The Effect of Secreted IL-10 from Mesenchymal Stem Cell on Immune Checkpoint Molecules.

Background: Immunosuppression in sepsis is hypothesized to result from the increased expression of the immune checkpoint molecules programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1). PD-1 and PD-L1 blockade therapies have been reported to increase survival in septic animals. Currently, the interleukin (IL)-10 within mesenchymal stem cell (MSC) secretome is known for its immunomodulatory capacity. Objective: To study the effect of IL-10 within MSC secretome on the expression of immune checkpoints in the rat model of sepsis. Methods: We used 48 male Rattus norvegicus rats in this research and divided them into four groups: sham (rats without sepsis induction and treatment), control (sepsis-induced rats without treatment), T1 (sepsis-induced rats treated with 150 µL of secreted IL-10 from MSC), and T2 (sepsis-induced rats treated with 300 µL of secreted IL-10 from MSC). Forty-eight hours after sepsis induction, we terminated the rats and collected the blood to examine the PD-1 and PD-L1 expression levels. Results: We found a decrease in the relative expression of PD-1 in the septic rat group given 150 µL and 300 µL of secreted IL-10 from MSC compared to the control group, but the decrease was not significant. We also found a decrease in the relative expression of PD-L1 mRNA in the septic rat group given 150 µL and 300 µL of secreted IL-10 from MSC compared to the control group. Conclusion: Administering secreted IL-10 from MSC reduces the expression of PD-1 and PD-L1 in sepsis. These findings suggest that MSC secretome can improve the immunosuppression in sepsis.

The Role of Mesenchymal Stem Cell Secretome in the Inflammatory Mediators and the Survival Rate of Rat Model of Sepsis.

In sepsis, simultaneously elevated levels of pro-inflammatory cytokines and interleukin (IL)-10 indicate immune response dysregulation, increasing the mortality of the host. As mesenchymal stem cell (MSC) secretome is known to have immunomodulatory effects, we aim to assess the role of MSC secretome in the inflammatory mediators (NF-κB p65 and p50, TNF-α, IL-10) and the survival rate of a rat model of sepsis. In this study, forty-eight male Rattus norvegicus rats were divided into one sham group and three groups with sepsis induction: the control group and the sepsis-induced rat groups treated with 150 µL (T1) and 300 µL (T2) of secretome. The survival rate was observed per 6 h for 48 h and plotted using the Kaplan-Meier method. Compared to the control group, T2 showed a significant decrease in the relative expression of NF-κB and the serum TNF-α level, and a significant increase in the serum IL-10 level. Meanwhile, T1 showed a significant decrease in the serum TNF-α level compared to the control group. The Kaplan-Meier Log Rank test did not show significance in the distribution of survival between T1, T2, and the control group. However, from the 18th to the 36th hour, the survival rate of T2 was lower than the survival rate of the control group and T1, with a noticeable difference between T2 and the control group, as well as T1 at the 36th hour. At the 42nd hour, the survival rate of T2 was the same as the control group and remained lower than T1. In conclusion, MSC secretome regulated the inflammatory mediators in rat model of sepsis, with a dose of 150 µL being more effective.

N-Cadherin Expression with Metastasis of Neck Lymph Nodes in Patients with Nasopharyngeal Carcinoma.

Background: Lymph node (LN) metastases were one characteristic of negative progress of NPC patient despite its advanced therapeutic approaches. One mechanism for the occurrence of epithelial to mesenchymal transition (EMT)-mediated metastases is by increasing N-cadherin expression. The purpose of this research is to determine investigating N-cadherin expression against metastatic LN in NPC cases. Methods: Samples were taken by unproportionate stratified random sampling. N-cadherin expression was examined using immunohistochemistry methods. N-cadherin expression was assessed visually by binocular light microscopy. We analyzed these data using Mann-Whitney U-test to examine N-cadherin expression and lymph node metastases. Results: A strong expression was found in N3 group by 63.6%; 27.3% in the N2 group and 9.1% in the N1 group. In patients with NPC N0 or without lymph node metastases, N-cadherin expression is 0%. The expression of N-cadherin is indeed an indicator of the occurrence of lymph node metastases in NPC with a statistically significant analysis of p = 0.026 (p < 0.05). Conclusion: There were correlations between N-cadherin expression and lymph node metastasis on NPC patients.

