Cordyceps militaris

Cordyceps militaris, commonly known as the caterpillar fungus, is a species of fungus in the family Cordycipitaceae, and the type species of the genus Cordyceps, which consists of hundreds of species. The species was originally described by Carl Linnaeus in 1753 as Clavaria militaris. Cordyceps militaris parasitizes insects and is used in traditional Chinese medicine and modern pharmaceuticals.

Description
The fungus forms 1–8 cm high, club-shaped and orange/red fruiting bodies, which grow out of dead underground pupae. The club is covered with the stroma, into which the actual fruit bodies, the perithecia, are inserted. The surface appears roughly punctured. The inner fungal tissue is whitish to pale orange.

Microscopic features
The spores are smooth, hyaline, long-filiform, and often septate. They decompose to maturity in 3–7 μm × 1–1.2 μm sub pores. The asci are long and cylindrical. Sometimes an anamorphic state, which is Isaria, is found. Masses of white mycelia form around the parasitized insect; however, these may not be of the same species.

Similar species
Cordyceps in the wild has more than 400 different species. Similar species include Cordyceps sobolifera, Elaphocordyceps capitata, and Elaphocordyceps ophioglossoides.

Distribution and habitat
Many authors consider C. militaris quite common, spread throughout the Northern Hemisphere, and fruiting bodies appear in Europe from August to November.

Ecology
Cordyceps' method of dispersal is through parasitizing insects. Researchers believe that the insect picks up the fungus while foraging for food. The fungus makes its way deeper into its hosts body, eventually taking over and controlling the insect's behavior. The fungus then makes its host climb to a high point, most likely the leaf of a nearby plant, and latch on, locking it in place. The fungus continues to eat at its host, killing it in the process. After a few days, the fungus's fruiting body begins to emerge from its host's body, where it then sends its spores out to infect more insects.

Uses


C. militaris can be cultivated in a variety of media, including silkworm pupae, rice, and liquid nutrition. It is considered inedible or "probably edible" by North American field guides. In Asia the fruiting body is cooked as a mushroom in dishes like chicken soup, pork bone soup and hot pot.

C. militaris is a potential carrier of bio-metabolites for herbal drugs. Traditional medicine systems believe it "revitalizes" various systems of the body. In traditional Chinese medicine, this fungus can serve as a cheap substitute for Ophiocordyceps sinensis. Both contain cordycepin. Studies have found that excessive use of C. militaris can exert pressure on the filtering and excretory functions of the liver and kidneys, potentially leading to damage in these organs.

C. militaris contains a protein CMP18 which induces apoptosis in vitro via a mitochondrion-dependent pathway. It is thought that it might be toxic when eaten. Cooking destroys this protein.

Research
Cordyceps militaris is well known within the realm of traditional Chinese medicine. Its anti-inflammatory, anti-tumor, anti-aging properties have been well documented. However, more thorough clinical trials of the fungus are difficult to construct, due to the biological complexity of the fungus. The medicinal properties of C. militaris can be attributed to a number of chemicals within the fungi, including cordycepin, cordymin, and many other extracts. Cordycepin is especially important, with current research investigating ways to expedite the production of the chemical within cordyceps.

The effects of C. militaris on general health is predicted to land it a substantial position in both medicinal areas as well as everyday diets.

Chemistry
Bai & Sheu 2018 found a new protein causing apoptosis. Song et al., 2009 finds microwave-assisted extraction to be a good technique for polysaccharide extraction from this fungus.

Like other members of the Cordyceps genus, C. militaris produces the pharmacologically active compound cordycepin. Cordycepin is a nucleoside analogue of adenosine-differing by only a single hydroxyl group. It has been shown to induce apoptosis, reduce inflammation, and inhibit RNA transcription in cell cultures. For these reasons, it is under study for its anti-metastatic properties.