Background

The negative effect of over-reliance on the use of synthetic pesticides have led to the search for natural alternatives to pest control. This study was designed to evaluate the toxicity effect of the crude plant extracts of Jatropha (Jatropha curcas Linn.) seeds in comparison with methomyl on some histopathological changes of the terrestrial snail species Monacha obstructa (Pfeiffer, 1842). The toxicity effect of methomyl and crude extracts of ethanol and acetone extracts of Jatropha curcas seeds were determined on some histological changes of the land snail, Monacha obstructa at four concentrations using the contact technique under laboratory conditions.

Results

The results revealed that the crude extracts of Jatropha exhibited obvious adequate effects compared with methomyl against M. obstructa land snails. The highest toxicity effects were obtained by methomyl followed by the ethanolic extract of Jatropha and hexane extract of Jatropha. The histopathological effect of LC₅₀ of Jatropha crude extract and methomyl on the digestive gland and foot tissues were examined in the land snails M. obstructa. The treated snails showed several histological changes in the digestive gland and foot compared with the control group snails. The histological examinations of the digestive tubules included destroyed and detached in the outer layer covering digestive tubules. In addition, marked increase in the width most of the digestive tubules lumen. The intertubular connective tissue between the digestive tubules showed great destruction, while the foot of treated snails showed rupture of the epithelium covering the foot and desquamation of the epithelium. We also observed the presence of areas of connective tissue necrosis and destruction of the muscular tissue.

Conclusions

It has been found that extracts of Jatropha seeds have a toxic activity that caused histopathological damage that led to the death of land snails, and thus it can be recommended as a source for the development of molluscicides.

Background

The negative effect of over-reliance on the use of synthetic pesticides have led to the search for natural alternatives to pest control. This study was designed to evaluate the toxicity effect of the crude plant extracts of Jatropha (Jatropha curcas Linn.) seeds in comparison with methomyl on some histopathological changes of the terrestrial snail species Monacha obstructa (Pfeiffer, 1842). The toxicity effect of methomyl and crude extracts of ethanol and acetone extracts of Jatropha curcas seeds were determined on some histological changes of the land snail, Monacha obstructa at four concentrations using the contact technique under laboratory conditions.

Results

The results revealed that the crude extracts of Jatropha exhibited obvious adequate effects compared with methomyl against M. obstructa land snails. The highest toxicity effects were obtained by methomyl followed by the ethanolic extract of Jatropha and hexane extract of Jatropha. The histopathological effect of LC₅₀ of Jatropha crude extract and methomyl on the digestive gland and foot tissues were examined in the land snails M. obstructa. The treated snails showed several histological changes in the digestive gland and foot compared with the control group snails. The histological examinations of the digestive tubules included destroyed and detached in the outer layer covering digestive tubules. In addition, marked increase in the width most of the digestive tubules lumen. The intertubular connective tissue between the digestive tubules showed great destruction, while the foot of treated snails showed rupture of the epithelium covering the foot and desquamation of the epithelium. We also observed the presence of areas of connective tissue necrosis and destruction of the muscular tissue.

Conclusions

It has been found that extracts of Jatropha seeds have a toxic activity that caused histopathological damage that led to the death of land snails, and thus it can be recommended as a source for the development of molluscicides.

The current study described the developmental sequence of the ventriculus of the post-hatching Muscovy ducks of both sexes ranging from 1-60 days old, by using gross-histomorphometic measurements and by using light microscope, scanning electron microscope and transmission electron microscope. The ventriculus was extended from the level of the 4th intercostal space to terminate behind the last rib at variable distances dependent on the age of the duck. The statistical analysis revealed that the length of the ventriculus from that of the stomach was decreased by the advancement of the age, while the weight was increased. At all developmental age-stages, the cuticula gastrica was composed of two layers; vertical rods and horizontal matrix. The vertical rods projected slightly as dentate processes beyond the surface of the mucosa at 30-60dys old. The type of the gizzard gland was different according to the age; it was simple tubular type lining by one type of cells (chief cells) at 1-15 days old, but were compound-branched type lining by two types of cells; chief and basal cells at 30-60 days old. By semithin sections, the secretory basophilic granules within the cells lining of the tubular glands were increased by ageing. Transmission electron microscopy exhibited that the chief cells had numerous large sizes electron dense and electron lucent secretory granules. In conclusion, there are wide variations in the morphometrical analysis and the structure of the ventriculus at the developmental age-stages of the duck.

The present study was carried out to investigate the synaptic ultrastructure of the mouse cerebellum using focused ion beam scanning electron microscopy (FIB-SEM). The experiment were performed using seven weeks old wild type mice. In the present work, we used a newly established morphological investigation method of axospinous synapses (FIB-SEM). This method enables fully automated acquisition of serial ultrastructural data at a spatial resolution of 10 nm in z-axis without the ultrastructure distortions. FIB-SEM enabled easily identification of axospinous synapses in the mouse cerebellum where individual synaptic ultra-structure can be easily identified and measured. The results indicated that, the cerbellum axospinous synapses have presynaptic and postsynaptic compartment. The presynaptic compartment consists of the presynaptic axonal varicosity, synaptic vesicles and mitochondria. The postsynaptic compartment consists of the dendritic spine, postsynaptic density and smooth endoplasmic reticulum and spine apparatus. The volume of presynaptic and postsynaptic compartments was varaible. The results indicated a significant positive correlation between presynaptic compartments as well as between postsynaptic compartments. Moreover, this study represented novel correlations between presynaptic and postsynaptic parameters.