Rats' umbilical-cord mesenchymal stem cells ameliorate mast cells and Hsp70 on ovalbumin-induced allergic rhinitis rats.

Aim Allergic rhinitis (AR) is a heterogeneous condition that has been associated with inflammatory responses and is characterized by clinical typical symptoms of nasal itching, sneezing, watery discharge and congestion. Mesenchymal stem cells (MSCs) are multipotent stem cells that have the immunoregulatory ability by secreting various cytokines which potent as a promising therapeutic modality for allergic airway diseases, including AR. The aim of this study was to investigate the effect of rat UC-MSCs on the number of mast cells, the expression of Hsp70 indicated by the nasal symptoms allergic, particularly nasal rubbing in ovalbumininduced AR rats. Methods Fifteen male Wistar rats (6 to 8 weeks old) were randomly divided into three groups (control group, sham group, and OVA+MSCs group). OVA nasal challenge was conducted daily from day 15 to 21, and UC-MSCs (1x106 ) were administrated intraperitoneally to OVA-sensitized rats on day 21. Nasal rubbing was observed from day 22 to 28. The rats were sacrificed on day 22 and day 28. The nasal cavity tissues were prepared for histological observations. Results The administration of UC-MSCs could reduce the number of mast cells and the expression of Hsp70 leading to reduction of nasal symptoms allergic, particularly nasal rubbing. Conclusion Based on this finding, MSCs present a promising immediate curative effect to the inflammatory reaction in AR rats.

The CD4+CD25+FoxP3+ Regulatory T Cells Regulated by MSCs Suppress Plasma Cells in a Mouse Model of Allergic Rhinitis.

BACKGROUND: Allergic Rhinitis (AR) is the most common immunological disease that has been associated with inflammatory responses and is characterized by sneezing. Previous studies found that AR's allergen exposure significantly induces plasma cells and reduces regulatory T (Treg) cells, a population that contributes to control AR. Therefore, upregulating Treg expression can regulate plasma cells leading to inhibit sneezing in AR. Mesenchymal stem cells (MSCs) are multipotent stem cells that have the immunoregulatory and antiinflammation ability by secreting various cytokines including IL-10 and TGF-ß which potent as a promising therapeutic modality for allergic airway diseases, including AR. OBJECTIVE: To investigate the role of MSCs in generating CD4+, CD25+, and Foxp3+ Regulatory T cells associated with suppressing plasma cell in AR model. METHODS: In this study, fifteen male Wistar rats (6 to 8 weeks old) were randomly divided into three groups (control group, sham group, and MSCs treatment group). OVA nasal challenge was conducted daily from day 15 to 21, and MSCs (1x106) were administrated intraperitoneally to OVA-sensitized rats on day 21. Sneezing was observed from day 22 to 28. The rats were sacrificed on day 22 and day 28. The expression of CD4+ CD25+ Foxp3+ in Treg and plasma cells was analyzed by flow cytometry assay. RESULTS: This study showed that the percentage of plasma cell and sneezing times significantly decreased in MSCs treatment. This finding was aligned with the significant increase of CD4+CD25+Foxp3+ Treg level. CONCLUSION: MSCs administration suppress plasma cells population and sneezing times by up regulating Treg to control AR.

Application of sodium alginate extracted from a Tunisian brown algae Padina pavonica for essential oil encapsulation: Microspheres preparation, characterization and in vitro release study.

In recent years, there has been considerable interest in essential oils encapsulation and in developing biodegradable microparticles. The aim of this present work was to prepare clove essential oil loaded microspheres, by a modified emulsification method, using sodium alginate extracted from a Tunisian Brown seaweed Algae Padina pavonica as biopolymer. The obtained microparticles were characterized by FT-IR, DSC and SEM. Loading capacity yield, encapsulation efficiency (%EE) and in vitro release of the essential oil were also investigated. Sodium alginate microspheres were successfully prepared as confirmed by physico-chemical characterizations. %yield of microspheres and %EE of essential oil were 72.73% and 24.77% ±â€¯7.47%, respectively. SEM showed pseudospherical microspheres with rough surface ranging, in size, from 1500 µm to 3000 µm. In vitro dissolution study indicates a controlled released of the essential oil which follows, mainly, classical Fickian diffusion. Thus, this present work highlighted the potential of this polysaccharide as a biopolymer to formulate polymeric microspheres.

