In vitro and in vivo anthelmintic effect of essential oil obtained from Thymus capitatus flowers against Haemonchus contortus and Heligmosomoides polygyrus.

Sheep haemonchosis is a disease that causes serious losses in livestock production, particularly with the increase of cases of anthelmintic resistance around the world. This justifies the urgent need of alternative solutions. The aim of this study was to determine the chemical profile, in vitro, and, in vivo, anthelmintic properties of Thymus capitatus essential oil. To evaluate the, in vitro, anthelmintic activity of the T. capitatus EO on Haemonchus contortus, two tests were used: egg hatch assay (EHA) and adult worm motility (AWM) assay. The nematicidal effect of this oil was evaluated, in vivo, in mice infected artificially with Heligmosomoides polygyrus using faecal egg count reduction (FECR) and total worm count reduction (TWCR). Chromatographic characterization of T.capitatus composition using gas chromatography coupled to mass spectrometry (GC-MS) demonstrated the presence of carvacrol (81.16%), as the major constituents. The IC50 values obtained was 1.9 mg/mL in the EHT. In the AWM assay; T. capitatus essential oil achieved 70.8% inhibition at 1 mg/mL after 8 h incubation. The in vivo, evaluation on H. polygyrus revealed a significant nematicidal effect 7 days post-treatment by inducing 49.5% FECR and 64.5% TWCR, using the highest dose (1600 mg/kg). The results of present study, demonstrate that T.capitatus EO possess a significant anthelmintic properties. Furthermore, it could be an alternative source of anthelmintic agents against gastrointestinal infections caused by H. contortus.

Phytochemical profile and anthelmintic effects of Laurus nobilis essential oil against the ovine nematode Haemonchus contortus and the murine helminth model Heligmosomoides polygyrus.

Small ruminant production in tropical and temperate countries faced substantial anthelmintic resistance due to the intensive use of commercial anthelmintic drugs. Therefore, alternative treatments including natural bioactive compounds with anthelmintic potential have been investigated looking for its successfully use in the parasite control. In the present study, we describe the chemical profile of Laurus nobilis essential oil (EO), the in vitro anthelmintic activity of L. nobilis EO against Haemonchus contortus and its in vivo anthelmintic effect against the murine helminth parasite model Heligmosomoides polygyrus. Chromatographic profile of L. nobilis (EO) extracted from the leaves of L. nobilis have shown the presence of monterpens 1,8-cineol (Eucalyptol) (29.47%), D-Limonène (18.51%) and Linalool (10.84%) in high fractions. The in vitro anthelmintic potential was expressed by an ovicidal effect against H. contortus egg hatching with inhibition value of 1.72 mg/mL and 87.5% of immobility of adult worms after 8 h of exposure to 4 mg/mL of L. nobilis EO. Regarding, the in vivo anthelmintic potential, L. nobilis (EO) at 2400 mg/kg bw completely eliminated the egg output of H. polygyrus after 7 days of oral treatment, together with a 79.2% of reduction in total worm counts. Based on the obtained results, L. nobilis EO showed promising in vitro and in vivo anthelmintic capacities against gastrointestinal parasites.

Assessment of anthelmintic potentials of Myrtus communis against Haemonchus contortus and Heligmosomoides polygyrus.

