Assessment of antioxidant enzymes during the development of the digenetic trematode parasite Gastrothylax crumenifer, infecting the rumen of Indian water buffalo, Bubalus bubalis

The presence of antioxidant enzymes in helminth parasites is well known. These enzymes help the parasites to survive in their hosts by detoxifying host-generated reactive oxygen species (ROS). The literature survey reveals that most of the studies related to antioxidant enzymes in helminth parasites are restricted to the adult stage while the larval stages are neglected. The present investigation is designed to evaluate the level of antioxidant enzymes in the adult and larval stages of rumen-infecting paramphistome parasites, Gastrothylax crumenifer. The larval stages include 0-day eggs, 4-day eggs, and eggs containing mature miracidia, cercariae, and metacercariae. Antioxidant enzyme assays were performed using standard assay protocols. Our findings revealed an increasing pattern in the level of Glutathione-S-Transferase (GST), Superoxide Dismutase (SOD), Glutathione Reductase (GR), and Glutathione Peroxidase (GPx) antioxidant enzymes during the development from 0-day eggs to the adult stage. Overall analysis shows that adult worms have higher antioxidant enzyme activity as compared to the larval stages, indicating that adult flukes are more adapted to oxidative stress. It can be concluded that the miracidia, cercarial, and metacercarial developmental stages of G. crumenifer possess a considerable level of antioxidant enzymes suitable to overcome the oxidative stress encountered during the development and help them in the completion of the life cycle and survival in the definitive host.

The anthelmintic potentials of medicinal plant extracts and an isolated compound (rutin, C27H30O16) from Terminalia catappa L. against Gastrothylax crumenifer

Paramphistomosis is a pathogenic disease that occurs frequently in tropical and subtropical countries including Thailand. This disease is affected in the parasites causing severe gastrointestinal disorders and death in infected animals. In the present study, we examined the anthelmintic efficacy of albendazole (ABZ) and crude plant extracts from barks of Bombax ceiba L., Diospyros rhodocalyx Kurz. and Vitex glabrata R.Br., and leaves of Terminalia catappa L. and Cassia alata L. against Gastrothylax crumenifer. The hightest anthelmintic activity on the parasites after 24 h incubation was observed in the n-butanol extract of T. catappa leaf. In this study, fractionation bioassay of n-butanol extract of T. catappa leaf was conducted to both separation and discrimination of rutin served as a new efficient compound (LC₅₀ = 28.96; LC₉₀ = 88.75 μg/mL) against G. crumenifer. This compound was confirmed by ¹H nuclear magnetic resonance (¹H NMR), ¹³C NMR, infrared (IR) and ultraviolet (UV) spectra as well as mass spectra data. The rutin-treated parasites with all dosages showed swift decrease of the motility and the relative motility (RM) and survival index (SI) were decreased obviously from 3 h until flukes were killed after 12 h of incubation. When observed with light microscopy, the parasites showed the earliest change in a limited region of the tegument. When observed by scanning electron microscopy, the parasites' tegument exhibited similar sequences of surface changes after treatments with rutin and ABZ, but less severity in ABZ treatment. The sequences of changes comprised swelling of folds and ridges, formation of blebbing, rupturing of blebs, erosions, lesions and the tegument demolition. Hence, rutin could be considered as the potential anthelmintic agent for treatment of paramphistomosis.

Preparation and characterization of excretory and secretory antigen of Cotylophoron cotylophorum and Gastrothylax crumenifer

Excretory and secretory antigen of adult Cotylophoron cotylophorum and Gastrothylax crumenifer was prepared and characterized by SDS-PAGE. Adult paramphistomes were collected in PBS from rumen of sheep slaughtered at Perambur and Villivakkam slaughter houses, Chennai, Tamil Nadu. Excretory/Secretory (E/S) antigens of G. crumenifer and C. cotylophorum were prepared by incubating in PBS at 28.3 °C overnight in a shaking incubator and centrifuged. The culture supernatant was used as antigen. The protein concentration of E/S antigens of C. cotylophorum and G. crumenifer ranged from 0.4 to 7.1 mg/ml and 3.3 to 5.9 mg/ml, respectively. SDS-PAGE analysis of E/S antigen of C. cotylophorum revealed two polypeptide bands from the range of 32 and 40 kDa. Whereas, SDS-PAGE analysis of E/S antigen of G. crumenifer revealed only one polypeptide band of 35 kDa. Excretory/secretory antigen may be used for serodiagnosis of paramphistomosis infection in sheep.

