Successive Extraction and Study of Total Phenolic and Flavonoids Content In Different Solvent Extracts of Onosma Bracteatum Leaves

Onosma bracteatum (Boraginaceae) is a plant species known for its traditional medicinal uses due to the presence of bioactive compounds such as phenolics, flavonoids, and other secondary metabolites. The current study aims to evaluate the total phenolic and flavonoid content in different solvent extracts of Onosma bracteatum leaves using a successive extraction method. The solvents used include chloroform, ethyl acetate, ethanol, and aqueous extracts. The study also investigates the phytochemical composition of the extracts and their potential antioxidant properties. The results indicated that the percentage yield of the extracts varied significantly, with the aqueous extract yielding the highest (9.21%), followed by ethanol (5.85%), ethyl acetate (2.36%), and chloroform (0.77%). Phytochemical screening revealed the presence of flavonoids, saponins, phenols, proteins, and carbohydrates in the extracts, with ethanol and aqueous extracts showing the highest levels of flavonoids and phenolic content. Total phenolic content (TPC) and total flavonoid content (TFC) were quantified using standard calibration curves, and the ethanol extract exhibited the highest TPC (3.12 mg/100mg) and TFC (2.68 mg/100mg). The findings suggest that Onosma bracteatum contains significant amounts of bioactive compounds, particularly phenolic compounds and flavonoids, which are known for their antioxidant, anti-inflammatory, and other therapeutic properties. These results support the potential use of Onosma bracteatum as a source of natural antioxidants for pharmaceutical and nutraceutical applications. Further studies are warranted to evaluate the biological activities of these extracts, including their potential in treating oxidative stress-related disorders.