Throughout the jungles of many Southeast Asian tropical rainforests, there is a rare and often overlooked species of fungi known as Calostoma insigne (C. insigne). In Thailand, this edible puffball mushroom has been nicknamed “Hed-Ta-Lo,” which translates to “Big Eye Mushroom” due to its unique appearance that resembles an eye because of its spiny ostiole, or pore opening.
Thai forest monks have held traditional beliefs that C. insigne consumption offers therapeutic benefits such as alleviating inflammatory bowel conditions, human gut diseases, and diabetes. These healing properties have been attributed to the cooling and softening properties of the mushroom’s gelatinous layers that act as the water element, quenching the body’s fire element.
To explore the scientific basis behind these traditional beliefs and the mushroom’s bioactive potential, a recent study has investigated the antioxidant, antimicrobial, anti-glucosidase, and anti-cancer activities of C. insigne.
The researchers of the study collected samples of C. insigne from certain regions of Northern Thailand, then carefully cleaned and prepared the gelatinous tissues of the immature fruiting bodies. From there, they soaked the tissues in an ethanol-based solution to extract its bioactive compounds.
Then, they conducted a multitude of tests, including testing the extract on colon cancer cells and molecular identification for gene analysis. The researchers also investigated the optimal conditions for the mushroom’s mycelial growth, a process essential for conservation and sustainable utilization.
The study revealed that the C. insigne extract possessed significant antioxidant activity, which indicates its potential to combat diseases related to oxidative stress – a trait common amongst several other species of medicinal mushrooms. The results also suggested that the mushroom extract had antimicrobial properties, as it exhibited inhibitory effects against common pathogenic bacteria like Staphylococcus aureus (Staph) and Escherichia coli (E. coli).
Furthermore, C. insigne demonstrated promising potential for diabetes management, as it had strong anti-glucosidase activity, which could help regulate blood sugar levels. Finally, the extract showed notable cytotoxicity towards the cancer cells it was tested on, indicating its potential as a natural anticancer agent (1).
This study is the first report to examine the bioactivities of C. insigne. The results validate some of the traditional beliefs about the mushroom’s health benefits. Given its potential for treating diabetes, along with its antioxidant, antimicrobial, and anticancer properties, the study suggests further investigations to examine the in vivo preventative effects of the extracts and the molecular structure of its active chemicals.
Unfortunately, C. insigne is endangered and falls under the IUCN Red List of Threatened Species. The species is ectomycorrhizal, meaning it forms symbiotic bonds with the Dipterocapceae trees that make up much of Southeast Asia’s neotropical forests.
Because of climate change, the forest area is expected to see a loss of over 50% from 2000 to 2050 (2). These forests also face significant deforestation rates, with an annual forest loss of around 1.2% due to logging, agricultural land clearing, and palm oil plantations. If the current pattern of deforestation persists, the region could see a loss of more than 40% of its biodiversity by 2100.
The study emphasizes the significance of conserving C. insigne and its natural habitat. The researchers also suggest the species should be studied for potential laboratory and farm propagation as a local food resource and medicine. Protecting these fragile environments from further loss is crucial not only to the survival of C. insigne but also to the broader ecological balance that maintains the rich biodiversity of Southeast Asian rainforests.