Evaluation of the effect of a plant alkaloid (berberine derived from Berberis aristata) on Trichomonas vaginalis in vitro.

Berberine is a quaternary alkaloid derived from the plant Berberis aristata having antibacterial, antiamoebic, antifungal, antihelminthic, leishmanicidal and tuberculostatic properties. The effect of berberine sulphate salt on the growth of Trichomonas vaginalis in vitro was compared to the efficacy of metronidazole as a reference drug. Results showed that berberine sulphate was comparable to metronidazole as regards potency with the advantage of being more safe and possible replacement in metronidazole resistant cases.

A novel chemotherapeutic combination for Trichomonas vaginalis targeting purine salvage pathways of the parasite.

A novel combination of chemotherapy (Dipyridamole/Allopurinol) targeting the possible purine salvage mechanisms of Trichomonas vaginalis was used in this study. The possible effect of these drugs either individually or in combination, on the multiplication of T. vaginalis in modified TYM axenic culture, was assessed on 24 hours intervals. The combination of both drugs at concentrations of 5 microM and 10 microM each showed a potent lethal effect on the parasite and an almost complete inhibition of parasite multiplication in culture. Each drug, individually, has a significant but partial inhibitory effect on parasite multiplication. Surprisingly, allopurinol, a competitive inhibitor of hypoxanthine, a nucleobase that is not salvaged by the parasite, showed a more potent inhibitory effect on parasite multiplication than dipyridamole, a specific inhibitor of the transport of adenosine, a favored nucleoside to T. vaginalis. However, the inhibitory effect of either drugs declines with time in contrast with that of the combination of both drugs which continues throughout all time points of the experiment. These results prove that a combination of dipyridamole and allopurinol could be useful, not only in the treatment of trichomoniasis, but also in other parasites that are unable of de novo purine synthesis.

Schistosoma mansoni egg specific antibodies and circulating antigens: assessment of their validity in immunodiagnosis of schistosomiasis.

A total of 127 individuals of different age and sex; 92 from Kafr-Sendewa, Qualyobia Governorate, Egypt, in comparison to 23 cases with hydatidosis and fascioliasis as a parasitic control group, and 12 healthy control group from non-endemic area. All cases were screened by clinical examination, urine, stool, rectal snip, abdominal ultrasonographic examination and indirect haemagglutination test (IHAT). Accordingly, they were grouped into active intestinal schistosomiasis group, seropositive group by (IHAT), normal control group from the same endemic area, parasitic control group and normal control group. All cases were subjected to detection of IgG, IgM, IgG4, anti-soluble egg antigen (SEA) and anti-excretory-secretory egg antigen (ESEA) by ELISA tests; and circulating egg antigens by double-sandwich ELISA techniques. The results showed that IgG4 anti-SEA is the best diagnostic test, as it gave the best diagnostic efficacy (90%). Also, it is a good screening test which can be used in endemic area as it gave significant difference between the active intestinal schistosomiasis cases with each of the endemic control group (P < 0.001) and the seropositive cases (P < 0.05). Other valid diagnostic egg specific antibodies tests were IgM anti-SEA and IgG anti-SEA as their diagnostic efficacy were 80% and 76.6% respectively (P < 0.05). The diagnostic efficacy of circulating antigen detection (C.Ag) test was 70% (P < 0.05). In addition, it was the most specific test with 100% specificity. IG4-anti-ESEA gave the least cross-reaction with other parasites (17.3%). The mean optical density (OD) level of circulating antigen detection test was significantly higher in the organomegalic (hepatosplenomegaly) cases than the non-organomegalic cases (P < 0.05).

Time factor and eosinophil count in relation to experimental Schistosoma mansoni infection.

The effects of diurnal variations of eosinophils on hostparasite relationship was studied in mice primarily exposed to S. mansoni infection. The eosinophil counts of 20 control normal mice showed different variations at different hours of the day with maximum level at midday and the minimum level at midnight. At these times, 2 groups of mice, each consists of 30 mice, were infected by about 100 S. mansoni cercariae. The infected mice in both groups showed more or less the same results as regards the worm burden, egg counts in tissues and histopathological changes in livers. Both infected groups showed marked eosinophil elevation versus normal control group yet the difference in-between them was insignificant. This means that the normal physiological variation in eosinophils in normal mice is useless in protection against infection. Complete ablation of eosinophils from animal using antieosinophilic sera, is essential for any study on eosinophils in relation to infection.

Biochemical studies on the terrestrial snail, Eubania vermiculata (Müller) treated with some pesticides.

The in vivo effects of methomyl, thiodicarb and metaldehyde on total soluble proteins, total lipids and glycogen content, in addition, the activity of glutamic oxaloacetic transaminase, (GOT), (GPT) glutamic pyruvic transaminase and catalase (CAT) enzymes of terrestrial E. vermiculata snails was studied. The experimental snails were treated with low concentration of 0.2% brain bait w/w of the pesticides for a period of 1,3,5,7 and 10 days. The results showed that methomyl and thiodicarb lead to significant reduction in total soluble proteins, lipids, and glycogen content, while significant increases in the activity of all enzymes tested were noted. Metaldehyde treatment showed no significant effect on total soluble proteins, lipids and GOT level, whereas a significant increase in GPT and CAT enzymes was observed. Also, metaldehyde resulted a significant reduction in glycogen content of snails.