QUANTITATIVE PHOTOCHEMICAL SCREENING, ANTIOXIDANT ACTIVITY AND CYTOTOXICITY OF CHIA SEED EXTRACTS

ABSTRACT Chia seeds (Salvia hispanica L.) have gained considerable attention due to their exceptional nutritional profile and promising therapeutic properties, particularly concerning their phytochemical composition, antioxidant capacity, and cytotoxic potential. This study sought to quantitatively assess the phytochemical content and evaluate the antioxidant and cytotoxic activities of chia seed extracts using ethanol and ethyl acetate as solvents. The extracts were subjected to analysis for their total phenolic content (TPC), total flavonoid content (TFC), antioxidant activity through the DPPH radical scavenging assay and total antioxidant capacity, as well as cytotoxicity using the brine shrimp lethality assay. Phytochemical analysis revealed that the ethyl acetate extract exhibited a higher total phenolic content of 202.25 mg GAE/g, based on gallic acid as standard (100 μg/mL gallic acid = 1.0 absorbance unit), and a flavonoid concentration of 65.38 mg QE/g, based on quercetin as standard (100 μg/mL quercetin = 1.1 absorbance units). The ethanol extract demonstrated superior antioxidant activity, with a total antioxidant capacity of 158.75 μg/mL, compared to the ethyl acetate extract at 104.15 μg/mL. Cytotoxicity testing revealed a concentration-dependent lethality effect in both extracts, with the ethanol extract showing an LC₅₀ value of 180.08 μg/mL, which is significantly less toxic when compared to the positive control standard potassium dichromate (LC₅₀ = 5.43 μg/mL). These results bolster the growing interest in chia seeds as a functional food and a promising source of natural bioactive compounds for pharmaceutical and nutraceutical applications. Further research is needed to isolate specific compounds and explore their mechanisms of action in vivo.