The most common medications for the treatment of zoonotic toxoplasmosis are pyrimethamine and sulfadiazine, which may cause serious undesirable side effects. Thus, there is an urgent need to develop novel therapeutics. Baicalein (BAI, C₁₅H₁₀O₅) has been shown to perform well against protozoan parasites including Leishmania and Cryptosporidium. In this study, the inhibition efficacy of BAI on Toxoplasma gondii was evaluated using plaque, invasion, and intracellular proliferation assays. BAI effectively inhibited T. gondii (half-maximum inhibitory concentration (IC₅₀)=6.457×10^-5 mol/L), with a reduced invasion rate (33.56%) and intracellular proliferation, and exhibited low cytotoxicity (half-maximum toxicity concentration (TC₅₀)=5.929×10^-4 mol/L). Further investigation using a mouse model shed light on the inhibitory efficacy of BAI against T. gondii, as well as the potential mechanisms underlying its anti-parasitic effects. The survival time of T. gondii-infected ICR mice treated with BAI was remarkably extended, and their parasite burdens in the liver and spleen were greatly reduced compared with those of the negative control group. Histopathological examination of live sections revealed effective therapeutic outcomes in the treatment groups, with no notable pathological alterations observed. Furthermore, alterations in cytokine levels indicated that BAI not only effectively suppressed the growth of T. gondii but also prevented excessive inflammation in mice. Collectively, these findings underscore the significant inhibitory efficacy of BAI against T. gondii, positioning it as a promising alternative therapeutic agent for toxoplasmosis.
Animals ; Toxoplasma/drug effects* ; Flavanones/therapeutic use* ; Mice ; Antiparasitic Agents/therapeutic use* ; Mice, Inbred ICR ; Toxoplasmosis/drug therapy* ; Female

Objective To investigate the mucosal immunity of L1 virus-like particles ( VLPs) of human papillomavirus ( HPV) types 16 and 18 plus JY adjuvant by intranasal immunization in cynomolgus. Methods Cynomolgus were immunized with low and high dosage of HPV types 16 and 18 L1 VLP with JY adjuvant for 3 times by intranasal route at weeks 0, 4 and 8, respectively, using PBS as control. Subsequently, vaginal secretion, oral secretion and nasal secretion were collected at weeks 0, 2, 4, 6, 8 and 16, respectively, and determined for mucosal immunity by ELISA.Results HPV-L1-specific sIgA antibodies were detected in all secretions, including oral, nasal and vaginal ones, the concentrations of sIgA antibody induced were much higher than those in PBS control group.There was no significant difference ( P>0.05) in sIgA antibody levels among cynomolgus vaccinated with low and high dosage of L1 VLP, as was between oral and nasal secretion ( P >0.05 ) , However, the concentrations of sIgA antibody in vaginal secretion were significant higher than those in oral and nasal secretion, differences were statistically significant ( P<0.01) .Conclusions Following intranasal immunization in cynomolgus, HPV types 16 and 18 L1 VLP with JY adjuvant can effectively induce sIgA antibody in vaginal secretion, and vaginal sIgA antibody concentrations were much higher than those in oral and nasal secretion.