Potential of fungi used in Chinese traditional remedies: the caterpillar fungus (Cordyceps chinensis)

by James Matthew Howard

2003

Abstract

Chinese traditional medicine uses a variety of natural products to treat illness, many of which have no sound medical reasoning. In this study I am to assess the evidence for and against the use of a particular fungus called Cordyceps chinensis, to determine whether or not there is any hard science to its curative effect or whether it is just blind faith. I found some promising material on the effects of the fungus especially in the use of athletics where field tests have been performed. The problems encountered were the reliability of the claims. This was because of where the information was gathered e.g. internet and Chinese journals, where we have to be a little sceptical whether the tests and reports have been properly monitored and checked. In conclusion I found that the use of this fungus medically seems bright but more controlled investigations need to be performed, especially in the West to dispel the myths about TCM.

Introduction

Traditional Chinese medicine (TCM) adopts a more holistic philosophy than in Western medicine. It emphasises the importance of balance in the mind and body and the smooth flow of an optimal amount of energy, known as chi or qi, in maintaining health. This balance is known as yin and yang[1]. There is a lot of evidence to show that some of these ideas are sound in the treatment and diagnosis of a patient. Perhaps the best example is to look at the hormone system. Western scientists have discovered two chemical messengers that allow cells to communicate, called cAMP and cGMP. These also seem to be opposites very much like yin and yang[2]. When Chinese doctors believe yin and yang is out of balance, western doctors see a change in the two chemical messenger levels, e.g. in the yin condition we find cAMP is low and cGMP is high and in the yang condition it, is the reverse. TCM says that every organ of the body has qi, and it has been found when TCM says a patients heart and circulation system has lack of Qi, they are often anaemic[2]. In Western medicine, the treatment is targeted specifically at the disease and the diseased organ. Where as in TCM the target is the whole patient since the treatment is based on the whole system being out of balance. A good example of this in practice is to take the treatment of asthma. The Western response is to administer drugs to relive the spasms of the bronchus, but TCM looks first at the patient, asks what imbalances they show, and since each patient will manifest slightly different symptoms they are treated individually. But patients might end up with the same drug. Ephedrine, which is prescribed by Western doctors for asthma, comes from a plant that Chinese doctors have used for hundreds of years[2].

Claims made for Cordyceps

There are many claims of what Cordyceps mushroom can do. In China the fungus is used to regulate and support the gonads, and as a lung and kidney tonic[9]. It was also recommended as a ‘for all illness’ tonic because of its claimed effects to improve; energy, appetite, stamina, endurance and sleeping patterns. According to some stockists the fungus can pretty much do everything ‘This is one of the most popular and precious longevity-promoting herbs because it strengthens the adrenal glands, increases sexual vitality, relieves bronchitis and emphysema, reduces blood fats and sugars, lowers blood pressure and improves blood circulation’[10]. It is also supposedly able to increase a person’s immune system. These effects are cause because of its high affinity to the Yin organs; the heart, kidneys and liver. According to the Zang Fu relationship[11] with the vital substances of the body in TCM (see table below) the apparent effects of the Cordyceps fungus can be understood, apart from maybe the effects of  relieving bronchitis and emphysema because it does not have an affinity for the lungs according to the literature I found.

Overview of Fungi

Fungi are a division of eukaryotic organisms that grow in irregular masses, without roots, stems, or leaves, and are devoid of chlorophyll or other pigments capable of photosynthesis[3].They contain ergosterol instead of cholesterol in their plasma membranes[4]. They reproduce sexually or asexually (spore formation), and may obtain nutrition from other living organisms as parasites or from dead organic matter as saprobes[3]. Fungi have a well-defined cell wall composed of polysaccharides and chitin; they can be moulds, yeasts, or dimorphic[4].

