Fasciola hepatica is a common parasite of grazing livestock in Guangxi Zhuang Autonomous Region in China, but its prevalence has not been studied. While triclabendazole is commonly used to treat F. hepatica infection in China, oxyclozanide has never been used. This study investigated the prevalence of F. hepatica infections in buffaloes in the Guangxi and evaluated the efficacy of oxyclozanide and triclabendazole as treatments. In the prevalence study, a total of 767 individual faecal samples were obtained from 58 farms in Guangxi to detect the prevalence of F. hepatica, and the total rate of infection was 87.35%. A subset of 277 infected buffaloes from these farms were randomly divided into 3 groups. Group 1 (n = 101) was treated with oxyclozanide at 10 mg/kg.bw; group 2 (n = 94) was treated with triclabendazole (12 mg/kg.bw); and group 3 (n = 82) was untreated. Faecal samples were taken on days 0, 7, 14, 21 and 28. Whole blood and serum were collected on days 0 and 14. Anthelmintic efficacy was assessed using faecal egg count reduction (FECR), buffaloes positive by coprology reduction (BPCR) as well as post-treatment improvement in biochemical and haematological indicators. After 28 days treatment, group 1 and 2 showed FECR% values above 98%, and BPCR% values of 97.03% and 77.66%, respectively. In addition, the biochemical indicators and haematological parameters were improved at 14 days post-treatment compared with those before treatment. These results indicate a high prevalence of F. hepatica in Guangxi, demonstrate that oxyclozanide and triclabendazole are effective against F. hepatica infection in buffaloes, and indicate that oxyclozanide could be used in China as an alternative drug.

Toxoplasma gondii (T. gondii) is an important health problem in human and animals, and the highlighting side effects of launched therapeutic chemicals cannot be ignored. Thus, it is urgent to develop new drugs to against the infection. Myrislignan originated from nutmeg exhibited excellent anti-T. gondii activity in vitro and in vivo, and was able to destroy mitochondrial function. However, the exact mechanism of action is still unknown. In this study, combining RNAs deep-sequencing analysis and surface plasmon resonance (SPR) analysis, the differentially expressed genes (DEGs) and high affinity proteins suggested that myrislignan may affect the oxidation-reduction process of T. gondii. Furthermore, the upregulating ROS activity after myrislignan incubation verified that myrislignan destroyed the oxidant-antioxidant homeostasis of tachyzoites. Transmission electron microscopy (TEM) indicated that myrislignan induced the formation of autophagosome-like double-membrane structure. Moreover, monodansyl cadaverine (MDC) staining and western blot further illustrated autophagosome formation. Myrislignan treatment induced a significant reduction in T. gondii by flow cytometry analysis. Together, these findings demonstrated that myrislignan can induce the oxidation-reduction in T. gondii, lead to the autophagy, and cause the death of T. gondii.

Oxyclozanide is an anthelmintic drug that is widely used to treat fasciolosis. However, the pharmacokinetics of oxyclozanide in cattle are not yet clearly understood. The present study was designed to develop a sensitive method to determine oxyclozanide levels in cattle plasma using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and to study its pharmacokinetics for application in cattle. A simple and rapid HPLC-MS/MS analytical method was established and validated to quantify oxyclozanide levels in cattle plasma using niclosamide as the internal standard (IS) in negative ion mode. Chromatographic separation of the analytes was achieved using a C18 analytical column (75 × 4.6 mm, 2.7 μm) at 30 °C. The mobile phase comprised 0.01% v/v acetic acid (HOAc) diluted in water:acetonitrile (MeCN) (90:10% v/v) and 5 mM ammonium formate in methanol (MeOH):MeCN (75:25, v/v) at a 10:90 ratio (v/v) and was delivered at a flow rate of 0.4 mL min− 1. A good linear response across the concentration range of 0.02048–25.600 μg/mL was achieved (r2 = 0.994). The method was validated with respect to linearity, matrix effect, accuracy, precision, recovery and stability. The lower limit of quantification (LLOQ) was 0.020 μg/mL, and the extraction recovery was > 98% for oxyclozanide. The inter- and intra-day accuracy and precision of the method showed the relative standard deviation (RSD) less than 10%. The method was successfully applied to an assessment of the pharmacokinetics of oxyclozanide in cattle plasma. In healthy cattle, a single oral dose of an oxyclozanide suspension followed the one-compartment model, with a half-life (T1/2) of 64.40 ± 30.18 h, a plasma clearance rate (CL/F) of 11.426 ± 2.442 mL/h/kg, and an average area under the curve (AUC) of 965.608 ± 220.097 h*μg/mL. The peak concentration (Cmax) was 15.870 ± 2.855 μg/mL, which occurred at a peak time (Tmax) = 22.032 ± 3.343 h. A reliable, accurate HPLC-MS/MS analytical method was established in our study and successful applied to study the pharmacokinetics of oxyclozanide in cattle plasma. These results will be useful for further evaluations of the pharmacokinetic properties of oxyclozanide or for monitoring therapeutic drugs in animals.