Salvia Ameliorates aβ25-35-induced Spatial Memory Impairment

Compound Danshen Tablet (CDT), a tablet containing Salvia miltiorrhiza, has been shown to reduce the spatial memory impairment in mice provoked by lateral ventricle injection of aβ 25-35 (an upheld method for modeling Alzheimer’s disease in mice) by affecting the aβ 1-42 deposition levels in the hippocampus and cortex.

CDT contains Salvia miltiorrhiza, Panax notoginseng (ginseng) and Borneol (also plant-based), in proportions of 450:141:8. Among the tablet’s main ingredients are Salvianolic acid B, sodium danshensu, rosmarinic acid, tanshinone, and cryptotanshinone.[7]

The researchers randomly had the mice divided into 5 groups which included a control group which received sham operation and a group that received only the aβ 25-35 injection and no treatment. Then, the remaining 3 groups also received only the aβ 25-35 injection, but were treated along with one of the following:

a small dose of CDT, 0.405g/kg

a large dose of CDT, 0.81g/kg

a positive drug of Huperzine A, 0.4mg/kg

The mice were behaviorally assessed using the Morris Water Maze test. As expected, the aβ 25-35 -treated mice performed very poorly, exhibiting signs of memory loss as demonstrated by increased escape latencies on the first day of testing.

On the second day of testing, to measure how well memory was maintained, a probe trial (in which the Morris Water Maze escape platform is removed) was administered to all groups. The aβ 25-35 -treated mice spent significantly less time in the target quadrant than the control group did. Furthermore, the CDT and Huperzine A groups spent a significantly greater amount of time in the target quadrant and had a greater number of platform crossings than the aβ 25-35 -treated mice did, indicating stronger memory retention[7].

Notably, CDT was able to change the aβ 1-42 deposition in both the cortex and the hippocampus. Between the drug Huperzine A group and the CDT group, there was no significant difference in aβ 1-42 deposition in these two brain areas, meaning that CDT was able to perform at the level of medication in this regard.

In addition to improving spatial memory, CDT administration protected the mice from aβ 25-35 -related neurotoxicity. Other interesting findings collected from this study (acquired as a result of brain tissue analysis) included:

the increase of brain-derived neurotrophic factor (BDNF) in the hippocampus

the increase of expressed choline acetyltransferase (ChAT) in the hippocampus and cortex (CDT performed at the level of the positive drug, Huperzine)

the inhibition of IL-6 and TNF-α levels

The significant effects on performance and the alterations in brain chemistry demonstrate the powerful ability of CDT and its constituents, such as Salvia miltiorrhiza, in decreasing memory deficits. Such potent, plant-based medications should continue to be researched, developed, and tested within human populations.

Salvia elegans’ Hydroalcoholic Extract Enhances Mood and Behavior

Remember that chia seed belong to a family of potent plants, all sharing similar active chemical compounds, such as flavonoids and phenolic acids. In the same family as the chia seed is the Salvia elegans which has recently been established by researchers to be able to induce both antidepressant and anxiolytic behaviors in mice.

Salvia elegans was of interest to a group of researchers based in Mexico, seeking to scientifically understand the cognitive and behavioral effects of this plant. These researchers noted that other Salvia plants were able to alter brain physiology and behavior, therefore Salvia elegans should, too. Yet, up to this point, minimal pharmacological research was done on Salvia elegans. So, they had a go at it.

The scientists used an array of behavioral tests to get a clearer and better understanding of the effects that this plant extract could have on animal behavior. Using hydroalcoholic acid to dilute the Salvia elegans leaves and flowers, an extract was derived for experimental purposes. The control groups were given either diazepam (an anxiolytic drug) at 1.0mg/kg, picrotoxin (an anxiety-producing drug) at 2.0mg/kg, or imipramine hydrochloride (an antidepressant drug) at 15mg/kg and the experimental groups were given varying dosages of the Salvia elegans extract.[8]

An Elevated-Plus Maze was used, due to the intensive validation that has been done showing its effectiveness in measuring rodent anxiety levels. The researchers found that the Salvia elegans extract increased the amount of time that the mice spent in the open arms of the Elevated-Plus Maze, meaning that the rodents were less anxious about being in open spaces (which are naturally avoided). Also, the percentage of entries to the open arms was higher in this group than the control, comparable to the behavioral profile exhibited by the rats in the diazepam group.

In the Light-Dark Apparatus, the experimental mice treated with Salvia elegans extract displayed improved performance. These mice were able to spend a significantly increased amount of time in the light area of the apparatus, just as the diazepam treated mice were able to do. Rodents prefer to spend time in dark, enclosed areas and find the opposite of that (light and/or open areas) to be anxiety provoking. The fact that the Salvia elegans-treated rodents were able to spend more time in the light area means that they were experiencing lower levels of anxiety.

Also, in the Forced-Swim Test, the Salvia elegans mice demonstrated decreased immobility time just as the imipramine group did. In animal research, immobility is considered to be a depressive-like state, so decreasing such a trend is seen as being a good thing. The decreased immobility from Salvia elegans supplementation was as statistically significant as the decreased immobility induced by the imipramine hydrochloride (the antidepressant) administration in one of the control group.

The behavioral results acquired, as a direct consequence of the administration of Salvia elegans, indicate that the effects of this plant’s hydroalcoholic extract have antidepressive and anxiolytic effects on behavior which are comparable to those from treatment medications.

The researchers supposed that these powerful effects were due to the essential oil linalool, which is an active component in the Salvia elegans extract and has been shown to have sedative effects in humans.[9] However, chia seed contain very small amounts of linalool [10] and are more concentrated in other chemical compounds, such as β-caryophyllene which is an active constituent in a variety of essential oil.[11] Β-caryophyllene has been shown by researchers to be implicated in anxiety and mood disorders, but more on that in the next section.