ABSTRACT
Objective:To investigate the therapeutic effect of artesunate on mice with acute Toxoplasma gondii ( T. gondii) infection. Methods:Based on body weight (16 - 18 g), sixty-four C57BL/6 female mice aged 6 - 8 weeks were divided into 4 groups by random number table method: uninfected control group without treatment; T. gondii-infected group (Tg group), each mouse was intraperitoneally (i.p.) infected with 100 tachyzoites of T. gondii RH strain; T. gondii-infected + artesunate treatment group (Tg + ART group), 3 hours after each mouse i.p. infected with 100 tachyzoites of T. gondii RH strain, artesunate solution was i.p. injected at a dose of 30 mg/kg, once a day for a total of 7 consecutive days; T. gondii-infected + sulfadiazine treatment group (Tg + SDZ group), 3 hours after each mouse i.p. infected with 100 tachyzoites of T. gondii RH strain, sulfadiazine solution was orally administrated at a dose of 100 mg/kg, once a day for a total of 7 consecutive days. There were 16 mice in each group, in which 10 mice were used to observe survival time and 6 mice were used to monitor body weight and collect tissue samples. Mice were weighed every day from day 1 post infection (p.i.); mice were sacrificed at day 7 p.i., the liver weights of mice were weighed and the liver indexes were calculated; liver tissues were paraffin-embedded, sectioned, and stained with hematoxylin-eosin (HE), and the pathological changes of liver tissues of mice in each group were observed under a light microscope. The expression levels of T. gondii major surface antigen 1 (SAG1) in the liver tissues of mice in each group were detected by real-time quantitative PCR for evaluating parasite load. Results:All mice in the uninfected control group were survived. The survival time was 7 - 9 days in Tg group, 8 - 11 days in Tg + ART group, and 9 - 13 days in Tg + SDZ group. Compared with Tg group, the survival times of mice in Tg + ART group and Tg + SDZ group were significantly longer ( P < 0.05). On day 7 p.i., compared with uninfected control group, Tg + ART group or Tg + SDZ group, the body weight of mice in Tg group was lower ( P < 0.05); however, there was no significant difference of body weight in Tg + ART group and Tg + SDZ group compared with uninfected control group ( P > 0.05). Compared with Tg group, Tg + ART group and Tg + SDZ group had lower liver indexes and SAG1 mRNA expression levels in the liver tissues ( P < 0.05 or < 0.001), and liver histopathological changes were milder. Compared with Tg + SDZ group, there was no significant difference in both liver index and SAG1 mRNA expression level in the liver tissue of Tg + ART group ( P > 0.05). Conclusion:Artesunate solution i.p. injection can prolong the survival time, reduce parasite load in the liver, and attenuate hepatic pathological damage, to a certain extent, of mice with acute T. gondii infection.
ABSTRACT
Objective:To investigate the regulation and mechanism of chronic Trichinella spiralis ( Ts) infection on liver immunopathology in mice co-infected with Plasmodium berghei ANKA( PbA). Methods:According to body weight, 64 specific pathogen free female Kunming mice (6 - 8 weeks old, weighting 22 - 25 g) were divided into 4 groups by using random number table method. Control group: uninfected; Ts group: mice were mono-infected with 30 Ts larvae by oral gavage on day 0; PbA group: mice were mono-infected with 1 × 10 6PbA-infected red blood cells in 0.1 ml of phosphate buffer (PBS) administered by intraperitoneal injection on day 121; co-infected ( Ts+PbA) group: mice were infected with 30 Ts larvae by oral gavage and intraperitoneal injected with 1 × 10 6PbA-infected red blood cells in 0.1 ml PBS on day 121 after Ts infection. There were 16 mice in each group, in which 10 mice in each group were monitored for the survival rate. The peripheral red blood cell parasitemia of PbA group and Ts + PbA group were monitored every other day by light microscope examination of Giemsa-stained thin tail-blood smears from day 3 after PbA infection. Mice were sacrificed at day 135 after Ts infection and/or at day 15 after PbA infection, the mouse body weight and liver weight were measured, and the liver index were calculated. Ts-infected mice were monitored by a light microscope examination of diaphragm compression slide. Under a light microscope, the liver pathology and liver fibrosis of mice were observed and compared with hematoxylin-eosin (HE) staining and Sirius red staining, respectively. The F4/80 + Kupffer cells in liver of mice were examined by immunohistochemical staining. Results:After infection with Ts or PbA, Ts larvae cysts were observed in diaphragm tissues and PbA were observed in red blood cells under the light microscope. After PbA infection, there was no significant difference in survival rate between PbA group and Ts+ PbA group ( P > 0.05). Compared with PbA group, the peripheral red blood cell parasitemia was significantly decreased in Ts+ PbA group on days 11 and 15 after PbA infection (%: 27.104 ± 7.623 vs 45.032 ± 9.849, 60.218 ± 2.776 vs 76.778 ± 6.351, P < 0.05), and the liver index and the liver pathology score were significantly decreased in Ts+ PbA group ( P < 0.05). Sirius red staining showed that the positive area of liver fibrosis in Ts+ PbA group was significantly higher than that in PbA group ( P < 0.05). Immunohistochemical staining showed that the average optical density value of F4/80 + Kupffer cells in Ts+ PbA group was significantly higher than that in PbA group ( P < 0.01). Conclusion:Chronic Ts infection may reduce the peripheral red blood cell parasitemia, increase F4/80 + Kupffer cells expression in liver, and attenuate liver pathology in mice co-infected with PbA.