Investigating the ABTS-based antioxidant potential and antiproliferative activity of pulp, skin and seeds extracts from Nephelium lappaceum, Manilkara zapota, and Meliccocus oliviformis on human prostate and colon cancer cells

Despite significant advancements in cancer treatments, cancer remains the second leading cause of death worldwide, creating a pressing need for effective and non-toxic therapies. Plant bioactive compounds, particularly phenolic acids, have shown promising antioxidant and anticancer properties. In this study, we investigated the antioxidant potential and antiproliferative activity of methanolic extracts obtained from the skin, pulp, and seeds of three exotic fruits commonly consumed in Mexico: <i>Manilkara zapota</i>, <i>Nephelium lappaceum</i>, and <i>Meliccocus oliviformis</i>. The antioxidant activity was assessed using the ABTS radical scavenging assay, and total phenolic content was quantified by a modified Folin-Ciocalteu method. Most extracts exhibited significant ABTS radical scavenging capacity, with the highest phenolic content detected in the skin and seeds of <i>N. lappaceum</i>. and <i>M. oliviformis</i>. Cytotoxic and antiproliferative effects were evaluated on human colon (HCT116) and prostate (DU145) cancer cell lines. The skin of <i>N. lappaceum</i> and the seeds of <i>M. zapota</i> and <i>M. oliviformis</i> showed strong antiproliferative activity. These findings highlight the therapeutic potential of underutilized fruit by-products and support further investigation into their bioactive constituents as complementary candidates for cancer treatment.