Amoebicidal, antimicrobial and in vitro ROS scavenging activities of Tunisian Rubus ulmifolius Schott, methanolic extract.

The present study aimed to evaluate the activity of methanolic extract of Rubus ulmifolius Schott against the Acanthamoeba castellani Neff Strain as well as its antioxidant and antimicrobial effects. The tested extract has a good amoebicidal activity with low IC50 (61.785 ± 1.322 µg/ml) and also has significant activity against both Gram-positive (S. aureus, S. agalactiae) and Gram-negative bacteria (E. coli, S. typhimurium) and against C. albicans. The inhibition zones diameters (IZD) and minimal inhibitory concentration (MIC) values were in the range of 22.5-50 mm and 02.29-4.76 mg ml-1, respectively. In the other hand, the in vitro ROS scavenging activity was evaluated, the tested extract exhibited a good effect on the ·OH radical (89.99% at a concentration of 100 µg/ml) when compared to the ascorbic acid (68.81%). Moreover, the inhibition percentage of superoxide generation by R. ulmifolius extract at 100 µg/ml was greater than ascorbic acid (79.55; 64.79%, respectively). Also, the tested extract showed a high percentage of H2O2 scavenging activity (99.95% at 100 µg/ml). Our findings suggest that R. ulmifolius could be a potential source of natural antioxidant in preventing many diseases associated with oxidative stress, amoebic and bacterial infections.

Non-cytotoxic Thymus capitata extracts prevent Bovine herpesvirus-1 infection in cell cultures.

BACKGROUND: Bovine herpes virus type 1 (BHV-1) still causes great economic loss to the livestock industry and trade because there aren't any available drugs that proved to be fully effective against it. In this study, the cytotoxicity and the antiviral activities of the Thymus capitata extracts were evaluated for the development of new, non toxic and specific anti-herpesvirus drug. Aqueous extracts (AE), ethanolic extracts (EE) and essential oil (EO) of the aerial parts of Thymus capitata were analyzed to determine their chemical compositions by gas chromatography, and high performance liquid chromatography combined with mass spectrometry. Their cytotoxicity and antiviral activities against Bovine Herpesvirus type 1 (BHV-1) were evaluated by quantifying the reduction of the viral cytopathic effect using Madin-Darby Bovine Kidney cell line with colorimetric assay. T. capitata extracts were added at different stages of the viral infection to investigate and better quantify their potential inhibitory effects. RESULTS: Polyphenols and flavonoids were the major compounds found in T. capitata EO, EE and AE. The cytotoxic concentrations at 50% were 48.70, 189 and 289 µg ml(-1) for EO, EE and AE, respectively. The inhibitor concentrations at 50% for the EO, EE and AE, were 3.36, 47.80 and 164 µg ml(-1), respectively. The selectivity index anti-BHV-1 values were 14.49, 3.95 and 1.81 for EO, EE and AE, respectively. Thus, the EO extracts were the most efficient antiviral compounds. T. capitata extracts affect mainly the adsorption of BHV-1 virus to host cells. CONCLUSION: T. capitata extracts inhibit the viral replication by interfering with the early stages of viral adsorption and replication. Thus, T. capitata is a potential candidate for anti-herpesvirus treatment.

Composition and Characterization of Cold Pressed Moringa oleifera Seed Oil.

The present study aims to investigate the volatile compound and the triacylglycerol profiles of Tunisian cold pressed Moringa oleifera seed oil (MoSO) and to assess its thermal properties and its biological activities. GC-MS analysis identified thirty six phyto-compounds amounting to 98.99% of the total oil. These compounds were classified into eleven groups among which the fatty acid one exhibited the highest intensity (91.63%). Cis, 6-octadecenoic acid was the most abundant compound (70.68%). The triacylglycerol composition of MoSO was characterized by the predominance of the glycerol trioleate (OOO) (32.42±0.12%). Thermogravimetric analysis of MoSO showed that the oil possess an interesting thermal stability with a highly Onset temperatures (Tonset) of 390.72°C and 357.47°C, respectively in nitrogen and air atmospheres. By using the ABTS assay, MoSO exhibited an interesting antioxidant capacity of 365 µM TEAC. The oil was also endowed with a relatively strong anti-inflammatory activity since its treatment at the different concentrations tested (75, 150 and 300 µg/mL). However, no antimicrobial activity was observed. On the basis of the obtained results, MoSO could be used in diverse industrial applications such as pharmaceutical, cosmetic, and food fields thanks to its thermal stability and interesting biological activities.

