The chemical composition of eight Tunisian Rosmarinus officinalis L. populations (A–H) from different bioclimatic areas has been examined by gas chromatography (GC) and GC-mass spectrometry. The essential oils are characterised by high amounts of oxygenated monoterpenes (58.2–71.7%) followed by monoterpene hydrocabons (15.1–26.7%). 1,8-Cineole, camphor, α-pinene and borneol are the main representative components. The antioxidant activity was investigated by 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), ferric reducing ability power assay and β-carotene bleaching test. Samples showed antiradical activity by inhibiting DPPH radical with IC50 values ranging from 375.3 to 592.8 μg mL− 1 for samples F and A, respectively. Sample A also showed the most promising activity in β-carotene bleaching test (IC50 of 31.9 μg mL− 1). The essential oils were also screened for acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity. Sample G showed the highest activity against AChE (IC50 of 64.7 μg mL− 1) while sample D (IC50 of 29.5 μg mL− 1) exhibited the most potent activity against BChE.

BACKGROUND:As a part of our investigation on Tunisian medicinal plants, we have carried out a phytochemical investigation of the hexane extracts from leaves of Cistus libanotis, C. villosus and C. monspeliensis, evualuating also their possible antiproliferative activity in vitro.RESULTS:The major compounds of hexane extracts were identified and quantified by GC-MS. The composition of the three species, although belonging to the same genus, is completely different. The antiproliferative activity was evaluated against murine monocyte/macrophages (J774.A1), human melanoma cells (A-375), and human breast cancer cells (MCF-7), showing major activity against the human melanoma cell line A-375.CONCLUSIONS:The chemical composition of the hexane extracts from the three Cistus species can be useful in the chemosystematics of this complex genus. The preliminary antiproliferative activity against human melanoma cell line A-375 deserve further investigations in order to determine the compounds, or their combinations, which are the main responsible for the antiproliferative activity and its possible mechanism(s) of action.

The present investigation focuses on the methanolic extract obtained from Geranium robertianum L. (Geraniaceae) (Herb Robert), a herbal plant used in traditional medicine for the treatment of human and animal diseases. The antioxidant capacities of the extract were evaluated using 1,1-diphenyl-2-picrylhydrazyl radical, β-carotene/linoleic acid and reducing power and metal chelating activity assays. The amount of total phenolic content, flavonoids and condensed tannins was very high, and the correlation between the antioxidant activity potential and total phenolic level of the extract was pointed out.

A comparative study of phytochemicals content and biological properties of eight Rosmarinus officinalis (rosemary) populations (RO1–RO8) collected in different areas of Tunisia was carried out. Two of the main rosemary constituents, rosmarinic and carnosic acids, were quantified by an NMR technique. Carnosic acid content was higher than that of rosmarinic acid. The non-polar constituents were examined by GC and GC–MS. Total phenols and flavonoids content were also determined in order to discuss the possible correlation between these phytochemicals and bioactivity. Antioxidant activity was investigated through different in vitro assays. Sample RO3 from a sub-humid area showed the highest potency in 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay (IC50 of 6.74 μg/mL) while RO5 from arid area exhibited the highest radical 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) scavenging activity (IC50 of 5.92 μg/mL). The most active sample in Ferric Reducing Antioxidant Power (FRAP) assay was RO4 (62.21 μM Fe(II)/g), followed by RO1–RO3 and RO8 harvested in sub-humid areas with values in the range 49.61–58.72 μM Fe(II)/g. Extracts were able to inhibit acethylcholinesterase (AChE) and butyrylcholinesterase (BChE). Sample RO5 exhibited a promising AChE inhibitory activity (IC50 of 4.47 μg/mL). Thus, we suggest rosemary extracts as a functional food ingredient for preventing AD.

