The aqueous extract of Codiaeum variegatum and its fractions exhibit in vitro antiparasitic activity against Giardia lamblia and Trichomonas vaginalis

Abstract

The leaf decoction of Codiaeum variegatum is used by Cameroonian local population in the treatment of
intestinal infections. The present study was carried out to investigate the antiparasitic activity of the aqueous
extract of C. variegatum and its fractions against axenic culture of G. lamblia and T. vaginalis. Trophozoites of
G. lamblia, and T. vaginalis were incubated separately with different concentrations of leaf aqueous extract of
C. variegatum fractions and sub-fractions for 24 and 48 hours. Metronidazole was used as the positive control.
The viability of trophozoites determined by using the quantitative colorimetric [3-(4,5-dimethilthiazol-2-yl)-2,5-
diphenyl tetrazolium bromide] (MTT) technique. All the extract fractions and sub-fractions were active against
G. lamblia and T. vaginalis. The sub-fraction SF9B showed the highest antiparasitic activity against G. lamblia
and T. vaginalis after 48 hours, but remain lower compared to metronidazole. Sub-fraction SF9, and SF9B2
showed moderate antiparasitic activities. Methanol, ethyl acetate fractions and aqueous extract exhibited low
antiparasitic activities. However, no significant difference was observed between the anti-trichomonal activity
of the methanol fraction compared to that of the SF9B2 (89.35 ± 5.02µg/mL) sub-fraction of C. variegatum after
48h of incubation. The aqueous extract, methanol, fraction, ethyl acetate, and sub-fractions SF9, SF9B and
SF9B2 isolated from Codiaeum variegatum exhibited giardicidal and antitrichomonal activities therefore
supporting the medicinal usage of this plant against intestinal infections.