Atividade antioxidante do fungo endofítico Ochrocladosporium elatum isolado dos frutos de Schinus terebinthifolia Raddi

Abstract

Chronic non-communicable diseases, the main causes of global death, are intrinsically associated to oxidative stress, resulting from an imbalance between oxidizing agents and the body's antioxidant defense systems. The prospecting of endophytic fungi in medicinal plants stands out as a promising source of bioactive compounds capable of mitigating the effects of oxidative stress. Schinus terebinthifolia Raddi, included in the list of medicinal plants of interest to the SUS, demonstrated potential for isolating endophytic fungi with in vitro antioxidant activity, particularly the fungus Ochrocladosporium elatum. Despite the promising results obtained in vitro, studies on the biological activity of this fungus are still scarce. Therefore, it is necessary to understand the effects of O. elatum compounds, both in vitro and in vivo. In this context, the present study aimed to evaluate the effects of the extract of metabolites from the endophytic fungus O. elatum (EFOe) against oxidative stress in biomolecules and in the preclinical model C. elegans, as well as its toxicity. The antioxidant activity of EFOe was evaluated at different concentrations (12.5 to 500 µg/mL). To evaluate its action on biomolecules, the ability of EFOe to preserve the integrity of BSA protein against AAPH-induced oxidation was investigated, as well as its protection of DNA against damage caused by UV radiation and H₂O₂. The results demonstrated that EFOe protected the integrity of BSA by about 71%, 83%, and 92% at concentrations of 100, 250, and 500 μg/mL, respectively. Furthermore, EFOe was effective in protecting DNA against oxidative damage, with approximately 80% and 90% protection at concentrations of 250 and 500 μg/mL. To evaluate the toxicity and antioxidant potential in vivo, the nematode C. elegans was used. In the toxicity assay, the nematodes were treated with EFOe, and viability was evaluated after 24 and 48 hours. EFOe showed no toxicity in vivo. To evaluate the effects of EFOe on subchronic oxidative stress, the nematodes were exposed to juglone (40 µM), and viability was evaluated after 24 and 48 hours. EFOe provided protection against juglone-induced damage, maintaining viability above 83% from 12.5 μg/mL at 24 hours and above 80% from 25 μg/mL at 48 hours. To evaluate the effects of EFOe on acute oxidative stress, the nematodes were exposed to juglone (250 µM), and viability was evaluated over 6 hours. The EFOe provided protection against the acute oxidative damage caused by juglone, maintaining viability at 77% in the first hour and 17% in the last hour of exposure. These results indicate that the metabolites of O. elatum have significant potential against oxidative stress in vitro and in vivo, without exhibiting toxicity. Collectively, these data open up possibilities for the development of a new biotechnological product with pharmacological potential in the prevention and treatment of oxidative stress-related diseases. However, further studies are needed to understand its mechanisms of action.