I recently attended a discourse on Buddhism in Contemporary Tibet. A lama from Larung Gar monastery spoke of complex rituals and spirituality, but nestled in between was the mention of a miraculous herb found exclusively on the Tibetan plateau. This miracle remedy reputedly worked wonders for the body, mind, and soul.
As a student of chemistry, the versatile herb intrigued me more than the spirituality. Working in a lab which focuses on drug discovery and cancer therapy research has taught me to be on constant lookout for new leads for cancer therapeutics. The mention of this herb made me wonder what pharmacologically relevant components are packed inside this alleged cure-all.
The lama’s translator told me this herb was, in fact, a parasitic fungus called yarsta gunbu, which literally translates to ‘summer grass, winter worm’. Ghost moth larvae get infected by spores of the parasitic cordyceps sinesis. A caterpillar larva either directly consumes fungal spores spread by the wind, or the spores lying on their bodies enter through their mouths or respiratory pores on the caterpillar's skin.
Either way, once inside, this parasite paralyses and eventually mummifies the caterpillar larvae leaving only the exoskeleton intact. As spring blossoms, the parasite spores inside the caterpillar's shell burst into bloom. The brown stroma, which is the vegetative and reproductive part of the fungus, sprouts from the head of the caterpillar shell like a miniature unicorn horn.
The Tibetan plateau and the Himalaya provide the perfect altitude and climate for the yarsta gunbu and there it grows in abundance. In the alpine meadows, the wild fungus stands hardly a few centimeters above the ground. Harvesters search for it on all fours, with faces quite close to the ground. On spotting the protruding brown stroma of the fungus, it is carefully unearthed using a small knife to keep the caterpillar shell intact. These are then sold to dealers who judge the quality of the cordyceps based on the size and plumpness of the ‘worm’.
Used extensively in traditional Chinese and Tibetan medicine, the gunbu is touted to be a miracle cure for a range of ailments from fatigue, erectile dysfunction, and heart, kidney and respiratory illnesses to cancer, HIV/AIDS, and diabetes. It is believed even yaks which graze on these fungi are ten times stronger and more virile. Traditionally, the entire specimen -- the mummified caterpillar and fungus within -- is used in teas, soups, stews and roast duck. A concoction is also made by steeping the gunbu in locally brewed arak (an alcoholic beverage) for two to three months. These brews are believed to have anti-ageing, aphrodisiac, and invigorating properties.
More recently, there has been an increasing scientific interest in the pharmacological properties of this oriental fungus. Scientists from China, Japan, India, Europe and the USA have published peer-reviewed research on the chemical composition and immunological efficiency of this parasite. A research article published in the Journal of Pharmaceutical and Biomedical Analysis found the number of scientific publications on the fungus cordyceps sinesis doubled between 2006 to 2014.
Advances in science have led us to look for reasons behind every extraordinary phenomenon. Herbal medicines that have cured ailments for centuries often have specific chemicals that are responsible for the cure. Many plants and animals contain compounds which have a direct biological effect on our bodies. These are called bioactives. It is believed the near-miraculous efficacy of yarsta gunbu is due to a combination of several bioactives.
Chemical analyses of the extracts have led scientists to identify key polysaccharides, nucleosides, mannitol and sterols among the many bioactive components in the fungus. Each of these contributes to various of its pharmacological properties. For example, in other research, these same polysaccharides have been proven to act as anti-inflammatories, anti-oxidants, anti-tumors and hypoglycemics (which help reduce blood sugar levels).
Cordycepin is the most prominent of the nucleosides found in cordyceps sinesis. (Nucleosides are the family of chain links for our DNA and RNA and Cordycepin is a nucleoside unique to fungi belonging to the cordyceps family.) It contributes to the anticancer, immunomodulatory (regulation of immune system) and antileukemic effects. Some studies have also isolated cyclic proteins that account for the anti-malarial benefits of the fungus. Other studies identify a wide spectrum of bioactive components that have curative effects for renal disorders, fat reducing and stress relieving benefits.
Although we know a good deal about the chemicals that have been identified within this fungus, the fungus itself hasn’t been studied thoroughly. The clinical studies and the methods used to isolate the bioactive components in cordyceps sinesis were not standardized and more work is needed to fully understand the fungus and rigorously test how or if it really works. Mycologist (or fungi expert) Dr. Russel Patterson reviewed the existing literature on cordyceps sinesis and its efficacy. His research says that the ambiguous nature of the reports should be taken with a pinch of salt but there are definite leads that should be further investigated.
Even though the scientific evidence regarding its efficacy doesn’t seem to hold much water, the market for the fungus isn’t diminishing. In China, demand is so high that the prices have skyrocketed and the treatment isn’t just considered medicine, it’s regarded as a symbol of opulence.
Its market value has increased so drastically that premium quality gunbu retails at $50,000 per pound. In regions where it is harvested, high demand, increased prices, and a large dependence on gunbu collection for household income have led to a series of territorial skirmishes and a raging black market. In 2009, seven ‘outsiders’ caught collecting gunbu in Nepal were murdered by some local harvesters.
Some pharmaceutical labs are getting in on this booming market, too. Advances in biochemical engineering have made it possible to derive the active components of cordyceps sinesis by artificial fermentation. While herbalists decry these as less effective, research shows these derivations can be just as effective.
Science has yet to explore the full potential of this fungus and its bioactive elements in situ. Extraction of active components from the fungus; chemical characterization of these extracts; and clinical studies to observe the effectiveness of the treatment should be strictly standardized and reported without ambiguity. Studies in sustainable methods to cultivate these would also help in market and price regulation without depriving the local people of their income.
More study is certainly needed. Growing western curiosity and scientific exploration of eastern medicine have the potential for a synergistic effort for novel drug discovery. Looking at the what is known about the cordyceps sinesis and its potential applications, one might say there’s ‘mush’room for improvement!