Rescued from the brink of extinction – The forgotten fungus amongst us – Lignosus rhinocerus, the Tiger Milk Mushroom

In the diary of John Evelyn (1664), a special mention was made of Tiger Milk Mushroom, referred to as Lac Tygridis, for looking like a mushroom but weighed like a metal and came from a hard coagulation of matter. Used by natives in Malaysia to treat diseases, Sir Henry Nicholas Ridley, the father of Malaya’s rubber industry attempted to cultivate the wild solitary mushroom as early as 1890 but did not succeed. With forest clearing and over time, this mushroom is almost forgotten due to its rarity in the wild. The Temuans utilized tiger milk mushroom as medicine to treat coughs and asthma and to strengthen weak constitution by consuming the underground sclerotium (tuber-like; the part with medicinal value) in the form of decoction. The Semai aborigines used Betes kismas (a common name for Tiger Milk Mushroom) for the treatment of asthma, cough, fever, cancer, liver-related illnesses, and joint pains. They are also used by men to revitalize their bodies and as medicines for women after childbirth. It was documented that in the state of Kelantan, Malaysia (where the mushroom is often given to mothers after childbirth), the sclerotium is pounded with raw rice, infused, and drunk. The local Malay and Chinese communities utilized the sclerotium of tiger milk mushroom to treat food poisoning, wounds, stomach cancer, breast cancer, and swellings. The Medicinal Mushroom Research Group (MMRG) from the University of Malaya, Malaysia initiated the safety assessment of the cultivated L. rhinocerus sclerotia powder (TM02, TRADEMARKED) in 2009 after its successful cultivation to ensure that the cultivar is competent for consumption. The sclerotium is the main source of food storage and medicinal material. It is a compact mass of hardened fungal mycelium and represents one of the stages in the fungal life cycle. This structure is a morphologically variable, nutrient-rich, multi-hyphal aggregate that serves as a food reserve and can remain dormant until favourable growth conditions arise. They are long-lived compared to mycelia due to the ability to survive environmental extremes. Anti-proliferative effect was demonstrated by proteins or protein-carbohydrate complex in high-molecular – weight fraction of the sclerotial cold water extract from cultivated L. rhinocerus against breast cancer (MCF7) and lung cancer (A549) cell lines, but not in the two corresponding human non-tumorigenic cell lines. Anticancer therapeutic properties from mushrooms have recently been in the limelight, and the Tiger Milk Mushroom shows promising worth for further evaluation as it shows selective cytotoxic mushroom properties which target only cancerous cells and not harm normal healthy cells. The cold water extract also exhibited anti-acute inflammatory activity and able to fully relax both the trachea and bronchus. The scientific findings have so far verified some of its traditional applications and revealed interesting data which shows potential for it to be further developed into possible nutraceutical. More scientific investigations are much needed to validate the medicinal properties of tiger milk mushroom across its species and to unveil potential biomolecules that may form a valuable foundation in pharmaceutical and industrial applications.