ABSTRACT

The quest for natural antioxidants has experienced substantial growth in recent years due to their potential health benefits and roles in preventing oxidative stress-related diseases. Ocimum citriodorum, commonly known as lemon basil, is an aromatic herb traditionally used for its medicinal properties. This study aims to evaluate the in vitro antioxidant potential of Ocimum citriodorum and analyze its amino acid composition to understand its bioactive constituents. Previous studies on various Ocimum species have highlighted their rich phenolic content and significant antioxidant activity. However, limited research is available specifically on Ocimum citriodorum. The literature suggests that the antioxidant properties of herbs are closely linked to their phenolic and amino acid compositions, which play crucial roles in scavenging free radicals and chelating metal ions. The antioxidant activity of Ocimum citriodorum was assessed using standard in vitro assays, including DPPH (2,2-diphenyl-1-picrylhydrazyl) Assay, FRAP (Ferric Reducing Antioxidant Power) Assay, TAC (Total Antioxidant Capacity) Assay, Nitric Oxide Scavenging Assay, and Hydroxyl Radical Scavenging Activity. The amino acid composition was determined using high-performance liquid chromatography (HPLC). The Ocimum citriodorum extracts showed strong antioxidant activity in all tests, with IC50 values similar to Ascorbic acid. Its inhibitory activity was higher in DPPH, nearly the same in the hydroxyl radical assay, and lowest in the nitric oxide assay. The HPLC analysis revealed a rich profile of essential amino acids, with Histidine and Glycine being the most predominant of other amino acids present, which are known to contribute to the plant’s overall antioxidant potential. The findings of this study demonstrate that Ocimum citriodorum possesses considerable in vitro antioxidant activity, attributed to its diverse amino acid composition and phenolic content. These results support the potential use of Ocimum citriodorum as a natural source of antioxidants in dietary supplements and functional foods.