In a recent study, researchers from Shinshu University have discovered Inaoside A, an antioxidant derived from Laetiporus cremeiporus mushrooms. This breakthrough sheds light on the potential of mushrooms as a source of therapeutic bioactive compounds.
Among a diverse array of natural products, mushrooms have emerged as a rich reservoir of bioactive molecules with potential pharmaceutical and nutraceutical applications.
The genus Laetiporus has attracted attention for its extracts exhibiting antimicrobial, antioxidant and antithrombin bioactivities. The species Laetiporus cremeiporus, spread across East Asia, has also been reported to show antioxidant properties.
However, the identification and characterisation of specific antioxidant compounds from this species have not been conducted.
Researchers from the Shinshu University, including Prof. Atsushi Kawamura and Hidefumi Makabe recently discovered the antioxidant compound derived from L. cremeiporus.
The researchers collected fresh fruiting bodies of L. cremeiporus from the Ina campus of Shinshu University. The obtained extracts were concentrated and partitioned between water and ethyl acetate.
After this, the extracts were subjected to advanced chromatographic techniques, which led to the successful isolation of Inaoside A, a new antioxidant phenolic compound, along with three other well-characterised bioactive compounds, i.e., 5'-S-methyl-5'-thioadenosine (MTA), nicotinamide and adenosine.
They reported their findings in an article that was made available online on 20 January 2024 and subsequently published in the journal Heliyon.
"Our study marks the pioneering discovery of Inaoside A from an extract of the edible mushroom Laetiporus cremeiporus. To date, there has been only one prior report on the biological function of an extract of L. cremeiporus. We are the first to uncover the isolation of an antioxidant compound from L. cremeiporus," states Professor Kawamura, highlighting the breakthrough research.
The mushroom extracts were isolated into fractions to determine the antioxidant activities of the four isolated bioactive compounds. These fractions were then examined by DPPH radical scavenging and superoxide dismutase assays. The findings were noteworthy as the DPPH radical scavenging activity exhibited by Inaoside A was significant, showing 80% inhibition at 100 μg/mL, indicative of its significant antioxidant properties. The IC50 value of Inaoside A was determined to be 79.9 μM, further highlighting its efficacy as an antioxidant agent.
The identification of Inaoside A as an antioxidant from Laetiporus cremeiporus marks a significant breakthrough in natural product research, highlighting the potential of mushrooms as a source of therapeutic bioactive compounds.
These findings may lead to the development of novel antioxidant-based therapies for various health conditions.