Phytochemical characterization and antioxidant activity of Hypericum perforatum L.

Abstract

Background: In recent years, global interest in naturally occurring antioxidants has surged, primarily driven by concerns regarding the potential toxicity and adverse side effects associated with synthetic antioxidants. Medicinal plants, characterized by their complex phytochemical profiles, have emerged as safe and effective alternatives for managing oxidative stress. Among these, Hypericum perforatum L. (common St. John's wort) stands out due to its diverse bioactive composition, including flavonoids, phenolic acids, naphthodianthrones (such as hypericin and pseudohypericin), and phloroglucinol derivatives like hyperforin. These constituents are known to possess significant antioxidant, anti-inflammatory, and neuroprotective properties. Despite extensive in vitro research, there remains a critical gap in our understanding of how these compounds affect oxidative markers in vital organs in vivo. Oxidative stress is a fundamental pathological factor in many chronic diseases, necessitating further research into the therapeutic efficacy of H. perforatum in living biological systems.  This study aimed to perform a detailed phytochemical profiling of Hypericum perforatum L. extract and to evaluate its antioxidant capacity in vivo, focusing specifically on its protective effects against lipid peroxidation in hepatic and cerebral tissues. Methods: The ethanol extract was derived from the aerial parts of Hypericum perforatum L. collected in Kotayk Province, Armenia. Phytochemical characterization was conducted using high-performance liquid chromatography coupled with mass spectrometry. The in vivo antioxidant activity was assessed using adult outbred male albino rats weighing 180–200g. The study measured malondialdehyde levels – a recognized marker of lipid peroxidation – in the liver and brain tissues following a seven-day regimen of oral administration of the extract at varying doses. Results: The results demonstrated a significant reduction in malondialdehyde levels in both tissues compared with the control group. This reduction indicates a potent inhibitory effect on lipid peroxidation. Notably, the protective effect was more pronounced in the liver than in the brain, reflecting differences in tissue-specific metabolism and antioxidant defense capacity. These findings strongly support the cytoprotective potential of the extract, likely mediated by direct free radical scavenging and modulation of intracellular antioxidant pathways. Conclusions: H. perforatum L. represents a rich source of bioactive compounds with substantial antioxidant capacity. The study confirms its efficacy in reducing oxidative stress in vivo, positioning the extract as a highly promising natural agent for the development of functional foods and therapeutic strategies aimed at preventing and managing oxidative stress-related pathologies.  Novelty of the Study: The novelty of the present study lies in the phytochemical characterization of Hypericum perforatum collected in Armenia and the in vivo evaluation of its antioxidant activity in different tissues. The study combines UPLC-QToF-MS profiling with the assessment of lipid peroxidation in both liver and brain tissues following oral administration of the extract at different doses. The findings provide new regional data on Armenian H. perforatum and demonstrate tissue-specific differences in the antioxidant response, contributing to a better understanding of its potential as a source of bioactive compounds for functional food applications. Keywords: Hypericum perforatum, LC-MS, antioxidant activity, MDA, flavonoids, oxidative stress, functional food