Ayurvedic Medhya Rasayanas Upregulate BDNF and Promote Hippocampal Neurogenesis in Models of Cognitive Decline

The Finding

In a 2026 narrative review, Muralidhara et al. (Formerly Chief Scientist and Head) synthesized preclinical evidence that Ayurvedic Medhya Rasayanas—including Bacopa monnieri, Centella asiatica, and Withania somnifera—consistently up‑regulate brain‑derived neurotrophic factor (BDNF) and promote hippocampal neurogenesis in models of cognitive decline; the abstract does not disclose a specific sample size.

How They Got There

The authors surveyed animal studies, cell‑culture experiments, and limited human pilot data that measured:

• BDNF protein or mRNA levels in hippocampal tissue


• Neurogenesis markers such as BrdU incorporation, doublecortin (DCX) expression, and Ki‑67 labeling


• Oxidative stress indices (e.g., malondialdehyde, superoxide dismutase activity)


• Inflammatory cytokines (TNF‑α, IL‑1β) and gut microbiota composition where reported

Each study compared herb‑treated groups with untreated or vehicle‑treated controls, allowing the authors to identify recurring patterns across disparate experimental designs.

The Mechanism: What Happens Biologically

Across the surveyed literature, several converging pathways emerge. Phytochemicals in Bacopa, Centella, and Withania activate the CRE‑binding protein (CREB) cascade, which drives BDNF transcription. Simultaneously, antioxidant constituents engage the Nrf2‑Keap1 axis, reducing reactive oxygen species that otherwise suppress neurogenesis. Anti‑inflammatory effects stem from inhibition of NF‑κB signaling, lowering cytokine‑mediated neuronal stress. Emerging data also link these herbs to short‑chain fatty acid production by gut microbes, a route that can indirectly enhance BDNF expression in the brain.

Study Limitations

• Reliance on rodent and in‑vitro models limits direct extrapolation to healthy adults.


• Absence of a quantitative meta‑analysis prevents assessment of effect size magnitude.


• Heterogeneous dosing regimens and extract preparations impede comparison across studies.

Practical Application

It is too early to apply these findings to a personal performance protocol. Robust, double‑blind randomized controlled trials in healthy adults are needed to establish effective doses, safety margins, and reproducible cognitive outcomes before any concrete regimen can be recommended.

Disclaimer: This article is for informational and educational purposes only. The information presented does not constitute medical advice, diagnosis, or treatment. Consult a qualified healthcare professional before modifying your diet, supplementation, or exercise routines. The scientific studies cited reflect the state of knowledge at their publication date and may be subject to revision.