Effects of raspberry and effective parts on learning and memory ability in aged rats

1.4 Instruments Morris Water Maze, Beijing Zhongshi Di Chuang Technology Development Co., Ltd.; one thousandth of analytical balance, Sartorius, Germany; -80 °C refrigerator, Thermo, USA.

1.5 Methods Rats were randomly divided into 5 groups: the elderly group, the ginkgo flavonoid positive group, the raspberry ethyl acetate group, the chloroform group, the whole drug group, and the young group (the 3 month old SD rat). The young group and the elderly group were intragastrically administered with normal saline 1m1 /100g, ethyl acetate group, chloroform group and whole drug group were given the corresponding extraction part of the raspberry 12g crude drug / kg, and the ginkgo flavonoid positive group was given ginkgo flavonoids. 785 mg / kg, dosing capacity 1 m1 / 100 g for 1 month.

1.5.1 The positioning and navigation test was carried out for 5 days. The rats were placed in the water from the water inlet points of the three different quadrants, and the time taken to find the platform within 60 seconds was recorded. This is the escape latency (escape). Latency). If the rat cannot find the platform within 60 seconds, the experimental rats will be pulled by the experimental operator to stay on the platform for 10 to 15 s, and participate in the literature [4].

1.5.2 Space exploration test On the 6th day of the experiment, remove the platform and choose 1

At the water inlet point, the rats were placed in water and recorded within 60 seconds: the number of times the animals crossed the virtual platform; in the space exploration experiment, the swimming time in the quadrant activity time of the original platform and the animal in the target quadrant (the quadrant of the original platform).

1.5.3 Detection of acetylcholinesterase and acetylcholine transferase activity After the water maze test, the brain tissue was taken and homogenized for 10% homogenate to detect the activity of acetylcholinesterase and acetylcholine transferase. The specific method was as follows. The instructions are carried out.

1.5.4 Total superoxide dismutase, glutathione peroxidase, catalase activity and malondialdehyde content detection 10% homogenate of brain tissue for total superoxide dismutase, glutathione The detection of glycopeptide peroxidase, catalase activity and malondialdehyde content was carried out according to the kit instructions.

1. Results

2.1 Effects of learning and memory on rat extracts from different parts of raspberry (Morris water maze method) In the water maze test: Compared with the young group, the escape latency of the aged group was significantly prolonged, and the number of crossing platforms was significantly reduced, suggesting that the elderly group was large. The learning and memory function of rats was reduced. Compared with the old rats, the escape latency of the rats in the ethyl acetate group, the chloroform group, the whole drug group and the ginkgo flavonoid-positive group was significantly shortened, and the number of crossing platforms was significantly increased. In the respective administration groups, the ethyl acetate group of raspberry had a more significant shortening of the escape latency of the rats, and the number of crossing platforms increased more obviously. The results are shown in Tables 1 and 2.

Table 2 Effects of different extraction sites of raspberry on spatial exploration of natural aging rats ( x珋± s, n = 10)

The results are shown in Table 3. Compared with the young group, the activity of acetylcholine transferase in the brain tissue of the aged group was significantly decreased, while the activity of acetylcholinesterase was significantly increased. Compared with the elderly group, the ethyl acetate fraction, chloroform fraction and positive drug of raspberry significantly increased the activity of acetylcholine transferase in the brain of aged rats and decreased the activity of acetylcholinesterase. Enzyme activity, catalase activity, and malondialdehyde content all have extremely significant differences, suggesting that the brain of aged rats with natural aging may have excessive free radical damage and excessive oxidative metabolism, which may cause a decline in learning and memory function. Compared with the old group, the glutathione peroxidase activity and catalase activity in the brain tissue of Ginkgo biloba-positive group were significantly increased, and the total superoxide dismutase content was significantly increased. The aldehyde content was significantly reduced. The glutathione peroxidase activity, total superoxide dismutase activity and catalase activity in the brain tissue of the raspberry ethyl acetate group were significantly increased, and the malondialdehyde content was extremely high. Significantly decreased; glutathione peroxidase activity, total superoxide dismutase activity, and catalase activity in the brain tissue of rats in the raspberry chloroform group were significantly increased, and the malondialdehyde content was extremely significant. Decrease; total superoxide dismutase activity and catalase activity in brain tissue of rats in the whole raspberry group were significantly increased, malondialdehyde content was significantly decreased, and glutathione peroxidase was decreased. There was no significant difference in enzyme activity.

