Bacopa monnieri has been studied in animals for its purported effects on the functions of the central nervous system in its various forms such as, crude, standardized extract, and compounded formulation known as Brahmi Rasayan.
Constituents of Brahmi Rasayan
| Herb | Plant part used | Ratio (w/w) |
|---|---|---|
| Bacopa monnieri | Leaves | 10 |
| Eugenia caryophyllus (cloves) | Flower | 2 |
| Piper longum (long pepper) | Stalks | 1 |
| Elettaria cardamomum (cardamom) | Seed | 1 |
| Sucrose | 40 |
The effect of Bacopa administered orally to rats on acquisition, retention and extinction of the newly learned skills
In a follow-up experiment, the same group of researchers evaluated the potential of the active saponin fractions of Bacopa monnieri , bacosides A and B, to enhance learning ability in rats. The bacosides were fed to rats at a single dose of 10 mg/kg, 90 minutes prior to teaching the animals a new skill. The treated animals were able to learn within a shorter time compared to the control group. In addition, their relearning ability was enhanced significantly even after the treatment was withdrawn. This implies that the administration of bacosides improved learning ability in the long run.
In another test, rats were taught to avoid drinking water containing lithium chloride, a chemical that causes unpleasant gastrointestinal symptoms. Rats treated with bacoside A and bacosides A & B at doses of 2.5 – 7.5 mg/kg showed a significant decrease in lithium chloride intake compared to the control group.
The results of the experiment revealed that the group of animals receiving bacoside A (I to V) and bacosides A & B (VI to X) learned to avoid lithium chloride faster and in a dose-dependent manner. The authors of this report commented that the positive effects of bacoside A and bacosides A & B manifested in learning enhancement with negative reinforcement (punishment) of the newly learned skill as well as with positive reinforcement (reward) of the new skills. This is a significant finding suggesting that bacosides are effective in enhancing learning ability under two different imposed conditions, viz., punishment and reward.
Summary of dosage regimen
| Group treatment | Dose of bacosides (mg/kg oral) |
|---|---|
| Bacoside A | |
| I Saline | 0.5 ml |
| II Bacoside | 2.5 |
| III Bacoside | 5.0 |
| IV Bacoside | 7.5 |
| V Bacoside | 5.0 (no LiCl incubation on day 1) |
| Bacosides A and B | |
| VI Saline | Saline 0.5 ml |
| VII Bacoside | 2.5 |
| VIII Bacoside | 5.0 |
| IX Bacoside | 7.5 |
| X Bacoside | 5.0 (no LiCl incubation on day 1) |
