Evaluation of Antimicrobial and Antiproliferative Activities of Sorghum Extracts Obtained by Green Extraction Technologies and Solid-State Fermentation

Sorghum contains several bioactive compounds, mainly phenolic acids, anthocyanins, and tannins, which have demonstrated biological properties, including antimicrobial and anticancer activities. In this study, we evaluated the antimicrobial and antiproliferative potential of four phenolic extracts from two sorghum genotypes, obtained through ultrasound-assisted (40% ethanol, 10 min) and microwave-assisted extraction (60% ethanol, 300 W, 7 min), as well as two extracts derived from solid-state fermentation with Aspergillus niger Aa210 (72 and 84 h at 30°C). Antimicrobial activity was determined against two bacteria and one fungus using disk diffusion and poisoned food techniques. Viability and cytotoxicity were assessed using MTT and LDH assays in A549 (human lung carcinoma) and NIH-3T3 (mouse embryonic fibroblast) cells. IC50 values were also calculated. Fermented extracts significantly inhibited Escherichia coli , Staphylococcus aureus , and Alternaria spp., which correlated with condensed tannin content. A549 viability was notably reduced by fermented extracts, with IC50 values of 51.20 ± 1.32 and 199.50 ± 1.17 µg/ml. NIH-3T3 cytotoxicity was highest for fermented extract. The observed bioactivities were attributed to phenolic content, compound diversity, and exposure duration. Our findings support further exploration of fermented sorghum extracts as natural, low-cost antimicrobial and anticancer agents.