Bacopa monniera supports the functions of the central nervous system

Bacopa monniera 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
HerbPlant part usedRatio (w/w)
Bacopa monnieraLeaves10
Eugenia caryophyllus (cloves)Flower2
Piper longum (long pepper)Stalks1
Elettaria cardamomum (cardamom)Seed1
Sucrose40
Beneficial effects on learning and memory

Preliminary studies established the role of Brahmi in improving learning and memory capabilities. Treatment with the plant produced improvement in maze learning in albino rats.

In a detailed study, the effects of an alcoholic extract of Bacopa plant fed to rats were evaluated on the learning ability of the animals. The rats were faced with three different situations which required learning new skills and memorizing the newly learned skills. One group of rats received Bacopa extract at a dose of 40 mg/kg/day, while the other group served as the control (untreated) group. After three consecutive days of feeding with Bacopa extract, it was observed that the treated rats significantly improved in the acquisition of new skills compared to the control group. They were also able to retain the skills acquired for the entire duration of the three-day treatment. However, the animals forgot these skills once treatment with Bacopa extract was discontinued. In order to sustain these beneficial effects, the animals had to be fed a maintenance dose of the extract for a number of days. The authors of this report suggest that Bacopa extract might facilitate learning ability in rats due to qualitative improvements in the neurons and their message-carrying connections. Based on these experiments, Bacopa was proven to exert significant but short-lived effects on memory in rats. The ease of acquisition of new skills indicated by the decrease in time taken to learn was enhanced by about 50% on treatment with Bacopa. In addition, the Bacopa treatment enhanced the retention of learning indicated by ease of “relearning” after a specific time interval by about 200%.

(a) Learning skills: ease of acquisition
(b) Relearning Index

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 monniera , 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 treatmentDose of bacosides
(mg/kg oral)
Bacoside A
I Saline0.5 ml
II Bacoside2.5
III Bacoside5.0
IV Bacoside7.5
V Bacoside5.0 (no LiCl incubation on day 1)
Bacosides A and B
VI SalineSaline 0.5 ml
VII Bacoside2.5
VIII Bacoside5.0
IX Bacoside7.5
X Bacoside5.0 (no LiCl incubation on day 1)
pharmacology

The effect of Bacopa administered orally to rats on acquisition, retention and extinction of the newly learned skills