Effects of pyrantel pamoate on adult and preadult Toxocara canis worms: an electron microscope and autoradiography study

Evaluation of anthelminthic and antiprotozoal activity of myrrh (Commiphora myrrha) methanolic extract

To treat and control parasitic infections, traditional medical remedies using plant products are utilized as antiparasitic agents rather than standard synthetic chemicals due to drug resistance. Myrrh, a resinous exudate of Commiphora myrrha (Burseraceae), is a powerful antioxidant with a variety of medicinal uses. This study aimed to investigate the effect of the myrrh methanolic extract (MyE) of three concentrations (100, 50, and 25 mg/ml) on the sporulation of oocysts and as an anthelminthic effector via in vitro study. Characterization of the plant was done by Fourier-transform infrared spectroscopy (FT-IR). The earthworm, Eisenia fetida, is used as a model worm to evaluate the anthelminthic activity of MyE. Eimeria labbeana-like oocysts are used as a model protozoan parasite in anticoccidial assays. The sporulation and inhibition (%) of E. labbeana-like were assessed by MyE compared to other chemical substances. FT-IR revealed the presence of twelve active compounds. Our results showed that paralysis and death of earthworms at MyE (100 mg/ml) were 7.88 ± 0.37 and 9.24 ± 0.60 min, respectively, which is more potency when compared to mebendazole (reference drug). In all treated worms, microscopic examinations revealed obvious surface architecture abnormality. This study shows that MyE affects oocysts sporulation in a dose-dependent manner. At 24 and 36 hr, a high concentration of MyE (100 mg/ml) inhibits sporulation by 90.95 and 87.17 %. At 36 hr, other concentrations of MyE (50 and 25 mg/ml), as well as amprolium, DettolTM, and phenol inhibits oocyst sporulation by 40.17 %, 29.34 %, 45.09 %, 85.11 %, and 61.58 %, respectively. According to our research, the MyE extract had powerful anthelmintic and anticoccidial properties.

Comparative in vitro effect of artemether and albendazole on adult Toxocara canis

Since the integrity of Toxocara canis cuticle is essential for the nutritive and protective functions, light and scanning electron microscopic studies were undertaken to assess, for the first time, whether artemether had any effect on the cuticle including lips and sensory organs following 24 and 48 h incubation in vitro. The results were compared with those observed in the worm cuticle following incubation in albendazole, as it was 100% effective against adult nematode. The body cover changes seen after in vitro administration of artemether were similar to that induced by albendazole sulfoxide, active form, (ABZ-SO). However, the earlier onset of those changes was recorded with the former. The swollen appearance of the anterior end of T. canis, including the lips, distortion of some sensory papillae, and appearance of a number of lesions on the lips, were observed during in vitro action of artemether. Cuticular disruption had also been observed in adult T canis exposed to ABZ-SO. The surface changes were more severe than those observed following incubation in artemether, with which limited loss of the cuticle occurred in the lips of nematode but was not as widespread as that seen with ABZ-SO. However, the cuticular swelling of the anterior end of T canis was more pronounced than that with ABZ-SO. In the present study, artemether presented itself as a drug that might become important in nematode chemotherapy, besides its broad spectrum of activity against various trematodes.

Pyrantel in small animal medicine: 30 years on

Pyrantel, a tetrahydropyrimidine nicotinic agonist anthelmintic, has been used in companion animal medicine since the 1970s to control two important nematode groups, the hookworms and the roundworms. Given the zoonotic potential of these parasites, pyrantel has served a dual role in helping to protect the health of both companion animals and the public for more than 30 years. This review describes the history and mechanism of action of this drug, and collates evidence that resistance to pyrantel has developed in at least one canine nematode, the hookworm Ancylostoma caninum. The role of in vitro diagnosis tests in managing anthelmintic resistance in companion animal parasites is discussed, as are management practices that may reduce the rate at which resistance develops.

A light and electron microscopic study on the synergistic effect of pyrantel and the febantel metabolite febendazole on adult Toxocara canis in vitro

In the present study, we investigated the in vitro effects on the motility and morphology of tissues and organs of Toxocara canis of the two drug components of Drontal Plus and Welpan, pyrantel and fenbendazole (the active metabolite of the prodrug febantel), both alone and in combination. Although there was no significant difference observable between the effects of the single drugs and the drug combination on worm motility, the synergistic effect of pyrantel and fenbendazole was manifested by morphological alterations seen by light and electron microscopy. Thus, an earlier onset of damage to worm tissues and organs could be observed compared to the application of the individual drugs. In addition, a higher degree of damage and an increased number of vital organs were involved. There was dramatic, significantly greater and irreversible damage to the hypodermis, longitudinal muscle, intestine, nerve cords and genital organs induced by the pyrantel/fenbendazole combination. We hypothesise that these synergistic effects will also take place when dogs are treated either with Drontal Plus or Welpan in which lower dosages will be sufficient to destroy the worms.

Aspects of Toxocara epidemiology: toxocarosis in dogs and cats

Toxocara canis and Toxocara cati are common roundworms of dogs and cats. In this review the life cycles of these parasites are described, including the various routes of transmission, such as transplacental, transmammary infection, and infection through paratenic hosts. The somatic and tracheal migration in the body of the hosts after infection with Toxocara eggs or larvae is discussed, with special reference to age resistance and differences between dog and cat. The clinical symptoms and pathology in adult and young dogs and cats are given. Diagnosis of patent infections can be obtained by fecal examination, and treatment consists of the use of anthelmintics. Control of the infection and disease is achieved by prevention of contamination of the environment, anthelmintic treatment strategy, and education. Special attention is given to the efficacy of anthelmintics against adult worms and against somatic larvae. It is concluded that education on the life cycles of the parasites, hygiene, and anthelmintic treatment schedules is required because of the zoonotic risks of Toxocara spp. Deworming of pregnant dogs and cats is not recommended.