Glutathione peroxidase activity and total superoxide degeneration in brain tissue of rats in the annual group

Table 4 Effects of different extraction sites of raspberry on the brain of natural aging rats ( x珋± s, n = 10)

112 Chinese Pharmacology and Clinical 2015; 31( 3)

Learning and memory plays an important role in cognitive activities and is also an important component of intellectual structure. The learning and memory function reflects the advanced integration function of the brain, and its function decline and loss are important signs of brain aging. The Morris circular water maze is mainly used to test the learning and memory ability of animals (large and small mice) for spatial position and azimuth. In this experiment, Morris water maze results show that compared with the young group, the escape latency of the elderly group is significantly prolonged. The number of crossing platforms was significantly reduced, suggesting that learning and memory function was reduced in the elderly group. Compared with the old rats, the escape latency of the rats in the drug-administered group, especially the ethyl acetate group, was significantly shortened, and the number of crossing the platform was significantly increased, suggesting that all parts of the raspberry can improve the learning and memory of the aged rats, and ethyl acetate. The improvement of the site is most obvious, followed by the chloroform site, and finally the whole drug site.

Acetylcholine is an important transmitter of central cholinergic nerves. It is synthesized by choline acetyltransferase (acetylcholine transferase), acetylcholinesterase (acetylcholinesterase), and exerts a biological effect through acetylcholine receptors. The acetylcholine balance is maintained by acetylcholine transferase and acetylcholinesterase. As the organism grows with age, the function of the cholinergic system gradually declines, manifesting as metabolic disorders, changes in the number of receptors and affinity, leading to central nervous physiology abnormalities. Studies have shown that increasing the activity of acetylcholine transferase in hippocampus of rats can improve the ability of spatial learning in rats. The results of the test by detecting acetylcholine transferase and acetylcholinesterase showed that the acetylcholine transferase activity in the brain tissue of the aged group was significantly decreased, while the acetylcholinesterase activity was significantly increased in the young group, suggesting that the aged group was associated with learning and memory. Alkaline neurotransmitter acetylcholine production source decreased and hydrolysis pathway increased, cholinergic function decreased. Compared with the elderly group, ethyl acetate, chloroform and positive drugs of raspberry can significantly increase the activity of acetylcholine transferase in brain tissue of aged rats and reduce the activity of acetylcholinesterase, but the whole drug only increases the acetylcholine transfer in the brain tissue of aged rats. Enzyme activity had no significant effect on acetylcholinesterase activity. At the same time, the ethyl acetate fraction of raspberry is more effective than the chloroform fraction, suggesting that the ethyl acetate fraction of raspberry can significantly increase the content of cholinergic neurotransmitter acetylcholine associated with learning and memory, and improve cholinergic function. The role of learning and memory protects the brain tissue function caused by aging.

The interaction between free radicals and excitatory amino acids in the hippocampus of the aged rats leads to the death of the hippocampus. Since the hippocampus is an important neuroanatomical structure for animal learning and recording, it leads to a decline in learning and memory. Free radicals, also known as free radicals, are atoms and atomic groups of unpaired electrons. They have highly reactive chemical properties that exchange electrons with adjacent materials for loss of tissue and damage. Biomacromolecules like amino acids are susceptible to free radical attack. Under normal conditions, the body's free radical content will be low and will be quickly destroyed by enzymes. However, as the age increases, the enzyme activity decreases and the metabolism of the body material changes, which inevitably leads to excessive free radical production. Free radicals in the hippocampus attack excitatory amino acids, causing neuronal death in the hippocampus, which leads to a decline in learning and memory in older rats. The experiment was conducted to detect the effects of raspberry on learning and memory of aged rats by detecting changes in glutathione peroxidase activity, total superoxide dismutase activity, catalase activity and malondialdehyde content in aged rat brain tissue. The results of this trial showed that the activities of aging-related enzymes glutathione peroxidase, total superoxide dismutase and catalase in the aged group were significantly lower than those in the young group, but related to aging. The malformaldehyde content of the metabolite was significantly increased, indicating that natural aging rats are desirable as a model for this trial. Compared with the elderly group, the aging-related enzymes glutathione peroxidase, total superoxide dismutase, and catalase activity in brain tissue increased to some extent, while aging-related metabolism The product malondialdehyde content also showed a downward trend, which indicates that raspberry can improve learning and memory by affecting the changes of free radicals in brain tissue of aged rats. And the ethyl acetate part of raspberry is the most obvious improvement, followed by the chloroform part, and finally the whole drug part.

The above results suggest that ethyl acetate, chloroform and whole medicine of raspberry can improve the learning and memory ability of natural aging rats. However, from the behavioral experimental data of the aged rat water maze and the biochemical indicators of acetylcholinesterase, acetylcholine transferase, aging-related enzymes and related metabolites, the ethyl acetate fraction of raspberry has the most obvious improvement effect, and the chloroform site has improved. Secondly, the improvement of the whole drug site is the weakest. However, the mechanism of learning and memory is more complicated, and there are many pathways. The specific mechanism and pathway of raspberry affecting learning and memory are still worthy of further study.

The specific components of these effective sites remain to be further explored.