Effects of borneol on arousal ability and cognitive function in rats with long-term continuous operation

Effects of borneol on arousal ability and cognitive function in rats with long-term continuous operation

Abstract 目的AIM: To investigate the intervention effect of borneol on arousal ability and cognitive impairment in rats with long-term continuous operation. Methods: Firstly, the long-time continuous operation model of rats was established by running the treadmill operation method. The model rats were divided into the running table borneol group and the treadmill control group, and the non-running stage control group was set up. Subsequently, the effects of borneol on the activity-stationary behavior, wakefulness time and active avoidance response of the shuttle box in long-term continuous operation rats were observed. RESULTS: Six rats in each of the three groups were included in the test. The results showed that the administration of 0.4 g / kg borneol (stomach feeding) increased the amount of spontaneous activity after long-term continuous operation in rats (the number of activities per minute was 54.1 ± 5.4 in the control group and 15.5 ± 8.3 in the treadmill control group). The running borneol group was 26.8± 7.8, the two groups were compared between the two groups, P <0.05) and the arousal time (639 min ± 46 min in the non-running control group and 411 min ± 36 min in the treadmill control group, The running platform borneol group was 501 min ± 52 min, and the two groups were compared between the two groups, P < 0.05). At the same time, the cognitive function of the long-term continuous operation rats was also improved (the shuttle box active avoidance was used as the test reaction time, The running control group was 5.63 s ± 1.01 s, the running control group was 6.85 s ± 1.24 s, the running borneol group was 6.26 s ± 0.96 s, and the three groups were compared between the two groups, P < 0.05. Conclusion: Borneol can reverse the damage of long-term continuous operation on the arousal ability and cognitive function of rats to a certain extent.

Key words borneol; long-term continuous operation in rats; arousal ability; cognitive function

Long-term continuous work has significant damage to arousal and cognitive functions. At present, the research on this issue has gradually attracted widespread attention at home and abroad [1, 2]. A variety of anti-fatigue drugs and neurostimulants have been developed and screened to date, including caffeine, theobromine, amphetamine (amphetamine) and modafinil. Although these drugs have long been used, their disadvantages such as addiction and poor selectivity have largely limited their widespread use. Therefore, the search for quick-acting, post-effect and small addictive and highly selective psychostimulants will inevitably become the focus of future research [3, 4]. As a treasure house of the motherland medicine, traditional Chinese medicine has broad prospects in screening ideal psychotropic drugs. Aromatic sputum drugs such as bezoar, borneol, musk, scutellaria and Suhexiang have been widely used in clinical practice [5,6]. Borneol (also known as dragon brain) is one of the commonly used aromatic medicinal herbs, which is a processed product of the dipterocarpic plant, dipterocarp, or a chemically synthesized product such as camphor or turpentine. The main chemical component of natural borneol is borneol, which also contains a large number of epihors of the borneol. Chinese medicine believes that the borneol tastes hard, slightly cold, heart, spleen, lung, and has the effect of opening up, refreshing, and passing through. Studies on the pharmacodynamics, pharmacokinetics and safety of borneol have shown that in addition to anti-inflammatory, anti-bacterial, anti-fertility and analgesic effects, borneol can also shorten the continuous sleep time of pentobarbital sodium, showing Brain refreshing and excitatory effects [7]; and borneol can also prolong the survival time of hypoxia in mice [8]. In addition, some prescriptions containing borneol, such as Angong Niuhuang Pill and Fufang Danshen Tablet, have been widely used in neurology, and have obvious curative effect on treating coma and improving cognitive function in patients with senile dementia [9-11]. In summary, we have reason to speculate that borneol may have improved long-term continuous working conditions to enhance the ability to awaken and cognitive function. In order to find out whether borneol has the effect of reversing or preventing long-term continuous operation, we established a long-term continuous operation rat model to observe the effect of borneol on the awakening ability and cognitive function of rats after 12 hours of continuous operation. .

