Phytochemical analysis and in vitro anthelmintic activity of Imperata cylindrica underground parts.

BACKGROUND: Imperata cylindrica is considered as an agricultural weed, but it is a valuable plant in the traditional medicines of Southeast Asia. In the Mizo traditional medicine of India and Myanmar, the rhizomes and roots are used as a remedy for bacterial, fungal and intestinal helminth infections. METHODS: An extract of the whole underground parts was prepared in Soxhlet apparatus using chloroform as a solvent. After concentrating in a vacuum rotary evaporator, the extract was analysed using gas chromatography-mass spectrometry. Anthelmintic activity was tested in vitro against the tapeworm Raillietina tetragona and the roundworm Ascaridia galli. Scanning electron microscopy was used to examine the structural changes on the helminths after treatment with the plant extract. RESULTS: Twenty-two compounds were identified from the plant extract out of which fatty acids were the predominant compounds. Palmitic acid was the most abundant. Bioactive phytosterols such as campesterol and stigmasterol were also detected. The plant extract was significantly effective on both the helminths and showed dose-dependent anthelmintic activity as that of albendazole. The tapeworm treated with the plant extract showed deformities on the suckers, clumping of the spines, tegumental folds and erosion of microtriches. Extensive damage was also seen on the roundworm including cuticular shrinkage, collapse of the lips, and formation of warty surface throughout the body. CONCLUSION: I. cylindrica extract effectively killed and caused detrimental effects on parasitic tapeworm and roundworm. The study therefore validates the traditional usage among the Mizo people, and guarantees further investigation on the exact compound(s) and mechanism of action.

Resistance to fenbendazole in Ascaridia dissimilis, an important nematode parasite of turkeys.

An important factor in efficient production of poultry is management of parasites. Ascaridia dissimilis is the most prevalent small intestinal nematode parasite of turkeys with up to 100% of flocks infected. High worm burdens can cause necrotic enteritis leading to high mortality in flocks. Recently, we were made aware of multiple cases where high burdens were seen at slaughter despite the administration of anthelmintics at frequent intervals, suggesting that resistance may have evolved in A. dissimilis. To address this issue, we obtained eggs of A. dissimilis from 4 commercial turkey farms and performed controlled efficacy tests to determine if fenbendazole resistance was present. Three farms had histories of frequent use of fenbendazole and worms found at slaughter, suggesting they may have resistance, and one was an organic farm where we had no additional history other than the farm had transitioned to organic production a few years earlier. For each worm isolate there were 2 treated and 2 untreated groups containing 9 birds each, with all groups being replicated in 2 separate rooms. Birds were infected with approximately 200 infective eggs, and treated groups received fenbendazole in the water (SafeGuard Aquasol, 1 mg/kg) for 5 consecutive days starting on day 24 post-infection. One week after the last treatment birds were necropsied, intestinal contents were collected and worms enumerated. Three of the four isolates demonstrated greater than 99% efficacy, indicating they were fully susceptible to fenbendazole. However, the fourth isolate demonstrated a significantly reduced efficacy of 63.89%, indicating the presence of resistance. Interestingly, this was the organic farm, whereas the 3 farms with "suspected" resistance all turned out to be fully susceptible. Given that 1 randomly acquired isolate of A. dissimilis, out of 4 tested, demonstrated resistance in this study, fenbendazole resistance may be a much larger problem on turkey farms than is currently recognized. Additional studies are needed to determine the prevalence of resistance, as well as the economic impact that resistant A. dissimilis have on turkey production.

Safety of fenbendazole in common peafowl (Pavo cristatus).

