Omega-3 content, antimicrobial and antioxidant activities of hexanic extract from seed and leaf of Hypericum scabrum from northwestern Iran

Abstract

The hexane extracts of leaf and seed of Hypericum scabrum which were collected from northwestern Iran were obtained by Soxhlet apparatus. The fatty acids were derived to methyl esters and determined by gas chromatography/flame ionization detector (GC/FID) and gas chromatography/mass spectrometry (GC/MS) systems. The hexanic extract from the seed and leaf contained ω-3 (37.6 and 43.2% respectively). The other main components of the leaf and seed extracts were ω-6 (3.4 and 6.9%), Bis (2ethylhexyl) phthalate (5.8 and 35.7%) and Nonacosane (3.7 and 3.9%) respectively. The hexane extracts of leaf and seed from H. scabrum detected as an important source of ω-3 and ω-6 compounds among several Hypericum species. The antimicrobial activity of the extracts of both samples were determined against seven Gram-positive and Gram-negative bacteria (Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae) as well as three fungi (Candida albicans, Saccharomyces cerevisiae and Aspergillus niger). The bioassay showed that the oil exhibited moderate antimicrobial activity. The antioxidant activity of those hexane extracts was evaluated by 1, 1-diphenyl-2-picrylhydrazyl (DPPH) method. The results indicate that hexane extracts from different parts of H. scabrum possess considerable antioxidant activity. The highest radical scavenging activity was detected in seed (IC50 = 135 μg/ml). This study reveals that the hexanic extracts of leaf and seed from this plant are attractive sources of ω-3 and other fatty acid components especially the essential ones as well as of effective natural antioxidants.