Chemical Composition and Biological Activity of <i>Hypericum</i> Species—<i>H. hirsutum</i>, <i>H. barbatum</i>, <i>H. rochelii</i>

Abstract

St. John’s wort (Hypericum perforatum, Hypericaceae) is the most well-known species in the genus Hypericum, which comprises several hundred species. This study investigates the biological and phytochemical potential of the under-researched Hypericum species, H. hirsutum, H. barbatum, and H. rochelii. A high level of similarity between the chemical profiles of H. hirsutum and H. barbatum and the official source of the herbal drug (H. perforatum) was shown, but a higher content of quercetin and rutin was also found in all three evaluated species (116–230 µg/g dry herb). The highest amount of phenolics (195 mg GAE/g) was recorded in H. hirsutum extract, while the highest amount of flavonoids (47 mg QE/g) was recorded in H. barbatum extract. The evaluated species were excellent scavengers of DPPH, OH, and NO radicals, as well as strong ferric ion reducers in the FRAP test. Prominent monoamine oxidase A and α-glucosidase inhibition was observed, compared to modest inhibition of monoamine oxidase B, α-amylase, and acetylcholinesterase. High activity against Gram-positive MRSA S. aureus was demonstrated for the tested species, with MIC/MBC values recorded at 12.5 µg/mL. Antifungal activity against Candida strains was not observed. The obtained results emphasize the need for further investigation of species of the genus Hypericum to discover potentially new sources of biologically active compounds.

Keywords

• <i>Hypericum</i>
• monoamine oxidase A
• α-glucosidase
• antimicrobial
• antioxidants