Anthelmintic resistance in grazing livestock systems has been spreading worldwide in prevalence and severity. Therefore, alternative measures including the use of herbal anthelmintic is considered as one of the successful approaches for the control of anthelmintic resistance. In the present report, we describe the chemical constituents of Myrtus communis essential oil, its in vitro anthelmintic effect against the most pathogenic gastrointestinal parasite of sheep; Haemonchus contortus and its in vivo anthelmintic potential using an in vivo gastrointestinal parasite model of rodents; i.e. Heligmosomoides polygyrus. Chromatographic analyzes of the essential oil (EO) extracted from the leaves of M. communis have shown that this oil was composed mainly of a α-pinene (33.59%), eucalyptol (23.85%) and limonene (14.70%). Regarding the in vitro anthelmintic potential, the ovicidal effect was confirmed in an egg hatch inhibition assay at IC50 = 0.7 mg/mL and with 95.83% of immobility of adult worm's after 8 h of exposure to 2 mg/mL of M. communis EO. The anthelmintic capacity of M. communis EO was also confirmed by in vivo assays conducted against the murine parasite H. polygyrus. In fact, at 1200 mg/kg bw of M. communis EO, a reduction of 99.70% in faecal egg counts was observed after 7 days of oral treatment, together with a 71.12% reduction in total worm counts. Based on the obtained results, M. communis EO showed relevant in vitro and in vivo anthelmintic effects against gastro-intestinal parasites.

Essential oil of Mentha pulegium induces anthelmintic effects and reduces parasite-associated oxidative stress in rodent model.

Following the previous findings reported by the present authors on the anthelmintic effect of hydro-ethanolic extract of Mentha pulegium, the volatile constituents of M. pulegium are now assessed in the present study by exploring its anthelmintic and its antioxidant proprieties using in vitro and in vivo assays. Egg hatch assay (EHA) and adult worm's motility assays (AWMA) were used to assess the in vitro activity against Haemonchus. contortus. The in vivo anthelmintic potential was evaluated in mice infected with Heligmosomoides polygyrus using faecal egg count reduction (FECR) and total worm count reduction (TWCR). M. pulegium EO demonstrated 100% inhibition in the EHA at 200 µg/mL (IC50 = 56.36 µg/mL). In the AWM assay, EO achieved total worms paralysis 6 h after treatment exposure. This nematicidal effect was associated to morphological damages observed in the cuticular's worm using environmental scanning electron microscopy (ESEM). At 400 mg/kg, M. pulegium oil showed 75.66% of FECR and 80.23% of TWCR. The antioxidant potential of this plant was also monitored by several in vitro assays: total antioxidant capacity was 205.22 mg GAE/g DW, DPPH quenching effect was IC50 = 140 µg/mL, ABTS activity IC50 = 155 µg/mL and FRAP effect of 660 µg/mL. Regarding the in vivo assay, M. pulegium EO demonstrated a protective effect against oxidative stress by increasing the activity of the endogenous antioxidants (SOD, CAT and GPx) during H. polygyrus infection.

Hydro-Ethanolic Extract of Mentha pulegium Exhibit Anthelmintic and Antioxidant Proprieties In Vitro and In Vivo.

INTRODUCTION: During recent decades, the emergence of chemoresistance among synthetic anthelmintic drugs has increased the interest in screening novel natural anthelmintic compounds derived from plants. The current study is aimed to determine the chemical profile, anthelmintic and antioxidant properties of Mentha pulegium hydro-ethanolic extract. MATERIALS AND METHODS: Two tests were used to assess the in vitro anthelmintic activity of the hydro-ethanolic extract of M. pulegium against Haemonchus contortus; egg hatch assay (EHA) and adult worm motility (AWM) assay. M. pulegium extracts at the doses of 500, 1000, 2000 and 4000 mg/kg were evaluated in vivo in mice infected with Heligmosomoides polygyrus. The anthelmintic efficacy was monitored using faecal egg count reduction (FECR) and total worm count reduction (TWCR). The antioxidant activity of M. pulegium extract was evaluated by testing the total antioxidant capacity and the DPPH free radical-scavenging ability. RESULTS: Chromatographic characterization of M. pulegium composition using RP-HPLC revealed the presence of phenolic acids such as syringic acid, ferulic acid and the presence of flavonoid compounds, such as isorhamnetin-3-O-glucoside and kaempferol-3-O-rutinoside. We observed 91.58% inhibition in the EHA at 8 mg/mL after 48 h of incubation (IC50=1.82 mg/mL). In the AWM assay, M. pulegium extract achieved 65.2% inhibition at 8 mg/mL after 8 h. The highest dose (4000 mg/kg) showed a significant nematicidal effect 7 days post-treatment by inducing 60.39% FECR and 71.6% TWCR. We also report strong in vivo antioxidant capacity of the extract, as revealed by a significant increase of the enzymatic activities of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzymes in mice infected with H. polygyrus. CONCLUSION: Together, the results in this paper suggest that M. pulegium possesses anthelmintic properties and could be a potential source of novel compounds for the control of helminth parasites as well as its associated oxidative damage.

