[Effect of Sheshang capsule on platelet function of rabbits bitten by Trimeresurus stejnegeri and its mechanism].

Objective: To investigate the effect of the Sheshang capsule on coagulation of the rabbits bitten by Trimeresurus stejnegeri and its mechanism.

Methods: The changes in platelet aggregation rate was observed after the establishment of rabbits model by subcutaneously injection with 0.75, 1.50, 2.25, and 3.00 mL/kg of Trimeresurus stejnegeri venom for 72 hours. Fifty New Zealand white rabbits were randomly divided into five groups, 10 rabbits in each group. Rabbit model was reproduced by subcutaneously injection with 0.75 mL/kg of Trimeresurus stejnegeri venom. The rabbits in sham group were injected with 0.75 mL/kg normal saline(NS). The rabbits were gavaged with 5, 10, 15 mL × kg⁻¹ × d⁻¹ of the Sheshang concoction to the low, intermediate and high dose groups respectively after 6 hours, and 10 mL × kg⁻¹ × d⁻¹ NS was fed in the sham group and model group. The platelet aggregation rate, platelet count (PLT), mean platelet volume (MPV), plateletcrit (PCT), platelet distribution width (PDW), cyclic adenosine monophosphate (cAMP) and protein kinase A (PKA) were determined after 1 week.

Results: (1) With the increase in the concentration of Trimeresurus stejnegeri venom, 1-min, 3-min, 5-min and maximum platelet aggregation rates showed a gradual declining trends. (2) Compared with the sham group, 5-min and maximum platelet aggregation rate in the model group were significantly decreased [35.5 (24.2, 42.5)% vs. 43.0 (38.2, 58.5)%, 39.5 (29.0, 45.0)% vs. 46.5 (39.2, 60.2)%, both P<0.05]. Compared with the model group, 5-min and maximum platelet aggregation rate in the intermediate dose group were significantly increased [44.0 (39.8, 45.0) % vs. 35.5 (24.2, 42.5) %, 45.5 (43.5, 46.2) % vs. 39.5 (29.0, 45.0) %, both P<0.05]. There was no significant difference in platelet aggregation rate among the other groups. Compared with the sham group, PLT count in model group was obviously reduced (410.3 ± 155.3 × 10⁹/L vs. 724.5 ± 220.7 × 10⁹/L, P<0.01), so as MPV and PCT done [MPV: 5.11 ± 1.09 fl vs. 6.34 ± 1.16 fl, P<0.01; PCT: 21.9 (18.6, 26.8) % vs. 34.8 (24.8, 45.4) %, P<0.05]. Compared with the model group, PLT and PCT in the low, intermediate and high dose groups were significantly increased [PLT: 702.4 ± 166.3 × 10⁹/L, 648.5 ± 160.2 × 10⁹/L, 789.3 ± 86.2 × 10⁹/L vs. 410.3 ± 155.3 × 10⁹/L, PCT: 38.8 (35.7, 42.9)%, 36.0 (29.8, 44.4)%, 43.1 (40.5, 48.8)% vs. 21.9 (18.6, 26.8)%, all P<0.01], and MPV in the intermediate dose group was significantly increased (6.26 ± 1.05 fl vs. 5.11 ± 1.09 fl, P<0.01). There was no significant difference in PDW among groups (P>0.05). Compared with the sham group, cAMP (47.57 ± 12.76 nmol/L vs. 36.67 ± 10.54 nmol/L) and PKA (14.68 ± 5.80 μg/L vs. 9.23 ± 4.05 μg/L) in the model group were significantly increased (both P<0.05). Compared with the model group, cAMP and PKA of each dose group were decreased, while cAMP in low dose group [(36.33 ± 11.08) nmol/L] and PKA in the intermediate dose group [(10.21 ± 5.31) μg/L] were significant decreased (both P<0.05).

Conclusions: In the range of experimental concentration (0-3 mL/kg), the higher the concentration, and the stronger the inhibition of platelet aggregation rate was. The Sheshang capsule can raise platelet aggregation rate and PLT, increase MPV and PCT, and act against inhibition of platelet aggregation effect of the venom, thus improve the haemostatic function of platelet. Sheshang capsule can be used to treat the coagulopathy induced by Trimeresurus stejnegeri venom through regulating cAMP/PKA pathways.