The present study was undertaken to find out the safety levels of fenbendazole in common peafowl. This bird, raised on aviaries and zoos, can be severely parasitized with Ascaridia galli (enteric worms) and Syngamus trachea (gapeworm) along with other parasitic worms. Fenbendazole is a highly effective benzimidazole-class anthelmintic in animals. The objective of this work was to provide target animal safety data in young peafowl and to demonstrate reproductive safety in adult birds. During the experimental study, diets containing fenbendazole at 0, 100, 200 and 300 ppm were fed for 21 days (three times the normal treatment duration). Data for feed consumption, feed conversion rate, and body weights were recorded for each bird in each group. Drug concentrations in different tissues of birds were determined to correlate concentrations with clinical observations, clinical pathology, and histologic findings. There were no morbidities or mortalities after study day 21. Additionally, there were no statistically significant treatment-related differences among above mentioned parameters. Analysis of fenbendazole concentrations in kidney, liver, leg/thigh, and breast muscle and skin with associated fat revealed that, even at the highest dose level used and with no feed withdrawal, fenbendazole concentrations were relatively low in these tissues. These findings indicate that fenbendazole has a relatively wide margin of safety in young peafowl and that the proposed dose of 100 ppm in the feed for 7 consecutive days is well within the margin of safety. In the reproductive safety study, five breeder peafowl farms fed fendbendazole at 100ppm for 7 days and collected data on hatching percentage of peahen eggs before and after treatment. Reproductive performance in peahen was not adversely affected.

RNA-Seq de novo assembly and differential transcriptome analysis of the nematode Ascaridia galli in relation to in vivo exposure to flubendazole.

The nematode Ascaridia galli (order Ascaridida) is an economically important intestinal parasite responsible for increased food consumption, reduced performance and elevated mortality in commercial poultry production. This roundworm is an emerging problem in several European countries on farms with laying hens, as a consequence of the recent European Union (EU) ban on conventional battery cages. As infection is associated with slow development of low levels of acquired protective immunity, parasite control relies on repeated use of dewormers (anthelmintics). Benzimidazoles (BZ) are currently the only anthelmintic registered in the EU for use in controlling A. galli and there is an obvious risk of overuse of one drug class, selecting for resistance. Thus we developed a reference transcriptome of A. galli to investigate the response in gene expression before and after exposure to the BZ drug flubendazole (FLBZ). Transcriptional variations between treated and untreated A. galli showed that transcripts annotated as mitochondrial glutamate dehydrogenase and cytochrome P450 were significantly down-regulated in treated worms, whereas transcripts homologous to heat shock proteins (HSP), catalase, phosphofructokinase, and a multidrug resistance P-glycoprotein (PGP1) were significantly up-regulated in treated worms. Investigation of candidate transcripts responsible for anthelmintic resistance in livestock nematodes led to identification of several tubulins, including six new isoforms of beta-tubulin, and several ligand-gated ionotropic receptors and ABC-transporters. We discovered several transcripts associated with drug binding and processing genes, but further characterisation using a larger set of worms exposed to BZs in functional assays is required to determine how these are involved in drug binding and metabolism.

Evaluation of benzimidazole resistance status in Ascaridia galli.

Susceptability of Ascaridia galli to benzimidazole (BZ) was investigated using faecal egg count reduction test (FECRT), in ovo larval development test (LDT) and genetic markers (mutations at codons 167, 198 and 200 of ß-tubulin gene). Six flocks (F1-F6) of a commercial laying hen farm with different number of exposure to BZ were recruited. The FECR was calculated by analyzing individual faeces (F1, F2, F4 and F5) before and 10 days after treatment. The LDT was performed on parasite eggs from pooled samples from F1 to F6 and LC50 and LC99 were calculated. DNA was extracted from 120 worms and sequenced for ß-tubulin gene. In all flocks, the FECRs were above 95% (lower CI above 90%). No significant difference was observed (p > 0·05) among obtained LC50 (F1/F4 and F2/F5 vs F3/F6) in the LDT. However, LC50 and LC99 were higher than suggested values for declaration of resistance in other nematode species. No variation was observed in codon positions involved in BZ resistance. Overall, our results indicated lack of evidence of resistance to BZ in A. galli. More research is needed to confirm these results and to further optimize the existing tools for detection and monitoring of anthelmintic resistance in A. galli.

Comparison between anthelmintic treatment strategies against Ascaridia galli in commercial laying hens.