Chamomile Methanolic Extract Mitigates Small Bowel Inflammation and ROS Overload Related to the Intestinal Nematodes Infection in Mice.

BACKGROUND: Chamomile (Matricaria recutita L.) is a plant which has been reported to be effective in treating several parasitic and digestive diseases. The present study was conducted to evaluate the anthelmintic activity of chamomile methanolic extract (CME). METHODS: In vitro, the anthelmintic activities of CME were investigated on the L3 larvae of Heligmosomoides polygyrus in comparison to albendazole. In vivo, Swiss albino mice were infected with infective third (L3) larval stage of H. polygyrus by intragastric administration. Moreover, the effect of CME and albendazole on worm eggs, adult worms, serum cytokine production, and oxidative stress was studied. RESULTS: All used doses of CME showed a potent anthelmintic activity both in vitro and in vivo and the effect being similar to treatment with albendazole. Moreover, H. polygyrus infestation was accompanied by an intestinal oxidative stress status characterized by an increased lipoperoxidation, a depletion of antioxidant enzyme activity, as well as an overload of hydrogen peroxide. We have also recorded an increase of pro-inflammatory mediator (TNF-α, IL-6, and IL-1ß) levels after treatment with CME (14 ± 0.8; 41 ± 2; 58 ± 4 pg/mg protein, respectively, with the concentration 800 mg/kg, body weight) when compared with infected control mice (20 ± 1; 59 ± 2, and 83 ± 4 pg/mg protein, respectively). However, extract treatment alleviated all the deleterious effects associated with H. polygyrus infection. CONCLUSION: These findings suggest that CME can be used in the control of gastrointestinal helminthiasis and associated oxidative stress.

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.

Leishmanicidal activity of α-bisabolol from Tunisian chamomile essential oil.

According to the World Health Organization, leishmaniasis is considered as a major neglected tropical disease causing an enormous impact on global public health. Available treatments were complicated due to the high resistance, toxicity, and high cost. Therefore, the search for novel sources of anti-leishmania agents is an urgent need. In the present study, an in vitro evaluation of the leishmanicidal activity of the essential oil of Tunisian chamomile (Matricaria recutita L.) was carried out. Chamomile essential oil exhibits a good activity on promastigotes forms of L. amazonensis and L. infantum with a low inhibitory concentration at 50% (IC50) (10.8 ± 1.4 and 10.4 ± 0.6 µg/mL, respectively). Bio-guided fractionation was developed and led to the identification of (-)-α-bisabolol as the most active molecule with low IC50 (16.0 ± 1.2 and 9.5 ± 0.1 µg/mL for L. amazonensis and L. infantum, respectively). This isolated sesquiterpene alcohol was studied for its activity on amastigotes forms (IC50 = 5.9 ± 1.2 and 4.8 ± 1.3 µg/mL, respectively) and its cytotoxicity (selectivity indexes (SI) were 5.4 and 6.6, respectively). The obtained results showed that (-)-α-bisabolol was able to activate a programmed cell death process in the promastigote stage of the parasite. It causes phosphatidylserine externalization and membrane damage. Moreover, it decreases the mitochondrial membrane potential and total ATP levels. These results highlight the potential use of (-)-α-bisabolol against both L. amazonensis and L. infantum, and further studies should be undertaken to establish it as novel leishmanicidal therapeutic agents.