Chemical analyses and anthelmintic effects of Artemisia campestris essential oil.

The present study aimed at analyzing the chemical composition and evaluating the in vitro and in vivo anthelmintic activity of Artemisia campestris essential oil aerial parts. The chemical composition was analysed by gaz chromatography/mass chromatography (GC/MS). Fifty compounds were identified representing 99.98% of the total oil. A. campestris essential oil was dominated by beta-pinene (36.40%) and 2-undecanone (14.7%). The in vitro anthelmintic activity tests of A. campestris essential oil were performed on Haemonchus contortus using egg hatch assay (EHA) and adult worm's motility assay (AWMA) compared with a reference drug albendazole. In the EHA 100% inhibition was observed at 2 mg/ml after 48 h incubation (IC50 = 0.93 mg/ml). In the AWMA, essential oil induced 66.6% inhibition at 0.5 mg/ml after 8 h post exposure. The nematicidal effect of essential oil was evaluated on Heligmosomoides polygyrus. It was monitored through faecal egg count reduction (FECR) and total worm count reduction (TWCR). Three doses (2000, 4000 and 5000 mg/kg) were studied using a bioassay. The dose of 5000 mg/kg showed a high nematicidal activity (72.1% FECR and 72% TWCR), 7 days post-treatment. The results of the present study suggest that A. campestris essential oil has a potential anthelmintic activity and further studies are required in order to establish its mechanisms of action.

Cigarette filter and the incidence of lung adenocarcinoma among Tunisian population.

Increasing incidence of lung adenocarcinoma (Ad) is observed for the last two decades in all over the world and may become the most frequent lung cancer subtype in the next years. Its increasing prevalence has been well documented in United States for the last two decades. Geographical differences in the increase of Ad prevalence was also reported in Europe where the Squamous Cell Carcinoma (SCC) still predominates but the increase of Ad incidence was shown in the beginning of 1980s. In Tunisia, the incidence of Ad was relatively low in 1990 when compared to western countries and was shown to continue to increase with a more important rise of Ad incidence over SCC type. In this study the time-dependent increased incidence of Ad is reported between USA, Europe and Tunisia. A lag-time period of 10 years is observed between Tunisia and Europe for this increased incidence in smokers and about 20 years between USA and Tunisia. According to the literature, changes in the types of cigarettes smoked as well as modifications in time and geographical trends seem to explain partly the increased incidence of Ad lung cancer.

Interaction between CYP1A2-T2467DELT polymorphism and smoking in adenocarcinoma and squamous cell carcinoma of the lung.

This study aimed to identify new genetic characteristics contributing to individual susceptibility to smoke-induced lung cancer. Despite functional evidence of a possible role of cytochrome P450 1A2 (CYP1A2) in lung cancer susceptibility, no studies have evaluated the influence of CYP1A2 genotypes on lung cancer risk. We investigated the interaction between CYP1A2-T2467delT (allele*1D) polymorphism and smoking in Tunisian lung cancer cases (n=101 male smokers) separately for the histological types squamous cell carcinoma (SCC) (n=60) and adenocarcinoma (n=41), and in controls (n=98 male smokers) using a case-only study design. A significant interaction between CYP1A2-T/delT or delT/delT genotypes and tobacco consumption (pack-years) adjusted for age was evident (OR (95% CI) 7.78 (1.52-42.8)) in the SCC cases who smoked relatively less (< or =33 pack-years, I quartile value), but not in adenocarcinoma and controls. Our results suggest that CYP1A2-T2467delT polymorphism has an important role in lung carcinogenesis, especially SCC, among smokers.

Mutational spectrum of dihydropyrimidine dehydrogenase gene (DPYD) in the Tunisian population.

