Toxicological and chemoprevention studies of Brazilian brown propolis from Araucaria sp .

Brazilian brown propolis (BBP) is a natural product derived predominantly from the south region of Brazil, where Araucaria forests are dominant. Despite its potential as a source of bioactive compounds with leishmanicidal, anti-inflammatory, nociceptive, and antimicrobial properties, BBP has not been comprehensively studied compared to green propolis. Therefore, this study aimed to determine the safety and chemopreventive potential of BBP. The cytotoxicity attributed to BBP was assessed using two different assays, while the Salmonella/microsome assay was employed to evaluate mutagenicity. The acute toxicity attributed to BBP was determined using a zebrafish model, while the chemopreventive potential was investigated utilizing Chinese hamster lung (V79) cell lines. Data demonstrated that BBP exerted cytotoxic effects at concentrations greater than or equal to 10 µg/ml and did not exhibit mutagenicity in Salmonella typhimurium strains TA98 and TA100. However, at the highest concentration tested (4000 µg/plate), BBP induced a significant increase in revertant colonies in S. typhimurium TA102 strain. The LC ₅₀ equivalent to 8.83 mg/L was obtained in the acute toxicity evaluation in zebrafish. BBP also showed antigenotoxic effect by significantly reducing chromosomal damage induced by the mutagen doxorubicin in V79 cell cultures at a concentration of 2.5 μg/ml. Compared to Brazilian green and red propolis, BBP exhibited greater toxicity. On the other hand, at lower concentrations, BBP displayed chemopreventive potential, which may be associated with the antioxidant capacity of the extract. These findings contribute to a better understanding of the biological properties and potential applications of BBP in treating various diseases.