Essential Oil Composition, Antioxidant Properties and Phytochemical Constituents of the Aerial Parts of Solenostemon monostachyus

Background and Objective: Plants are a valuable source of secondary metabolites, providing a vast assortment of chemical compounds beneficial for human use. This study aimed to investigate the essential oil obtained from the aerial parts of Solenostemon monostachyus, as well as evaluate its antioxidant potential and phytochemical composition. Materials and Methods: The essential oil was obtained through hydrodistillation using a Clevenger-type apparatus, while the aqueous extract was prepared via infusion. Results: Analysis of the essential oil using Gas Chromatography-Mass Spectrometry (GC-MS) identified twenty-two compounds, with limonene (55.40%) and neral (10.39%) as the predominant constituents, followed by trans-verbenol (6.43%) and decanal (3.25%). Phytochemical screening of the aqueous extract revealed various bioactive compounds, including terpenes, alkaloids, sterols, tannins, reducing sugars, flavonoids, saponins and anthraquinones. High-Performance Liquid Chromatography (HPLC) detected sixteen key compounds, notably tannins, caffeic acid, rutin, ferulic acid, morin and apigenin. The antioxidant activity of Solenostemon monostachyus was assessed across a concentration range from 20-0.08 mg/mL, demonstrating the presence of strong antioxidant compounds. Both aqueous and hydroalcoholic extracts of Solenostemon monostachyus exhibited significant antioxidant effects. Conclusion: This study revealed that the aerial parts of Solenostemon monostachyus are rich in phytochemicals and essential oils, exhibiting significant antioxidant and antimicrobial properties. Toxicity tests indicated that the plant is safe for use as an herbal remedy for various ailments. The findings support the traditional use of Solenostemon monostachyus leaves, as both the essential oil and aqueous extracts demonstrated noteworthy antimicrobial and antioxidant activities.