against carbon tetrachloride-induced hepatotoxicity in rats and characterisation of its bioactive compounds by HPLC-MS.

The objective of this study is to explore the preventive effects of ethyl acetate fraction from Citrus aurantium leaf extract (EACA), associated with its phytochemical content, against the toxic impacts of acute exposure to carbon tetrachloride (CCl4) in the liver of adult rats. HPLC analysis of ethyl acetate fraction from extract C. aurantium revealed eight compounds. Administration of a single dose of CCl4 caused hepatoxicity as monitored by an increase in lipid peroxidation (thiobarbituric acid reactive substances) and in protein carbonyl level but a decrease in antioxidant markers in the liver tissue. The pre-treatment with EACA; significantly prevented the increased plasma levels of hepatic markers and lipid levels induced by CCl4 in rats. Furthermore, this fraction ameliorated biochemical and histological parameters as compared to CCl4-treated group. Our results suggest that C. aurantium contains promising substances to counteract the CCl4 intoxication and can be efficient in the prevention of hepatotoxicity complications.

Phytochemical composition and antioxidant activity of Tunisian Laurus nobilis.

We study the composition of Tunisian laurel leaves essential oil (EO), the fatty acid composition of laurel seed fixed oil and the total phenolics, flavonoids and tannins of laurel leaves methanolic extract. We also evaluated its free radical scavenging activity by the DPPH test. The predominant chemical class in Tunisian Laurus nobilis leaves EO was represented by oxygenated monoterpenes accounting for 64.29% of whole EO with the major compound was 1,8-cineole (46.8%). The predominant fatty acid was oleic acid (C18: 1) with an amount of 42.0%. Total polyphenols were present in the methanolic extract of Laurusnobilis leaves at an amount of 174.1 mg GAE.g-1dry matter. Total flavonoids and total tannins accounted respectively for 149.2mg CE.g-1 dry matter and 24.9mg CEg-1 dry matter. Furthermore, concerning free radical scavenging activity, Laurus nobilis leaves methanolic extract presented a significant IC50 (3mg/mL).

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.

Effect of drought on safflower natural dyes and their biological activities.

Drought is the main abiotic constraint that affects crop species behaviour regarding bio-chemical 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 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 < 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.

Thermal stability of corn oil flavoured with Thymus capitatus under heating and deep-frying conditions.

BACKGROUND: The thermal stability of corn oil flavoured with thyme flowers was determined and compared with that of the original refined corn oil (control). The oxidative stability index (OSI) was measured and samples were exposed to heating (30 min at 150, 180 and 200 °C) and deep-frying (180 °C). Changes in peroxide value (PV), free fatty acid (FFA) content, specific absorptivity values (K(232) and K(270)), colour and chlorophyll, carotenoid and total phenol contents were monitored. RESULTS: The OSI and heating results showed that thyme incorporation was effective against thermal oxidation based on the increased induction time observed for the flavoured oil (6.48 vs 4.36 h), which was characterised by lower PV, FFA content, K(232) and K(270) than the control oil after heating from 25 to 200 °C, with higher red and yellow colour intensities and chlorophyll, carotenoid and total phenol contents. The deep-frying test showed the accelerated deterioration of both oils in the presence of French fries. CONCLUSION: Compared with the control oil, the thyme-flavoured oil showed improved thermal stability after heating. This could be attributed to the presence of thyme pigments and antioxidant compounds allowing extended oil thermal resistance.

Nitrogen effects on proteins, chlorophylls and fatty acids during the growth of Arthrospira platensis.

Spirulina platensis (=Arthrospira platensis) is a tunisian strain which has been isolated for the first time in Oued Essed (Sousse, Sidi Bou Ali). Biomass evolution, proteins, chlorophylls and fatty acids composition of this alga were monitored by varying nitrogen concentrations in the culture medium. Nitrogen stress was provoked by adding sodium nitrate (NaNO3) in the culture medium with concentrations varying from 0 to 5 g/l. Results obtained showed that nitrogen depletion increased total proteins and total chlorophylls. The addition of NaNO3 (5g/l) led to an increase of total fatty acids amounts and modify fatty acids composition. Optimal quantities of palmitic, gamma -linolenic and oleic acids were obtained with NaNO3 free-cultures. Thus, the tunisian strain has valuable biological substances, worthy to determine the optimal conditions for its propagation.

Comparison of pistachio hull essential oils from different Tunisian localities.

Pistachio (Pistacia vera L.) fruit is well known for its oleaginous and edible seed. Less information is available about the hull constituted by the epicarp and the mesocarp. This part of the fruit contains an essential oil that can be valorized. Tunisia is one of the countries cultivating pistachio trees. This work presents essential oil composition of pistachio hulls (Mateur variety) from different geographical localities: Grombalia (North-East), Kairouan (Middle) and Sfax (Middle-East). Yields were more important in Sfax samples (0.53% on a dry weight basis). Alpha-terpinolene was the major compound for Grombalia fruits (35.7%), whereas Kairouan and Sfax samples where characterized by alpha-pinene (42.5 and 43.8% respectively). For all samples, monoterpene hydrocarbons predominated (more than 79.8% of the essential oil).

Chlorophylls, proteins and fatty acids amounts of arthrospira platensis growing under saline conditions.

Spirulina platensis (Arthrospira platensis) is a Tunisian strain isolated for the first time, in Tunisia, in Oued Essed (Sidi Bou Ali, in Sousse region). Evolution of biomass, proteins, chlorophylls and fatty acids (FA) has been followed during Spirulina growth. Experiments were carried out by varying sodium chloride concentrations in the culture medium in a range from 1 g L(-1) (natural environment) to 60 g L(-1). Results analysis showed an increase in chlorophyll amounts at 15 g L(-1) NaCl in 10 days old cultures but a decrease at high NaCl concentrations. Optimal proteins amounts was observed at 15 g L(-1) NaCl in young cultures (5 and 10 days). FA composition was modified by NaCl and depended on culture age. Cultures exposed to high salinity concentrations showed not only a decrease in growth rate but also a loss in total fatty acids TFA quantities. Samples cultured over 15 days at 30 g L(-1) NaCl rendered optimal quantities of lipids and gamma-linolenic acid.