Cordyceps fungus

The Caterpillar fungus, or Cordyceps chinensis, consists of a complex of the stroma of the fungus Cordyceps sinensis and the larva corpse of a caterpillar from the family Hepialidae, on which the fungus is parasitic. In ancient China, because if its scarcity, the fungus was used in the Emperor’s Palace. ‘Approximately 5 grams were stuffed into the stomach of a duck and roasted until well cooked, then the Cordyceps was removed and the duck was slowly eaten, twice daily over a period of 8-10 days’[5]. This way of preparing Cordyceps is believed to be as ‘potent as 50 grams of Panax Ginseng’[5]. It is naturally found in mountainous areas of China, Tibet and Nepal of mountains over 4’000m high where there is good drainage. The fungus is worth more than its weigh in gold and can sell for $350 per kg. Because of this the fungus is the main income for the villages where it is found in the spring, after the caterpillars have died and the snow is just melting, the farmers crawl the ground collecting the dead insects. They are collected at dawn because the dew drops formed on the heads of the larvae radiate off the sunlight causing them to become iridescent and thus easier to see. The fungus is also very easy to culture and grow, this is because the raw materials are easy to get hold of, for example caterpillars are produced in mass quantities for use in sterilization techniques in the wild and also for other uses such as a food for certain type for ‘exotic’ pet.

Images of the Cordyceps mushroom (ref. 6)

In 1957 the chemical constituent of Cordyceps were determined by Chatterjee et al. [described in ref. 8]. A crystalline substance was isolated and named ‘cordyceps acid’[7]. The acid was later identified to be D-mannitol by Sprecher and Sprinson. Further studies were performed to determine the constituents of the fungus but no new structures with significant pharmacological effects were found, only a series on know substances. The chemical substances isolated were; ‘amino acids, steric acid, D-mannitol, mycose, ergosterol, uracil, adrenine, adenosince, palmitic acid, cholesterol palmitate and 5α-8α-epidioxy-5α-ergosta-6,22-dien-3β-ol’ [8].

5α-8α-epidioxy-5α-ergosta-6,22-dien-3β-ol [8]

Evidence and Studies

Various reports have been conducted in order to find what the curative effects of Cordyceps are. It has been found to have effects on hepatic function, renal function, endocrine and steroid system, cardiovascular system, anticancer activities, immunomodulation, hypoglycaemic activity in STZ-induced diabetes and in erythropoiesis and hemopoiesis[12]. First I will deal with its effects on the cardiovascular system, stamina and endurance. The fungi made sports headlines in 1993 at the Chinese National Games, when the women’s team broke 9 world records including the 10,000 metre run by an unprecedented 42 seconds. The team had all been reported to be given a cocktail of TCM drugs and tonics including the Cordyceps mushroom. Several reports and studies have been done to provide evidence for the effects of the fungi on human performance since then. A study which was published in the Medicine & Science in Sports & Exercise Journal, 2001, concluded that CS-4(is a fermentable strain of the mycelia) supports normal fat mobilization and beta-oxidation, thereby preserving glycogen usage during prolonged exercise[13].

‘A double blind, placebo-controlled Chinese study performed on mice was conducted to find if oral administration of CS-4 resulted in enhanced endurance and resistance to fatigue. After three weeks of administration, the groups given CS-4 were able to swim significantly longer than the control groups. The results of the study were dose dependent with results of one group showing a 30% increase in endurance and the second group showing a 73% increase in endurance. The study concluded that the cardiotonic action, inhibition of tracheal constrictions and relaxation of vascular contractions (which CS-4 evokes) elevates the ability and endurance of exercise’[14]. Another double blind, placebo-controlled study to test the effects on physical performance was performed in 1998 led by S. Morrissey of Beijing Medical University Sports Research Institute. They took 30 males and place them in three groups. Each group was given a different concoction, one a placebo, the second 500mg of the formula and the third group received 1000 mg of the formula. Blood samples measuring lactate levels were taken before, during max and after exercise. They found that the group given the most of the formula containing cordyceps experienced improved lactate clearance. ‘Researchers concluded that lactate clearance improved due to improved lactate energy metabolism within the cell. The author concluded that using this herbal formulation would enhance lactate clearance and allow athletes greater anaerobic performance’[15].