This study analyses the chemical composition and invitro antioxidant activity of both the essential oil and the 80% aqueous acetone extract of Tetraclinis articulata leaves. The GC-MS analysis of the essential oil identified 66 components that comprise 93.5% of the oil. The major constituents of the oil are: bornyl acetate (31.4%), -pinene (24.5%) and camphor (20.3%). Antioxidant activities of the samples were determined using four different test systems, namely DPPH, -carotene/linoleic acid, reducing power and metal chelating activity assay. Test results from the DPPH system showed the strongest radical scavenging activity was exhibited by the 80% aqueous acetone extract (IC50=5.5 mu gmL(-1)), which was two times higher than the positive control (BHT). The amount of the total phenolics, flavonoids and condensed tannins was very high in the 80% aqueous acetone extracts. The correlation between the antioxidant activity potential and total phenolic level of the extract was noted.

Transgene integration into plant genomes is a complex process accompanied by molecular rearrangements. Classic methods that are normally used to study transgenic population genetics are generally inadequate for assessing such integration. Two major characteristics of transgenic populations are that a transgenic genome may harbor many copies of the transgene and that molecular rearrangements can create an unstable transgenic locus. In this work, we examined the segregation of T1, T2 and T3 transgenic tobacco progenies. Since transfer DNA (T-DNA) contains the NptII selectable marker gene that confers resistance to kanamycin, we used this characteristic in developing a method to estimate the number of functional inserts integrated into the genome. This approach was based on calculation of the theoretical segregation ratios in successive generations. Mendelian ratios of 3:1, 15:1 and 63:1 were confirmed for five transformation events whereas six transformation events yielded non-segregating progenies, a finding that raised questions about causal factors. A second approach based on a maximum likelihood method was performed to estimate recombination frequencies between linked inserts. Recombination estimates varied among transformation events and over generations. Some transgenic loci were unstable and evolved continuously to segregate independently in the T3 generation. Recombination and amplification of the transgene and filler DNA yielded additional transformed genotypes.

This study is designed to examine the phenolic content and composition and antioxidant activity of the methanol extracts of Coriandrum sativum L. seed, whole fruit and pericarp.Seed presented the higher antioxidant capacities with 77.46 mg GAE/g followed by whole fruit (65.58 mg GAE/g) and pericarp (61.41 mg GAE/g). Total phenol contents were 15.55 mg GAE/g in seed, 12.10 mg GAE/g in whole fruit and 2.92 mg GAE/g in pericarp. Concerning total flavonoid contents, they were 13.20 mg CE/g in whole fruit, 19.98 mg CE/g in seed and 1.01 mg CE/g in pericarp. Condensed tannins were present in whole fruit and seed with 0.70 and 0.62 mg CE/g, respectively. Pericarp showed the lower tannin content (0.24 mg CE/g). Among the polyphenols studied, 18 were identified in whole fruit, 15 in seed and 10 in pericarp. The main phenolic compound was dihydroxyphenolic acid with 85.01 mg/100 g in whole fruit, 101.5 mg/100 g in seed and 10.52 mg/100 g in pericarp.Antioxidant activities of the methanolic extract from coriander fruit different parts were evaluated by using DPPH radical scavenging, beta-carotene-linoleic acid bleaching and the reducing power tests. All fruit parts extracts showed remarkable DPPH radical scavenging activity with IC50 values of 42 and 32 mu g/mL in seed and whole fruit, respectively. However, in pericarp extract DPPH scavenging ability was higher than that of BHT (IC50 = 25 mu g/mL). The extracts had lower beta-carotene bleaching activity than BHA and BHT. Coriander fruit extracts presented a very low reducing power ability (EC50 approximate to 700 mu g/mL) compared to ascorbic acid (EC50 = 40 mu g/mL).

This study is designed to examine the fruit essential oil composition, the total phenolic amounts and the antioxidant activities in methanolic extracts of Coriandrum sativum under saline conditions. Increasing NaCl levels to 75mM reduced significantly the fruit yield by 36%. The essential oil yield was 0.30%, based on the dry weight; it increased by 77% and 84% at 50 and 75mM NaCl, respectively, in comparison to the control. The major constituents were linalool and camphor, whose amounts increased with increasing NaCl concentrations. Antioxidant activities of the methanol extracts were determined by three different test systems, namely DPPH, β-carotene/linoleic acid and reducing power assays. In these three test systems, the highest activity was exhibited in control plants and was reduced significantly with increasing NaCl levels. In control plants, the total phenolic amount was 1.04mg GAE/g DW which decreased by 43% and 66% at 50 and 75mM NaCl, respectively.

