In vitro evaluation ofβ-carboline alkaloids as potential anti-Toxoplasma agents.
BMC Res Notes. 2013 May 10 ;6:193. Epub 2013 May 10. PMID: 23663567
Maria L Alomar
BACKGROUND: Toxoplasmosis is a worldwide infection caused by the protozoan parasite Toxoplasma gondii, which causes chorioretinitis and neurological defects in congenitally infected newborns or immunodeficient patients. The efficacy of the current treatment is limited, primarily by serious host toxicity. In recent years, research has focused on the development of new drugs against T. gondii.β-Carbolines (βCs), such as harmane, norharmane and harmine, are a group of naturally occurring alkaloids that show microbicidal activity. In this work, harmane, norharmane and harmine were tested against T. gondii.
FINDINGS: The treatment of extracellular tachyzoites with harmane, norharmane and harmine showed a 2.5 to 3.5-fold decrease in the invasion rates at doses of 40μM (harmane and harmine) and 2.5 μM (norharmane) compared with the untreated parasites. Furthermore, an effect on the replication rate could also be observed with a decrease of 1 (harmane) and 2 (norharmane and harmine) division rounds at doses of 5 to 12.5 μM. In addition, the treated parasitespresented either delayed or no monolayer lysis compared with the untreated parasites.
CONCLUSIONS: The threeβC alkaloids studied (norharmane, harmane and harmine) exhibit anti-T. gondii effects as evidenced by the partial inhibition of parasite invasion and replication. A dose-response effect was observed at a relatively low drug concentration (<40μM), at which no cytotoxic effect was observed on the host cell line (Vero).