The efficacy of a sustainable deworming strategy based on targeted treatments (TT) against Ascaridia galli was investigated for the first time in laying hen flocks on a Swedish commercial farm. Three experimental protocols with different levels of treatment, e.g. targeted treatment (TT), conventional treatment (CT) and untreated (UT), were tested in randomly allocated flocks of two different bird hybrids. Every second week faecal egg counts (FECs) were determined from pooled faecal materials collected on trays (20×27cm) placed for a maximum of 12h on the litter belts. In the TT, anthelmintic administration (fenbendazole, 1mg/kg body weight for 5days) started at 22 weeks post placement (wpp) and was repeated twice when the pooled FECs surpassed the assigned threshold of 200 egg per gram faeces (EPG). The CT flocks were treated once at 27wpp using the same anthelmintic. Hens in the UT were not dewormed and served as controls. Additionally, FECs on cloacal contents, worm fecundity and worm burdens were determined at 19, 35 and 45wpp. None of the flocks became infected until after 16wpp. The cumulative pooled FECs at the end of the study were significantly (p<0.01) lower in the TT compared to both CT and UT. Although repeated treatment in the TT protocol did not affect the fecundity, a worm density-dependent increase in fecundity was observed. Cloacal FECs and the number of adult A. galli in TT at 35 and 45wpp were significantly lower compared to other flocks. This study provides evidence that the TT strategy is better in terms of lower worm burden and decreased cumulative environmental parasite egg numbers compared to CT strategy. The TT strategy should be considered as an alternative to the CT strategy with regard to A. galli control in commercial laying hens.

Effects of alcoholic extract of Curcuma longa on Ascaridia infestation affecting chicken.

Ascaridia galli, the common intestinal nematode, remains a major cause of economic loss in the poultry industry in developing countries. Treatments using chemicals are not only expensive but also affect host health. Plant extracts as better alternative is gaining significance. Here, we have studied the effects of alcoholic extract of turmeric, Curcuma longa L. (Zingiberaceae) roots, against A. galli infection in chicken. Different concentrations of C. longa root extract were tested in vitro on 5 groups of adults A. galli worms and in vivo on 6 groups of chicks. The results showed that the turmeric root extract @ 60 mg mL(-1) in vitro significantly (P < 0.001) proved paralytic and fatal against worms (16.80 ± 1.28 h). In vivo, chicken groups (G2-G6) were infected with an average of 300 ± 12 embryonated eggs of A. galli. The G2 was not given any treatment while G3 was treated with piperazine (@ 200 mg kg(-1) body wt.); and Groups 4, 5 and 6 were given turmeric @ 200, 400 and 600 mg kg(-1) body wt., respectively. The mean number of worms extracted at the end of the trial in G2 (untreated) was 18.10 ± 2.42, while the G3 treated with piperazine had no worms. Groups 4 and 5 did not show any significant difference compared to G2. However, G6 that had 3.20 ± 1.33 worms was statistically significant. Higher concentrations of turmeric given to infected chickens significantly reduced the length and weight of worms. The study showed that the worm infestation damaged the intestinal villi, and.treatment with high concentration of C. longa had healing effects and restored the integrity of intestinal mucosa. The results have demonstrated the ameliorating effect of C. longa turmeric on A. galli infested chickens.

Parasiticidal and brine shrimp cytotoxicity potential of crude methanolic extract of rind of Punica granatum Linn against round worms and tape worms.

