Science Update

Recent Review Explores the Actions of Potentially Neuroprotective Botanicals

As the world’s population ages, brain function and neurological health become increasingly relevant. Certain botanicals have been used for centuries in support of memory and other aspects of cognitive health.

In a recent review, Kumar and colleagues explore the mechanisms of action of several botanicals known to have a supportive role in neurological health and cognitive function. They describe the role of the botanical Bacopa (Bacopa monniera) for neurological health.

Bacopa has been shown to attenuate memory decline in animal studies. It has also been shown to rescue memory impairment and neurodegeneration, and even delay the onset of cognitive aging in laboratory studies involving certain neurodegenerative diseases.

A randomized double-blind placebo-controlled study was conducted with elderly individuals. Daily supplementation with Bacopa for 12 weeks was shown to significantly improve cognitive processing, attention, and working memory.

Studies indicate that bacopa may also play a supportive role in the presence of stress and certain psychiatric conditions. Supplementation with Bacopa was shown to improve certain behavioral parameters related to depression in animal studies. In clinical trials, Bacopa was also shown to improve anhedonia, a common symptom related to depression.

A randomized controlled trial evaluated the impact of Bacopa supplementation on healthy individuals. The study found improvements in the mood and stress hormone levels of these healthy subjects.

Curcumin (Curcuma longa) has a wide range of supportive actions for neurological health outlined by Kumar and colleagues. Curcumin may also support the body’s response to inflammation and oxidative stress. Studies indicate that curcumin may additionally support the prevention of amyloid-beta aggregation and tau hyperphosphorylation.

Improvements in memory impairment and decreased amyloid-beta protein expression have been observed in animal studies. Curcumin has also been shown to act on epigenetic modifiers, such as sirtuins, which may promote healthy aging and neurogenesis.

Curcumin has also been shown to attenuate neuroinflammation through multiple pathways, including the inhibition of nuclear factor-kappa B (NF-κB) and nitric oxide release. Curcumin may also inhibit reactive astrocytes and microglia, and it may reduce the secretion of pro-inflammatory cytokines, such as interleukin (IL)-1 beta, IL-26, IL-6, and tumor necrosis factor-alpha. In addition, curcumin has been shown to induce hippocampal neurogenesis through the modulation of a pathway related to the brain-derived neurotrophic factor (BDNF). BDNF is a protein that plays an important role in synaptic plasticity, nervous system modulation, memory formation, and the growth, maintenance, and survival of neurons.

Other botanicals described by Kumar and colleagues include ashwagandha (Withania somnifera) for its ability to regulate neuronal and astrocytic differentiation marker expression, to inhibit certain pro-inflammatory cytokines and NF-kB signaling pathways, and to delay senescence. Extracts from Vitis vinifera, such as resveratrol, may also support neurological health. Resveratrol has been shown to activate sirtuin-1 and help the body’s response to oxidative stress, and to increase hippocampal neurogenesis and inhibit amyloid-beta expression.

Botanicals, such as bacopa, curcumin, and ashwagandha, may play a role in supporting healthy aging, neurological health, memory, and cognitive function. Future clinical trials assessing the role of neuroprotective botanicals may provide further information related to their impact on human health.

By Colleen Ambrose, ND, MAT