EFFICIENT RECOVERY OF ANTIOXIDANT-RICH EXTRACTS FROM BOGBEAN (MENYANTHES TRIFOLIATA L.) LEAVES

Bogbean (Menyanthes trifoliata) is a plant belonging to the Menyanthaceae family, growing in peatlands and marshes, and is distributed across Europe, North America, and Asia. Traditionally, it has been used in folk medicine for its antioxidant, antimicrobial, immunomodulatory, antipyretic, sedative, and tonic properties [1]. However, the phytochemical composition, biological activity, and potential applications of this plant remain insufficiently studied. The aim of this study was to extract valuable bioactive compounds from M. trifoliata using conventional (infusion, Soxhlet extraction) and modern (ultrasound-assisted extraction-UAE, pressurized liquid extraction – PLE) methods, employing non-toxic solvents (ethanol and water). The study sought to assess the phytochemical composition, antioxidant properties of the extracts, and optimize the PLE process by varying temperature (40–130 °C), time (15–45 min), and ethanol/water ratio, utilizing central composite design and response surface methodology (CCD-RSM). The dependent variables were extraction yield and antioxidant activity, determined using in vitro assays (CUPRAC and ABTS) as well as total phenolic content (TPC). The results showed that PLE optimization yielded extracts ranging from 8.2 to 45.6 g/100 g dry weight. Compared to Soxhlet extraction (17.7–20.4 g/100 g), infusion (10.2 g/100 g), and UAE (11.3 g/100 g), the PLE method achieved the highest yield in a shorter time. Phytochemical analysis revealed that extracts contained significant amounts of total phenolic compounds (45–56 mg GAE/g extract) and flavonoids (10–11 mg QE/g extract), along with strong antioxidant activity, as determined by TEACABTS (198–206 mg TE/g), TEACCUPRAC (252–294 mg TE/g), and TEACORAC (603–697 mg TE/g) assays. Additionally, the sun protection factor (SPF) was evaluated at different concentrations. The results indicated that all extracts prepared from M. trifoliata leaves exhibited SPF > 6 [2] at ≥ 0.25 mg/ml concentration, demonstrating their potential for use in cosmetic and phytodermatological product formulations, particularly as natural UV-protective agents in sunscreens and skincare products.