Decreased Protein Kinase C Expression in the Cochlear Fibroblasts of Diabetic Rat Models Induced by Curcumin.

OBJECTIVES: Microcirculation and hemodynamic disturbances, including in the cochlea, are commonly found in diabetic patients. A study on diabetic rats discovered histopathological changes in outer hair cells and the spiral ganglion and mitochondrial damage in the ear. Hyperglycemia can increase the activation of protein kinase C (PKC). Curcumin as an antioxidant also affects the regulation of PKC and Ca2+. The aim of this study was to determine the role of curcumin in decreasing PKC expression in the cochlear fibroblasts of diabetic rats. MATERIALS AND METHODS: An experimental study was performed on 24 Wistar rats divided into the following 6 groups: group 1: control group; group 2: diabetic group without curcumin administration; groups 3 and 4: diabetic groups with curcumin administration (200 mg/kg and 400 mg/kg for 3 days, respectively); groups 5 and 6: diabetic groups with curcumin administration (200 mg/kg and 400 mg/kg for 8 days, respectively). Cochlear tissues were taken from all groups and immunohistochemistry-stained, and the PKC expression scores were analyzed with one-way ANOVA (a significance level of 0.05). RESULTS: Significant differences in PKC expression (p<0.05) were found between group 1 and group 2, and group 2 and groups 3, 4, 5, and 6. There was no significant difference in PKC expression regarding the different doses and the duration of curcumin administration. CONCLUSION: Curcumin can reduce PKC expression in the cochlear fibroblasts of diabetic rats.

Correlation of P38 Mitogen-Activated Protein Kinase Expression to Clinical Stage in Nasopharyngeal Carcinoma.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is uncommon and usually diagnosed at the advanced stage. A subfamily of mitogen-activated protein kinase which is called p38 mitogen-activated protein kinase (MAPK) involved in response to stress, and plays an important role in cell regulation. There is a suggestion that p38 mitogen-activated protein kinase could be a potential biomarker to determine the clinical stage of nasopharyngeal carcinoma. AIM: The aim of this study is for observing and analysing the correlation of p38 mitogen-activated protein kinase expression in regards to nasopharyngeal carcinoma patient's clinical stage. METHODS: This study involved 126 nasopharyngeal carcinoma patients admitted to Haji Adam Malik General Hospital. RESULTS: The result of this study indicates that nasopharyngeal carcinoma mostly found in the age group 41-60 years, male, non-keratinizing squamous cell carcinoma, and stage IV group. In immunohistochemistry evaluation, most of p38 mitogen-activated protein kinase overexpressed in non-keratinizing squamous cell carcinoma, T3-T4, N2-N3 and clinical stage III-IV. Spearman's test for categorical correlation yield p-value of < 0.001. CONCLUSION: In conclusion, there is a significant correlation between p38 mitogen-activated protein kinase expression and the clinical stage of nasopharyngeal carcinoma.

Cyclooxygenase-2 Expression and Its Correlation with Primary Tumor Size and Lymph Node Involvement in Nasopharyngeal Carcinoma.

AIM: This study aimed to observe the cyclooxygenase-2 expression and its correlation with tumour size and lymph node involvement in nasopharyngeal carcinoma. METHODS: This study was cross-sectional, that enrolled 126 samples diagnosed with nasopharyngeal carcinoma in Haji Adam Malik General Hospital, Medan, Indonesia which fulfilled the inclusion criteria. RESULTS: Based on this study, we found that the age peak incidence of nasopharyngeal carcinoma patients about a 41-60-year-old group (57.1%), dominated by men (71.4%). Through histopathological examination, non-keratinizing squamous cell carcinoma is the most predominant type (79.4%). We also found T3 is the most prevalent primary tumour size (32.5%) with prominent lymph node involvement N3 (45.2%), and stage IV (54.8%). Cyclooxygenase-2 overexpression is prevalent among nonkeratinizing squamous cell carcinoma (81.1%), T3 primary tumour size (41.1%), N3 node involvement (60.0%), and IV clinical stage (71.6%). In addition, we found a significant relationship between cyclooxygenase-2 expressions towards tumor size (p < 0.001) and lymph node involvement (p < 0.001) in nasopharyngeal carcinoma. CONCLUSION: It is proved that the overexpression of cyclooxygenase-2 will increase the susceptibility of nasopharyngeal carcinoma patients having advanced primary tumour size and lymph node involvement.

