Therapeutic effect of Leonuri Herba aqueous decoction on primary dysmenorrhea in rats and its metabolomic analysis / 中国中药杂志

This study aimed to investigate the therapeutic effect of Leonuri Herba aqueous decoction on primary dysmenorrhea(PD) and explore the underlying mechanism in conjunction with untargeted metabolomics. Forty adult female rats were randomly divi-ded into a normal group, a model control group, ibuprofen(0.12 g·kg~(-1)) group, and high-and low-dose Leonuri Herba aqueous decoction(5 and 2.5 g·kg~(-1)) groups, with eight rats in each group. The PD rat model was prepared using intramuscular injection of estradiol benzoate combined with intraperitoneal injection of pitocin. Drugs were administered by gavage from the 4th day of modeling for 7 d. After the last administration, pitocin was injected intraperitoneally, and the writhing latency and writhing times within 30 min were recorded. The uterine and ovarian coefficients were determined. Estradiol(E_2), progesterone(Prog), oxytocin(OT), cyclooxyge-nase 2(COX-2), prostaglandin E_2(PGE_2), prostaglandin F_(2α)(PGF_(2α)), and Ca~(2+) levels in uterine tissues were measured by ELISA and biochemical kits. Morphological changes in uterine and ovarian tissues were observed by hematoxylin-eosin(HE) staining. The protein expression of oxytocin receptor(OTR), prostaglandin E_2 receptor 3(EP3), and estrogen receptor alpha(ERα) in uterine tissues was detected by immunohistochemistry. The mRNA expression of OTR, PGE_2 receptors 1-4(EP1, EP2, EP3, and EP4), and PGF_(2α) receptor(FP) in uterine tissues was detected by quantitative real-time PCR. Untargeted metabolomics analysis was performed by ultra-high-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry(LC-QTOF-MS) technology to screen potential biomarkers and enrich metabolic pathways. The results showed that Leonuri Herba was able to significantly reduce the writhing times in PD rats(P<0.05 or P<0.01), significantly reduce the uterine and ovarian coefficients(P<0.01), and improve their histomorphology. After treatment with Leonuri Herba, PGE_2 content was significantly increased(P<0.05), COX-2, PGF_(2α) and Ca~(2+) content, and PGF_(2α)/PGE_2 was significantly decreased(P<0.05 or P<0.01), and OT content was decreased, while E_2 and Prog content tended to further increase in uterine tissues of PD rats. Correspondingly, OTR and EP3 protein expression was significantly downregulated(P<0.05 or P<0.01) and ERα protein expression was upregulated(P<0.05) in uterine tissues. The mRNA expression of FP and EP4 in uterine tissues was significantly downregulated(P<0.01), and the mRNA expression of EP1, EP3, and OTR showed a decreasing trend. The untargeted metabolomics results showed that 10 differential metabolites were restored in the plasma of PD rats after Leonuri Herba treatment. The results indicate that Leonuri Herba is effective in the prevention and treatment of PD, and the underlying mechanism may be attributed to the regulation of PGs synthesis and corresponding receptor binding.

Effects of maternal enflurane exposure on NR2B expression in the hippocampus of their offspring

This work aims to study the pathogenesis of learning and memory impairment in offspring rats resulting from maternal enflurane anesthesia by focusing on the expression of the N-methyl-d-aspartic acid receptor subunit 2B (NR2B) in the hippocampus of the offspring. Thirty female Sprague-Dawley rats were randomly divided into three groups: control (C group), 4 h enflurane exposure (E1 group), and 8 h enflurane exposure (E2 group) groups. Eight to ten days after the initiation of pregnancy, rats from the E1 and E2 groups were allowed to inhale 1.7% enflurane in 2 L/min oxygen for 4 h and 8 h, respectively. Rats from the C group were allowed to inhale 2 L/min of oxygen only. The Morris water maze was used to assay the learning and memory function of the offspring on postnatal days 20 and 30. RT-PCR and immunohistochemistry assays were then used to measure the mRNA levels and protein expression of NR2B, respectively. Relative to offspring rats from the C group, those from the E1 and E2 groups exhibited longer escape latencies, lesser number of crossings over the platform, and less time spent in the target quadrant in the spatial exploration test (P < 0.05). In addition, the mRNA and protein expression levels of NR2B in the hippocampus of offspring rats in the E1 and E2 groups were down-regulated (P < 0.05). No significant differences between the E1 and E2 groups were observed (P > 0.05) in terms of mRNA levels and protein expression of NR2B. The cognitive function of the offspring is impaired when maternal rats are exposed to enflurane during early pregnancy. A possible mechanism of this effect is related to the down-regulation of NR2B expression.

Este trabalho objetiva o estudo da patogênese de deficiência no aprendizado e memória de prole de ratos resultante da anestesia maternal por enflurano, por meio da expressão da subunidade 2B do receptor do ácidoN-metil-D-aspártico (NR2B) no hipocampo dos filhotes. Dividiram-se, aleatoriamente, 30 fêmeas de ratos Sprague-Dawley em três grupos: controle (grupo C), exposição ao enflurano por 4 h (grupo E1) e por 8 h (grupo E2). De oito a 10 dias após o início da gravidez, os ratos dos grupos E1 e E2 inalaram enflurano 1,7% em 2 L/min de oxigênio, por 4 h e 8 h, respectivamente. Ratos do grupo C inalaram apenas 2 L/min de oxigênio. O labirinto de água de Morris foi empregado para analisar as funções de aprendizado e memória da cria em 20 e 30 dias após o nascimento. Utilizaram-se ensaios de RT-PCR e de imuno-histoquímica para medir os níveis de mRNA e expressão da proteína do NR2B, respectivamente. Em comparação com os ratos controle do grupo C, aqueles dos grupos E1 e E2 exibiram latências de escape mais longas, menor número de travessias na plataforma e menos tempo gasto no quadrante alvo no teste de exploração espacial (P < 0,05). Adicionalmente, os níveis de expressão de mRNA e de proteína do NR2B no hipocampo dos filhotes nos grupos E1 e E2 estavam reduzidos (P < 0,05). Não se observaram diferenças significativas entre os grupos E1 e E2 (P < 0,05) quanto aos níveis de mRNA e à expressão de proteína de NR2B. A função cognitiva dos filhotes é prejudicada quando as mães são expostas ao enflurano durante o início da gravidez. O mecanismo possível para esse efeito está relacionado à diminuição na expressão de NR2B.