Effect of baicalin on growth state of attention deficit hyperactivity disorder animal model and its regulation on Ca MKⅡ and ERK1/2 / 中国中药杂志

The aim of this study was to observe the effect of baicalin on the growth state of attention deficit hyperactivity disorder animal model and its regulation on Ca MKⅡand ERK1/2.In the present study,a total of 40 SHR rats were randomly divided into model group,methylphenidate hydrochloride group,and low,medium,and high dose baicalin groups,with 8 rats in each group.Eight WKYrats were selected as a normal control group.The methylphenidate hydrochloride group(0.07 g·L~(-1))and the low(3.33 g·L~(-1)),medium(6.67 g·L~(-1)),and high dose(10 g·L~(-1))baicalin groups received corresponding drugs by gavage administration according to the body weight(0.015 m L·g~(-1)),while the normal group and the model group received the same volume of normal saline by gavage.Thegavage administration lasted for 4 weeks,twice a day.The body weight of the rats and the amount of remaining feed were weighed daily,and the growth state of the rats was statistically evaluated weekly.Percoll density gradient centrifugation was used to prepare brain synaptosomes and an electron microscope was used to observe their structures.The Ca MKⅡand ERK1/2 protein and mRNA expression levels were detected with Western blot and Real-time PCR methods,respectively.RESULTS: showed that baicalin did not affect the normal eating and weight gain of rats,and the weight gain of rats was even more significant than that in the normal group(P<0.05).In the study of its effects on Ca MKⅡand ERK1/2 protein expression in rat synaptosomes,the expression of both proteins in each drug-administered group was higher than that in the model group(P<0.05);besides,the expression levels of Ca MKⅡand ERK1/2 protein were significantly increased in both baicalin high dose group and the methylphenidate hydrochloride group(P<0.05).The relative expression of Ca MKⅡand ERK1/2 mRNA in synaptosome was detected by PCR.The results showed that medium and high doses of baicalin and methylphenidate hydrochloride significantly increased the relative expression of Ca MKⅡand ERK1/2 mRNA in synaptosomes of SHR rats(P<0.05).In conclusion,baicalin does not affect the normal growth and development of SHR rats,so it is safe for administration.Both baicalin and methylphenidate hydrochloride could up-regulate the relative expression of Ca MKⅡand ERK1/2 in mRNA and protein,and the pharmacodynamic stability of baicalin is in a dose-dependent manner to certain extent.

Role of extracellular signal-regulated kinase 1/2 in pathogenesis of stree-induced gastric ulcer / 第二军医大学学报

Objective: To investigate the role of extracellular signal-regulated kinase 1/2 (ERK1/2) signal pathway in the pathogenesis of stress-induced gastric ulcer. Methods: Animal model of stress-induced gastric ulcer was established in rats with water-immersion restraint (WIR) stress. The mucosal activation of ERK1/2 was observed before and 5, 15 and 30 min, and 1, 2 and 3.5 h after WIR stress. Some animals were also treated with an intravenous injection of PD98059 (1 mg/kg), a specific ERK1/2 inhibitor, 1 h prior to WIR stress. Expression of total ERK1/2 and caspase-3 were detected by Western blot analysis; ERK1/2 activity was measured by kinase activity assay using myelin basic protein as a specific substrate. DNA-binding activities of the transcription factors activator protein-1 (AP-1) and nuclear factor-κB (NF-κB) were determined by electrophoretic mobility shift assays (EMSA). Mucosal TNF-α and IL-1β mRNA expression was analyzed by Northern blot analysis. The degrees of the gastric mucosal lesions were expressed as ulcer index (UI) and pathological evaluation. Apoptosis in the gastric mucosa was examined by an in situ TdT-mediated dUTP nick-end labeling (TUNEL) method. Results: Activated ERK1/2 was very weakly expressed in the gastric mucosa of normal rats. ERK1/2 was rapidly activated in the gastric mucosa of rats 15 min after WIR stress and the activity reached the maximal after 3.5 h. Pretreatment with PD98059 significantly inhibited ERK1/2 activation, decreased AP-1 and NF-κB activities and TNF-α and IL-β mRNA expression, and obviously relieved gastric mucosal lesions, accompanied by caspase-3 activation and increased apoptosis. Conclusion: The present results indicate that ERK1/2 activation plays an important role in the development of stress-induced gastric ulcer.