Anti-melanoma action of small molecular peptides derived from Brucea javanica(L.)Merr.globulin in vitro

Objective:The morbidity of malignant melanoma keeps increasing annually.It has high risks of metastasis,drug resistance,and poor prognosis in clinics.Moreover,the available medicines used commonly,such as dacarbazine,temozolomide,the v-Raf murine sarcoma viral oncogene homolog B1(BRAF)inhibitor vemurafenib,and the programmed cell death protein 1 inhibitor pembrolizumab,have some limitations at some extent.Therefore,a more effective therapeutic strategy is still urgently necessary.Methods:In this study,Brucea javanica(L.)Merr.globulins were hydrolyzed with pepsin,then ultra-filtrated to collect small molecular peptides(≤3 kDa).The peptides were then analyzed by antiproliferative assay,cell-cycle distribution,apoptosis assay,and in vitro wound-scratch assay.Finally,western blotting was conducted to elucidate the underlying anti-melanoma mechanism.Results:The small molecular peptide from B.javanica significantly inhibited malignant melanoma cell proliferation with the IC_(50) of 2.72 mg/mL for 72 h.Further analysis indicated that B.javanica peptides arrested cell cycle at the S and G2/M phases and induced apoptosis by upregulating p21,p53,Bax,caspase-3,and cleaved PARP while downregulating Bcl-2 expression.The inhibitory migration effects were also confirmed by wound-healing assay.Conclusion:The small molecular biopeptides from B.javanica may be a promising bioactive agent candidate for melanoma treatment.