Dihydropyrimidine dehydrogenase enzyme (DPD) deficiency is a pharmacogenetic syndrome leading to severe side-effects in patients receiving therapies containing the anticancer drug 5-fluorouracil (5-FU). The aim of this population study is to evaluate gene variations in the coding region of the dihydropyrimidine dehydrogenase gene (DPYD) in the Tunisian population. One hundred and six unrelated healthy Tunisian volunteers were genotyped by denaturing HPLC (DHPLC). Twelve variants in the coding region of the DPYD were detected. Allele frequencies of DPYD*5 (A1627G), DPYD*6 (G2194A), DPYD*9A (T85C), A496G, and G1218A were 12.7%, 7.1%, 13.7%, 5.7%, and 0.5%, respectively. The DPYD alleles DPYD*2A (IVS 14+1g>1), DPYD*3 (1897 del C) and DPYD*4 (G1601A) associated with DPD deficiency were absent from the examined subjects. We describe for the first time a new intronic polymorphism IVS 6-29 g>t, found in an allelic frequency of 4.7% in the Tunisian population. Comparing our data with that obtained in Caucasian, Egyptian, Japanese and African-American populations, we found that the Tunisian population resembles Egyptian and Caucasian populations with regard to their allelic frequencies of DPYD polymorphisms. This study describes for the first time the spectrum of DPYD sequence variations in the Tunisian population.

Correlation of polyphenolic content with radical-scavenging capacity and anthelmintic effects of Rubus ulmifolius (Rosaceae) against Haemonchus contortus.

Phenolic content, antioxidant and anthelmintic activities of herbal extracts are of particular interest to drug industry; plant extracts with significant anthelmintic activity have the potential to be used as alternatives to conventional chemical drugs. In the present study, Rubus ulmifolius fruit extracts obtained using solvents of increasing polarity (water, methanol, chloroform and hexane) were examined for their antioxidant and anthelmintic activities in correlation with their polyphenolic content. In vitro antioxidant activity of all extracts was carried out using free radical-scavenging activity by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis-(3-ethilenebenzotiazolin)-6-sulfonic acid (ABTS) radical cation. In vitro anthelmintic activities were investigated on the egg and adult worms of Haemonchus contortus from sheep in comparison to albendazole. Total polyphenol content of R. ulmifolius was higher in more polar extract, ranging from 64.5 in aqueous extract to 1.57 mg gallic acid equivalents per gram of dry weight (GAE/g DW) in hexanic extract. Likewise, highest amounts of flavonoids and condensed tannins were found in aqueous extract (28.06 mg QE/g and 7.42 mg CE/g DW, respectively) compared to hexanic extract (0.71 mg QE/g and 0.29 mg CE/g DW, respectively) (p<0.05). Both DPPH and ABTS antioxidant assays showed that all tested extracts possess free radical scavenging activity, while the inhibitory concentration 50% (IC50) range values were similar for both assays (2.13-45.54 µg/mL and 1.2-43.82 µg/mL, respectively). All plant extracts showed ovicidal activity at all tested concentrations. Fruit methanolic (IC50=2.76mg/mL) and aqueous (IC50=2.08 mg/mL) extracts showed higher inhibitory effects than chloroformic (IC50=7.62 mg/mL) and hexanic (IC50=12.93 mg/mL) extracts on egg hatching (p<0.05). There was a significant correlation of total polyphenol, flavonoids and tannins content with scavenging of either DPPH (r=0.722, 0.764 and 0.752, p<0.01, respectively) or ABTS radicals (r=0.893, 0.765 and 0.722, p<0.01, respectively) and with inhibition of egg hatching (r=0.874, 0.883 and 0.862, p<0.01, respectively). Highest inhibition of motility (100%) of worms was observed 8h post-exposure in aqueous and methanolic extract at 8 mg/mL. To our knowledge, these results depict for the first time that R. ulmifolius possesses in vitro anthelmintic properties.

In vitro evidence that the pastoral Artemisia campestris species exerts an anthelmintic effect on Haemonchus contortus from sheep.

Occurrence of anthelmintic resistant strains of helminths is increasing. The aim of this study was to evaluate the in vitro anthelmintic activity of Artemisia campestris in comparison to albendazole against Haemonchus contortus of sheep. In this respect, in vitro anthelmintic activities of crude aqueous and crude ethanolic extracts of aerial parts of A. campestris were investigated on eggs and adults of Haemonchus contortus. Chemical analyses revealed that overall profile of both extracts samples were dominated by flavonoids among them quercetin and apigenin derivatives were the most abundant phenolics constituents. Both extract types completely inhibited egg hatching at a concentration close to 2 mg/ml. Lethal concentration 50% of A. campestris ethanolic and aqueous extracts were 0.83 and 1.00 mg/ml respectively (p < 0.05). The ethanolic extract showed better in vitro activity against adult parasites than the aqueous extract in terms of the paralysis and/or death of the worms at different hours post-treatment. Dose dependent activity was also observed for both extract. After 8 and 24 h of exposure, the ethanolic extract induced 91.3 and 100% mortality at the highest tested concentration respectively, while the aqueous extract induced 3.22 and 70.96% at the same concentration respectively.To our knowledge, these results depict for the first time that A. campestris possesses in vitro anti-Haemonchus contortus properties.

