Objective:

2

To investigate the hemostatic effect of modified Sijunzi Granules (MSG) in primary immune thrombocytopenia (ITP) zebrafish model and explore the potential mechanism.

Methods:

2

AB strain wild type zebrafish were treated with simvastatin (6 μmol/L) for 24 h to establish the hemorrhage model (model control group). The zebrafish were treated with MSG at different doses (55.6

167

and 500 μg/mL)

respectively. The hemostatic effect was assessed by examining the intestinal bleeding and hemostatic rate. 5-hydroxytryptamine (5-HT) content was determined using enzyme-linked immunosorbent assay (ELISA) assay. The expressions of 5-HT2aR

5-HT2bR

and SERT genes were detected by quantitative real-time polymerase chain reaction(PCR). The protein expressions of protein kinase B (Akt)

p-Akt

extracellular regulated protein kinases (Erk)

and p-Erk were examined using Western blot analysis.

Results:

2

The intestinal bleeding rate was 37%

40%

and 80% in the 55.6

167

and 500 μg/mL dose of MSG

respectively

in which

55.6 and 167 μg/mL MSG dose groups were associated with significantly decreased intestinal bleeding rate when compared with the model control group (70%

P

<

0.05). Significantly higher hemostatic rates were also observed in the 55.6 μg/mL (54%) and 167 μg/mL (52%) MSG dose groups (

P

<

0.05). MSG increased the 5-HT content and mRNA expression levels of 5-HT2aR

5-HT2bR

and SERT (

P

<

0.05). In addition

caspase3/7 activity was inhibited (

P

<

0.05). Significant increase in p-Akt and p-Erk was also detected after treatment with MSG (

P

<

0.05).

Conclusions:

2

MSG could reduce the incidence and severity of intestinal bleeding in zebrafish by activating MAPK/Erk and PI3K/Akt signal pathways through regulating the levels of 5-HT and its receptors

which may provide evidence for the treatment of ITP.