The plant species Libidibia ferrea (Mart. ex Tul.) LP Queiroz var. ferrea basionym of Caesalpinia ferrea (Mart. ex Tul.) is used in various regions of Brazil in folk medicine in the treatment of several health problems, especially in acute and chronic inflammatory processes. Most of the preparations employed are alcoholic. Therefore, this study aimed to evaluate the acute toxicity of the hydroethanolic extract of fruits of Libidibia ferrea (EHEFLf) in zebrafish, emphasizing the possible changes in the organic-cellular level of the gills, liver, kidneys, and intestine and on embryos. The result obtained by LC-M/MS from EHEFLf indicated a high concentration of possible polyhydroxylated substances. EHEFLf, at a dose of 2 g/kg orally, produced non-significant alterations of the analyzed organs. However, for embryos, the treatment with different concentrations demonstrated heart toxicity that was concentration-dependent. There is no evidence of a correlation of the observed effects with the phytochemical composition, and considering the species of animal used, it can be suggested that the oral use of L. ferrea hydroethanolic extract has an acceptable degree of safety for use as an oral medicinal product. and embryo results have shown significant affinity to the heart; however, it is perceived to be related to the concentrations used.

Hydroethanolic preparations of the botanical species Acmella oleracea L. are used in the north of Brazil for the treatment of various diseases. However, few studies have been conducted to evaluate the toxicity of this species. The objective of this study was to evaluate the acute toxicity of the hydroethanolic extract of A. oleracea L. (EHFAo) flowers in zebrafish by immersion and oral administration. The extract was analyzed by ultra-performance liquid chromatography–mass spectrometry (UPLC–MS). EHFAo was administered orally (44.457, 88.915, 199.94, 281.83, and 448.81 mg/kg) and by immersion (250, 300, 350, 400, and 450 µg/L). Behavioral and histopathological analysis of gills, liver, intestine, and kidney were performed. The presence of (2E,6Z,8E)-N-isobutyl-2,6,8-decatrienamide (spilanthol) in EHFAo was identified by ultra-high-re.solution liquid chromatography–electrospray ionization mass spectrometry (UHPLC–ESI-MS). Treatment with EHFAo caused significant behavioral changes and death. The calculated median lethal dose (LD₅₀) was 148.42 mg/kg, and the calculated median lethal concentration (LC₅₀) was 320 μg/L. In the histopathological study, it was observed that upon oral treatment, the tissue alterations that compromised the normal functioning of the organism occurred with EHFAo doses of 88.915, 199.53, and 281.83 mg/kg, the intestine being the most affected. When the treatment was performed by immersion, the most toxic EHFAo concentrations according to the histopathological evaluation were 300, 350, and 400 μg/L, with the most affected organ being the gills. Finally, EHFAo in this study was shown to be more toxic to the liver, intestine, and kidneys when administered orally and to gills, liver, and kidneys when administered by immersion in water. Therefore, considering the results obtained and the chemical characteristics of the main phytochemical marker of EHFAo, spilanthol, it can be suggested that, depending on the dose, this compound can lead to histopathological damages in the organs highlighted in this study.

Hancornia speciosa Gomes is a tree native to Brazil and has therapeutic potential for several diseases. Ethnopharmacological surveys have reported that the plant is used as a hypoglycemic agent and to lose weight. This study aimed to evaluate the effects of the aqueous extract from H. speciosa latex (LxHs) in a zebrafish model of diabetes. The extract was evaluated through high-performance thin-layer chromatography (HTPLC), nuclear magnetic resonance (NMR), and Fourier-transform infrared spectroscopy (FT-IR). We then tested treatments with LxHs (500, 1000, and 1500 mg/kg) by assessing blood glucose levels in alloxan-induced diabetic animals, and metformin was used as a control. The toxicity was evaluated through histopathology of the pancreas and biochemical assessment of serum levels of AST, ALT, creatinine, and urea. The extract was also assessed for acute toxicity through several parameters in embryos and adult animals. Finally, we performed in silico analysis through the SEA server and docking using the software GOLD. The phytochemical study showed the compounds cornoside, dihydrocornoide, and 1-O-methyl-myoinositol (bornesitol). The treatment with all doses of LxHs significantly decreased alloxan-induced hyperglycemia without any significant histological or biochemical abnormalities. No significant frequency of teratogenesis was observed in the embryos exposed to the extract, and no significant behavioral changes or deaths were observed in adult animals. In silico, the results showed a potential interaction between inositol and enzymes involved in carbohydrates’ metabolism. Overall, the results show a hypoglycemic activity of the extract in vivo, with no apparent toxicity. The computational studies suggest this could be at least partially due to the presence of bornesitol, since inositols can interact with carbohydrates’ enzymes.

