ANATOMICAL, TOXICOLOGICAL, AND BIOACTIVITY EVALUATION OF Swartzia langsdorffii FRUITS

Swartzia langsdorffii (Fabaceae, Papilionoideae) is a tree species native to the Atlantic Forest, whose fruits contain edible arils and release a salmon-colored exudate when the pericarp is injured. Despite its potential as a source of bioactive compounds, its anatomical, phytochemical, and toxicological characteristics remain poorly explored. This study aimed to characterize the secretory structures of the pericarp of S. langsdorffii and evaluate the phytochemical, toxicological (in vitro and in vivo), and antioxidant potential of fruit extracts and exudate, providing preliminary data on their potential for human consumption. Anatomical analyses were performed using conventional plant anatomy techniques. For phytochemical profiling, the pericarp, seeds, and arils of healthy fruits were subjected to dynamic maceration in 60% ethanol, yielding three hydroethanolic extracts, which were subsequently partitioned with methanol and hexane to obtain three methanolic fractions. The samples were analyzed by liquid chromatography coupled with mass spectrometry (HPLC-MS/MS). Cytotoxicity was evaluated in VERO cells as a mammalian cell model using the MTT assay. The extracts and fruit exudate were also analyzed by spectrophotometry to quantify total phenolic compounds (Folin-Ciocalteu), O-diphenols (sodium molybdate), and flavonoids (AlCl₃), while antioxidant capacity was assessed using FRAP and ABTS assays. For the in vivo assay, Galleria mellonella larvae were used as an alternative non-vertebrate model and exposed to different concentrations of the most promising samples based on in vitro toxicity and antioxidant assays, followed by H₂O₂ challenge. The pericarp exhibited articulated anastomosing laticifers associated with latex secretion. The main annotated compounds were saponins, phenylpropanoids, and lipids. The CC₅₀ values of the aril and seed ethanolic extracts, as well as the methanolic fractions of aril, pericarp, and seed, ranged from 59.1 to 506.4 μg/mL. Notably, the pericarp ethanolic extract (PE) and fruit latex (FL) showed no toxicity at the concentrations tested. PE and FL exhibited the highest total phenolic contents (788.47 ± 38.32 and 252.03 ± 22.37 mg GAE/g), O-diphenol contents (104.12 ± 8.69 and 38.15 ± 0.43 mg CAE/g), and antioxidant capacities (FRAP = 2763.39 ± 256.67 and 971.60 ± 34.67 μmol Fe²⁺/g; ABTS = 0.94 ± 0.01 and 0.58 ± 0.08 mmol TE/g). PE and FL did not exhibit toxic effects in G. mellonella and increased hemocyte counts under H₂O₂-induced oxidative stress. These results suggest that laticifers may be involved in the production and accumulation of phenolic compounds. The cytotoxicity observed for some extracts and fractions may be related to compound concentration during extraction and does not necessarily reflect the toxicity of the fruit in natura. PE and FL stand out for their high content of bioactive compounds, antioxidant activity, and absence of toxicity at the concentrations tested, as well as their protective effect in vivo, reinforcing the potential of traditionally underutilized fruit parts.