Rind of Punica granatum is traditionally used for anthelmintic purposes. The current work describes the possible anthelmintic activity of crude methanolic extract of Punica granatum (Pg. Cr) against round worms (Ascaridia galli) and the tape worms (Raillietina spiralis). Brine shrimp cytotoxicity is also performed. Brine shrimp cytotoxic activity was tested using different concentrations (1000 µg/mL, 100 µg/mL and 10 µg/mL) of Pg.Cr. In vitro anthelmintic activity of Pg. Cr was determined against the parasites using albendazole and piperazine citrate as standard anthelmintic drugs in concentration 10 mg/ml. LC50 value for Brine shrimp cytotoxicity was 189.44 ±28 µg/mL. In test concentration of 40mg/ml of the Pg. Cr, Raillietina spiralis was paralyzed in 23 minutes. However, for parasiticidal activity (death of the parasite), it took less time (40 minutes) as compared to standard Albendazole. Time taken for death of the parasite Raillietina spiralis, in concentration 40 mg /ml, is 40 min. While standard drugs took more time to kill the Raillietina spiralis. Pg. Cr took 19 minutes to paralyze the Ascaridia galli at concentration 40 mg/ml whereas; it took 48 minutes for to kill the parasite Ascaridia galli. The current work confirms the traditional use of rind of Punica granatum as anthelmintic against Raillietina spiralis and Ascaridia galli. Results of brine shrimp cytotoxicity assay warrant for the isolation of cytotoxic compounds. List of abbreviation- Pg. Cr = Crude methanolic extract of Punica granatum.

Heavy metals analysis, phytochemical, phytotoxic and anthelmintic investigations of crude methanolic extract, subsequent fractions and crude saponins from Polygonum hydropiper L.

BACKGROUND: Polygonum hydropiper L decoctions are traditionally used in the treatment of various ailments including inflammation, dyspepsia, diarrhea, menorrhagia, hemorrhoids, helminthiasis and CNS disorders. Present study was undertaken to investigate P. hydropiper L. for heavy metals content, phytoconstituents, Phytotoxic and anthelmintic activities to explore its toxicological and pharmacological potentials and rationalize its ethnomedicinal uses. METHODS: Plant crude powder, methanolic extract, fractions and soil samples were analyzed for heavy metals using atomic absorption spectrophotometer. Qualitative phytochemical analysis of the plant extracts was carried out for the existence of alkaloids, flavonoids, glycosides, anthraquinones, saponins, terpenoids, sterols and tannins. Radish seeds phytotoxicity assay was used to study phytotoxic action of plant extracts. Pheretima posthuma and Ascaridia galli were used to study anthelmintic potential of the plant using albendazole and levamisole HCl as standard drugs. RESULTS: Plant crude powder, methanolic extract (Ph.Cr), its subsequent fractions; n-hexane (Ph.Hex), chloroform (Ph.Chf), ethyl acetate (Ph.EtAc), n-Butanol (Ph.Bt), aqueous (Ph.Aq), saponins (Ph.Sp) and soil samples were found to contain copper (Cu), iron (Fe), chromium (Cr), zinc (Zn), lead (Pb), nickel (Ni), cadmium (Cd) and lead (Pb) in different concentrations. In crude powder of the plant, heavy metals concentrations were within WHO specified limits, whereas different fractions and soil samples exhibited high metals content. Ph.Cr was tested positive for the presence of alkaloids, flavonoids, saponins, tannins, triterpenoids and anthraquinone glycosides. Among different fractions Ph.EtAc, Ph.Sp, Ph.Chf and Ph.Bt were most effective causing 89.32, 89.25, 86.68 and 85.32% inhibition of seeds in phytotoxicity assay, with IC50 values of 50, 60, 35 and 100 µg/ml respectively. In anthelmintic study, Ph.Sp, Ph.Chf, Ph.EtAc and Ph.Cr were most effective against P. posthuma at 10 mg/ml concentration with an average death time of 50, 64.67, 68.67 and 71 minutes respectively. Ph.EtAc, Ph.Chf and Ph.Aq were most effective against A. galli with average death time of 7, 9 and 10 min respectively at 1 mg/ml concentration. CONCLUSIONS: Our findings indicate that P. hydropiper contains different heavy metals and secondary metabolites. Different fractions exhibited phytotoxic and anthelmintic activites comparable to control drugs, thus provide pharmacological basis for ethnomedicinal uses of this plant.

Survival of Ascaris suum and Ascaridia galli eggs in liquid manure at different ammonia concentrations and temperatures.