1 Materials and methods

1.1 Main reagents and instruments

Pentobarbital, natural borneol, liquid paraffin; take appropriate amount of borneol crystals before the experiment, grind finely, and use liquid paraffin to form 8% borneol paraffin oil suspension. Analytical balance, stereotactic instrument, multi-channel physiological signal acquisition and processing system, small animal running platform, shuttle box active avoidance behavior testing device, video monitor, video capture and analysis software.

1.2 Experimental animals and grouping

Healthy adult male SPF SD rats weighing (250 ± 10) g. All rats were acclimated for at least 2 weeks in the set indoor environment. Indoor environment: light-dark cycle 12 h: 12 h (lighting at 7:00), natural light, temperature 24~26 °C. Animals are free to drink and eat. The experiment was divided into 3 groups, 6 rats in each group: 1 no treadmill control group: no treadmill operation, free movement in the cage, food and drinking time and other treatment factors are consistent with the operation group; Taiwan ice tablets group: long-term continuous running operation, after the end of the operation, 0. 4 g / kg borneol paraffin oil solution; 3 running block paraffin oil group: after the long-term continuous treadmill operation is given and the running platform borneol group The same volume of paraffin oil solution.

1.3 EEG electrode placement and electrocorticogram (ECOG) recording specific methods refer to the previous literature [12]. After sodium pentobarbital anesthesia (30 mg/kg, ip), the rat's head was fixed to the stereotactic frame. The copper screws were inserted into the frontal and parietal cortex through the skull to contact the dura mater for recording cortical EEG activity. The brain electrode is fixed to the skull with dental cement. After the surgery, the animals were allowed to recover for 2 weeks in the above indoor environment. EEG recording was performed using RM 6240 multi-channel physiological signal acquisition and processing system.

1.4 Long-term continuous operation method

Long-term continuous operation is carried out on the small animal treadmill, using our established (18+6 h) × 2 operation mode [12]. The operation process includes a 20 min job + 20 min job suspension, and the job and job suspension are considered as 1 cycle. Runway parameter setting: 0° at the time of operation, speed 15 m / min; slope 0° when the work is suspended, speed 7m / min. During the suspension of the operation, the speed of the running platform is relatively slow. Since the runway is about 1 m long, the animal can have a motion pause time of up to 9 s at a time. At this time, the influence of the sports factor is minimized, but only the purpose of sleep deprivation is achieved. So we call this process a job pause. The entire process is continuously given electrical stimulation with a stimulation intensity of 20 V and a frequency of 60 Hz. Once the animal enters the electrical stimulation zone, it is subjected to an electric shock, forcing it to continue to move. Animals were placed in cages for free movement after every 4 cycles, free to eat and drink 15m in. All animals did not undergo treadmill adaptation training before the operation. This experiment uses continuous 48 h (two day and night cycle) operation mode, and each day and night cycle includes two parts: the operation phase and the rest phase. (1) Operation stage of the treadmill: On the first day from 19: 00 to the second day at 13: 00, the treadmill operation training; (2) the rest period: on the second day 13: 00 to 19: 00, the rat is in the squirrel cage Free to move, free to eat and drink.

1.5 method of administration

Reference dose [9], borneol used dose of 0. 4 g / kg, administered through a homemade gavage tube. The administration was carried out at 5. 5 h (18: 30) after the end of the treadmill operation (13: 00) and completed within 30 min.

1.6 Awakening ability and cognitive function evaluation

The animal's arousal ability and cognitive function were evaluated by three indicators, namely, the behavioral state distribution pattern, the awakening time, and the active avoidance behavior test of the shuttle during the awakening period (19: 00 to 7: 00).

1.7 Data Analysis and Statistics

Measurement data were expressed as x±s, and one-way analysis of variance (ANOVA) was performed using SPSS1.0 software.