The Antiapoptotic Effect of Curcumin in the Fibroblast of the Cochlea in an Ototoxic Rat Model.

INTRODUCTION: This study aimed to show the potency of curcumin as an antiapoptotic agent that decreases the apoptotic index in the cochlea lateral wall in ototoxic rat models. MATERIALS AND METHODS: A total of 24 Rattus norvegicus were divided into eight groups: Group 1 (control group), Group 2 (gentamicin (+)), Group 3 (gentamicin + curcumin 20 mg/day), Group 4 (gentamicin + curcumin 40 mg/day), Group 5 (gentamicin + curcumin 20 mg/day for 7 days), Group 6 (gentamicin + curcumin 40 mg/day for 7 days), Group 7 (curcumin 20 mg/day for 3 days + gentamicin), and Group 8 (curcumin 40 mg/day for 3 days + gentamicin). After the division, the rats were terminated in order to measure the apoptotic index using a terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling (TUNEL) assay in the fibroblasts of the cochlea lateral walls. The data were analyzed using analysis of variance (ANOVA), and P<0.05 was used as the cut-off for statistical significance. RESULTS: Administration of gentamicin showed significant differences (P<0.05) in the apoptotic index. Groups undergoing curcumin treatment at a higher dose (200 mg/kg bw) and the prevention groups showed significant differences compared with groups not treated with curcumin. CONCLUSION: This study concluded that the apoptotic index can be decreased by curcumin and has a preventive benefit toward ototoxic rat models. The administration of curcumin depended on the dose and duration.

Structure-activity relationship study of hypoxia-activated prodrugs for proteoglycan-targeted chemotherapy in chondrosarcoma.

Due to an abundant chondrogenic, poorly vascularized and particularly hypoxic extracellular matrix, chondrosarcoma, a malignant cartilaginous tumour, is chemo- and radio-resistant. Surgical resection with wide margins remains the mainstay of treatment. To address the lack of therapy, our strategy aims to increase anticancer drugs targeting and delivery in the tumour, by leveraging specific chondrosarcoma hallmarks: an extensive cartilaginous extracellular matrix, namely the high negative fixed charge density and severe chronic hypoxia. A dual targeted therapy for chondrosarcoma was investigated by conjugation of a hypoxia-activated prodrug (HAP) to quaternary ammonium (QA) functions which exhibit a high affinity for polyanionic sites of proteoglycans (PGs), the major components of the chondrosarcoma extracellular matrix. Based on preclinical results, an imidazole prodrug, ICF05016, was identified and provided the basis for a lead optimization study. A series of 27 QA-phosphoramide mustard conjugates, differing by the type of QA function and the length of the alkyl linker, was yielded by a common multi-step sequence involving phosphorylation of a key 2-nitroimidazole alcohol. Then, a screening was realized by surface plasmon resonance technology to assess biomolecular interactions between QA derivatives and aggrecan, the most abundant PG in chondrosarcoma. Results revealed that affinity depends more on the type of QA function, than on the linker length. Moreover, the presence of a benzyl group enhanced affinity to aggrecan. Twelve compounds were shortlisted and evaluated for antiproliferative activity (i.e., growth inhibiting concentration 50), under normoxic and hypoxic conditions using the human extraskeletal myeloid chondrosarcoma cell line (HEMC-SS). For all prodrugs, hypoxic selectivity was maintained and even increased, compared with the lead. From this study, compound 31f emerged as the most effective PG-targeted HAPs with a dissociation constant of 2.10 µM in the SPR experiment, a hypoxia cytotoxicity ratio of 24 and an efficient reductive cleavage under chemical and enzymatic conditions.