Correlation of radical-scavenging capacity and amoebicidal activity of Matricaria recutita L. (Asteraceae).

Some Acanthamoeba strains are able to cause Granulomatous Amoebic Encephalitis (GAE) and Acanthamoeba keratitis (AK) worldwide because of their pathogenicity. The treatment of Acanthamoeba infections is complicated due to the existence of a highly resistant cyst stage in their life cycle. Therefore, the elucidation of novel sources of anti-Acanthamoeba agents is an urgent need. In the present study, an evaluation of the antioxidant and anti-Acanthamoeba activity of compounds in flower extracts of Tunisian chamomile (Matricaria recutita L.) was carried out. Chamomile methanol extract was the most active showing an IC50 of 66.235 ± 0.390 µg/ml, low toxicity levels when checked in murine macrophage toxicity model and presented also antioxidant properties. Moreover, a bio-guided fractionation of this extract was developed and led to the identification of a mixture of coumarins as the most active fraction. These results suggest a novel source of anti-Acanthamoeba compounds for the development of novel therapeutic agents against Acanthamoeba infections.

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.

Amoebicidal activity of α-bisabolol, the main sesquiterpene in chamomile (Matricaria recutita L.) essential oil against the trophozoite stage of Acanthamoeba castellani Neff.

Acanthamoeba genus includes opportunistic pathogens which are distributed worldwide and are causative agents of a fatal encephalitis and severe keratitis in humans and other animals. Until present there are not fully effective therapeutic agents against this pathogen and thus the need to search for novel anti-amoebic compounds is urgent. Recently, essential oils of aromatic and medicinal plants have shown activity against Acanthamoeba strains. Therefore, this study was aimed to evaluate the activity of main component of chamomile essential oil (a sesquiterpene) namely α-bisabolol against the Acanthamoeba castellani Neff strain. After evaluation of the activity and toxicity of this molecule, IC50 values of 20.839 ± 2.015 for treated amoebae as well as low citotoxicty levels in a murine macrophage cell line was observed. Moreover, in order to elucidate mechanism of action of this molecule, changes in chromatin condensation levels, permeability of the plasmatic membrane, the mitochondrial membrane potential and the ATP levels in the treated amoebic strains were checked. The obtained results revealed that α-bisabolol was able to induce apoptosis, increase the permeability of the plasmatic membrane and decrease both mitochondrial and ATP levels in the treated amoebae. Therefore, and given the obtained results, α-bisabolol could be used a future therapeutic agent against Acanthamoeba infections.

First report of the in vitro nematicidal effects of camel milk.

Antipathogenic properties of camel milk have been investigated to substitute for drugs hence overcome drug resistance. The main objective of this present study was to investigate the anthelmintic activity of camel milk in relationship to its chemical composition. In vitro anthelmintic effects of camel milk against Haemonchus contortus from sheep were ascertained by egg hatching and worm motility inhibitions in comparison to milks from cow, ewe and goat as well as a reference drug albendazole. Chemical composition revealed that camel milk has higher contents of protective protein (lactoferrin) and vitamin C than other species' milk. It showed ovicidal activity at all tested concentrations and completely inhibited egg hatching at a concentration close to 100mg/mL (inhibitory concentration (IC50)=42.39mg/mL). Camel milk revealed in vitro activity against adult parasites in terms of the paralysis and/or death of the worms at different hours post treatment. After 8h of exposure, it induced 100% mortality at the highest tested concentration. There was 82.3% immobility of worms in albendazole 8h post-exposition. No such effects were seen with the other species' milks. Bioactive compounds such as lactoferrin and vitamin C may be involved in such an effect. To our knowledge, these results depict for the first time that camel milk possesses in vitro anthelmintic properties and further in vitro and in vivo trials against different parasite species and stages are required to make use of this milk for the control of gastrointestinal nematode parasites.

