Sunday, August 31, 2014

Cordyceps Fungi: Bringers of Death, Givers of Life

Cordyceps sp. growing
from a lepidopteran
Today, I'm going to stretch your parasitophilia into a realm it has seldom explored. Today, we will look at a genus full of fungal parasites! First and foremost, if you don't know much about fungi, especially parasitic fungi, you should take some time to read up on them because they are really fascinating organisms. Like something straight out of science fiction, parasitic fungi are capable of everything from mind control to mummification. Such feats are unimaginable to the non-mycophiliac, but don't worry...I'll convert you! ;)

For this blogpost, we will look specifically at one of my favorite genera of parasitic fungi, the genus Cordyceps. The name for this genus comes Latin root words meaning "club" and "head", which relate to the characteristic shape of the fungi's fruiting bodies (i.e. "mushrooms"). Although Cordyceps spp. can be found in lots of places, the majority of species are described from Asia as the fungi prefer humid environments like tropical forests. There are approximately 400 species within this genus that can be found all over the world. All of these species (as far as I know) are parasitic. Most species parasitize insects or other arthropods, but some feed on other fungi. These fungi, like all fungi, produce mycelia (mats of fungal structures called "hyphae", which are kind of like super-awesome roots...they are used for nutrition absorption and help to anchor the fungi), however, unlike other fungi the mycelia from these fungi invade and eventually replace host tissues. The replacement of the host tissues with Cordyceps mycelia effectively mummifies the host and feeds the fungus in the process so that it can produce fruiting bodies, which will then produce reproductive spores by the thousands.

Look! A photo of a Cordyceps sp. taken at UNL!

Paras and Parasect
Cordyceps fungi have gained pop culture popularity for their creepiness. Even the gaming industry has picked up on how sci-fi-esque these little guys can be. For example, think back to your childhood and consider the Pokemon character, Paras. Paras starts as this crab-like creature with two mushrooms on its back. It evolves into Parasect once it reaches level 24. At this point, the fungus takes over the arthropod and the animal's eyes become milky-white in submission. The parasitic fungus induces the animals to live in caves and other dark, moist environments so that the fungus can grow. Swarms of Parasects can devour trees for nutrients. These have GOT to be inspired by Cordyceps, though I'm not aware of any directly-stated connections. Some games are less subtle; part of the plotline in the video game The Last of Us centered around a mutated strain of Cordyceps that turned people into zombie-like creatures. (Sounds right up my alley, huh?) Additionally, these fungi have made their way into some amazing artwork.

Poster from The Last of Us
featuring mutated Cordyceps.

A piece from DeviantArt
featuring a Cordyceps-like fungus.
Getting back to reality (oh, there goes gravity), a wide range of Asian cultures have utilized these kinds of fungi for traditional medicines. These have been used as aphrodisiacs, treatments for kidney and lung issues, and for revitalizing the fatigued elderly. Scientific researchers have even identified active compounds from these fungi that have pharmocological potential for treating cancer, liver disease, depression, and diabetes. (That's right, these things have hypoglycemic effects too...who knew?) In fact, a paper came out this past April that was titled: "Extract of Cordyceps militaris inhibits angiogenesis and suppresses tumor growth of human malignant melanoma cells". To translate for those of you struggling with the terminology, angiogenesis is the formation of blood vessels, which is necessary for tumor formation. This paper described how using an extract from the fungus not only slowed down angiogenesis, it also induced apoptosis (programmed cell death) in malignant melanoma cells (the bad, quickly-growing kind of melanoma). This study suggested the potential use of this fungus in the treatment of solid, cancerous tumors for its potent effectiveness. Aside from this, there have been a number of other studies looking to various Cordyceps species for their anti-cancer properties, but why stop there? It turns out that members of this genus also have anti-inflammatory properties, antioxidants, anti-fibrotic bioactivity, and even anti-trypanosomal activities! How awesome is that?!?!

The Moral of the Story
As most things in nature, Cordyceps has two sides...that of the villain and that of the hero. Their excitedly terrifying capabilities to suck their hosts dry to the point of becoming mummified cases of their former selves makes them the perfect organisms for science fiction stories. Their medicinal properties bring the potential for life and a sense of hope to those suffering from a wide variety of illnesses. Yes, the Cordyceps fungi exist as the duality of life and death, hope and despair, love and fear. It's a group of parasitic fungi worthy of reverence and deserving of our admiration.

Also, here's a link to a sweet Cordyceps video clip from the BBC narrated by none other than David Attenborough. Enjoy! :)
I'm not going to tell him....

2 comments:

  1. I am totally confused that which part of the cordyceps is strong, the villain part or hero part? Would you please mentioned it.

    ReplyDelete
  2. Thanks for the comment Ariful! I'm not sure exactly what you are asking...could you please specify what you mean by "strong" so that I can try to answer more appropriately? Thanks!

    ReplyDelete