Effect of Naozhenning Granules on Energy Metabolism of Cortical Mitochondria in Rat Model of Post-concussion Syndrome / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo explore the effects of Naozhenning granules on the memory function and neuron cells in the rat model of post-concussion syndrome based on mitochondrial biosynthesis. MethodSPF-grade Wistar rats were used to establish the multiple cerebral concussion （MCC） model by the weight-drop method. The successfully modeled rats were assigned into model， piracetam （0.324 g·kg-1）， and low-， medium-， and high-dose （2.25， 4.5， and 9 g·kg-1， respectively） Naozhenning groups. The rats were administrated with corresponding drugs by gavage and those in the blank group and model group were administrated the same volume of normal saline once a day for 14 days. The general state of rats was observed before and after treatment. The open field test and new object recognition test were conducted to examine the motor and memory abilities of rats. Hematoxylin-eosin staining was employed to observe the pathological changes of cortical neurons in rats. Western blot and real-time polymerase chain reaction were employed to determine the protein and mRNA levels， respectively， of peroxisome proliferator-activated receptor γ-coactivator-1α （PGC-1α）， nuclear respiratory factor-1 （NRF-1）， and transcription factor A mitochondrial （TFAM） in rat cortex. ResultCompared with the blank group， the model group showed anxious and manic mental status， yellow and messy fur， and reduced food intake. In the open field experiment， the model group showed reduced total movement distance， times of entering the central grid， and times of rearing decreased and increased resting time compared with the blank group （P<0.01）. The model group had lower recognition index of new objects than the blank group （P<0.01）. In addition， the modeling caused reduced neurons with sparse distribution and deformed， broken， and irregular nucleoli and down-regulated the mRNA and protein levels of PGC-1α， NRF-1， and TFAM in the cortex （P<0.01）. Compared with the model group， piracetam and Naozhenning improved the mental state， coat color， food intake， and activities of rats. In the open field test， piracetam and Naozhenning increased the total movement distance， the times of entering the central grid， and the times of rearing and shortened the resting time （P<0.05， P<0.01）. The piracetam and Naozhenning groups had higher recognition index of new objects than the model group （P<0.05， P<0.01）. Compared with the model group， the piracetam and Naozhenning groups showed increased neurons with tight arrangement and large and round nuclei， and some cells with irregular morphology and turbid cytoplasm. Furthermore， piracetam and medium-dose Naozhenning upregulated the protein levels of PGC-1α， NRF-1， and TFAM （P<0.01）. Low-dose Naozhenning upregulated the protein levels of NRF-1 and TFAM （P<0.01）， and high-dose Naozhenning upregulated the protein levels of PGC-1α and TFAM in the cortex （P<0.01）. The mRNA levels of PGC-1α， NRF-1， and TFAM in the cortex were upregulated in the piracetam group and Naozhenning groups （P<0.05， P<0.01）. ConclusionNaozhenning granules can improve the motor， memory， and learning， repair the neuronal damage， and protect the nerve function in the rat model of MCC by promoting mitochondrial biosynthesis.