Eggs of Ascaris suum from pigs are highly resistant and commonly used as a conservative indicator of pathogen inactivation during slurry storage. Eggs of Ascaridia galli, the poultry ascarid, are also known to be highly resistant but the suitability as an indicator of pathogen inactivation has never been tested. Pig slurry has to be stored for several months to inactivate pathogens but chemical treatment of slurry may reduce this time. The suitability of A. galli as an indicator of slurry sanitation was tested by comparing the survival of eggs of A. suum and A. galli in pig slurry. In addition, the effect of urea treatment on inactivation of ascarid eggs in relation to storage time was also tested. Nylon bags with 10,000 eggs of either species were placed in 200 ml plastic bottles containing either urea-treated (2%) or untreated pig slurry for up to 120 days at 20°C, 6 days at 30°C, 36h at 40°C or 2h at 50°C. At all the temperatures in both slurry types, A. galli eggs were inactivated at a significantly faster rate (P<0.05) compared to A. suum eggs. For each 10°C raise in temperature from 20°C, T50 (time needed to inactivate 50% of eggs) for both types of eggs was reduced markedly. At all temperatures, viability of eggs of both species was significantly higher (P<0.05) in untreated slurry compared to urea-treated slurry except A. galli eggs at 20°C where no significant difference was detected. In untreated slurry, the levels of pH (6.33-9.08) and ammonia (0.01-1.74 mM) were lower (P<0.0001) compared to that of urea-treated slurry (pH: 8.33-9.28 and ammonia 1-13 mM). The study demonstrated that A. galli eggs are more sensitive to unfavourable conditions compared to A. suum eggs. The use of A. galli eggs as hygiene indicator may thus be suitable to assess inactivation of pathogens that are more sensitive than A. galli eggs. Addition of urea may markedly reduce the storage time of slurry needed to inactivate A. suum and A. galli eggs.

In vitro and in vivo screening of anthelmintic activity of ginger and curcumin on Ascaridia galli.

Intestinal helmintic infection, continue to be a cause of major concern in several parts of the world, particularly in the developing nations. The use of plant extracts to control poultry helminths is increasing in different rearing systems. The anthelmintic activity of ginger and curcumin was studied on the nematode Ascaridia galli. In vitro and in vivo studies were allocated. Live parasites for in vitro studies were collected from the intestine of naturally infected chickens. Some living worms were incubated at 37 °C in media containing ginger at three concentration levels (25, 50, and 100 mg/ml), and others were incubated in media containing curcumin at the same concentration levels. Another living worm group was incubated in media containing albendazole at a dose of 7.5 mg/ml. The extracts' efficacy was exhibited in a concentration-time-dependent manner mainly at 100 mg/ml and after 48 h. The in vivo study takes place on experimentally infected chickens. Group of infected chickens was treated with ginger extract at dose of 100 mg, another group was treated with curcumin extract at dose of 100 mg, and a third group was treated with albendazole at dose of 7.5 mg. In vivo study of ginger and curcumin recorded lower mortality rates than the in vitro study. It is concluded that ginger and curcumin extracts have potential anthelmintic properties against A. galli. Ginger in all concentrations used exhibited a higher death rate observed than curcumin. Their wormicidal effect is concentration-time dependent.

Acute toxicity, brine shrimp cytotoxicity, anthelmintic and relaxant potentials of fruits of Rubus fruticosus Agg.