2 results

2.1 Effects of borneol on long-term continuous operation of rats - the distribution of resting behavioral activities In this experiment, the independent activities of rats were continuously observed and recorded by video monitor, and the results were analyzed by video analysis system (RMVID EO). Rat autonomic activities are simplified into active and static states, and the amount of autonomous activity is calculated as the average number of activities per minute. The results are shown in Table 1. The non-running control group was mainly active throughout the night (19: 00- 7: 00); the activity of the running platform borneol group was significantly more than that of the running-off paraffin oil group (P < 0.05). However, it is still less than the non-running control group (P <0.01). 2.2 The effect of borneol on long-term continuous operation of rats. The sleep and wakefulness of animals are mainly judged by EC OG: δ wave (0. 25～ 4 H z) can usually be used as a predictor of slow wave sleep [13]. Awakening time test results: (639±46) min for the non-running control group, (411±36) min for the running-off paraffin oil group, and (501±52) min for the running platform borneol group; The difference was statistically significant (P < 0.05).

2.3 Effect of borneol on active avoidance response of long-term continuous operation of rat shuttle box After the administration, the rats in the three groups were tested for active avoidance behavior of the shuttle box, and the tests were carried out at 21: 00. The reaction time of each group was (5. 63 ± 1. 01) s in the non-running control group, (6. 85 ± 1. 24) s in the running-off paraffin group, and 6.26 ± in the running platform borneol group. 0. 96) s; the difference between the three groups was statistically significant (P < 0.05).

3 Discussion

Long-term continuous operation has complex effects on various systems and various normal functions, mainly due to the decline of arousal ability (ie, awakening, ar ousaldef i ci t) and impairment of cognitive function [13-16], ie work The state is damaged. Therefore, the current research on the protective measures against the long-term continuous operation is mainly focused on exploring the improvement of the state of awakening and the restoration of cognitive function. A large number of literatures have shown that the current prevention and control measures in the operation process mainly include two aspects: non-pharmaceutical intervention and drug intervention [2~5]. Chinese medicine believes that aromatic sputum drugs (such as bezoar, borneol, musk, Shichangpu and Su Hexiang, etc.) have the function of clearing, opening and closing, and are used to treat closed syndrome. Modern medical research has shown that certain aromatic sputum drugs have an exciting nervous system, improve working conditions and reduce sleep [6-11]. For example, small doses of musk can shorten the sleep time induced by sodium pentobarbital; sputum scented agents give intravenous injections to awake rabbits, first causing excitation of the cerebral cortex, which is characterized by de-synchronization of EEG, followed by high-voltage complexes of EEG. However, behavior has always been vigilant, no sleepiness and sleep tendency, no convulsions, convulsions [17, 18]. In another example, Angong Niuhuang Pill can widely promote the expression of c-f os gene in the brainstem, thalamus and cortex-associated awakening brain regions, suggesting that the drug may promote awake by activating these brain regions [19]. The brain-wakening and excitatory effects of single-flavored borneol have been reported in the literature [9]. On this basis, we observed the effects of borneol on the arousal ability and cognitive function of rats in long-term continuous operation. In the experiment, we first established a continuous operation rat model by running the treadmill. After the operation process, the rats were given an appropriate amount of borneol. The results showed that the borneol can restore the activity ability of the long-term continuous operation rats to a certain extent and increase the arousal. Time, while also improving cognitive function. It should be noted that the dose of borneol administered in this experiment (0.4 g/kg) is based on previous reports [9], and the experimental animals used in this literature are mice, but the rats used in this experiment, but The conclusion of both is consistent, that is, the borneol has a significant arousal effect at this dose. On the other hand, it has been confirmed in the literature that borneol can change the content of norepinephrine, dopamine, histamine and serotonin in the hypothalamus [20], and these transmitters in the hypothalamus are closely related to the occurrence and maintenance of the body's arousal state. Therefore, we speculate that the effects of borneol on the arousal ability and cognitive function of long-term continuous operation rats may involve changes in the above-mentioned transmitter levels. Whether this speculation is established or not requires experimental proof. Although our research has initially revealed that the adverse effects of borneol on long-term continuous operation can play a certain role in intervention, its mechanism of action and the pharmacokinetics, pharmacodynamics and side reactions of borneol require more experiments. Prove. In addition, whether other aromatic sputum drugs can also interfere with the adverse effects caused by long-term continuous operations, and further research is needed.