BACKGROUND: It is hard to cure the open traumatic brain injury (TBI), especially for the brain functional recovery after brain injury. In this regard, traditional Chinese medicine (TCM) has a wide prospect.OBJECTIVE: To observe the effect of Huayu capsule on limb-catching capability of rat models of open TBI,and investigate its possible mechanism.DESIGN: Randomized and controlled study.SETTING: Grade 3 Pharmacological Laboratory of TCM, State Administration of TCM, Chengdu University of TCM.MATERIALS: This study was performed from October 2005 to January 2006. Fifty Sprague-Dawley rats of either gender, aged 3 months old, weighing from 190 to 220 g, were involved in this study. Huayu capsule was made and supplied by the Department of TCM Processing of Chengdu University of TCM, Lot No.050121; Xuefuzhuyu oral liquid was manufactured by Jilin Aodong Yanbian Pharmaceutical Industry Co.,Ltd., Lot No. 050406.METHODS: Open right parietal lobe TBI rat models were made as described in references. The involved rat models were randomized into 5 groups according to gender and body mass: model group, high-, middle-,low-dose Huayu capsule groups and Xuefuzhuyu oral liquid group, with 10 rats in each. Rats in the model group were administrated with distilled water of 5 mL/kg; Rats in the high-, middle- and low-dose Huayu capsule groups were administrated with 1.030, 0.515, 0.258 g/kg raw herbs; Rats in the Xuefuzhuyu oral liquid group were administrated with Xuefuzhuyu oral liquid of 5 mL/kg, intragastrically once a day for 7 days successively for all after recovering consciousness from anesthetization. ① One hour after administration on the 6th day, rats in each group were placed on a 100 cm fine straight iron wire paralleling to the ground and 20 cm above the operational table. The time of the rats keeping on the wire was counted and it indicated the nerve-muscle catching capability. The longer the remained time, the better the nerve-muscle catching capability.② Twenty-four hours after the administration on the 7th day, the samples of the whole brain were carefully taken out and stained by toluidine blue for observing the morphology of cells in the injured brain tissue. ③ The nerve cells in 4 visual fields from 4 directions (upper, lower, left, right) of injured area of brain tissue were counted. The amount was the total number of the four visual fields. The nerve cells in the injured brain tissue were measured by the same way. ④ On the basis of nerve cell counting, the content of Nissls body in the corresponding nerve cells was measured.MAIN OUTCOME MEASURES: ①Nerve-muscle catching capability. ② Histopathomorphological examination of the injured areas in brain. ③Measurement of nerve cells and macrophages in the injured areas of brain. ④Measurement of content of Nissls body in the injured areas of brain.RESULTS: All the 50 rats were involved in the final analysis. ①The catching time of rats in the high- and middle-dose Huayu capsule groups as well as Xuefuzhuyu oral liquid group was extended to (23.6±10.12), ( 18.6 ± 8.17 ) and (22.6 ± 9.43) s, respectively, which was significantly higher than that in the model group [ (12.1±4.15) s, P ＜ 0.05 - 0.01]. ② The injured areas of brain tissue of rats in the Huayu capsule-treated groups and Xuefuzhuyu oral liquid group were decreased to different extents. The nerve cells adjacent to brain injured area were increased. ③ The number of macrophages around the brain injured area of rats in the high- and middle-dose Huayu capsule groups as well as Xuefuzhuyu oral liquid group was 63.9±7.99,59.7 ± 7.41 and 62.9 ± 7.37, respectively, which was significantly larger than that in the model group (49.2 ±8.00, P ＜ 0.01 ) . The number of nerve cells adjacent to brain injured area of rats in the high-, middle-, and low-dose Huayu capsule groups as well as Xuefuzhuyu oral liquid group was 86.2±25.93, 93.5±31.79,92.1 ± 14.54 and 125.2±34.25, respectively, which was significantly larger than that in the model group (62.5±16.98, P ＜ 0.05 - 0.01 ) . ④ The total area, the total and integral absorbance, the average gray degree of Nissls body in the cytoplasm of nerve cells of rats in the Huayu capsule-treated groups and Xuefuzhuyu oral liquid group were all significantly increased (P ＜ 0.05 - 0.01).CONCLUSION: Huayu capsule at different doses can promote the limb-catching capability of rat models of open TBI to different extent. This promoting effect may be related to increasing macrophages in the injured area, lessening the apoptosis of nerve cells and increasing the content of Nissls body in the nerve cells.