Taenia crassiceps WFU cysticerci synthesize corticosteroids in vitro: Metyrapone regulates the production

Taenia solium and Taenia crassiceps WFU cysticerci and tapeworms have the ability to synthesize sex steroid hormones and have a functional 3β-hydroxisteroid dehydrogenase. Corticosteroids (CS) like corticosterone and dexamethasone have been shown to stimulate in vitro estrogen production by Taenia crassiceps WFU cysticerci. The aim of this work was to study the ability of T. crassiceps WFU cysticerci to synthesize corticosteroids, and the effect of the inhibitor metyrapone on the CS synthesis. For this purpose T. crassiceps WFU cysticerci were obtained from the abdominal cavity of mice, thoroughly washed and pre-incubated in multiwells for 24 h in DMEM plus antibiotics/antimycotics. The tritiated CS precursor progesterone (3H-P4) was added to the culture media and parasites cultured for different periods. Blanks containing the culture media plus the 3H-P4 were simultaneously incubated. Blanks and parasite culture media were ether extracted and analyzed by thin layer chromatography (TLC) in two different solvent systems. Corticosterone production was measured in the culture media by RIA. In some experiments metyrapone (0.1–0.5 mM) was added for 24, 48 or 72 h. Results showed that cysticerci mainly synthesized tritiated 11-deoxy corticosterone (DOC) and small amounts of corticosterone that was also detected by RIA. Small amounts of 3H-11-deoxy cortisol were also found. Corticosteroid synthesis was time dependent. The addition of metyrapone significantly inhibited tritiated DOC, deoxycortisol and corticosterone synthesis. These results show for the first time that parasites have the capacity to synthesize CS that is modulated by metyrapone. Data suggest that DOC is the main corticosteroid in the parasites.

► Corticosteroid synthesis was studied in WFU Taenia crassiceps cysticerci by thin layer chromatography (TLC).
► Tritiated 11-deoxycorticosterone (DOC), 11-deoxycortisol and corticosterone were synthesized from 3H-progesterone.
► DOC was the most abundant corticosteroid synthesized by the parasites.
► Incubation of cysticerci with metyrapone decreased the synthesis of corticosteroids.
► The results demonstrate for the first time, that a parasite has the metabolic pathways to synthesize corticosteroids.