The species Trattinnickia rhoifolia Willd, (T. rhoifolia), which belongs to the Burseraceae family, is widely used in ethnopharmacological cultural practices by traditional Amazonian people for anti-inflammatory purposes, sometimes as their only therapeutic resource. Although it is used in teas, infusions, macerations and in food, the species is still unexplored in regard to its pharmacophoric potential and chemical profile. Therefore, the aim of this study was to conduct a phytochemical characterization of the hydroethanolic extract of T. rhoifolia leaves (HELTr) and to evaluate the acute toxicity and anti-inflammatory activity of this species using zebrafish (Danio rerio). The extract was analyzed by gas chromatography–mass spectrometry (GC-MS). The evaluation of the acute toxicity of the HELTr in adult zebrafish was determined using the limit test (2000 mg/kg), with behavioral and histopathological evaluations, in addition to the analysis of the anti-inflammatory potential of HELTr in carrageenan-induced abdominal edema, followed by the use of the computational method of molecular docking. The phytochemical profile of the species is chemically diverse, suggesting the presence of the fatty acids, ester, alcohol and benzoic acid classes, including propanoic acid, ethyl ester and hexadecanoic acid. In the studies of zebrafish performed according to the index of histopathological changes (IHC), the HELTr did not demonstrate toxicity in the behavioral and histopathological assessments, since the vital organs remained unchanged. Carrageenan-induced abdominal edema was significantly reduced at all HELTr doses (100, 200 and 500 mg/kg) in relation to the negative control, dimethyl sulfoxide (DMSO), while the 200 mg/kg dose showed significant anti-inflammatory activity in relation to the positive control (indomethacin). With these activities being confirmed by molecular docking studies, they showed a good profile for the inhibition of the enzyme Cyclooxygenase-2 (COX-2), as the interactions established at the sites of the receptors used in the docking study were similar to the controls (RCX, IMN and CEL). Therefore, the HELTr has an acceptable degree of safety for acute toxicity, defined in the analysis of behavioral changes, mortality and histopathology, with a significant anti-inflammatory action in zebrafish at all doses, which demonstrates the high pharmacophoric potential of the species. These results may direct future applications and drug development but still require further elucidation.

The antioxidant capacity and modulation of oxidative stress by industrially processed açaí pulp extract from the Amazon (APEA) and its major anthocyanins, cyanidin 3-glucoside (C3G) and cyanidin-3-O-rutinoside (C3R), were evaluated as potential strategies for preventing cardiovascular diseases. The APEA was chemically characterized using ultrafast liquid chromatography-mass spectrometry (UFLC-MS), which revealed six main phenolic compounds. Notably, 9-(2,3-dihydroxypropoxy)-9-oxononanoic acid, acanthoside B, roseoside, cinchonine, and nonanedioate were identified for the first time in açaí extracts. In vitro antioxidant assays demonstrated that APEA exhibited strong DPPH- and ABTS-radical-scavenging activities (up to 80% inhibition and 65 mmol TE/100g DW, respectively) and showed ferrous- and copper-ion-chelating activities comparable to those of EDTA-Na₂ at higher concentrations (up to 95% inhibition). Hydroxyl and superoxide radical scavenging activities reached 80% inhibition, similar to that of ascorbic acid. In H₂O₂-treated H9c2 cardiomyocytes, APEA significantly reduced the intracellular ROS levels by 46.9%, comparable to the effect of N-acetylcysteine. APEA also attenuated menadione-induced oxidative stress in H9c2 cells, as shown by a significant reduction in CellROX fluorescence (p < 0.05). In vivo, APEA (100 mg/kg) significantly reduced CCl-induced hepatic lipid peroxidation (MDA levels), restored glutathione (GSH), and increased the antioxidant enzymes CAT, GPx, and SOD, demonstrating superior effects to C3G and C3R, especially after 21 days of treatment (p < 0.001). These findings suggest that Amazonian açaí pulp (APEA) retains potent antioxidant activity after industrial processing, with protective effects against oxidative damage in cardiomyocytes and hepatic tissue, highlighting its potential as a functional food ingredient with cardioprotective and hepatoprotective properties.