Following our last discussion on cancer, let us look at the effectiveness of nutraceuticals on neurological conditions.

Ginseng (Panax spp.) is a widely used immune modulator in the traditional medicine of East Asia. Ginseng is also known to protect against neurodegeneration and neuroinflammation. Calabrese [4] reviewed the available literature on the hormetic dose-response effects of ginseng and its constituents (ginsenosides Rg1, Rb1, Rc, Rd, Re, ginseng saponins, gintonin, polyacetylenes). The author found evidence supporting the generality of such effects, especially in the neuroprotective studies of Parkinson’s disease, Alzheimer’s disease, stroke, and neonatal brain hypoxia. Hormesis is characterized by low-dose stimulation and high-dose inhibition. Hence, due to its popularity, overconsumption of ginseng in the population can be a public health concern.

Chou et al. [5] studied the effects of glucosamine in brain cognitive performance with an in vivo model. Glucosamine is an amino sugar and a prominent precursor in the biochemical synthesis of glycosylated proteins and lipids. The study found evidence of glucosamine exerting a cognition-enhancing function in the experimental mice through upregulating the brain-derived neurotrophic factor (BDNF) levels via the dependency pathway of cyclic adenosine 3′,5′-monophosphate (cAMP), protein kinase A, and cAMP response element-binding protein. As abnormal BDNF levels might be due to the chronic inflammatory state of the brain, glucosamine may also have applications in neuroinflammatory disorders such as Alzheimer’s disease, Parkinson’s disease, fibromyalgia, multiple sclerosis and chronic pain.

Peripheral nerve injuries (PNI) can also induce neuroinflammation. Vitamin B complex was explored as a potential treatment by Ehmedah et al. [6] with a femoral nerve injury rat model. Treatment with B vitamins appeared to enhance the M1-to M2-macrophage polarization and accelerate the transition from the non-myelin to myelin-forming Schwann cells. Hence, B vitamins could potentially promote nerve repair through PNI-triggered processes of neuroinflammation and neuroregeneration.

[References]

4. Calabrese, E.J. Hormesis and ginseng: Ginseng mixtures and individual constituents commonly display hormesis dose responses, especially for neuroprotective effects. Molecules 2020, 25, 2719, doi:10.3390/molecules25112719.
5. Chou, L.Y.; Chao, Y.M.; Peng, Y.C.; Lin, H.C.; Wu, Y.L. Glucosamine enhancement of BDNF expression and animal cognitive function. Molecules 2020, 25, 3667, doi:10.3390/molecules25163667.
6. Ehmedah, A.; Nedeljkovic, P.; Dacic, S.; Repac, J.; Draskovic-Pavlovic, B.; Vučević, D.; Pekovic, S.; Nedeljkovic, B.B. Effect of vitamin B complex treatment on macrophages to schwann cells association during neuroinflammation after peripheral nerve injury. Molecules 2020, 25, 5426, doi:10.3390/molecules25225426.