Tocopherol contents of Tunisian Laurus nobilis vegetative organs were screened for antioxidant activity. Tocopherol isomers extracted by probe sonication and micro-scale saponification were analysed by reversed-phase high performance liquid chromatography (RP-HPLC) with UV detection to determine the optimum extraction method. Total phenolic, flavonoid and proanthocyanidin contents were determined spectrophotometrically. Significant variations in the amounts of α-, γ- and δ-tocopherols were observed with the two different extraction methods as well as with different plant parts. Leaf extract contained the highest amount of α-tocopherol (139mg/100g fresh weight), but root extract contained the highest content of flavonoids (11.12mgcatechin equivalents (CE)/gdry weight or DW), total phenolics (55.45±2.9mgGAE/gDW) and condensed tannins (9.76±0.1mgCE/gDW). Acetonic extract of laurel leaf exhibited the highest antioxidant activity response to lipid peroxidation in the β-carotene–linoleic acid system, which may have been due to the high content of α-tocopherol. These findings suggest that laurel leaf may be a source of natural α-tocopherol and that it may be increasingly important for human consumption, as well as for the agro-food, cosmetic and pharmaceutical industries.

Melanin plays an important role in the prevention of DNA damage and protection of skin tissues from UV irradiation. However, excessive accumulation of melanin can also cause freckle and melanoma. Thus, we focused on the melanogenesis regulation effect of Tunisian aromatic plants. The melanin synthesis system is known as melanogenesis, and tyrosinase is a key enzyme of melanogenesis (Fang and Setaluri, 1999; Kameyama et al., 1995). Currently, many research efforts have focused on the specific mechanism involved in melanogenesis. It has been reported that ERK1/2 phosphorylation is related to the inhibition of melanogenesis (Kim et al., 2006). Murine melanoma B16 cells were treated with the extract of Tunisian aromatic plants, namely, Capparis spinosa, Erica multiflora and Thymelaea hirsuta, and then cell viability and synthesized melanin content were measured. The C. spinosa and E. multiflora extract increased the synthesized melanin content in B16 cells without cytotoxity. The tyrosinase expression was clearly increased in cells treated with the extracts. The T. hirsuta extract significantly decreased the synthesized melanin content in B16 cells without cytotoxicity. ERK1/2 was immediately phosphorylated in cells just after treatment with the extract. The tyrosinase expression was inhibited in cells treated with the extracts.

This study was designed to examine the chemical composition and antioxidant activity of the essential oils and methanol extracts of Myrtus communis var. italica L. leaf, stem and flower. Myrtle leaf and flower were the valuable organs for the essential oil production representing a yield of 0.61% and 0.30% (w/w), respectively. The essential oil composition of myrtle leaf and flower was characterized by high proportions of alpha-pinene, the main compound of monoterpene hydrocarbon class, with 58.05% for leaf and 17.53% for flower. Stem was rich in oxygenated monoterpenes, largely due to 1,8-cineole with 32.84%. The total phenol contents varied between different myrtle parts; leaf extract had higher total phenol content (33.67 mg GAE/g) than flower (15.70 mg GAE/g) and stem (11.11 mg GAE/g) extracts. Significant differences were also found in total tannin contents among different myrtle parts, representing 26.55 mg GAE/g in leaf, 11.95 mg GAE/g in flower, 3.33 mg GAE/g in stem. The highest contents of total flavonoids and condensed tannins were observed in stem (5.17 and 1.99 mg CE/g, respectively) and leaf (3 and 1.22 mg CE/g, respectively) extracts. The HPLC analysis indicated that the main phenolic class was hydrolysable tannins (gallotannins) in leaf (79.39%, 8.90 mg/g) and flower (60.00%, 3.50mg/g) while the stem was characterized by the predominance of flavonoid class (61.38%, 1.86 mg/g) due to the high presence of catechin (36.91%, 1.12 mg/g). Antioxidant activities of the essential oil and the methanolic extract from different myrtle parts were evaluated by using DPPH radical scavenging, beta-carotene-linoleic acid bleaching, reducing power and metal chelating activity assays. In all tests, methanolic extracts of different myrtle parts showed better antioxidant activity than essential oils.

