Protective Effects of Chinese Herbal Medicine Rhizoma drynariae in Rats After Traumatic Brain Injury and Identification of Active Compound

• Published in: Molecular neurobiology 2016-09, Vol.53 (7), p.4809-4820
• Main Authors: Wang, Wenzhu, Li, Haigang, Yu, Jintao, Hong, Michael, Zhou, Jing, Zhu, Lin, Wang, Yang, Luo, Min, Xia, Zian, Yang, Zeng-Jin, Tang, Tao, Ren, Ping, Huang, Xi, Wang, Jian
• Format: Article
• Language: English
• Subjects: Administration, Oral; Animals; Biomedical and Life Sciences; Biomedicine; Blood levels; Brain Injuries, Traumatic - drug therapy; Brain Injuries, Traumatic - pathology; Brain Injuries, Traumatic - psychology; CD3 antigen; CD4 antigen; Cell activation; Cell Biology; Chinese medicine; Chromatography, High Pressure Liquid - methods; Cognitive ability; Drugs, Chinese Herbal - administration & dosage; Drugs, Chinese Herbal - chemistry; Escape Reaction - drug effects; Escape Reaction - physiology; Flavanones - chemistry; Flavanones - isolation & purification; Herbal medicine; Immunomodulation; Inflammation; Interleukin 10; Interleukin 6; Liquid chromatography; Lymphocytes T; Macrophages; Male; Maze Learning - drug effects; Maze Learning - physiology; Monocytes; Neurobiology; Neurology; Neuroprotection; Neuroprotective Agents - administration & dosage; Neuroprotective Agents - chemistry; Neurosciences; Oral administration; Polypodiaceae; Random Allocation; Rats; Rats, Sprague-Dawley; Traditional Chinese medicine; Traumatic brain injury; Treatment Outcome
• ISSN: 0893-7648; 1559-1182
• DOI: 10.1007/s12035-015-9385-x

Traumatic brain injury (TBI) is a leading cause of death and disability in the USA. Effective therapeutic strategies for TBI are needed, and increasing attention is turning toward traditional herbal medicine. Rhizoma drynariae is a traditional Chinese medicine that has immunomodulatory and anti-inflammatory effects. Here, using the controlled cortical impact model of TBI in rats, we examined whether oral administration of R. drynariae can reduce TBI-induced brain injury in rats. We also identified the likely active compound among its four major phytochemicals in decoction. We found that post-treatment with R. drynariae decreased brain lesion volume, improved neurologic and cognitive function, and reduced anxiety- and depression-like behaviors. These changes were accompanied by reduced blood levels of IL-6 and increased IL-10. R. drynariae treatment also reversed the TBI-induced decrease in blood monocyte numbers and percentage of blood CD3 and CD4 T lymphocytes while inhibiting microglial/macrophage activation. Furthermore, by using ultra performance liquid chromatography and comparing retention times with authentic standards, we identified eriodictyol as the putative active compound of R. drynariae extract in the blood of rats with TBI. These novel findings indicate that the traditional Chinese herbal medicine R. drynariae protects brain against TBI-induced brain injury, possibly via immune-promoting, anti-inflammatory, and neuroprotective effects. Eriodictyol could be its active compound.