EVALUATION OF JABOTICABA PEEL EXTRACT SELECTIVITY IN TUMOR AND NON-TUMOR PROSTATE CELL LINES

Polyphenol-rich natural extracts have been investigated for their potential antitumor effects. In this context, jaboticaba peel extract (JPE) has shown promising biological properties in prostate cancer (Lamas et al., 2018, Kido et al., 2022, Rezende et al., 2025, Schievano et al., 2026, Gianchetto et al., 2026). However, recent evidence suggests that its effects may vary depending on the biological context, highlighting the importance of investigating its selectivity across different cellular models (Rezende et al., 2025; Gianchetto et al., 2026). Therefore, this study aimed to evaluate the selectivity of JPE in tumor and non-tumor prostate cell lines at different exposure times. To this end, tumor (LNCaP and PC-3) and non-tumor (PNT1A) prostate cells were cultured and treated with different concentrations of JPE (31.25–500 µg/mL) for 24, 48, and 72 hours. The number of viable cells following treatment was determined using the Trypan Blue exclusion assay, and the half-maximal inhibitory concentration (IC₅₀) and selectivity index (SI) were calculated. The results demonstrated that the three cell lines exhibited distinct response profiles to JPE. After 24 hours, both tumor cell lines showed greater sensitivity to JPE than the non-tumor PNT1A cell line. However, selectivity decreased with prolonged exposure. At 48 hours, LNCaP cells remained significantly more sensitive than PNT1A cells, whereas no significant difference was observed between PC-3 and PNT1A cells. After 72 hours, no statistically significant differences in IC₅₀ values were observed among the three cell lines, and the selectivity indices indicated comparable extract activity across them. Thus, the greater initial sensitivity of LNCaP cells may be associated with biological differences between the cell lines, including their distinct androgen signaling profiles. Furthermore, the reduction in selectivity with prolonged exposure suggests that exposure duration influences the responses of both tumor and non-tumor cells. Nevertheless, as the analysis was based exclusively on viable cell counts, the observed effects may reflect both cytostatic and cytotoxic mechanisms. Taken together, these findings indicate that JPE exhibited greater apparent selectivity toward tumor prostate cells at earlier exposure times, particularly in the androgen-responsive LNCaP cell line. However, the reduction in selectivity following prolonged exposure underscores the importance of considering effects on non-tumor cells when investigating the antitumor potential of the extract.

Funding Agency: FAPESP 2025/25963-3