Plasmodium falciparum, antimicrobial

Akompong T, Ghori N, and Haidar K (2000b) In vilro aclivily of riboflavin againsi Ihe human malaria parasite Plasmodium falciparum. Antimicrobial Agents and Chemotherapy 44, 88-96. 

A rapid semiautomated microdilution method for the microbiological assay of the chloroquine has been developed by Desgardins (26). Antimalarial activity of chloroquine may be studied against cultured Plasmodium falciparum, microplates are used to prepare serial dilution of the drug. Parasites obtained from continuous stock cultures are subcultured in the micro-plates for 42 h. Inhibition of uptake of a radio labeled nucleic acid precursor by parasites serves as the indicator of antimicrobial activity. 

Fosmidomycin is an antimicrobial drug that acts by inhibiting 1-deoxy-D-xylulose 5-phosphate reductoisomerase, a key enzjme of the non-mevalonate pathway of isopre-noid biosynthesis. It inhibits the synthesis of isoprenoids by Plasmodium falciparum and suppresses the growth of multidrug-resistant strains in vitro. 

Rhus retinorrhoea Steud. ex Olive (leaves) Biflavanone (I-25,II-25)-I-7,II-7-di-0-methyl-I-2,3,II-2,3-tetrahydroamento-flavone (56). Used in traditional medicine because of the antimicrobial and cytotoxic properties. Insecticidal activities against aphids. Moderate antimalarial activity against Plasmodium falciparum (W2 Clone) weak activity against P. falciparum (D6 Clone). Ahmed et ah, 2001[68]. 

There have also been reports of antimicrobial activity in this family of alkaloids. AlstiphyUanine B (38), alstiphyllanine C (39), and alstiphyllanine D (40) were reported to have moderate in vitro antiplasmodial activity against Plasmodium falciparum Scholarisin I (60), scholarisin II (61), scholarisin III... 

Berberine possesses antimicrobial activity against bacterial [13, 94-96], fungal [97], protozoan [98, 99], and viral [100-102] infections. In vitro studies have shown that berberine is effective against Entamoeba histolytica, Giardia lamblia, Trichomonas vaginalis [98, 103], Candida spp. [97, 104], Plasmodium falciparum [99], Staphylococcus aureus [95, 105, 106], influenza virus [100], human immunodeficiency virus (HIV) [107], human cytomegalovirus [101], herpes simplex virus, [102] Chlamydia trachomatis [105], Helicobacter pylori [96], and Leish-mania donovani [99]. 

Dihydrofolate reductase (DHFR), a classic target in antimicrobial and anticancer chemotherapy, has been shown to be a useful therapeutic target in plasmodium, toxoplasma, and eimeria species. Pyrimethamine is the prototypical DHFR inhibitor, exerting inhibitory effects in all three groups. However, pyrimethamine resistance in P falciparum has become widespread in recent years. This is largely attributable to specific point mutations in P falciparum DHFR that have rendered the enzyme less susceptible to the inhibitor. 

---