News Update on Plasmodium Berghei Research: Jan – 2020

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News Update on Plasmodium Berghei Research: Jan – 2020

January 6, 2020 Microbiology 0

Drug resistance in Plasmodium bergheiVincke and Lips, 1948. I. Chloroquine resistance

By treating mice infected with Plasmodium bergheiVincke and Lips, 1948, with increasing doses of chloroquine parenterally, a strain (RC) was developed which was immune to the utmost dose of the drug which the host could tolerate. The ED50 (dose which produced a 50% suppression of parasitaemia by the 5th day after infection when given during the primary four days) of chloroquine within the normal (N) strain was 2.45 mg. per kilogram weight . That of the RC strain was >60 times greater. The RC strain also exhibited clear cross-resistance to amodiaquine, mepacrine, and quinine that the ED50s were >70, ~ 65, and >6 times those of the N strain, and a small but significant resistance to primaquine. [1]

Intravital Observation of Plasmodium berghei Sporozoite Infection of the Liver

Plasmodium sporozoite invasion of liver cells has been a particularly elusive event to review . within the prevailing model, sporozoites enter the liver by passing through Kupffer cells, but this model was based solely on incidental observations in fixed specimens and on biochemical and physiological data. to get direct information on the dynamics of sporozoite infection of the liver, we infected live mice with red or green fluorescent Plasmodium berghei sporozoites and monitored their behavior using intravital microscopy. Digital recordings show that sporozoites entering a liver lobule abruptly adhere to the sinusoidal cell layer, suggesting a high-affinity interaction. They glide along the sinusoid, with or against the bloodstream, to a Kupffer cell, and, by slowly pushing through a constriction, traverse across the space of Disse. Once inside the liver parenchyma, sporozoites move rapidly for several minutes, traversing several hepatocytes, until ultimately settling within a final one. [2]

Development of infectivity by the Plasmodium berghei sporozoite.

Studies were done on the event of infectivity during ontogeny of the sporozoite of the rodent plasmodium , Plasmodium berghei. Populations of sporozoites were separated from the oocysts, the hemocoel, and therefore the salivary glands, with special precautions being taken to avoid cross-contamination between the various populations. The results indicated that populations of exocrine gland sporozoites were quite 10,000 times as infective as populations of oocyst sporozoites from an equivalent mosquitoes. the event of this infectivity appears to be asynchronous, in some cases happening within the hemocoel, while in other cases not occurring until after the sporozoites have invaded the salivary glands. Thus, the event of infectivity seems to be time-dependent instead of site-dependent. [3]

Nuclear Pore Complex Components in the Malaria Parasite Plasmodium berghei

The nuclear pore complex (NPC) may be a large macromolecular assembly of around 30 different proteins, so-called nucleoporins (Nups). Embedded within the nuclear envelope the NPC mediates bi-directional exchange between the cytoplasm and therefore the nucleus and plays a task in transcriptional regulation that’s poorly understood. NPCs display modular arrangements with an overall structure that’s generally conserved among many eukaryotic phyla. However, Nups of yeast or human origin show little primary sequence conservation with those from early-branching protozoans leaving those of the plasmodium unrecognized. [4]

Effect of Methanolic Leaf Extract of Carica papaya on Plasmodium berghei Infection in Albino Mice

Aim: The work was designed to research the antmalarial activity of methanolic leaf extract of papaya on Plasmodium berghei NK65 strain infection in vivo .

Place and Duration of Study: Department of Biochemistry and National Institute of Pharmaceutical Research and Development, Abuja, Nigeria, between August and October 2016.

Materials and Method: Twenty five mice were intraperitoneally infected with chloroquine sensitive P. berghei strain and shared into 5 equal groups. Group 1 mice were infected and administered only normal saline (negative control). Groups 2, 3 and 4 were treated, after infection, with 100, 200 and 400 mg extract/kg weight of mouse respectively while group 5 was treated with 5 mg chloroquine /kg weight . The phytochemical constituents of the plant extract were evaluated. [5]

Reference

[1] Peters, W., 1965. Drug resistance in Plasmodium berghei. I. Chloroquine resistance. Experimental parasitology, 17(1), (Web Link)

[2] Frevert, U., Engelmann, S., Zougbédé, S., Stange, J., Ng, B., Matuschewski, K., Liebes, L. and Yee, H., 2005. Intravital observation of Plasmodium berghei sporozoite infection of the liver. PLoS biology, 3(6), (Web Link)

[3] Vanderberg, J.P., 1975. Development of infectivity by the Plasmodium berghei sporozoite. The Journal of parasitology, 61(1), (Web Link)

[4] Nuclear Pore Complex Components in the Malaria Parasite Plasmodium berghei
Jessica Kehrer, Claudia Kuss, Amparo Andres-Pons, Anna Reustle, Noa Dahan, Damien Devos, Mikhail Kudryashev, Martin Beck, Gunnar R. Mair & Friedrich Frischknecht
Scientific Reports volume 8, (Web Link)

[5] Y. Longdet, I. and A. Adoga, E. (2017) “Effect of Methanolic Leaf Extract of Carica papaya on Plasmodium berghei Infection in Albino Mice”, European Journal of Medicinal Plants, 20(1), (Web Link)

 

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