BACKGROUND: Rubus fruticosus is used in tribal medicine as anthelmintic and an antispasmodic. In the current work, we investigated the anthelmintic and antispasmodic activities of crude methanol extract of fruits of R. fruticosus on scientific grounds. Acute toxicity and brine shrimp cytotoxicity activity of the extract were also performed. METHODS: Acute toxicity study of crude methanol extract of R. fruticosus was performed on mice. In vitro Brine shrimp cytotoxicity assay was performed on shrimps of Artemia salina. In vitro Anthelmintic activity was tested against Raillietina spiralis and Ascaridia galli. Relaxant activities were tested on spontaneous rabbits' jejunal preparations. Calcium chloride curves were constructed to elucidate possible mode of action of the extract. RESULTS: LD 50 of the extract for acute toxicity studies was 887.75 ± 9.22 mg/ml. While CC 50 of the extract for Brine shrimps cytotoxicity assay was 13.28 ± 2.47 µg/ml. Test samples of crude methanolic extract of R. fruticosus (Rf.Cr) at concentration 20 mg/ml showed excellent anthelmintic activity against Raillietina spiralis. Anthelmintic activity was 1.37 times of albendazole against the Raillietina spiralis at concentration 40 mg/ml. At higher concentration (40 mg/ml), Rf.Cr has 89. 83% parasiticidal activity. The mean EC50 relaxation activity for spontaneous and KCl-induced contractions was 7.96 ± 0.1 and 6.45 ± 0.29 mg/ml, respectively. EC 50 (Log[Ca++]M) for control calcium chloride curves was -1.75 ± 0.01 vs. EC 50 -1.78 ± 0.06 in the presence of 3.0 mg/ml of Rf.Cr. Similarly, EC 50(Log[Ca++]M) in the absence and presence of verapamil (0.1 µM) were -2.46 ± 0.01 and -1.72 ± 0.02, respectively. CONCLUSIONS: The anthelmintic and relaxant activities explained traditional uses of R. fruticosus on scientific grounds. Relaxant activity follows the inhibition of voltage gated channels. Although the plant extract has cytotoxic effects, yet it is evident from acute toxicity study that it is safe in concentration 100 mg/kg. Further work is required to isolate pharmacologically active compounds.

Anthelmintic effects of citrus peels ethanolic extracts against Ascaridia galli.

The use of phytogenic bioactive compounds to control poultry helminthes is increasing in different production systems. In vitro and in vivo anthelmintic activity of citrus peels against Ascaridia galli was investigated. Ethanolic extracts of three citrus peels species were suspended in 0.5% dimethyl sulfoxide (DMSO) to form an experimental composition (EC). EC was mainly composed of Limonene (96%), followed by ß-Pinene (1.5%), α-Pinene (0.5%), and Sabinene (0.3%). For in vitro investigation, adult A. galli worms (n=225) were collected from naturally infected chickens and distributed to 3 equal groups. Groups 1, 2, and 3 were exposed to Fenbendazole (0.5mg/ml), EC (50mg/ml), and 0.5% DMSO, respectively. For in vivo investigation, 200 Lohmann Selected Leghorns chicks were infected at 1-day old with 250 embryonated A. galli eggs. At 6 weeks of age, 150 A. galli infected birds were randomly allocated into 5 equal groups. Groups 1, 2, and 3 were treated with 300, 600, and 1200 mg EC kg(-1) body weight, respectively. Group 4 was treated with Fenbendazole (50 mg kg(-1)). Group 5 was left as control. Birds were euthanized 2-weeks post-treatment, and all worms were collected from their intestines. EC possessed significant (P<0.001) in vitro anthelmintic properties on live worms. No significant (P>0.05) difference was quantified between number of motile worms exposed either to EC or Fenbendazole 7h post-exposure. A significant (P<0.0001) reduction in fecal egg count was observed 14 days post-treatment with 1200 mg kg(-1) EC. No significant differences were observed in worm burden of the 300 mg EC-treated group compared to the controls. In contrast, the 600 and 1200 mg EC-treated groups showed significant (P<0.0001) reduction in worm burden. Fenbendazole was the most effective in reducing A. galli burden (Efficacy=97%) followed by 1200 mg EC kg(-1) (68%), 600 mg EC kg(-1) (66%), and 300 mg EC kg(-1) (5%). It is concluded that citrus peels extracts have potential anthelmintic properties against A. galli.

Anthelmintic and relaxant activities of Verbascum Thapsus Mullein.

