Phytochemical Analysis and Antioxidant Potential of Trapa Natans Peel and Nigella Sativa Oil: A Comparative Study

Abstract

Plants have long been used in traditional medicine for their natural healing properties, and modern research continues to explore their role as safe and effective alternatives to synthetic drugs. This study compared the phytochemical composition and antioxidant potential of Trapa natans (water chestnut) peel and Nigella sativa (black cumin) oil. The extracts were prepared using ethanol at different concentrations (20%, 40%, 60%, and 80%) and analyzed through phytochemical screening, FTIR spectroscopy, antioxidant assays (DPPH, FRAP, TAC, and enzymatic tests), and cytotoxicity evaluation using a hemolytic assay.The results showed that T. natans peel contained a wider range of phytochemicals, including phenolics, flavonoids, tannins, and saponins, while N. sativa oil was mainly rich in steroids and fatty acids. Quantitative analysis revealed that 40% ethanol was most effective for extracting phenolic compounds, while 20% ethanol yielded the highest flavonoid content. The antioxidant assays confirmed that fractions with higher phenolic and flavonoid levels had stronger radical scavenging activity, with the 20% ethanol fractions showing the best performance. FTIR analysis validated the presence of functional groups such as hydroxyl, carbonyl, and aromatic bonds associated with antioxidant activity. Hemolysis tests showed that extracts from lower ethanol fractions were safer, while higher ethanol fractions exhibited mild cytotoxicity.Overall, the findings suggest that both Trapa natans peel and Nigella sativa oil are promising sources of natural antioxidants. Their potential applications extend to nutraceuticals and pharmaceuticals, particularly when extracted with aqueous ethanol fractions that balance high antioxidant activity with safety.

Keywords: Trapa Natans, Nigella Sativa, Phytochemicals, Antioxidant Activity, FTIR Analysis, Cytotoxicity