Evaluation of biological potential of red onion skin extract for anticancer and antimicrobial activities

Chemotherapy, while effective in combating cancer, frequently induces severe adverse effects and lacks specificity. This investigation aims to assess the potential of red onion skin, a byproduct abundant in polyphenols and flavonoids, as a reservoir of natural compounds possessing anticancer and antimicrobial properties. Two extracts, specifically ethanolic red onion skin (EROS) extract, and chromatographic red onion skin (CROS) extract were subjected to comprehensive biological analysis. Gas chromatography-mass spectrometry (GC-MS) and infrared (IR) spectroscopy revealed that the CROS extract predominantly encompasses dihydroxy benzoic acid (DHBA) and its derivatives, alongside fatty acids recognized for enhancing DHBA penetration into cellular membranes. The antimicrobial activity of the extracts was systematically evaluated against Gram-positive bacteria, Gram-negative bacteria, and yeast using the agar well diffusion method, the minimum inhibition concentration (MIC), and the minimum microbicidal concentration (MMC) tests. The results unequivocally demonstrated that the CROS extract exhibited markedly superior antibacterial efficacy against E. coli, B. cereus, and C. albicans at concentrations of 50, 60, and 70 µg/ml, respectively. Moreover, mice administered with CROS extract enhanced biochemical profiles, including superoxide dismutase (SOD) levels, and improved liver histology compared to those treated with the whole extract. These discerning findings propose that CROS extract harbors substantial promise as a natural and innocuous therapeutic intervention for cancer and microbial infections. Nevertheless, further more research is imperative to support these findings and unravel the intricate mechanisms of its action.