Partial purification and characterization of glutathione S-transferase from the somatic tissue of Gastrothylax crumenifer (Trematoda: Digenea)

AIM

Aim of the present study was to carry out the partial purification and biochemical characterization of glutathione S-transferase (GST) from the somatic tissue of ruminal amphistome parasite, Gastrothylax crumenifer (Gc) infecting Indian water buffalo (Bubalus bubalis).

MATERIALS AND METHODS

The crude somatic homogenate of Gc was subjected to progressive ammonium sulfate precipitation followed by size exclusion chromatography in a Sephacryl S 100-HR column. The partially purified GST was assayed spectrophotometrically, and the corresponding enzyme activity was also recorded in polyacrylamide gel. GST isolated from the amphistome parasite was also exposed to variable changes in temperature and the pH gradient of the assay mixture.

RESULTS

The precipitated amphistome GST molecules showed maximum activity in the sixth elution fraction. The GST subunit appeared as a single band in the reducing polyacrylamide gel electrophoresis with an apparent molecular weight of 26 kDa. The GST proteins were found to be fairly stable up to 37°C, beyond this the activity got heavily impaired. Further, the GST obtained showed a pH optima of 7.5.

CONCLUSION

Present findings showed that GST from Gc could be conveniently purified using gel filtration chromatography. The purified enzyme showed maximum stability and activity at 4°C.

The complete mitochondrial genome of Gastrothylax crumenifer (Gastrothylacidae, Trematoda) and comparative analyses with selected trematodes

In the present study, we sequenced and analyzed the mitochondrial (mt) genome of Gastrothylax crumenifer and compared it with other selected trematodes. The full mt genome of G. crumenifer was amplified, sequenced, assembled, analyzed and then subjected to phylogenetic analysis. The complete mt genome of G. crumenifer is 14,801 bp in length and contains two rRNA genes, two non-coding regions (LNR and SNR), 12 protein-coding genes, and 22 transfer RNA genes. The gene organization of the G. crumenifer mt genome is the same as that of other trematodes, except for Schistosoma haematobium and Schistosoma spindale. All the genes are transcribed in the same direction and rich in "A + T", which is in accordance with other trematodes, such as Fasciola hepatica, Paramphistomum cervi, and Fischoederius elongatus. Phylogenetic analysis using concatenated amino acid sequences of the 12 protein-coding genes showed that G. crumenifer is closely related to F. elongatus. The availability of mt genome sequence of G. crumenifer can provide useful DNA markers for studying the molecular epidemiology and population genetics of this parasite and other paramphistomes.

Molecular characterization of Gastrothylax crumenifer (Platyhelminthes: Gastrothylacidae) from goats in the western part of India by LSU of nuclear ribosomal DNA

The rumen parasite, Gastrothylax crumenifer (Platyhelminthes: Gastrothylacidae), is a highly pathogenic trematode parasite of goat (Capra hircus). It sucks blood that causes acute disease like anemia, and severe economic losses occur due to morbidity and mortality of the ruminant infected by these worms. The study of these rumen paramphistomes, their infection, and public health importance remains unclear in India especially in the western part of state Uttar Pradesh (U.P.), Meerut, India, where the goat meat consumption is very high. This paper provides the molecular characterization of G. crumenifer recovered from the rumen of Capra hircus from Meerut, U.P., India by the partial sequence of 28S rDNA. Nucleotide sequence similarity searching on BLAST of 28S rDNA from parasites showed the highest identity with those of G. crumenifer from the same host Capra hircus. This is the first report of molecular identification of G. crumenifer from this part of India.