An Uncommon Occurrence of Pleomorphic Adenoma in the Submandibular Salivary Gland: A Case Report.

BACKGROUND: Pleomorphic adenoma is a salivary gland tumour and mostly found in the parotid gland and quite uncommon in the submandibular gland. Pleomorphic tumours are a mixed tumour (benign mixed tumour) consisted of epithelium, myoepithelium, and mesenchyme and made of a view component variation of it. CASE REPORT: We reported a fifty-three years old man with pleomorphic adenoma that has been complaining swelling on the left neck for the last twenty years and treated with surgical excision. Computed tomography of the neck showed soft tissue tumour in the left submandibular. CONCLUSIONS: The best management for pleomorphic adenoma is surgery, the tumour tissue must be removed as a whole because the remaining parts of a tumour can easily become recurrent or turn into a malignant tumour.

Chemical composition of 8 eucalyptus species' essential oils and the evaluation of their antibacterial, antifungal and antiviral activities.

BACKGROUND: In 1957, Tunisia introduced 117 species of Eucalyptus; they have been used as fire wood, for the production of mine wood and to fight erosion. Actually, Eucalyptus essential oil is traditionally used to treat respiratory tract disorders such as pharyngitis, bronchitis, and sinusitis. A few investigations were reported on the biological activities of Eucalyptus oils worldwide. In Tunisia, our previous works conducted in 2010 and 2011 had been the first reports to study the antibacterial activities against reference strains. At that time it was not possible to evaluate their antimicrobial activities against clinical bacterial strains and other pathogens such as virus and fungi. METHODS: The essential oils of eight Eucalyptus species harvested from the Jbel Abderrahman, Korbous (North East Tunisia) and Souinet arboreta (North of Tunisia) were evaluated for their antimicrobial activities by disc diffusion and microbroth dilution methods against seven bacterial isolates: Haemophilus influenzae, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus pneumoniae and Streptococcus pyogenes. In addition, the bactericidal, fungicidal and the antiviral activities of the tested oils were carried out. RESULTS: Twenty five components were identified by GC/FID and GC/MS. These components were used to correlate with the biological activities of the tested oils. The chemical principal component analysis identified three groups, each of them constituted a chemotype. According to the values of zone diameter and percentage of the inhibition (zdi, % I, respectively), four groups and subgroups of bacterial strains and three groups of fungal strains were characterized by their sensitivity levels to Eucalyptus oils. The cytotoxic effect and the antiviral activity varied significantly within Eucalyptus species oils. CONCLUSIONS: E. odorata showed the strongest activity against S. aureus, H. influenzae, S. agalactiae, S. pyogenes, S. pneumoniae and against all the tested fungal strains. In addition, E. odorata oil showed the most cytotoxic effect. However, the best antiviral activity appeared with E. bicostata. Virus pretreatment with E. bicostata essential oil showed better antiviral activity (IC(50) = 0.7 mg/ml, SI = 22.8) than cell-pretreatment (IC(50) = 4.8 mg/ml, SI = 3.33). The essential oil of E. astringens showed antiviral activity only when incubated with virus prior to cell infection. This activity was dose-dependent and the antiviral activity diminished with the decreasing essential oil concentration.

Correlation between chemical composition and antibacterial activity of essential oils from fifteen Eucalyptus species growing in the Korbous and Jbel Abderrahman arboreta (North East Tunisia).

The essential oils of fifteen Eucalyptus species harvested from the Jbel Abderrahman and Korbous arboreta (North East Tunisia) were screened for their antibacterial activities by the agar disc diffusion method. Eighteen major components as identified by GC/FID and GC/MS were selected for a study of the chemical and biological activity variability. The main one was 1,8-cineole, followed by spathulenol, trans-pinocarveol, α-pinene, p-cymene, globulol, cryptone, ß-phellandrene, viridiflorol, borneol, limonene and isospathulenol. The chemical principal component analysis identified five species groups and subgroups, where each group constituted a chemotype, however that of the values of zone diameter of the inhibition (zdi) identified six groups of Eucalyptus oils, characterized by their antibacterial inhibition ability. The strongest activity was shown by E. platypus oil against Enterococcus faecalis and by E. lamannii oil against Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. A correlation between the levels of some major components and the antibacterial activities was observed.

