Viruses continue to cause a number of serious global epidemics, especially in those cases where antiviral chemotherapies and vaccines are unavailable or significantly limiting drug efficacy by the emergence of drug-resistant strains. Compared to bacterial infection, viral infection is difficult to treat or control by traditional antibiotics and specific antiviral agents are urgently required. Hence, this is high time to explore for the natural product based drugs that could prove effective against viral infections. Mushrooms are here to help us and could be the possible solution of this problem that are known to produce plethora of potentially active natural products which has been screened for antiviral activity. Belonging to the kingdom fungi, mushrooms are known to possess active components against human immunodeficiency virus (HIV), herpes simplex virus (HSV), hepatitis virus, influenza virus, and many other human pathogenic viruses like enterovirus-71 and respiratory syncytial virus (RSV).
For last one year, the humankind has been experiencing a huge loss of life due to the emergence of a novel strain of a virus named Coronavirus. They belong to the family of viruses that are involved in causing illnesses like common cold, severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS). The name coronavirus assigned to this virus is due to its appearance under microscope, corona means crown. They come under the category of enveloped viruses that means they have the capability to stick to surfaces, but are also able to be killed with disinfectants. The coronavirus first appeared with an animal population and then transmitted to humans and now can be transmitted from human to human. Human immune system have never experienced this particular strain of virus before, that is why we have not developed immunity against this strain of virus which has the potential of worldwide distribution.
For millennia mushrooms have been used for various medicinal purposes. Mushrooms themselves require antibacterial and antiviral compounds for existence in the wild, so they naturally possess a number of these substances. A large number of mushroom species are giving purported benefits ranging from supporting liver and heart health to enhancing energy and many more. One of the most influencial effects of medicinal mushrooms is their powerful antiviral and immune-enhancing properties. Many mushrooms, in fact, have been shown fruitful against respiratory viruses like common cold and flu viruses which is remarkable considering the highly infectious nature of viruses and their ability to get easily mutated.
The isolation of antiviral compounds from mushrooms have emerged as part of an exciting field in the treatment and antiviral drug development. Mushrooms are packed with the powerful constituents like beta-D-glucans, beta-glycosides and many other constituents that are known to stimulate our innate immune system. These compounds not only assist in giving kickstart to our immunity but also help to subside inflammation. They are also known to possess vital elements such as selenium, magnesium and zinc all of which play a direct or indirect role against influenza virus. Research is still going on in order to extract the power of mushrooms against other life threatening diseases and the day is not far when these are going to rule the world of pharmaceutical industry and will be frequently taken as nutraceuticals.
The predominant group of mushrooms that shows promising results against virus infection are polypores (mushrooms that inhabit wood)- also known as woody conks and these are also believed to be the ancestors of most mushrooms, if not all, gilled mushrooms. It is a matter of great interest that till date no poisonous polypore is known whereas more than 100 poisonous species of gilled mushrooms, of which nearly 20 are deadly poisonous are known. Mushrooms acting as functional food are a rich source of number of bioactive compounds that further offers great therapeutic potential for the treatment and control of many diseases. Therefore extraction and identification of these compounds from crude mushroom extracts are much required in order to assort which compound is responsible for the observed antiviral activity.
Viruses are known to cause global serious outbreaks with varied symptoms and mortality along with enormous economic burden for society. Moreover, the constant emergence of new serotypes of viruses with high mutation rate further adds challenges against these viruses. Therefore, it is suggested that the testing of mushroom bioactive compounds against a number of viruses could be interesting. The mechanism of how mushroom compounds act against viruses is also poorly understood, thus investigating the same will definitely suggest some compounds or combinations to be used as therapeutics, thereby reducing the chances of emergence of resistant viruses. Due to the shortage of antiviral drugs in the market, exploration of new antiviral compounds from mushrooms could add to the existing armament of antivirals. Inclusively mushrooms are an exceptionally excellent source of antioxidant, anti-inflammatory and a broad range of antiviral compounds that further inspires for the exploration of novel antivirals.