BACKGROUND: Verbascum thapsus is used in tribal medicine as an antispasmodic, anti-tubercular agent and wormicide. In this study, we investigated the antispasmodic and anthelmintic activities of crude aqueous methanolic extract of the plant. METHODS: V. thapsus extracts were tested against roundworms (Ascaridia galli) and tapeworms (Raillietina spiralis). Each species of worm was placed into a negative control group, an albendazole treatment group, or a V. thapsus treatment group, and the time taken for paralysis and death was determined. In addition, relaxation activity tests were performed on sections of rabbit's jejunum. Plant extracts were tested on KCl-induced contractions and the relaxation activities were quantified against atropine. V. thapsus calcium chloride curves were constructed to investigate the mode of action of the plant extracts. RESULTS: We detected flavonoids, saponins, tannins, terpenoids, glycosides, carbohydrates, proteins, fats and fixed oils in V. thapsus. For both species of worm, paralysis occurred fastest at the highest concentration of extract. The relative index values for paralysis in A. galli were 4.58, 3.41 and 2.08, at concentrations of 10, 20 and 40 mg/ml of plant extract, respectively. The relative index for death in A. galli suggested that V. thapsus extract is wormicidal at high concentration. Similarly, the relative indexes for paralysis and death in R. spiralis suggested that the extract is a more potent wormicidal agent than albendazole. The mean EC(50) relaxation activity values for spontaneous and KCl induced contractions were 7.5 ± 1.4 mg/ml (6.57-8.01, n = 6) and 7.9 ± 0.41 mg/ml (7.44-8.46, n = 6), respectively. The relaxation activity of the extract was 11.42 ± 2, 17.0 ± 3, 28.5 ± 4, and 128.0 ± 7% of the maximum observed for atropine at corresponding concentrations. The calcium chloride curves showed that V. thapsus extracts (3 mg/ml), had a mean EC(50) (log molar [calcium]) value of -1.9 ± 0.06 (-1.87 - -1.98, n = 6) vs. control EC(50) = -2.5 ± 0.12 (-2.37 - -2.56, n = 6), whereas the verapamil (0.1 µM) EC(50) was -1.7 ± 0.1 (-1.6 - -1.8, n = 6) vs. control EC(50) = -2.4 ± 0.09 (-2.3 - -2.47, n = 5). CONCLUSIONS: Our results suggest that V. thapsus, which is currently used by some tribes in the Malakand region of Pakistan, has anthelmintic and antispasmodic value.

Surface topographical and ultrastructural alterations of Raillietina echinobothrida and Ascaridia galli induced by a compound isolated from Acacia oxyphylla.

The stem bark of Acacia oxyphylla Graham ex Bentham is used as an anthelmintic by the natives of Mizoram (North-East India). Therefore, the aim of the study was to assess the effect of the active compound isolated from A. oxyphylla on the tegument of adult Raillietina echinobothrida and Ascaridia galli. The test parasites R. echinobothrida and A. galli were incubated in physiological buffered saline containing 0.0005, 0.001, 0.05, 0.1 and 1mg/ml of the isolated compound. The alterations in the tegument of the parasites post paralysis were examined using electron microscopes. The compound reduced the cestode's motility soon after incubation, but did not induce paralysis in the nematodes till about 11-14 h at highest concentration. The compound caused extensive digestion of cestode tegument as evident by electron microscopy. Disorganization of muscle bundles, loss of cell-cell contact, extreme vacuolization and oedema were some of the changes observed. Loss of cellular organelles combined with distortion of those present was markedly noted throughout the parasite tissue. Deformation and disorganization of epicuticle, disruption of mitochondrial and nuclear membrane were also observed in nematode exposed to the active compound of the plant. Substantial structural deformities in the treated parasites are indicative of an efficient vermicidal activity of the isolated compound against cestodes and nematodes.

The effects of dietary non-starch polysaccharides on Ascaridia galli infection in grower layers.

This study examined whether Ascaridia galli infection can be controlled by dietary non-starch polysaccharides (NSP) in chickens. One-day-old chicks were fed either a basal diet (CON) or CON plus insoluble NSP (I-NSP), or CON plus soluble NSP (S-NSP) for 11 weeks. Three weeks later, birds from half of each feeding group were inoculated with 250 embryonated eggs of A. galli, and slaughtered 8 weeks post-infection to determine worm counts. Both NSP diets, particularly S-NSP, increased prevalence of infection (P<0·05) and worm burden (roughly +50%) of the birds (P<0·001). A. galli infection caused a less efficient (P=0·013) feed utilization for body weight gain (BWG) resulting in lower body weights (P<0·001) irrespective of type of diet consumed. NSP-fed birds, particularly those on I-NSP, consumed more (+8%) feed per unit BWG and showed retarded (P<0·001) BW development compared to CON-fed birds. Intracaecal pH was lowered by S-NSP (P<0·05). Both NSP diets increased the volatile fatty acids pool size in caeca (P<0·001) with S-NSP exerting a greater effect (+46%) than I-NSP (+24%). It is concluded that both NSPs supplemented diets alter gastrointestinal environment in favour of the nematode establishment, and thus have no potential for controlling A. galli infection in chickens.

