NATIVE ATLANTIC FOREST EDIBLE MUSHROOMS: NUCLEOSIDES AND OXYLIPINS AS CANDIDATE COMPOUNDS FOR BIOACTIVITY AFTER DIGESTION AND INTESTINAL TRANSPORT

Edible mushrooms are valuable sources of nutrients and bioactive compounds, but gastrointestinal digestion and intestinal absorption may substantially influence their biological activities. This study characterized five wild edible mushrooms under domestication (Pleurotus albidus, Pleurotus djamor, Oudemansiella platensis, Irpex rosettiformis, and Lentinula raphanica) and evaluated changes in their antioxidant and anti-inflammatory activities after simulated gastrointestinal digestion and intestinal transport. We extracted freeze-dried samples with water (1:20) using ultrasonication, digested them using INFOGEST static in vitro protocol, and transported them across Caco-2 cell monolayers. Extracts (EX), digested fraction (DF), and basolateral fraction (BF) were assessed for antioxidant capacity by ABTS and oxygen radical absorbance capacity (ORAC) assays, with Trolox as the reference standard. Anti-inflammatory activity was investigated in macrophages RAW-Luc 264.7 transfected and stimulated with lipopolysaccharide (LPS), by evaluating NF-κB pathway activation and TNF-α levels, while cytotoxicity was evaluated using the MTT assay. Chemical composition was characterized by untargeted metabolomics (UHPLC-Q-TOF-MS) with putative annotation. Digestion process increased ABTS radical-scavenging capacity in all species, reaching 513.09 and 506.08 µmol Trolox equivalents (TE)/g in P. albidus and P. djamor, respectively. Values rose further in BF, notably for P. djamor (1,830.25 µmol TE/g) and O. platensis (1,271.45 µmol TE/g), which also showed higher ORAC than their EX and DF. All DF samples reduced NF-κB activation (14–80%) and TNF-α levels. P. djamor was the most effective, with reductions of up to 80% in NF-κB activation and 98% in TNF-α, followed by O. platensis (37% and 94%, respectively) and L. raphanica (63% and 81%, respectively). P. djamor was the only sample whose BF showed a reduction in NFkB and TNF-α (23% and 19%, respectively). Putative annotation revealed purine nucleosides and nucleotides, with guanosine and inosine being the most widely distributed, detected in EX, DF, and BF of most species. We also detected oxygenated fatty acids and lipoxygenase-derived oxylipins, including 9-HODE, 9,10-DiHOME, 9-HOTrE, and hydroperoxides (9-/13-HPODE), with distinct distributions among species and fractions. We hypothesize that the persistence of guanosine and inosine, small polar molecules with reported antioxidant and immunomodulatory properties, possibly released from nucleotide precursors during digestion, through the basolateral fractions contributes to the increased radical-scavenging capacity of P. djamor and O. platensis. In parallel, 9-HODE and HPODEs, detected in P. djamor, O. platensis, and L. raphanica, may contribute to the reduction of NF-κB activation and TNF-α levels, since 9-HODE is a PPARγ ligand and oxidized fatty acids can modulate inflammatory signaling. Other constituents may contribute, and annotations are putative and based on detection, not quantification. Simulated digestion and intestinal transport substantially shaped bioactivity, and P. djamor stood out for its basolateral antioxidant capacity and pronounced anti-inflammatory effects in digested samples. Structural confirmation, quantification, and in vivo studies are warranted to establish bioavailability and physiological relevance.