Microalgae-Derived Carotenoid Extract and Biomass Reduce Viability, Induce Oxidative Stress, and Modulate the...

Cutaneous melanoma (CM) is an aggressive and metastatic tumor, resulting in high mortality rates. Despite significant advances in therapeutics, the available treatments still require improvements. Thus, purinergic signaling emerged as a potential pathway to cancer therapy due to its involvement in cell communication, proliferation, differentiation, and apoptosis. In addition, due to safety and acceptable clinical tolerability, carotenoids from microalgae have been investigated as adjuvants in anti-melanoma therapy. Then, this work aimed to investigate the in vitro anti-melanogenic effect of carotenoid extract (CA) and total biomass (BM) of the Scenedesmus obliquus microalgae on two cutaneous melanoma cell lines (A375 and B16F10). Cells were cultivated under ideal conditions and treated with 10, 25, 50, and 100 μM of CA or BM for 24 h. The effects of the compounds on viability, oxidant status, and purinergic signaling were verified. The IC50 cell viability results showed that CA and BM decreased B16F10 viability at 24.29 μM and 74.85 μM, respectively and decreased A375 viability at 73.93 μM and 127.80 μM, respectively. Carotenoid treatment for 24 h in B16F10 and A375 cells increased the release of reactive oxygen species compared to the control. In addition, CA and BM isolated or combined with cisplatin chemotherapy (CIS) modulated the purinergic system in B16F10 and A375 cell lines through P2X7, A2AR, CD39, and 5'-nucleotidase. They led to cell apoptosis and immunoregulation by activating A2A receptors and CD73 inhibition. The results disclose that CA and BM from Scenedesmus obliquus exhibit an anti-melanogenic effect, inhibiting melanoma cell growth.