Anticoccidial effects of Phyllanthus emblica (Indian gooseberry) extracts: Potential for controlling avian coccidiosis.

The protozoan parasite Eimeria causes avian coccidiosis, impacting the poultry industry worldwide. Resistance development to current anticoccidials are a concern and cost effective, environmentally friendly alternatives are needed. Anti-malarial effects of Phyllanthus emblica encouraged us to investigate its anticoccidial effects. Aqueous extracts and dried-powder of P. emblica leaf and fruit were tested for effect(s) on oocyst sporulation in vitro and oocyst infectivity in vivo. Eimeria tenella oocysts were randomly assigned to groups and treated with different concentrations (0.001, 0.1, 1, 5, 25, 50 and 100%) of P. emblica crude extracts in triplicates for three repeats. Sporulated, unsporulated, deformed and lysed oocysts were recorded at 24, 48 and 72 h. Broiler chicks (21 days old) were randomly assigned into four groups with 5 chicks each and experimentally infected on Day 0 with 1 × 104 oocysts/bird: (A) infected and un-supplemented diet, (B) infected and supplemented diet (P. emblica powder 1 g/bird/day), (C) infected with P. emblica-treated oocysts and un-supplemented diet and (D) infected and diet supplemented only from day14. In vivo experiments were terminated on day28. Significant sporulation inhibition and oocyst lysis (p < 0.05) in vitro were observed in a concentration-dependent with P. emblica treatment. In in vivo experiments, group B showed the highest weight gain, lowest fecal oocyst excretion and mildest histopathological lesions. Extracts of P. emblica remarkably inhibited oocyst sporulation, reduced the oocyst infectivity and lowered the fecal oocyst excretion, and reduced the pathogenicity of E. tenella in chickens. Therefore, P. emblica extract demonstrates great potential to be an effective alternative anticoccidial agent.

Proteases and pseudoproteases in parasitic arthropods of clinical importance.

Parasitic arthropods feed on blood or skin tissue and share comparable repertoires of proteases involved in haematophagy, digestion, egg development and immunity. While proteolytically active proteases of multiple classes dominate, an increasing number of pseudoproteases have been discovered that have no proteolytic function but are pharmacologically active biomolecules, evolved to carry out alternative functions as regulatory, antihaemostatic, anti-inflammatory or immunomodulatory compounds. In this review, we provide an overview of proteases and pseudoproteases from clinically important arthropod parasites. Many of these act in central biological pathways of parasite survival and host-parasite interaction and may be potential targets for therapeutic interventions.