Mahmoud, Moaaz Mohamed, Esraa MAboul‑Enein, Ahmed MDiab, Ayman AShalaby, Emad A2023-05-032023-05-032023-04https://doi.org/10.1007/s13399-023-04216-7http://repository.msa.edu.eg/xmlui/handle/123456789/5566Mango (Mangifera indica) and guava (Psidium guajava) seeds have several pharmaceutical applications and biological activities because as they have been recognized with diferent bioactive molecules (phenolic compounds) such as favonoids, phenolic acids, and catechins, so they have antioxidant and anticancer activities. The aim of the present study was to assess in vitro antioxidant and anticancer activities of successive extracts and semi-purifed fractions from mango seeds. In this work, mango and guava seeds were collected and extracted using two solvents (ethanol 70% and ethyl acetate) followed by phytochemical screening and determination of biological activities such as antioxidant activity using fve assays (DPPH, ABTS, KMnO4, Methylene blue and H2O2) additionally the antiradical activity and hybrid reaction for ethanolic extract of mango seeds as promising extract. The total phenolic, favonoid, and catechin compounds were determined for all successive extracts, and fnally, the anticancer activity of extracts was evaluated using MTT assay against HepG2 cell line and phenolic compounds were identifed by HPLC. The phytochemical screening and TLC showed the primary investigation for phenolic compounds of ethanol extracts of both kind of seeds and only ethyl acetate of guava extract as promising extracts. However, HPLC determination of these three extracts showed high amount of gallic acid, naringenin, ellagic acid, and ferulic acid as they have anticancer and antioxidant activities. The antioxidant tests showed that the ethanolic mango extract is the highest antioxidant extract against DPPH by 84.0%, but recorded 82.0% with methylene blue and ABTS assays when compared with ascorbic acid. The ethyl acetate of guava extract showed strong cytotoxic efect with IC50 75.5 μg/mL against HepG2 cell line in all tested concentrations. From the obtained results, it could be concluded that mango ethanolic extract and its fractions are the most promising as antioxidants and ethyl acetate of guava extract the most promising in the anticancer activity.en-USMango and guava seeds ·Chemical constituents ·Biological activities ·HPLCArticlehttps://doi.org/10.1007/s13399-023-04216-7