Neuro-Pharmacognosy: Is It Nature’s Answer For Neuropathy?

Neuropathy literally means sick nerves. There are a number of different reasons why people develop neuropathy. Neuropathy quite commonly is associated with diabetes, vitamin deficits, inflammation of the nerves and toxins that poison the nerves. We have discussed many of the conditions that cause nerves to become sick in patients in other articles. Patients suffering from the signs and symptoms of neuropathy experience pain, burning, numbness and other odd sensations known as paresthesias most often starting in the feet and progressing throughout the rest of the body. The pain and other symptoms can be debilitating and incapacitating regardless of the reason for the neuropathy.

The nervous system in higher animals like humans is a highly complex collection of specialized cells known as neurons. Neurons have several unique features, including a wire-like process known as an axon. The axon functions very much like an electrical wire and it carries encoded electrical signals known as nerve impulses throughout the body. Just like a copper wire, the nerve axon has insulation around it known as myelin. Unlike a copper wire, a nerve cell and its wire-like axon is living tissue. The neuron contains all the necessary cellular machinery to produce energy, maintain itself and generate energy to support its function of transmitting and receiving electrical signals. Each neuron is an electrochemical marvel and is in essence a living battery. This amazing communication network occurs at the microscopic level and consumes incredible amounts of energy to function properly.

The myelin insulation surrounding the nerve axon is also a living tissue and the nerve cell and its myelin cell partners are intimately arranged to maintain and support one another.

The nervous system typically does a remarkable job of sending and receiving formation from various parts of the body and acts both as a sensor system to monitor what is going on in the body and also as an effector system which drives necessary changes in the body based on the input from the sensors.

Because of its complexity the nervous system and its supporting myelin cells is vulnerable to the slightest disruption in metabolism. The axons are like a microscopic spider’s web yet they travel great distances within the body. They can become dys-regulated very easily by trauma or compression.

Think of the nervous system as a living, delicate, vulnerable communications network that consumes extraordinary amounts of energy for proper function and maintenance. It is no wonder that the nervous system is susceptible to injury, illness, metabolic abnormalities, immune problems and many other afflictions that can make it sick and malfunction.

Malfunctioning of the peripheral nervous system occurs frequently and when this happens people develop the cardinal symptoms of poly-neuropathy.

Despite the fact that poly-neuropathy is one of the most common diseases of the peripheral nervous system, there are few FDA approved drugs available to treat it. Many patients that try traditional prescription medication for relief of their neuropathy symptoms are disappointed with the results.

Too often newer drugs in the research pipeline appear promising, but fail due to unwanted side effects. The research and data obtained from failed drug development experiments can sometimes be applied to herbal medicine where natural substances may work in a similar manner as artificial chemicals, but with less harsh side effects. The scientific study of natural substances that may mimic artificial drugs is known as Pharmacognosy. When this knowledge is applied to the nervous system we call it Neuropharmacognosy. You can translate this as the study of the pharmacology of natural substances that may influence the function of the nervous system. There are a number of natural substances that may mimic the pharmacology of drugs used to treat neuropathy. We have discussed them in other articles, but we will review them together here.

Based on experimental data on nerve function and disease a number of broad classes of chemicals may have theoretical application in the relief of symptoms of neuropathy.

It appears when nerves become sick that raising a chemical known as GABA may calm down irritable and inflamed nerves and provide relief for people struggling with the symptoms of neuropathy. You can think of GABA as a brake pedal that slows down the symptoms of neuropathy. There is research that suggest the herbs valerian root and lemon balm may increase GABA thus applying the body’s brake on run away nerve pain. Valerian root may block an enzyme known as GABA-T that breaks down and neutralizes GABA in the nervous system. By blocking the breakdown of GABA, valerian root may prolong the braking effect of GABA on the nerve and slow down neuropathy symptoms. Lemon Balm appears to increase the effect of GABA in a slightly different way. Rather than blocking the breakdown of GABA, Lemon Balm may stimulate an enzyme known as GAD which is responsible for building GABA. So the braking action of GABA on the sick nerve is supported by the increased production of this neurotransmitter

If GABA acts like the body’s brake on a runaway nervous system, Glutamate is the nerve’s gas pedal. Studies suggest that injured nerves become hyper-sensitive because Glutamate is released after the nervous system is irritated. This has the effect of sensitizing the nerve and contributing to the signs and symptoms of neuropathy. There are two potentially important herbs that may block the effects of Glutamate on the nervous system in neuropathy. The first is Theanine a protein derived from green tea. Theanine is believed to act as a Glutamate analog. This means that Theanine is processed by the body like Glutamate, but does not have the nerve stimulating effects of Glutamate. Think of Theanine as a blank bullet that has the net effect of reducing the actions of Glutamate. The other herb that may reduce the excitatory effects of Glutamate, is Magnolia Bark. Magnolia Bark is believed to bind to a specific Glutamate receptor and block it. This suggests that Magnolia Bark is a specific antagonist to Glutamate and might be a more specific way to take-the-foot-off-the-gas-pedal in nerves damaged by neuropathy.

