A study published online in May 2012 reports that silymarin, a constituent of milk thistle, exhibits neuroprotective activity after an experimentally induced ischemic stroke in animal models.
Researchers induced ischemic strokes in rats. The investigators administered:
- Silymarin, a polyphenolic flavonoid with potent antioxidant activity; it is a free radical scavenger and activates antioxidative defensive mechanism by elevating cellular glutathione content;
- Piracetam, a derivative of GABA, which improves higher cerebral integrative functions like dementia, learning and memory and has a protective effect on brain function after ischemia; or
- Protocatechuic acid ethyl ester (PCA), which has neuroprotective activity by promoting enzyme antioxidants, and prevents free radical formation and hydrogen peroxide-induced oxidative damage.
The researchers assessed the rats for biochemical changes including lipid peroxidation, reduced glutathione, the enzyme catalase, nitrite content and brain water content. The investigators also evaluated changes in behavior such as memory impairment and motor control and overall neurological score. Additionally, the scientists determined the area of dead tissue (infarct size) and alterations in the anatomy of diseased tissue (histopathological changes).
The scientists found that silymarin and PCA treatment significantly improved behavioral, biochemical and histopathological changes, as well as reduced water content and infarct size in the rats after ischemia and reperfusion (return of blood flow to organs and/or tissue). Piracetam only improved behavioral and histopathological changes, reduced water content and infarct size.
Researchers concluded, “The findings indicate that silymarin exhibits neuroprotective activity better than PCA and piracetam.”
Reference:
Muley MM, et al. Pharmacol Biochem Behav. 2012;2:286-93.
Source: Milk Thistle Constituent Studied for Stroke