Immunoaffinity chromatographic analysis for purification of specific diagnostic antigens of Paramphistomum epiclitum

Polypeptide profile of somatic antigen of Paramphistomum epiclitum (PSAg) and Gastrothylax crumenifer (GSAg) was studied by SDS-PAGE. PSAg and GSAg showed 14 and 19 polypeptides in the range of 14.9-95.5 and 13.7-129.6 kDa with six common polypeptides of mol wt 16.8, 21.8, 23.7, 35.5, 43.4 and 70.8 kDa. P. epiclitum experimentally infected sheep sera were used for identification of specific immuno-dominant peptide in the range of 37-40 kDa against P. epiclitum by western blotting. Hyperimmune sera (HIS) was raised in rabbit against the identified polypeptide, IgG was separated from HIS and an immunoaffinity column was constructed with a binding percentage of 83.74 of IgG with CNBr activated Sepharose 4B. Purification of somatic antigen (PSAg) was done with immunoaffinity chromatography and 37-40 kDa protein antigen was isolated in pure form with recovery percentage of 2.97%. This purified fraction of somatic antigen can be used as a candidate antigen for development of serological assay for early diagnosis of paramphistomosis among livestock.

Potentilla fulgens (Family Rosaceae), a medicinal plant of north-east India: a natural anthelmintic?

The cestode parasite, Raillietina echinobothrida and the trematode, Gastrothylax crumenifer were exposed to the ethanolic root peel extract of Potentilla fulgens, an antiparasitic local medicinal plant of Meghalaya, India, to evaluate the anthelmintic efficacy of the plant. The parasites were incubated in 1, 5, 10, 20, 50 and 100 mg crude alcoholic extract per ml of phosphate buffered saline (PBS) at a temperature of 37 ± 1°C. Paralysis and death were observed at 2.00 ± 0.05 and 2.80 ± 0.06 h for the cestode and 1.21 ± 0.06 and 2.18 ± 0.04 h for the trematode parasites at the highest test concentration of the plant extract. The commercial anthelmintic, Praziquantel (PZQ) showed higher activity at the tested concentration (0.02 mg/ml). To further investigate the efficacy of the plant extract, vital tegumental enzymes of the parasite viz. Acid phosphatase (AcPase), Alkaline phosphatase (AlkPase) and Adenosine triphosphatase (ATPase) were studied. Quantitatively, the total enzyme activity of AcPase, AlkPase and ATPase was found to be reduced significantly by 69.20, 66.43 and 29.63% for R. echinobothrida and 47.96, 51.79 and 42.63% for G. crumenifer, respectively compared to the respective controls; histochemical study also showed reduction in the visible staining of the enzymes. The reference drug, PZQ also showed more or less similar effect like that of the plant extract. The result suggests that phytochemicals of P. fulgens have anthelmintic potential.

Characterization of the glutamate dehydrogenase activity of Gigantocotyle explanatum and Gastrothylax crumenifer (Trematoda: Digenea)

Glutamate dehydrogenase (GLDH) (EC 1.4.1.3) is a ubiquitous enzyme, which is present at the protein and carbohydrate metabolism crossroads. The enzyme activity was investigated in biliary and rumen amphistomes, Gigantocotyle explanatum and Gastrothylax crumenifer, respectively, infecting the Indian water buffalo Bubalus bubalis. The enzyme activity was consistently higher in G. explanatum as compared to G. crumenifer, where NAD(H) was utilized as coenzyme and the pH optima was recorded at 8. The K(m) and V(max) values for α-ketoglutarate were 2.1 mM and 9.09 units in G. explanatum, whereas 3.03 mM and 1.90 units in G. crumenifer, respectively. Among the allosteric modulator nucleotides, AMP, ADP, ATP, GMP, CMP and UMP, only AMP enhanced GLDH activity in G. crumenifer while ADP was stimulatory in G. explanatum. The amino acid leucine stimulated the GLDH activity in both the amphistomes while alanine was stimulatory only in G. crumenifer. Pronounced interspecific differences in response to different metabolic inhibitors like diethyldithiocarbamate, semicarbazide hydrochloride and mercurial ions were also observed. The osmotic stress alters the enzyme activity, particularly in hypertonic saline the GLDH activity increased significantly (p < 0.01) in G. explanatum, while insignificant effects were observed in rumen dwelling G. crumenifer. Histoenzymology revealed region/tissue specific distribution of GLDH with prominent staining in tissues like vitellaria, lymph system and tegument/subtegument, thus showing specific distribution of GLDH indicating differential metabolic state. Such intergeneric differences in GLDH activity could also be a consequence of occupying different microenvironments within the same host.