Cordyceps has also been used in the treatment of cancers. Reported effects that have been found include[16]:

      Inhibits the production of  DNA and RNA synthesis in cancer cells[17],

      enhancement of cell differentiation[18],

      restructuring of cytoskeleton in cells[19],

      inhibition of protein kinase activity[20]

      antitumor activity on bladder, kidney, colon, lung carcinoma as well as fibroblastoma[21]

      inhibition of the infection and reverse transcriptase activity of human immunodeficiency virus type I[22]

      inhibition of methylation of nucleic acid[23]

      inhibition of chemotaxis and specific proteins synthesis of the macrophage cell line[24]

Cordyceps sinensis has also been found to act as an immunomodulatory agent. ‘Effects of various fractions of methanol extracts from fruiting bodies of Cordyceps sinensis on the lymphoproliferative response, natural killer cell activity, and phytohemagglutinin stimulated interleukin-2 (IL-2) and tumour necrosis factor-alpha production on human mononuclear cells were studied’[25]. It was found that two of the 15 column fractions used, CS-36-39 and CS-48-51, significantly inhibited the blastogenesis response, natural killer cell activity and interleukin-2 production of human mononuclear cells stimulated by phytohemagglutinin. Tumour necrosis factor-alpha production in human mononuclear cells cultures was also blocked by CS-36-39 and CS-48-51. These results indicated that neither CS-36-39 nor CS-48-51 was cytotoxic on human mononuclear cells, and that immunosuppressive ingredients are contained in Cordyceps sinensis.[25]

It has also been found that a ‘polysaccharide (CS-F30)’[26] found in a culture of Cordyceps sinensis has a potent effect on glucose metabolism in the liver of a mouse. The polysaccharide was intraperitonealy administrated into genetic diabetic mice. The mice showed hypoglycaemic activity, ‘and the plasma glucose level was quickly reduced in normal and streptozotocin-induced diabetic mice after intravenous administration’[26]. Administration to normal mice of the polysaccharide significantly increased the activities of ‘hepatic glucokinase, hexokinase and glucose-6-phosphate dehydrogenase, although the glycogen content in the liver was reduced’[26]. In addition CS-F30 was shown to lower the cholesterol level and the plasma triglyceride level in mice.

Discussion

The scientific proof of the effects of the Cordyceps mushroom seems to be quite promising but we have to question the reliability of the claims and evidence. Most of the proved effects I found can be summarised as in the table below (taken from reference 12):

The main problem I found with gathering evidence for this report is the obscurity of the references. A lot of the information came from the internet and so we have to question the reliability of the claims since there is nothing to tell us that what is said is true, and most of the sites were trying to sell the product to you which brings up even more questions.

The vast majority of journals used were obscure ones and ones published in China and so the reliability and scrutiny of how they were conducted also have to be taken into mind. I think that from the evidence I found Cordyceps chinensis looks very promising but the lack of study performed specifically on humans leads me not to make a conclusion on its potency.

I do find its endurance effects very promising though especially in light of the unprecedented performance of the Chinese athletes in the early 1990s. Although these haven’t been researched into fully to give unquestionable proof; ‘Some substances have been shown in Chinese studies to help animals adapt to stress. If you feed Cordyceps sinensis, a caterpillar fungus, to rats and then throw them in a pool of water, they will survive longer than rats that don’t get the fungus. This endurance affect has obvious implications for athletic performance, thought no human studies have been performed.

“There have been thousands of studies done [on animals] in Asia” says Dan Bensky, codirector of the Seattle Institute of Oriental Medicine. “Western scientists tend to look down their noses at Asian studies, often because they haven’t read them.” Even if these studies are valid, it is unclear what an athlete would get out of such substances.’[27].

