Cowhage, a plant known for both its irritating and beneficial properties, has a long history in traditional medicine and is now the subject of modern scientific inquiry. This tropical legume, often encountered through its notorious itch-inducing seed pods, also contains compounds of interest for various therapeutic applications.
What is Cowhage?
Cowhage, scientifically known as Mucuna pruriens, is a tropical legume belonging to the Fabaceae family. It is an annual climbing shrub with vines that can extend over 15 meters in length. The plant is commonly referred to by several names, including velvet bean, Bengal velvet bean, Florida velvet bean, and cowitch.
Native to tropical Africa and Asia, Mucuna pruriens is now widely naturalized and cultivated across various tropical and subtropical regions globally. When young, the plant is covered with fuzzy hairs, which become sparser as it matures. Its leaves are typically trifoliate, meaning they are composed of three leaflets. The distinctive seed pods, ranging from 4 to 13 centimeters long, are covered in loose, orange hairs.
The Notorious Itch
The most recognized characteristic of cowhage is the intense itching sensation it produces upon contact with skin. This reaction is primarily caused by barbed spicules, or trichomes, that cover the plant’s seed pods. These spicules measure approximately 2 mm by 20 micrometers and are easily detachable.
The key compound responsible for this potent irritation is a cysteine protease called mucunain. When the spicules embed in the skin, mucunain directly activates specific nerve fibers known as mechano-sensitive C-nociceptors, which are different from the fibers activated by histamine. This activation triggers histamine release from mast cells and direct nerve stimulation, resulting in a burning, stinging, and intensely itchy sensation. Historically, cowhage spicules have been used in research to study pruritus (itching) and understand histamine-independent itch pathways.
Traditional and Therapeutic Applications
Beyond its irritant properties, Mucuna pruriens has a long history of use in traditional medicine systems, particularly Ayurveda. In these practices, various parts of the plant, especially the seeds, have been utilized for a range of conditions. Modern scientific investigation has focused on some of these traditional uses, particularly its potential in neurological health.
Research highlights cowhage’s high L-DOPA (L-3,4-dihydroxyphenylalanine) content, a direct precursor to dopamine. Its seeds contain 4% to 7% L-DOPA by weight, making it one of the richest natural sources. This L-DOPA content has generated interest for managing Parkinson’s disease symptoms, a condition characterized by dopamine deficiency. Studies suggest Mucuna pruriens preparations may act more quickly and last longer than synthetic L-DOPA, possibly due to other beneficial phytochemicals.
Cowhage has also been traditionally used as an aphrodisiac and for supporting male fertility. Research in infertile men has shown that Mucuna pruriens supplementation may improve sperm count and motility, and regulate reproductive hormones. This effect is thought to involve its antioxidant properties and its action on the hypothalamus-pituitary-gonadal axis, which is involved in hormone regulation. Additionally, cowhage has been investigated for its potential in reducing anxiety and stress, and for its neuroprotective effects, which may extend beyond its L-DOPA content due to a complex mixture of compounds. While promising, further clinical trials are needed to establish efficacy and optimal application.
Safety Considerations and Precautions
Despite its potential benefits, the use of Mucuna pruriens requires careful consideration due to its potent compounds and possible side effects. Common side effects associated with oral ingestion can include gastrointestinal issues such as nausea, bloating, and vomiting. Some individuals may also experience headaches, a pounding heartbeat, restlessness, or insomnia.
Higher doses or prolonged use can lead to more severe side effects, including psychosis-like symptoms such as agitation, confusion, hallucinations, and delusions. This is attributed to its L-DOPA content, which can lead to excessively high dopamine levels.
Certain groups should avoid Mucuna pruriens due to contraindications. It is not recommended during pregnancy or breastfeeding, as L-DOPA exposure may not be safe for an infant or fetus. Individuals with liver or kidney problems should also exercise caution or avoid its use. Cowhage can interact with several medications, especially those affecting dopamine levels. It should not be used concurrently with L-DOPA-containing medications for Parkinson’s disease, as this can lead to dangerously high dopamine levels. Additionally, it may interact with blood pressure medications, potentially causing blood pressure to drop too low, and with monoamine oxidase inhibitors (MAOIs) and other psychotropic drugs, which could lead to severe adverse effects. Consulting a healthcare professional before using Mucuna pruriens is important, especially for those with existing medical conditions or taking other medications.