Effects of glutathione S-transferase M1 and T1 deletions on epilepsy risk among a Tunisian population.

Glutathione-S-transferases enzymes are involved in the detoxification of several endogenous and exogenous substances. In this present study, we evaluated the effects of two glutathione-S-transferase polymorphisms, (GSTM1 and GSTT1) on epilepsy risk susceptibility in a Tunisian population. These polymorphisms were analyzed in 229 healthy subjects and 98 patients with epilepsy, using a polymerase chain reaction (PCR). Odds ratio (ORs) was used for analyzing results. The study results demonstrated that individuals with the GSTM1 null genotype were at an increased risk of developing epilepsy [OR=3.80, 95% confidence interval (CI) (2.15-4.78)], whereas no significant effects were observed between individuals with GSTT1 null genotype and epilepsy risk [OR=1.15, 95% CI (0.62-2.12)]. These genotyping finding revealed that the absence of GSTM1 activity could be contributor factor for the development of epilepsy disease.

Thymus capitatus from Tunisian arid zone: chemical composition and in vitro anthelmintic effects on Haemonchus contortus.

The increasing prevalence of anthelmintic resistant strains of helminths, the drug residues in animal products and the high cost of conventional anthelmintics has created an interest in studying medicinal plants as an alternative source of anthelmintics. Thymus capitatus (Lamiales: Lamiaceae) is used traditionally by people as spices and reported to possess some biological effects. The objective of this study is to evaluate the anthelmintic efficacy of T. capitatus in comparison to albendazole against the gastrointestinal nematodes of sheep. To fulfil the objectives, in vitro anthelmintic activities of crude aqueous and crude ethanolic extracts of aerial parts of T. capitatus were investigated on the eggs and adults of the nematode parasite Haemonchus contortus. Both extract types of T. capitatus completely inhibited egg hatching at a concentration close to 2 mg/ml. LC50 of ethanolic extract of T. capitatus was 0.368 mg/ml while that of aqueous extract was 6.344 mg/ml (p<0.05). The ethanolic extract showed higher in vitro activity against adult parasites than the aqueous one in terms of the paralysis and/or death of the worms at different hours post-treatment. Dose dependent effect was observed for both extracts. Chemical analyses revealed that the overall profile of both extracts was dominated by oxygenated constituents. In addition, ethanolic extract is mainly composed of phenols among which thymol (71.22%) and camphor (17.18%). As far as the literature could be ascertained, this is the first publication on anthelmintic activity of T. capitatus. The results of the present study suggest that T. capitatus extracts are a promising alternative to the commercially available anthelmintics like albendazole for the treatment of small ruminants' gastrointestinal nematodes.

CYP1A2 genetic polymorphisms and adenocarcinoma lung cancer risk in the Tunisian population.

AIMS: In this study, the effects of four single nucleotide polymorphisms (SNPs), -3860G>A, -2467delT, -739T>G and -163C>A, of CYP1A2 gene on lung cancer were evaluated in Tunisian population. MAIN METHODS: Four polymorphisms of CYP1A2 gene were analysed in 109 healthy smokers and in 101 lung cancer cases, including 63 with squamous cell carcinoma (SCC) and 41 with adenocarcinoma (AD). The genotyping for the SNPs -3860 G>A, -2467delT, -739T>G and -163C>A was performed by polymerase chain reaction (PCR)-restriction fragment length polymorphism analysis. KEY FINDINGS: The results showed that smokers with CYP1A2 gene polymorphisms were associated with an increased risk for the development of lung AD. There was however no significant increased risk of developing lung SCC in smokers having CYP1A2 gene polymorphisms. An increased risk of developing AD was observed in smokers who are carriers of at least one copy of -3680A or -739G giving a significant odds ratio (OR) of 6.02 (CI=2.91-12.9) and 3.01 (CI=1.54-5.98), respectively. SIGNIFICANCE: These genotyping data are consistent with the hypothesis that tobacco-specific-N-nitrosamines (TSN) such as 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) are major contributors to the development of lung AD and that CYP1A2 gene product plays an important role in the metabolic activation of NNK. This study suggests that SNPs of CYP1A2 could be considered as promising biomarkers in the aetiology of lung AD in smokers.