I think that the prospects of this fungus seem bright but I feel that a lot of questions are still not fully answered. If as the Chinese journals tell us, Cordyceps does have all the wide medical uses why is it not widely used or respected in Western medicine when other TCMs such as acupuncture or substances such as ginseng are?

I think that the other things we have to be wary about is the purity of the fungus obtained from a supplier. In some tests different forms of the mushroom were used but not compared with other forms and thus I can not conclude whether each various form gives the same effects. Some website shops claimed varying things about the product, such as this product is wild and it can not be cultured, where others claimed it could be. This leads us to think whether what we are buying from the shops is actually Cordyceps or just ‘bits and bobs’ from some factory floor in Asia.

In conclusion I think that some of the ideas in TCM are useful and make sound reasoning where as others are just nonsense e.g. “some Chinese women athletes were given Viagra by their coaches” and “one popular potion called Dalishen Oral Liquid consists mainly of seal penis and testes”[27], and so in order to increase the effectiveness of some treatments I think we should combine Western and Chinese medicine in treating a patient instead of separating them, as this will help leave out con-men and eliminate some confusion in what we are taking and why. 

References

1. Exploring TCM by Khen-Wei Yeoh, Student BMJ http://www.studentbmj.com/back_issues/1100/life/424.html
2. Greater than the parts, New Scientist vol 170 issue 2292 – 26 May 2001
3. Stedmans Concise Medical Dictionary 4^th Edition
4. Pathology by O’Connor, Jones Second Edition
5. http://www.bestproducts.com/rejuveyou/cat-guar.html
6. http://www.internations.net/jp/timspage/qinghai/fungus.html
7. Chinese Drugs of Plant Origin, Chemistry, Pharmacology and Use in Traditional and Modern Medicine by W.Tang, G.Eisenbrand
8. Lu RM, Yang YC, Yue DC, Wang SF, Fan TJ, Hui ZM, Wang CF, Yang YP (1982) Chemical composition of the submerged culture of Cordyceps sp. No 1. Weishengwuxue Tongbao 9:166-168
9. http://www.herbmed.com/corydyceps.html
10. http://www.naturalways.com/liver-Enhancer.htm
11. http://tcm.health-info.org/Zang%20Fu%20foundation/TCM-functions-of-internal-organs-Zangfu.htm - Functions of Internal Organs (Zang Fu)
12. Journal of Food and Drug Analysis, Vol 8, No. 4, 2000, Pages 248-257 Pharmacological Functions of Chinese Medicinal Fungus Cordyceps sinensis and Related Species by Sheng-Yuan Wang and Ming-Shi Shiao
13. Medicine & Science in Sports & Exercise, 2001
14. Akinobu, et al. 1995
15. Burke, Edmund, 1998
16. http://psp.bc.ca/Cancer-and-ulcers/e-Cordycep.htm
17. Plageman and Erabe, 1971
18. Mathew et al., 1989
19. Deitchand, 1979, Zieve and Roemer, 1988
20. Glazer and Juo, 1977
21. Hubell et al., 1985
22. Montefiori et al., 1989; Muller et al., 1991
23. Noval-fernandez and Leory, 1980
24. Aksamit et al., 1983
25. Cordyceps sinensis. Kuo YC; Tsai WJ; Shiao MS; Chen CF; Lin CY , National Research Institute of Chinese Medicine, Veterans General Hospital, Taipei, Taiwan. ,Am J Chin Med, 24(2):111-25 1996
26. Kiho T; Yamane A; Hui J; Usui S; Ukai S ,Gifu Pharmaceutical University, Japan. ,Biol Pharm Bull, 19(2):294-6 1996 Feb .
27. Newsweek September 18, 2000 A Natural Advantage? Who needs drugs? >> China’s athletes take a panoply of herbs and tonics