Chemical composition of the essential oils of the berries of Juniperus oxycedrus L. ssp. rufescens (L. K.) and Juniperus oxycedrus L. ssp. macrocarpa (S. & m.) Ball. and their antioxidant activities.

This study is outlined to probe the chemical composition of essential oil and in vitro antioxidant activity of Juniperus oxycedrus ssp. macrocarpa (S. & m.) Ball. and Juniperus oxycedrus L. ssp. rufescens (L. K.) berries, collected from four sites, according to their maturity phase. The chemical composition of the hydrodistilled essential oil was analysed by GC-MS. Forty-eight compounds were identified, accounting for approximately 79.8-98.9% of the oil. The main constituents were α-pinene, germacrene D, myrcene, abietadiene and cis-calamenene, their mean percentage vary according to their phenological stage. The antioxidant activity of the samples was determined by the ABTS and DPPH radical scavenging activities. Hawaria essential oil extracted from mature berries showed the highest antioxidant capacity.

Variation in volatile leaf oils of five Eucalyptus species harvested from Jbel Abderrahman arboreta (Tunisia).

Hydrodistillation of the dried leaves of five species of the genus Eucalyptus L' Hér., viz., E. dundasii Maiden, E. globulus Labill., E. kitsoniana Maiden, E. leucoxylon F. Muell., and E. populifolia Hook., harvested from Jbel Abderrahman arboreta (region of Nabeul, northeast of Tunisia) in April 2006, afforded essential oils in yields varying from 0.9±0.3 to 3.8±0.6%, dependent on the species. E. globulus and E. Kitsoniana provided the highest and the lowest percentage of essential oil amongst the species examined, respectively. Analysis by GC (RI) and GC/MS allowed the identification of 127 compounds, representing 93.8 to 98.7% of the total oil composition. The contents of the different samples varied according to the species. The main components were 1,8-cineole (2; 4.7-59.2%), followed by α-pinene (1; 1.9-23.6%), trans-pinocarveol (6; 3.5-21.6%), globulol (8; 4.3-12.8%), p-cymene (3; 0.5-6.7%), α-terpineol (1.5-4.5%), borneol (0.2-4.4%), pinocarvone (1.1-3.8%), aromadendrene (1.4-3.4%), isospathulenol (0.0-1.9%), fenchol (4; 0.1-2.5%), limonene (1.0-2.4%), epiglobulol (0.6-2.1%), viridiflorol (9; 0.8-1.8%), and spathulenol (0.1-1.6%). E. leucoxylon was the richest species in 2. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) separated the five Eucalyptus leaf essential oils into four groups, each constituting a chemotype.

Variation in volatile leaf oils of seven eucalyptus species harvested from Zerniza arboreta (Tunisia).

Leaves of seven species of the genus Eucalyptus L'Hér., viz., E. cladocalyx F. Muell., E. citriodora Hook., E. diversicolor F. Muell., E. fasciculosa F. Muell., E. grandis W. Hill, E. ovata Labill., and E. botryoides Sm., were harvested from Zerniza arboreta (region of Sejnene, northwest of Tunisia) in June 2007. Of the latter species, leaves were collected from trees having two origins, Morocco and Italy. Hydrodistillation of the dried leaves provided essential oils in yields varying from 0.4±0.0 to 3.3±0.1%, according to the species. E. citriodora had the highest mean percentage of essential oil amongst the species examined, whereas the lowest one was obtained for E. botryoides originating from Morocco. Analysis by GC (RI) and GC/MS allowed the identification of 140 compounds, representing 92.5 to 99.4% of the total oil composition. The contents of the different samples varied according to the species. The main components were 1,8-cineole (2), followed by α-pinene (1), p-cymene, borneol, α-terpineol, cryptone, spathulenol, trans-pinocarveol (4), bicyclogermacrene (5), caryophyllene oxide, and ß-phellandrene. Principal components analysis and hierarchical cluster analysis separated the eight Eucalyptus leaf essential oils into five groups, each constituting a chemotype.