Pochonia chlamydosporia fungal activity in a solid medium and its crude extract against eggs of Ascaridia galli.

The present study aimed to evaluate the ovicidal activity (type 3 effect) of VC1 and VC4 isolates of Pochonia chlamydosporia in a solid medium and the action of a crude extract of P. chlamydosporia against eggs of Ascaridia galli. To evaluate ovicidal activity in culture medium, 1000 A. galli eggs were plated on Petri dishes containing 2% water-agar with grown fungal isolates (VC1 or VC4) and without fungus (control group) and were examined at 1, 3 and 5 days post-inoculation (assay A). Then, to test the action of crude extracts of P. chlamydosporia (VC1 or VC4), 500 eggs of A. galli were plated on Petri dishes of 4.5 cm diameter with 5 ml of fungal filtrate from each tested isolate. The control group consisted of 500 eggs of A. galli with 10 ml of distilled water on each Petri dish (assay B). Fungal isolates were effective (P < 0.01) at destroying these eggs, showing a type 3 effect at the studied intervals. On the other hand, the crude extract of isolates (VC1 or VC4) reduced the number of A. galli eggs in the treated group compared with the control group by 64.1% and 56.5%, respectively. The results of the present study show that P. chlamydosporia is effective at destroying eggs of A. galli and could therefore be used in the biological control of nematodes.

Structure-activity relationship of anthelmintic cyclooctadepsipeptides.

The relationship between cyclooctadepsipeptides and their anthelmintic efficacy was examined by converting the natural products, PF1022A, PF1022E and PF1022H. Some analogues substituted at the para position of the phenyllactate moiety showed higher or equivalent activity against the parasitic nematode, Ascaridia galli in chicken when compared with the parent compounds. It is suggested that lipophilicity and the polar surface area, in addition to structural requirements of the derivatives, influenced the anthelmintic efficacy in vivo.

Efficacy of allicin from garlic against Ascaridia galli infection in chickens.

The use of garlic as a treatment against helminth infections is increasing in organic layer farms in several European countries. Its efficacy against these parasites, however, has not been demonstrated thus far. Therefore, a study was conducted to determine the efficacy of a commercially available garlic product consisting of a high concentration of allicin (i.e., the main active component of garlic) against experimentally induced Ascaridia galli infection in chickens. In total, 450 Lohmann LSL-Classic cockerels were used. Group 1, the uninfected, untreated group, consisted of 50 chickens. Groups 2 to 5, each consisting of approximately 100 chickens, were inoculated with 300 embryonated A. galli eggs/chicken at 6 wk of age. Group 2 was not treated, whereas groups 3 through 5 were given daily individual oral treatments from 13 wk of age onward. Group 3 received the recommended dose of allicin for 2 wk, whereas group 4 received a 10-fold dose of allicin. Group 5 was given 10 mg of flubendazole/kg of BW for 1 wk. Necropsy of 20 birds of all groups was performed weekly between 13 and 16 wk of age to determine adult worm loads. Group 1 remained free of A. galli. The experimental infection in the other groups resulted in a mean adult worm load of approximately 16 worms/bird. No significant differences were observed in worm counts of the allicin-treated groups (groups 3 and 4) compared with the infected, untreated group (group 2) at any week (P > 0.05). In contrast, no worms were found in chickens after flubendazole treatment (group 5). It was concluded that allicin does not represent an alternative to flubendazole for the treatment of A. galli infections in chickens.