Polygala tenuifolia is an herb that has been used for many centuries in Traditional Chinese medicine. While it is known for many therapeutic uses, one use that has recently been proven effective in medical research is its ability to improve cognition. In fact, it may well be a therapy to consider for Alzheimer’s and dementia.
In Chinese medicine, Polygala tenuifolia is also called Yuan Zhi. It is known for being warming, bitter and for balancing shen. It is also known to relax the nerves and reduce stress. The root is primarily used, and a number of medicinal constituents have been found in the root.
One is the triterpenoid saponin called PGS32. This extract has been shown to increase synaptic transmission among the gyrus and stimulate neurons in the hippocampus(1).
Researchers from Seoul’s National University College of Medicine gave the root extract of P. tenuifolia or placebo to 53 elderly adults. Of the total, 28 adults were given the P. tenufolia extract, and 25 were given the placebo. The P. tenufolia group experienced increases in constructive recall, memory and word list recognition. Boston Naming Test scores were significantly improved among the P. tenuifolia extract group as well(2).
The principal mechanism of action in this study appeared to be its ability to inhibit the acetylcholinesterase enzyme. Inhibiting acetylcholinesterase stops the cholinesterase enzyme from breaking apart acetylcholine. This has the effect of making the important cognitive neurotransmitter acetylcholine more available, which is healthy for brain cells.
In 2007, researchers from Japan’s Okayama University Graduate School of Medicine studied the effect of Polygala tenuifolia root extract on spatial cognition in rats. They utilized special mazes, and found that rats that consumed the extract navigated the eight-arm radial maze far better than the placebo group. They found that those that ate the extract had less errors and more efficiency in completing the task(3).
Laboratory researchers in Japan found that Polygala tenuifolia root blocked memory impairment in mice. These tests also confirmed that the extract decreased inhibited acetylcholinesterase activity, making this important brain cell neurotransmitter more available(4).
Japanese researchers also found that Polygala tenuifolia root extract containing the constituents tenuifoliside B and 3,6′-disinapoylsucrose were able to reverse and prevent brain cell death(5).
Polygala tenuifolia root extract was also tested by pharmacology researchers from the Seoul National University College of Medicine. They confirmed that Polygala tenuifolia root extract inhibited acetylcholinesterase. They also found that Polygala tenuifoliae prevented neurotoxicity and reduced metabolites of amyloid precursor proteins (APP), including amyloid beta protein (A beta) known to be implicated in Alzheimer’s disease (6).
These studies clearly indicate that this traditional Chinese herb has the ability to improve cognition and prevent or delay dementia. This and other simple medicinal herbs have a long history of safe and successful use. With dementia and Alzheimer’s disease rates increasing dramatically, shouldn’t we be giving alternative medicines such as Polygala tenuifolia careful consideration?
This information is for research purposes only not intended to treat or cure any disease. Be sure to consult your health professional if you suspect you or your family members have any disease, and before making any significant changes to your diet, lifestyle or supplements.
1: Xue W, Hu JF, Yuan YH, Sun JD, Li BY, Zhang DM, Li CJ, Chen NH. Polygalasaponin XXXII from Polygala tenuifolia root improves hippocampal-dependent learning and memory. Acta Pharmacol Sin. 2009 Sep;30(9):1211-9.
2: Shin KY, Lee JY, Won BY, Jung HY, Chang KA, Koppula S, Suh YH. BT-11 is effective for enhancing cognitive functions in the elderly humans. Neurosci Lett. 2009 Nov 13;465(2):157-9.
3: Sun XL, Ito H, Masuoka T, Kamei C, Hatano T. Effect of Polygala tenuifolia root extract on scopolamine-induced impairment of rat spatial cognition in an eight-arm radial maze task. Biol Pharm Bull. 2007 Sep;30(9):1727-31.
4: Karakida F, Ikeya Y, Tsunakawa M, Yamaguchi T, Ikarashi Y, Takeda S, Aburada M. Cerebral protective and cognition-improving effects of sinapic acid in rodents. Biol Pharm Bull. 2007 Mar;30(3):514-9.
5: Park CH, Choi SH, Koo JW, Seo JH, Kim HS, Jeong SJ, Suh YH. Novel cognitive improving and neuroprotective activities of Polygala tenuifolia Willdenow extract, BT-11. J Neurosci Res. 2002 Nov 1;70(3):484-92.
6. Xue W, Hu JF, Yuan YH, Sun JD, Li BY, Zhang DM, Li CJ, Chen NH. Polygalasaponin XXXII from Polygala tenuifolia root improves hippocampal-dependent learning and memory. Acta Pharmacol Sin. 2009 Sep;30(9):1211-9.