In keeping with our car analogy, if GABA is the brake on the nerve in neuropathy and Glutamate acts like the gas pedal, a third chemical known as Glycine might be thought of as the transmission. Glycine slows the nervous system down. Think of shifting the nerve into low gear. Glycine down shifts the nerve in neuropathy directly thus slowing down and inhibiting painful transmission of nerve signals, but also it also may indirectly compete with Glutamate. The mechanism by which Glycine might provide relief to patients suffering from neuropathy is a little less direct. If a patient would take a large dose of Glycine, the nerves would slow down. This effect would not last long however, because in the nervous system Glycine is carried away from the nerve by what is known as a Glycine Transporter. The Glycine Transporter has the net effect of getting rid of Glycine which effectively shifts the nervous system back into high gear. This Glycine Transporter system is so effective that it renders Glycine as a treatment for neuropathy impractical. Because of the Glycine Transporter, the nerve simply cannot keep enough Glycine in the nerve to slow down the function of a hypersensitive nerve in a meaningful way. However there are substances which may inhibit the Glycine Transporter and this appears to be a promising way to enhance the suppression of nerve hyper-excitability such as occurs in neuropathy. The herb Prickly Ash Bark appears to be a meaningful Glycine Transporter Inhibitor. Prickly Ash has a long history of use for relief of pain. Likewise the naturally occurring compound Sarcosine is a known Glycine Transporter inhibitor. Both of these naturally occurring substances appear to be candidates for the relief of the signs and symptoms of neuropathy.

Another pathway that may be exploited for neuropathy relief is the endogenous cannabinoid receptor system. This system is activated by marijuana and is believed to suppress pain at the higher levels of the nervous system. The receptors of the endogenous cannabinoid system can be activated for pain relief without producing a “high” and the side effects associasted with marijuana drug use by certain breakdown products of fatty acids in the nervous system. Substances that block the enzyme fatty acid amide hydrolase or FAAH appear to activate the endogenous cannabinoid system and are currently being investigated for the treatment of neuropathic type pain. There appears to be naturally occurring FAAH inhibitors in Red Clover and the herb MACA. This suggests that these herbs through their potential to modulate the activity of the enzyme FAAH may be capable of activating the endogenous cannabinoid system and providing relief from neuropathic pain.

Finally with particular reference to neuropathy associated with diabetes, the Protein Kinase C or PKC enzyme and its relationship with T-Type Calcium Channels may be therapeutic targets. It appears that elevated blood glucose unregulates PKC in diabetic nerves. PKC appears to drive specific calcium channels in diabetic nerves known as T-Type Calcium Channels. These changes are believed to drive hyper-sensitivity and excitability at least in nerves affected by diabetic neuropathy.

Chelidonium Majus is an herbal remedy that may modulate PKC. The alkaloid chelerythrine found in this herb is a potent antagonist of Protein Kinase C. This suggests a possible benefit of this herb in polyneuropathy. While generally safe some reports of liver toxicity associate with Chelidonium Majus appear in the medical literature.

Picrorhiza Kurroa is an herb that contains the phytochemical Apocynin. At least one study suggests that apocynin prevented or markedly reduces the up-regulation of Cav3.1 and Cav3.2 T-Type Calcium Channels. This suggests that Picrorhiza Kurroa may be able to down regulate the over expression of T-Type Cav3.2 Calcium channels believed to contribute to the hyper-excitability of nerves seen in diabetic neuropathy.

A final note and warning about using internet information to try to treat a medical condition. Don’t do it! The use of this article is provided solely for patients to discuss the contained information with their licensed healthcare provider. Herbal treatments while generally safe can have unwanted or unpredictable side effects. Only a licensed practitioner that is familiar with your specific healthcare condition can safely diagnose and advise you about treatment for your particular condition. Always consult with and inform your doctor before making additions or changes to your treatment regime.