(P12-011-25) The Role of Sorghum in Antioxidant Systems

Objectives: Cancer progression is strongly influenced by oxidative stress, which damages DNA and promotes cancer cell survival. Dietary micronutrients, such as those in Sorghum bicolor, may mitigate oxidative stress, but the mechanisms underlying their antioxidant effects, especially in vivo, remain unclear. This study aims to investigate the effects of polyphenol-rich sorghum extracts on the antioxidant system in Girardia dorotocephala planaria (in vivo) and HepG2 human liver cancer cells (in vitro).

Methods: Planaria and HepG2 cells were treated with sorghum plant extracts, derived from the leaf (SC Leaf) and bran (SC Bran) provided by the USDA ARS, at concentrations of 1µL/mL and 2 µL/mL. Locomotion assays were used to observe planaria motility response to sorghum extracts with 5-min video recordings at 1-, 8-, and 24-h time points. Cytotoxicity of sorghum extracts (0.25- 32 µL/mL) were assessed in HepG2 cells. Quantitative PCR (qPCR) and western blot analyses are used to evaluate the effect of sorghum on expression of antioxidant genes (e.g., SOD1/2, CAT) in both systems. Results are analyzed with two-way ANOVA and Tukey’s post-hoc analyses, as applicable, in GraphPad Prism.

Results: Preliminary findings in planaria show that extracts from SC Leaf increased locomotion responses, whereas extracts from SC Bran caused behavioral abnormalities and even mortality at low concentrations. Similarly, cell viability in HepG2 cells remained unaffected by the addition of extracts from SC Leaf at 0.25- 32 µL/mL, whereas extracts from SC Bran reduced cell viability in a dose-dependent manner, with decreases of ~10% at 0.25 µL/mL, 40% at 1.0 µL/mL, and 70% at 2.0 µL/mL. Preliminary analyses suggest a possible shared mechanism, likely linked to oxidative stress.

Conclusions: Extracts from SC Leaf showed no adverse effects on HepG2 cell viability or G. dorotocephala locomotion. In contrast, SC Bran treatments significantly reduced HepG2 cell viability and G. dorotocephala locomotion, with planaria exhibiting behavioral stereotypies and mortality, even at 1µL/mL concentration.

Funding Sources: This research is supported by the USDA ARS Kansas and Towson University.