Background: Giardia lamblia
is a parasite that causes giardiasis in humans and other mammals. The common treatment includes different drugs,
which were described to produce unpleasant side effects.
Citrus aurantifolia
, popularly known as “lima”, is a plant used in traditional medicine to treat
gastrointestinal symptoms. The aim of the present study was to evaluate the anti-Giardia activity of 10 pure compounds obtained from a hexanic
extract of Mexican lime on the basis of trophozoite growth inhibition.
Materials and Methods: A hexanic extract obtained from fresh fruit peels of
Citrus aurantifolia was tested on
G. lamblia strain 0989:IMSS
trophozoites cultured in TYI-S-33 medium. The concentration of all standard drugs, analyzed by gas chromatography, was adjusted at 10 mg/mL.
Metronidazole was used as a positive control. Growth inhibition was determined by counting the number of trophozoites using a Neubauer chamber.
The 50% inhibitory concentration (IC
50) of each drug was calculated by probit analysis and 95% confidence limits were calculated.
Results: 4-hexen-3-one, citral and geraniol showed IC
50 values of 34.2, 64.5 and 229.49 μg/ml in axenic cultures after 24 hr of incubation,
respectively. When these results were compared with a positive control of metronidazole; 4-hexen-3-one was 66 times; citral was 112 and geraniol
was 441 times less active respectively. The other tested compounds did not inhibit the growth of cultured
G. lamblia trophozoites.
Conclusion: The obtained results lead us to propose that these tested compounds from
C. aurantifolia have potential for use as therapeutic agents
against giardiasis.
