Biochemical and ultrastructural changes in Raillietina echinobothrida in vitro exposed to extract of Lysimachia ramosa

Anthelmintic evaluation of three ayurvedic formulations: a transmission electron microscopy study in Raillietina sp. (Cestoda)

Ayurveda is one of the ancient traditional medicine systems in India. However, several Ayurvedic medicines lack scientific evidence about their efficacy. This study reports the in vitro anthelmintic effects of three common Ayurvedic formulations, Krimimudgar Ras, Kriminol, and Birangasav on a poultry cestode Raillietina sp., using transmission electron microscopy (TEM). Adult cestodes were exposed to different concentrations of Ayurvedic formulations and the paralyzed parasites from the highest concentration (50 mg/mL) of Ayurvedic formulations, the reference anthelmintic praziquantel (PZQ) together with control were picked up and processed for TEM. The TEM studies of control cestode parasites revealed a normal arrangement of microthrix layer, basal lamina, longitudinal muscle layer, and a normal nucleus and mitochondria. Importantly, the cestodes that were exposed to 50 mg/mL concentration of Krimimudgar Ras revealed the most prominent ultrastructural alterations in the body of parasites in the form of a disrupted microthrix layer, basal lamina, muscle layer and mitochondria. The nucleus also appeared dense and irregular in shape with scattered chromatin and disrupted nuclear membrane. Kriminol-treated worms revealed considerably less damage, whereas Birangasav-treated worms revealed destructive effects in microthrix layer, nucleus and mitochondria. Through the findings of the present study, it can be concluded that of the three common Ayurvedic formulations studied, Krimimudgar Ras causes maximum degree of internal alterations in cestode parasites and thus may be considered as a good anthelmintic agent.

Anthelmintic efficacy of Holarrhena pubescens against Raillietina spp. of domestic fowl through ultrastructural, histochemical, biochemical and GLCM analysis

Globally, traditional knowledge systems are a powerhouse of information which can revolutionise the world, if decoded accurately and logically. Plant-based ethno-traditional and folklore curatives/medicines has a firm basis in the psyche of the common masses of West Bengal and Holarrhena pubescens is a representative example of it. This article communication on depicting the anthelmintic efficacy of ethanolic extract and Ethyl acetate fraction of the stem bark of Holarrhena pubescens against the cestode Raillietina spp. through efficacy studies, ultra-structural observations, histochemical and biochemical analysis on some tegumental enzymes i.e., Acid Phosphatase (AcPase), Alkaline Phosphatase (AlkPase), Adenosine Triphosphatase (ATPase) and 5'-Nucleotidase (5'-Nu) along with Gray Level Co-occurrence Matrix (GLCM) analysis of histochemical study. Praziquantel was used as the reference drug. Investigations revealed 10mg/ml dosage of crude extract was the most efficacious dose and amongst the fractions the ethyl acetate fraction showed the most anthelmintic property. Ultrastructural studies through Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) clearly depicted the damage in head, sucker, proglottids, proximal and distal cytoplasm (DC), microtriches (MT), basal lamina (BL), nuclear membrane (NM), and, nucleolus (NL) in the treated worms. Histochemical studies revealed decrease in staining intensity for all the tegumental enzymes in the treated worms compared to control. The GLCM analysis strongly supported the result of histochemical studies. Biochemical studies revealed marked reduction in enzyme activity in the treated worms with maximum reduction in the activity of 5'- Nu (77.8%) followed by ATPase (63.17%).

Whole-organism phenotypic screening methods used in early-phase anthelmintic drug discovery

Diseases caused by parasitic helminths (worms) represent a major global health burden in both humans and animals. As vaccines against helminths have yet to achieve a prominent role in worm control, anthelmintics are the primary tool to limit production losses and disease due to helminth infections in both human and veterinary medicine. However, the excessive and often uncontrolled use of these drugs has led to widespread anthelmintic resistance in these worms - particularly of animals - to almost all commercially available anthelmintics, severely compromising control. Thus, there is a major demand for the discovery and development of new classes of anthelmintics. A key component of the discovery process is screening libraries of compounds for anthelmintic activity. Given the need for, and major interest by the pharmaceutical industry in, novel anthelmintics, we considered it both timely and appropriate to re-examine screening methods used for anthelmintic discovery. Thus, we reviewed current literature (1977-2021) on whole-worm phenotypic screening assays developed and used in academic laboratories, with a particular focus on those employed to discover nematocides. This review reveals that at least 50 distinct phenotypic assays with low-, medium- or high-throughput capacity were developed over this period, with more recently developed methods being quantitative, semi-automated and higher throughput. The main features assessed or measured in these assays include worm motility, growth/development, morphological changes, viability/lethality, pharyngeal pumping, egg hatching, larval migration, CO₂- or ATP-production and/or enzyme activity. Recent progress in assay development has led to the routine application of practical, cost-effective, medium- to high-throughput whole-worm screening assays in academic or public-private partnership (PPP) contexts, and major potential for novel high-content, high-throughput platforms in the near future. Complementing this progress are major advances in the molecular data sciences, computational biology and informatics, which are likely to further enable and accelerate anthelmintic drug discovery and development.

A kaempferol derivative isolated from Lysimachia ramosa (Wall ex. Duby) induced alteration of acetyl cholinesterase and nitric oxide synthase in Raillietina echinobothrida

Lysimachia ramosa has been used as a traditional medicine among the tribal population of Meghalaya, northeast India, for the control of helminthosis. The anthelmintic efficacy of L. ramosa has been documented earlier. In the present study, the active compound from L. ramosa has been isolated and identified using mass and NMR spectra. It's in vitro anthelmintic activity was evaluated against Raillietina echinobothrida, one of the most pathogenic cestode of domestic fowl. The isolated active compound was characterized to be a kaempferol derivative which showed potent anthelmintic activity against R. echinobothrida by changing surface ultrastructure and also inhibiting the activity of two neurotransmitter enzymes: acetyl cholinesterase (AChE) and nitric oxide synthase (NOS), both of which are known to perform dynamic roles in the intracellular communication mediated through neuromuscular system. Motility reduction, deformation in the surface architecture, extensive ultrastructural alterations and reduced histochemical stain intensity in both AChE and NOS was observed in the treated parasites. Biochemical result also revealed alteration in the enzyme activities in the treated parasites. Further, depletion in the nitric oxide (NO) production in the bioactive component exposed tissues of R. echinobothrida was also detected. The results provided evidence that the bioactive compound could be further explored to control helminthosis at a large scale.