Enteromorpha compressa extract induces anticancer activity through apoptosis and autophagy in oral cancer

Marine algae are an auspicious source of innovative bioactive compounds containing possible therapeutic agents against mammalian cancers. However, the mechanism by which bioactive algal compounds exhibit anticancer activity against oral squamous cell carcinoma (OSCC) is scant. The main objective of the current study was to explore the properties of the Enteromorpha compressa solvent extracts that induced autophagy and apoptosis with reference to their potent phytochemical and antioxidant properties. The presence of bioactive compounds were confirmed by UV and FT-IR spectroscopy. The free radical scavenging activity were analyzed by evaluating H2O2, DPPH, superoxide and hydroxyl activity. The anticancer activities of the extracts were investigated by employing clonogenic and scratch assay. The apoptosis potential was evaluated by DAPI and MMP by Rh123 fluorescence assay. Moreover, the CAT, SOD, GPX, APX, and GR activities were measured. The autophagy potential was evaluated by LC3 puncta formation, acridine orange in addition to LysoTracker staining. The present investigation revealed that the methanolic extract of E. compressa elicited robust free radical scavenging activity that discerns its antiproliferative potency. Moreover, the methanolic algal extract boosted intrinsic apoptosis against OSCC by downregulating protective antioxidant enzymes. Furthermore, it also revealed induction of autophagy to promote cell death in oral cancer cells. The presence of novel bioactive compounds in E. compressa has uncovered possible therapeutic value against OSCC by modulating antioxidant defense system, apoptosis and autophagy that could be used to explore very competent algal candidates for the development of potential alternative anticancer drugs.