Inactivated horse serum

Rat pheochromocytoma PC12 cells were purchased from China Center for Type Culture Collection (CTCC, Wuhan, China) and cultured in RPMI1640 medium (Gibco BRL, Grand Island, New York, NY, USA) containing 10% inactivated horse serum (Gibco BRL, Grand Island, New York, NY, USA) supplemented with 10% FBS. PC12 cells were grown in a humidified atmosphere containing 5.0% CO₂ at 37 °C. Fucoxanthin was provided by Biopurify Co., Ltd. (Chengdu, Sichuan, China), for which the purity of Fucoxanthin was 98%, as determined using HPLC detection [40 (link)]. Additionally, Fucoxanthin was dissolved in dimethyl sulfoxide (DMSO, Sigma, St. Louis, MO, USA) and then diluted to desired concentrations.

The referred faecal specimens are routinely examined by microscopy for parasitic infections using the direct smear method with saline and iodine. Samples from suspected patients, if negative by direct microscopy, are further examined after trichrome permanent staining and according to the formalin ethyl acetate concentration. For this study, each collected sample was split into two parts; one part was kept at -20 °C, and the other part was inoculated in culture media and transferred to the medical parasitology laboratory of the Faculty of Medicine at Umm Al Qura University for sub-culturing and molecular analysis. The culture medium consisted of Dulbecco's modified Eagle medium (DMEM) (Gibco, Thermo Fisher Scientific, MA, USA) containing 12 mg/ml ampicillin and 4 mg/ml streptomycin supplemented with 20% inactivated horse serum (Gibco) sterilized by filtration [25 (link)]. The samples were cultured in 11 × 100 mm sterile screw-capped tubes containing 3 ml of media and were incubated at 37 °C in an anaerobic gas pack (BD gas pack-Becton, Dickinson, USA). A drop of culture was examined after 72 h by direct microscopy.