Assessment of acute toxicity of crude extract rich in carotenoids from Cantaloupe melon (Cucumis melo L.) and the gelatin-based nanoparticles using the zebrafish (Danio rerio) model

Bioactivity of Talisia esculenta extracts: Antioxidant and anti-inflammatory action on RAW 264.7 macrophages and protective potential on the zebrafish exposed to oxidative stress inducers

ETHNOPHARMACOLOGICAL RELEVANCE

Talisia esculenta is a fruit tree commonly found in various regions of Brazil. Its fruit is consumed by the local population, and the leaves are used in infusions within traditional Brazilian medicine. These infusions are employed to alleviate pathological conditions such as rheumatic diseases and hypertension, both of which are strongly linked to oxidative stress and chronic inflammation. The investigation of plant extracts represents a promising field of research, as bioactive compounds abundant in plants exhibit pharmacological effects against a variety of pathological conditions.

AIM OF THE STUDY

To investigate the antioxidant, anti-inflammatory activities, and toxicity of the infusion and hydroethanolic extracts of T. esculenta leaves (IF and HF) and fruit peels (IC and HC).

MATERIALS AND METHODS

Initially, the cytotoxicity and the effects of the extracts on oxidative stress in RAW264.7 macrophages were assessed through exposure to H₂O₂, as well as their impact on NO production in RAW264.7 macrophages exposed to LPS. Additionally, the toxicity and ROS production in zebrafish larvae were evaluated using two oxidative stress inducers: H₂O₂ and CuSO₄ combined with ascorbate.

RESULTS

The MTT assay indicated that the extracts exhibited low cytotoxicity, with HF and IF demonstrating protective effects against H₂O₂ exposure. HC reduced NO production in macrophages by 30%. The zebrafish analysis showed that all four T. esculenta extracts (100 μg/mL) were non-toxic, as they did not affect the survival, heart rate, or body size of the animals. Furthermore, all extracts were capable of reducing ROS levels in zebrafish larvae exposed to the H₂O₂ stressor. Notably, ROS reduction by HF, IF, and HC extracts exceeded 50% compared to the positive control (H₂O₂ alone). T. esculenta extracts also demonstrated a significant ability to reduce ROS levels in zebrafish larvae exposed to CuSO₄, with a 70% reduction observed for leaf extracts and over 30% for fruit peel extracts.

CONCLUSION

This study demonstrated that T. esculenta extracts exhibit significant activity against oxidative damage and contain components with anti-inflammatory properties. Among the extracts, those obtained from leaves were the most effective in providing oxidative protection, supporting the traditional use of leaf infusions.

Acute toxicity of trypsin inhibitor from tamarind seeds in embryo and adult zebrafish (Danio rerio)

The trypsin inhibitor isolated from tamarind seeds (TTI) is being investigated for potential applications in the treatment of noncommunicable diseases (NCD), such as hypertension, obesity, and diabetes. This study aimed to assess TTI embryotoxicity and acute toxicity in adult zebrafish (Danio rerio). TTI was extracted and isolated from tamarind seeds. Embryonic and adult zebrafish were exposed for 96 hours to three concentrations of TTI (12.5, 25, and 50 mg/L). Zebrafish embryos (n=60 per group) were evaluated for survival, hatching, malformations, and potential developmental marker alterations, in addition to cardiotoxicity and neurotoxicity tests. For acute toxicity assessment in adults (n=20 per group), survival and locomotor and anxiety-like behaviors were assessed, along with genotoxicity (micronucleus) evaluation. Embryos exposed to TTI showed no significant adverse effects, presented normal heart rates and positive reflex response in the neurotoxicity tests. In adult fish, TTI did not cause mortality or significant behavioral changes, suggesting no neurotoxicity and no genotoxicity. Histopathological analyses of the whole body showed only changes in the liver and spinal cord, similar to those observed in the control group not exposed to TTI. These findings indicate TTI's biosafety and therapeutic potential in complex organisms. Further research is required to evaluate its long-term effects and efficacy in treating non-communicable diseases.

Recent Advances in the Therapeutic Potential of Carotenoids in Preventing and Managing Metabolic Disorders

Carotenoids constitute compounds of significant biological interest due to their multiple biological activities, such as antimicrobial, anticancer, antiadipogenic, antidiabetic, and antioxidant properties. Metabolic syndrome (MetS) comprehends a series of metabolic abnormalities (e.g., hypertension, obesity, and atherogenic dyslipidemia) that can affect children, adolescents, and the elderly. The treatment of MetS involves numerous medications, which, despite their efficacy, pose challenges due to prolonged use, high costs, and various side effects. Carotenoids and their derivatives have been proposed as alternative treatments to MetS because they reduce serum triglyceride concentrations, promote insulin response, inhibit adipogenesis, and downregulate angiotensin-converting enzyme activity. However, carotenoids are notably sensitive to pH, light exposure, and temperature. This review addresses the activity of carotenoids such as lycopene, lutein, fucoxanthin, astaxanthin, crocin, and β-carotene towards MetS. It includes a discussion of sources, extraction methods, and characterization techniques for analyzing carotenoids. Encapsulation approaches are critically reviewed as alternatives to prevent degradation and improve the biological performance of carotenoids. A brief overview of the physiopathology and epidemiology of the diseases, including MetS, is also provided.

Embryotoxic Effects of Pesticides in Zebrafish (Danio rerio): Diflubenzuron, Pyriproxyfen, and Its Mixtures

Diflubenzuron (DFB) and pyriproxyfen (PPF) are larvicides used in crops to control insect plagues. However, these pesticides are known to impact non-target organisms like fish and mammals. Here, we aimed at assessing the embryotoxicity of purified DFB, PPF, and their mixtures in a non-target organism-zebrafish. Zebrafish embryos were exposed to different concentrations for 120 h: 0.025, 0.125, 0.25, 1.25, 2.5, and 10 mg/L of purified PPF and purified DFB, while we used 0.025 mg/L PPF + 10 mg/L DFB (Mix A), 0.125 mg/L PPF + 10 mg/L DFB (Mix B), and 0.25 mg/L PPF + 10 mg/L DFB (Mix C) for the mixtures of PPF + DFB. We observed mortality, teratogenicity, and cardiotoxicity. For the neurotoxicity tests and evaluation of reactive oxygen species (ROS) levels in the brain, embryos were exposed for 120 h to 0.379 and 0.754 mg/L of PPF and 0.025 and 0.125 mg/L of DFB. We established the LC50 for PPF as 3.79 mg/L, while the LC50 for DFB was not determinable. Survival and hatching were affected by PPF concentrations above 0.125 mg/L, DFB concentrations above 1.25 mg/L, and the lower pesticide mixtures. PPF exposure and mixtures induced different types of malformations, while a higher number of malformations were observed for the mixtures, suggesting a potentiating effect. Pesticides diminished avoidance responses and increased the levels of ROS across all concentrations, indicating neurotoxicity. Our findings underscore the detrimental impact of PPF and DFB exposure, spanning from biochemistry to morphology. There is a critical need to reconsider the global use of these pesticides and transition to more ecologically friendly forms of pest control, raising an alarm regarding repercussions on human and animal health and well-being.