Investigation of the effect of different extraction techniques on the phytochemical analysis of onosma briquetii plant

The utilization of various Onosma species as medicinal plants for addressing a range of health issues in countries such as Iraq, Turkey, Iran, China, and India represents a long-standing tradition that has persisted for centuries. This study aimed to reveal the antioxidant and enzyme inhibition activities of methanol extracts obtained from the endemic Onosma briquetii (Boraginaceae) plant using different extraction techniques, including maceration (MAC-ME), Soxhlet extraction (SOE-ME), and ultrasound-assisted extraction (UAE-ME), as well as to identify the phytochemical contents of the extracts using Electron Spin Ionization Liquid Chromatography-Mass Spectrometry (LC-ESI-MS/MS). The total phenolic content in methanol extracts obtained through all three methods was found to be approximately 20 mg GAEs/g extract. The total flavonoid contents for the MAC-ME, SOE-ME, and UAE-ME extracts were calculated as 35.27, 38.75, and 39.82 mg REs/g extract, respectively. LC-MS/MS analysis identified 4-hydroxybenzoic acid (634-707 µg/g extract), rosmarinic acid (491-509 µg/g extract), and ferulic acid (371-396 µg/g extract) as the predominant components in the extracts, with concentrations varying depending on the extraction technique employed. The MAC-ME extract demonstrated superior antioxidant activity in CUPRAC (EC50: 1.92 mg/mL), FRAP (EC50: 1.33 mg/mL), DPPH radical scavenging (EC50: 3.35 mg/mL), and ferrous ion chelating (EC50: 1.40 mg/mL) assays. While the UAE-ME extract exhibited more effective inhibition of acetylcholinesterase and alpha-amylase enzymes, the MAC-ME extract showed significant inhibition of the tyrosinase enzyme. These findings suggest that extracts from O. briquetii may serve as a valuable and significant resource for the pharmaceutical, food, and cosmetic industries.