# Antioxidant and Cytotoxic Evaluation of Aqueous Extracts from Hymenochaetaceae Fungi Associated with Endemic Chilean Sclerophyll Forest Trees

## TL;DR

This study explores antioxidant and cytotoxic properties of fungi from Chilean forests, finding Inonotus sp. to be a promising natural antioxidant with low toxicity.

## Contribution

The study identifies Inonotus sp. as a novel low-cytotoxicity natural antioxidant source from native Chilean fungi.

## Key findings

- Fulvifomes sp. showed the highest antioxidant activity and polyphenol content.
- Inonotus sp. had the lowest cytotoxicity, making it suitable for aquaculture applications.
- P. boldo had high protein but lower antioxidant activity and higher cytotoxicity at higher concentrations.

## Abstract

In the search for safe and effective natural antioxidants, this study investigates the antioxidant and cytotoxic properties of aqueous extracts obtained from three fungi of the family Hymenochaetaceae: Inonotus sp., Fulvifomes sp., and Phylloporia boldo, all associated with endemic trees of the Chilean sclerophyll forest. Antioxidant capacity was assessed through DPPH, ABTS, and hydroxyl radical scavenging assays. Fulvifomes sp. exhibited the highest antioxidant activity across all methods, which was consistent with its elevated polyphenol content. P. boldo, on the other hand, had the highest protein concentration but comparatively lower antioxidant activity. Cytotoxicity was evaluated using the WST-1 assay in the RTgill-W1 salmonid cell line, revealing that Inonotus sp. displayed the lowest cytotoxicity at both tested concentrations, suggesting it may be suitable for bioactive applications in aquaculture. In contrast, Fulvifomes sp. and P. boldo showed significant cytotoxic effects at higher concentrations. These findings highlight the potential of Inonotus sp. as a natural antioxidant with low cytotoxicity and encourages further exploration of native forest fungi as sources of functional bioactive compounds for food, nutraceutical, or aquaculture applications.