Variation in volatile leaf oils of eleven eucalyptus species harvested from korbous arboreta (Tunisia).

Hydrodistillation of the dried leaves of eleven species of the genus Eucalyptus L'Hér., i.e., E. astringens Maiden, E. camaldulensis Dehnh., E. diversifolia Bonpl., E. falcata Turcz., E. ficifolia F. Muell., E. gomphocephala DC., E. lehmannii (Schauer) Benth., E. maculata Hook., E. platypus Hook., E. polyanthemos Schauer, and E. rudis Endl., harvested from Korbous arboreta (region of Nabeul, northeast of Tunisia) in April 2006, afforded essential oils in yields varying from 0.1+/-0.1 to 3.8+/-0.1%, dependent on the species. E. astringens and E. ficifolia showed the highest and the lowest mean percentage of essential oil amongst all the species examined, respectively. Analysis by GC (RI) and GC/MS allowed the identification of 138 components, representing 74.0 to 99.1% of the total oil. The contents of the different samples varied according to the species. The main components were 1,8-cineole, followed by trans-pinocarveol (1), spathulenol (2), alpha-pinene, p-cymene, (E,E)-farnesol, cryptone, globulol (3), beta-phellandrene, alpha-terpineol, viridiflorol, and alpha-eudesmol. The principal-component and the hierarchical-cluster analyses separated the eleven Eucalyptus leaf essential oils into seven groups, each constituting a chemotype.

Leaf essential oil of Juniperus oxycedrus L. (Cupressaceae) harvested in northern Tunisia: composition and intra-specific variability.

The essential oil composition of leaves of 60 individual trees of Juniperus oxycedrus L. growing in four locations in Tunisia harvested in three different seasons were investigated by GC and GC/MS. Seventy compounds were identified in the oils, and a relatively high variation in their contents were found. All the oils were dominated by terpenic hydrocarbons, with alpha-pinene (27.35-58.03%) as the main component, followed by geranyl acetone (13; 1.96-7.14%), 13-epimanoyl oxide (16; 1.35-6.95%), and eudesma-4(15),7-dien-1-ol (11; 1.39-4.18%). The 18 major oil components were processed by hierarchical clustering and principal component analysis (PCA) allowing to establish four groups, one divided into two subgroups, of populations according to the location and season of harvest. Their oils were differentiated by one compound or more, showing a clear seasonal and geographical polymorphism in their chemical composition allowing the identification of specific chemotypes. The pattern of geographic variation in the essential oil composition indicated that the oils of the populations from the continental site (Makthar) were clearly distinguished from those of the littoral localities (Tabarka, Hawaria, and Rimel).

Variation in volatile leaf oils of 13 Eucalyptus species harvested from Souinet arboreta (Tunisia).

Hydrodistillation of the dried leaves of 13 species of the genus Eucalyptus L' Hér., viz., E. bicostata Maiden, Blakely & Simmonds, E. cinerea F. Muell. ex Benth., E. exerta F. Muell., E. gigantea Hook. f., E. gunnii Hook. f., E. macarthurii Deane & Maiden., E. macrorrhyncha F. Muell., E. maidenii F. Muell., E. odorata Behr., E. pauciflora Sieber ex Sprengel, E. sideroxylon A. Cunn. ex Woolls, E. tereticornis Sm., and E. viminalis Labill., harvested from Souinet arboreta (region of Ain Draaham, north of Tunisia) in June 2006, afforded essential oils in yields varying from 0.5+/-0.2 to 3.9+/-0.4%, dependent on the species. E. cinerea and E. exerta provided the highest and the lowest percentage of essential oil amongst all the species examined, respectively. Analysis by GC (RI) and GC/MS allowed the identification of 142 components, representing 81.5 to 98.9% of the total oil. The contents of the different samples varied according to the species. The main components were 1,8-cineole (1), followed by cryptone, spathulenol (4), p-cymene (2), viridiflorol (6), globulol (7), beta-eudesmol, alpha-terpineol (5), limonene (8), D-piperitone, alpha-pinene (3), cuminal, and gamma-eudesmol. The principal component and the hierarchical cluster analyses separated the 13 Eucalyptus leaf essential oils into three groups, each constituting a chemotype.