Effect of the infection with the nematode Haemonchus contortus (Strongylida: Trichostrongylidae) on the haematological, biochemical, clinical and reproductive traits in rams.

This study aimed to investigate the effect of Haemonchus contortus infection on rams' haematological, biochemical and clinical parameters and reproductive performances. A total number of 12 Barbarine rams (control and infected) were included in the experiment. The infected group received 30 000 H. contortus third-stage larvae orally. Each ram's ejaculate was immediately evaluated for volume, sperm cell concentration and mortality rate. At the end of the experiment (day 82 post-infection), which lasted 89 days, serial blood samples were collected in order to assess plasma testosterone and luteinising hormone (LH) concentrations. There was an effect of time, infection and their interaction on haematological parameters (p < 0.001). In infected rams, haematocrit, red blood cell count and haemoglobin started to decrease from 21 days post-infection. There was an effect of time and infection for albumin. For total protein, only infection had a statistically significant effect. For glucose, only time had a statistically significant effect. Concentrations were significantly lower in infected rams compared to control animals. A significant effect of infection and time on sperm concentrations and sperm mortality was observed. The effect of infection appears in time for sperm concentrations at days 69 and 76 post-infection. Sperm mortality rate was significantly higher in infected animals at day 46 post-infection when compared to control group (p < 0.05). Finally, plasma testosterone traits (average concentration, cumulated levels during the sampling period and pulse frequency) were depressed in infected rams when compared to control counterparts; none of these endocrine traits were affected for plasma LH.

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.

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.

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.

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.

Epidemiological study of sympatric Haemonchus species and genetic characterization of Haemonchus contortus in domestic ruminants in Tunisia.

Parasitic gastroenteritis caused by Haemonchus spp. is a major cause of economic losses in the livestock industry, especially in tropical and subtropical areas. The correct identification of various species, as well as knowledge regarding the epidemiology and genetic characterization of the principal circulating species, is essential for the establishment of sustainable control strategies. A study was carried out to determine the prevalence of Haemonchus species in sheep, goats and cattle slaughtered in Béja abattoir from January to June 2010 and also to analyse the genetic differences of Haemonchus contortus in these ruminants. During the study period 364, 271 and 152 abomasa of sheep, goats and cattle respectively, were examined showing overall prevalence rates of 17%, 33.6% and 7.23%, respectively. In addition, spicules morphometric study of 300 male worms randomly collected from sheep showed the presence of 239 (79.66%) H. contortus and 61 (20.33%) H. placei. Likewise, out of 508 adult male Haemonchus from goats, 325 (63.97%) H. contortus and 183 (36.02%) H. placei worms were identified. Whereas for cattle, out of 84 adult male Haemonchus, 52 (61.9%) H. contortus and 32 (38.09%) H. placei worms were identified. The study showed the association of H. contortus and H. placei as a predominant type of infection in all hosts, co-infection concerned 62.5% of sheep, 54.71% of goats and 37.5% of cattle. Using the polymerase chain reaction, the second Internal Transcribed Spacer region (ITS-2) of the nuclear ribosomal DNA (rDNA) of H. contortus was amplified and sequenced. A total of 16 ITS-2 sequences were identified (five from sheep, three from cattle and eight from goats). The 231 base pairs of different ITS-2 sequences were aligned and analysed. Distance based analysis using Neighbour-Joining method and parsimony analysis were used to construct phylogenetic trees to elucidate genetic relationships. The analyses categorized the ITS-2 sequence of H. contortus into four groups. Groups 1 and 4 were found exclusively in goats, whereas groups 2 and 3 were found in sheep and cattle. This study demonstrates variability in nucleotide sequence within the ITS-2 region that reveals genetic diversity among populations of H. contortus, including those from different domestic ruminant species in Tunisia. To our knowledge, this is the first work in North Africa describing the genetic diversity of H. contortus in domestic ruminants.