The variation in the content and composition of Origanum majorana L. essential oil has been studied. Plant material has been harvested at four phenological stages (early vegetative, late vegetative, budding and full-flowering). Essential oil yield varied from 0.04 to 0.09% reached during the full-flowering stage. Analysis of the essential oils by GC and GC/MS revealed the presence of 38 components represented mainly by oxygenated monoterpenes (64.01–71.4%), monoterpene hydrocarbons (21.73–29.92%) and sesquiterpene hydrocarbons (1.47–4.05%). The main components were terpinen-4-ol (29.13–32.57%), cis-sabinene hydrate (19.9–29.27%), trans-sabinene hydrate (3.5–11.61%), γ-terpinene (2.11–8.20%), bornyl acetate (1.52–2.94%) and linalool (1.05–1.39%). On the other hand, phenolic contents varied from 2.706 to 6.834mg/g of dry weight obtained during the later vegetative stage. RP-HPLC analysis of the methanolic extract of O. majorana L. dried aerial parts showed the predominance of phenolic acids during the early vegetative stage whereas flavonoids predominate during the other stages of growth. The main phenolic acids identified were trans-2-hydroxycinnamic, rosmarinic, vanillic, chlorogenic, gallic and cinnamic whereas the main flavonoids were amentoflavone, apigenin, quercetin, luteolin, coumarin and rutin. Results obtained showed that later vegetative stage is characterized by the highest contents of bioactive compounds and therefore it could be considered as the best stage for harvesting marjoram plants.

A glasshouse experiment was conducted to assess the effect of different NaCl concentrations (25, 50, 75 and 100mM) on plant growth, essential oil production and composition of Salvia officinalis fruits. The first results showed that increasing NaCl levels to 100mM reduced significantly the plant growth by 65%. While, the essential oil yield increased significantly from control to 75mM and decreased only at 100mM NaCl. Salt stress affect also the essential oil compounds mainly the major ones. Hence, viridiflorol was the main essential oil compound at control and 25mM NaCl, 1,8-cineole became the predominant compound at 50 and 75mM and manool prevailed at 100mM. The oxygenated monoterpenes were the main class at all the treatments except at severe one when the diterpenes were the main ones.

Hair growth problems can affect human physical and mental health and are of particular relevance during the aging process. In an effort to resolve such problems, we attempted to find plants having hair growth regulation activity and thus collected plant extracts from Tunisia for bioprospecting purposes. Among them, we investigated the Erica multiflora extract to evaluate the hair growth promotion activity by using the MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide) assay and cell cycle assay on human dermal papilla cells in vitro and an administration assay on mouse dorsal skin in vivo. The results showed that the Erica multiflora extract promotes dermal papilla cell growth and cell cycle with high activity, and induced hair growth in vivo by induction of anagen phase from telogen phase.

In the present investigation, seed methanolic extracts of three Vitis vinifera (Muscat d’Italie, Syrah and Carignan) were assayed for their antioxidant activities. Results showed that there are strong variations in the contents of total phenols (440.97–121.94mg GAEg−1DW), flavonoids (48.07–16.81mgECg−1DW) and tanins (37.15–14.9mg ECg−1DW) from the studied seeds. The phenolic composition of these extracts was determined by RP–HPLC after acid hydrolysis. The main phenolic compound was quercetin with 27.2% in Muscat d’Italie, 48.8% in Syrah and 28.4% in Carignan. Besides, all seed extracts showed remarkable DPPH radical scavenging activity with IC50 values ranged from 1.8 to 30μgml−1. EC50 values of reducing power activity ranged from 100 to 120μgml−1. The high phenolic content and the considerable antioxidant activities of vitis seed extracts could potentially be considered as an expensive source of natural antioxidants.

