[Animal modeling] Study on the effect of Siwu Mixture on primary dysmenorrhea model mice induced by oxytocin

  Objective To study the effect of Siwu mixture on primary dysmenorrhea in mice and its possible mechanism.

  Methods Sixty healthy SPF KM female mice were randomly divided into four groups: normal group, model group, Tongjingbao granule group and Siwu mixture group. The mouse model of primary dysmenorrhea induced by estrogen combined with oxytocin was used. After 3 days of adaptive feeding, the mice were subcutaneously injected with estradiol benzoate (2mg/kg) for 10 consecutive days. From the 4th day, the normal group and the model group were given the same dose of distilled water, the positive drug Tongjingbao Granules group was given 4g/kg, and the Siwu Mixture group was given 8mL/kg for 7 consecutive days. The analgesic effect of Siwu mixture was investigated by taking the times of writhing and the latency of writhing within 30 minutes after oxytocin injection as the min observation indexes, and the superoxide dismutase (SOD) and malondialdehyde (MDA) in serum were measured; Detection of prostaglandin F2 in uterine tissue by ELISA α (PGF2 α )、 Interleukin 6 (IL-6), tumor necrosis factor α (TNF- α) Content; The pathological sections of uterus were prepared to observe the gland hyperplasia and inflammatory cell infiltration, and the expression of cyclooxygenase-2 (COX-2) was detected by immunohistochemistry.

  Results Compared with the normal group, the times of writhing in the model group were significantly increased and the latency of writhing was significantly shortened within 30 minutes (P<0 01), the serum MDA level increased significantly (P<0 01), uterine tissue PGF2 α 、 TNF- α The level of IL-6 and IL-6 increased significantly (P<0.01) 05); The expansion of endometrial glands showed papillary hyperplasia, interstitial edema, proliferation and infiltration of inflammatory cells, and increased COX-2 expression. Compared with the model group, the times of twisting in 30 minutes in the positive drug group and Siwu mixture group decreased (P<0 05, P<0.01), the writhing latency of Siwu mixture group increased (P<0. 01) 05), the level of serum MDA in positive drug group and Siwu mixture group decreased (P<0 01), uterine tissue PGF2 α The level decreased (P<0.01, P<0 05),IL-6、TNF- α The content of COX-2 was decreased (P<0.05), the hyperplasia of glands was decreased, the stroma was compact, the infiltration of inflammatory cells was reduced, and the expression of COX-2 was decreased.

  Conclusion Siwu Mixture can significantly reduce the number of writhing in 30 minutes and prolong the latency of writhing in mice with primary dysmenorrhea. Its mechanism may be to reduce the content of MDA in serum and PGF2 in uterine tissue α 、 IL-6、TNF- α The level of COX-2 and COX-2 expression are related to the improvement of histopathological changes, which is worthy of further study.