Background: Metastatic melanoma stands out as the most lethal form of skin cancer because of its high propensity to spread and its remarkable resistance to treatment methods. Methods: In this review article, we address the incidence of melanoma worldwide and its staging phases. We thoroughly investigate the different melanomas and their associated risk factors. In addition, we underscore the principal therapeutic goals and pharmacological methods that are currently used in the treatment of melanoma. Results: The implementation of targeted therapies has contributed to improving the approach to patients. However, because of the emergence of resistance early in treatment, overall survival and progression-free periods continue to be limited. Conclusions: We provide new insights into plant serine protease inhibitor therapeutics, supporting high-throughput drug screening soon, and seeking a complementary approach to explain crucial mechanisms associated with melanoma.

Inga cylindrica, a tropical fruit tree of the Fabaceae family (subfamily Mimosoideae), is native to South America. The seeds from this family are an essential source of trypsin inhibitors, which display promising bioactivity for increasing host defense against pathogens. The aim of the present study was to characterize the antimicrobial and antibiofilm activities of the trypsin inhibitor extracted from I. cylindrica seeds, ICTI. ICTI demonstrated antifungal activity with a minimum inhibitory concentration (MIC) of 32.11 μmol.L^-1, and a minimum fungicidal concentration (MFC) of 32.1 μmol.L^-1, against Cryptococcus gattii, Candida albicans, Candida glabrata and Candida guilliermondii. Combining ICTI with Amphotericin B had a significant synergistic effect, reducing the concentration of the antibiotic by 75% for C. albicans and 94% for C. gatti. The significant increase (16 x) in activity observed with ergosterol (1.01 mol.L^-1) for C. albicans and C. gatti, and the lack of activity against bacterial strains, suggests that ICTI interferes with the integrity of the fungal cell membrane. Treatment with ICTI at 10 x MIC resulted in a 51% reduction in biofilm formation and a 56% decrease in mature biofilm colonies for C. albicans. Finally, ICTI displayed no toxicity in the in vivo Galleria mellonella model. Given its antifungal and antibiofilm properties, ICTI could be a promising candidate for the development of new antimicrobial drug prototypes.

Cancer therapy remains limited by drug resistance and poor selectivity, while inflammation-driven tumor progression further complicates treatment outcomes. Antimicrobial peptides (AMPs) have emerged as promising therapeutic alternatives due to their multifunctional properties. In this study, we investigated the anticancer and immunomodulatory activities of KI17, a rationally designed peptide derived from GL18, a peptide fragment identified from the talisin protein of Talisia esculenta. KI17 exhibited dose-dependent antiproliferative effects against murine and human melanoma (B16F10-Nex2, SK-MEL-2, A375) and cervical cancer (HeLa) cell lines, while displaying reduced cytotoxicity toward non-tumoral BV-2 microglial cells, resulting in a favorable selectivity index. Mechanistic analyses revealed that KI17 induces morphological alterations, mitochondrial dysfunction, caspase activation, and late-stage apoptosis, together with G0/G1 cell cycle arrest accompanied by accumulation of the Sub-G0 population, indicating coordinated regulation of cell death and cell cycle progression. KI17 effectively suppressed lipopolysaccharide (LPS)-induced microglial activation, markedly reducing pro-inflammatory cytokine and nitric oxide production without compromising cell viability. These biological activities are consistent with the peptide’s optimized physicochemical features, including increased cationicity, amphipathicity, and α-helical folding. Overall, our findings demonstrate that KI17 combines selective anticancer activity with potent immunomodulatory effects, highlighting its potential as a bioinspired peptide for further preclinical development in cancer therapy.