Natural pain modulation

Townsend Letter for Doctors and Patients, Jan, 2005 by Jason Barker, Chris Meletis

Piscidia has a reputation as a toxic herb, mainly due to its potent neuromuscular sedative effects. Piscidia has been used as a fish poison; the leaves were crushed and used to stun fish, allowing them to be easily caught. In fact, the name is derived from Latin meaning "fish killer." Additionally, extracts of this plant are effective natural pesticides. The main toxic constituent, rotenone is a mitochondrial toxin that interferes with oxygen consumption in cold-blooded animals. With this information in mind, limited amounts must be used and the risk to benefit ratio should always be assessed when using this herb. Perhaps best used for short, acute episodes of pain, and until further information is learned, Piscidia should be used for short periods of time with caution.

Corydalis cava (Corydalis) and Eschscholzia californica (California poppy)

Both of these plants have a long history of use in pain management and are often used in combination. Corydalis is typically utilized for pain resulting from nerve damage, tremors, and skeletal muscle spasms. Other uses include hypertension and gastrointestinal spasms as well. Corydalis has powerful effects; it is mainly classified in the literature as a mild sedative while other sources label it as a tranquilizer. There are several purported active ingredients in Corydalis, most of which are classified as Protoberberine alkaloids, type 2. One of these constituents, tetrahydropalmatine (THP) is a neuroactive alkaloid with analgesic and hypnotic actions. (11)

Much remains to be learned regarding the exact effects of this herb as well. Similarly, California poppy has historical use for general aches and pains, nervous conditions (stress), insomnia, sedation, and even bedwetting in children and other bladder disorders. The active constituents of California poppy (derived from the dried stem and leaves) are identified as isoquinoline alkaloids. (12) Sometimes confused with Papaver somniferum, the opium poppy, California poppy is only distantly related (same family, different genera) and does not produce opium.

The few existing studies on these plants utilized a proprietary combination of both herbs known as Phytonoxon N that is widely used in Germany. The alkaloids derived from Corydalis rhizome (protoberberine alkaloids) exhibited a positive binding affinity to gamma amino butyric acid (GABA) receptors in one experiment. (13) GABA receptors in the human brain, when activated, promote a down regulatory function. Meaning, that when GABA receptors are activated, certain neural activities are slowed or decreased. The effect of calming and sedation can be correlated with these receptors in the human brain.

A group of peptide chemicals in the brain, endorphins and enkephalins, are widely regarded for their pain modulating effects in humans under a number of physical stressors. These chemicals bind opioid receptors in the pain-interpreting area of the brain and can therefore alter one's perception of pain. Interestingly, extracts of Corydalis and Eschscholzia were shown to slow the degradation process of some pain-regulating peptides in the brain. This effect serves to prolong the functional activity of these peptides, thereby increasing pain modulation. (14) In this particular study, Corydalis was shown to exert a greater effect on preserving pain-related peptides than did Eschscholzia. Additionally, investigators demonstrated the additive effects of both herbs on maintaining elevated levels of catecholamines; this is thought to explain the hypnotic, sedative and antidepressive activity of these medicines. These studies highlight the fascinating effects of these herbs on neurotransmitter metabolism and provide definitive answers as to how these herbs work at pain modulation.