The effect of Tunisian Capparis spinosa L. aromatic plant extract on melanogenesis regulation in B16 murine melanoma cells was investigated. B16 cells were treated with 0.0005, 0.005, and 0.05% (w/v) C. spinosa extract after which the melanin content and cell viability were measured. To clarify the mechanism behind melanogenesis regulation, the expression of tyrosinase was determined. Results showed that the extract had a significant stimulative effect on melanogenesis in B16 cells in a dose-dependent manner without cytotoxicity. Western blot analysis showed that expression of tyrosinase in cells treated with 0.03% (w/v) C. spinosa extract increased by 12.5- and 20-fold after 24 and 48 h of incubation, respectively, compared with untreated cells. HPLC analysis of the extract revealed the presence of 1% quercetin, a known melanogenesis stimulator, indicating that our findings may be attributed to quercetin; however, other compounds present in the extract may also have an effect on the overall ability of the extract to stimulate melanogenesis. We report here that Tunisian C. spinosa leaf extract can stimulate melanogenesis in a dose-dependent manner without cytotoxicity by increasing tyrosinase protein expression and has the potential to be used as a possible tanning agent or as a treatment for hair depigmentation.

The chemical composition of Tunisian Nigella sativa L. seeds was investigated. The results showed that linoleic acid (C18:2) was the major fatty acid with 65.1% of total fatty acids (TFAs) followed by oleic acid (C18:1) with 12.7% of TFAs. Neutral lipids (NLs) were mainly composed of triacylglycerols with 98.4% of total NLs. Polar lipids were mainly composed of phosphatidylcholine as the major phospholipid subclass, whereas digalactosyldiacylglycerol was the major galactolipid. Total sterols (TSs) represented 2.2% of the fixed oil and were composed of (-sitosterol as the major sterol representing 60.2% of the TSs. The results indicated that the sterols were mainly present in the esterified and in the free forms with 51.2 and 36.1%, respectively, of TS content. Finally, the aroma composition of the volatile oil from oleoresin exhibited the presence of many bioactive compounds such as p-cymene as the major component followed by ocimene, alpha-thujene, octen-3-ol with appreciable rates of 1,8-cineole and thymol.

The Anacardiaceae family is known for its species producing essential oil, such as Pistacia genus. As for pistachio tree (Pistacia vera), its fruit is composed by a fleshy and odorant envelope or hull (mesocarp + epicarp) covering the hard shell (endocarp) containing an edible seed. We aimed to characterize the oils of pistachio hulls (Pistacia vera L.) during fruit development. Fruits were sampled in the region of Kairouan (Middle of Tunisia). Yields generally increased and ranged between 0.1-0.4% on a dry weight basis. Monoterpene hydrocarbons, mainly represented by alpha-pinene (15.0-47.4%) and terpinolene (32.2-51.1%) were prominent during all fruit development, reaching 90.3% of the oil at full ripeness.

Phytosterols are bioactive components of all vegetable foods. Their most studied and outstanding properties being their cholesterol-lowering activity. This property has led to the development of functional foods enriched with plant sterols. In the present study, total and conjugated sterols of Tunisian safflower seeds were investigated and their kinetic of accumulation was surveyed during the ripening stages. The results obtained revealed that total and individual phytosterols were actively accumulated during the first stages of seed development then their levels decreased until full maturity. In the other hand, the sterol profile was marked by the predominance of beta-sitosterol during all ripening stages. As for Free Sterols (FS) and Esterified Sterols (ES), they were the major components and were actively accumulated from the beginning of seed development. Nevertheless, their amounts decreased at the end of maturity while Steryl Glycosides (SG) and acylated sterylglycosides (ASG) were practically stable during the ripening of seeds.