Bioactive potential of tropical highland apple (Malus domestica cv. Anna) crude extract: opportunities for food waste revalorization

Background The third most produced fruit crop in the world, apples ( Malus domestica Borkh) are one of the most accessible and widely consumed fruits, with known benefits for human health. Although they are a temperate crop, apple cultivation has been successfully implemented in lower latitudes. Tropical highland Costa Rican apples (cv. Anna) have shown high total polyphenol content, and cytotoxic effects against human cancer cell lines. However, most reports originate from purified fractions, obtained using methods which are not easily translatable for commercial applications. In this study, we prepared a polyphenol-rich bioactive extract from Costa Rican Anna apples, using food-grade solvents and simple techniques, aiming towards easy translation of the extraction protocols to small local producers. Results The whole apple crude extract (AE) was investigated for its total polyphenol content, general phytochemical profile, cytotoxicity against human breast and lung cancer cells, and regenerative potential in murine skin fibroblast monolayers. The AE showed total polyphenol amounts comparable to that obtained using more refined extractions in previous studies, and exhibited cytotoxic activity against human breast (MCF7) and lung (NCI-H460) cancer cells, and inhibition of cell proliferation in the scratch-wound-healing assay. Conclusions Food-grade simple protocols were successful for obtaining a polyphenol-rich bioactive extract from Costa Rican Anna apples. The easy-to-implement extraction protocols and biochemical tests could provide a source of bioactive phytochemicals to be used in circular production systems.