Comparative Study of the Antioxidant Constituents, Activities and the GC-MS Quantification and Identification of Fatty Acids of Four Selected Helichrysum Species

Kolajo Adedamola Akinyede; Gail Denise Hughes; Okobi Eko Ekpo; Oluwafemi Omoniyi Oguntibeju

doi:10.3390/plants11080998

Comparative Study of the Antioxidant Constituents, Activities and the GC-MS Quantification and Identification of Fatty Acids of Four Selected Helichrysum Species

Plants (Basel). 2022 Apr 7;11(8):998. doi: 10.3390/plants11080998.

Authors

Kolajo Adedamola Akinyede^{1

2}, Gail Denise Hughes¹, Okobi Eko Ekpo^{1

3}, Oluwafemi Omoniyi Oguntibeju⁴

Affiliations

¹ Department of Medical Bioscience, University of the Western Cape, Bellville, Cape Town 7530, South Africa.
² Department of Science Technology, Biochemistry Unit, The Federal Polytechnic P.M.B.5351, Ado Ekiti 360231, Nigeria.
³ Department of Anatomy and Cellular Biology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi P.O. Box 127788, United Arab Emirates.
⁴ Phytomedicine and Phytochemistry Group, Department of Biomedical Sciences, Faculty of Health and Wellness Sciences, Cape Peninsula University of Technology, P.O. Box 1906, Bellville, Cape Town 7535, South Africa.

Abstract

Helichrysum Mill. (Asteraceae) is a plant genus comprising distinctively of aromatic plants of about 500-600 species. Since most of these plants have not been previously studied, extensive profiling helps to validate their folkloric uses and determine their potential value as sources of plant-derived drug candidates. This study, therefore, aims to investigate the antioxidant activity (DPPH, NO, FRAP); total antioxidant capacity, total phenolic, total flavonoid, and fatty acid compositions of the aqueous acetone extracts from four Helichrysum plants namely, Helichrysum pandurifolium, Helichrysum foetidum, Helichrysum petiolare, and Helichrysum cymocum. The results obtained showed that the H. cymocum extract had the best DPPH radical scavenging activity (IC₅₀ = 11.85 ± 3.20 µg/mL) and H. petiolare extract had the best nitric oxide scavenging activity (IC₅₀ = 20.81 ± 3.73 µg/mL), while H. pandurifolium Schrank extract (0.636 ± 0.005 µg/mL) demonstrated the best ferrous reducing power, all of which are comparable with results from ascorbic acid used as the standard. The IC₅₀ values of the radical scavenging activity ranged from 11.85-41.13 µg/mL (DPPH), 20.81-36.19 µg/mL (NO), and 0.505-0.636 µg/mL (FRAP), for all the plants studied. The H. petiolare has the highest total antioxidant capacity (48.50 ± 1.55 mg/g), highest total phenolic content (54.69 ± 0.23 mg/g), and highest total flavonoid content (56.19 ± 1.01 mg/g) compared with other species. The fatty acid methyl esters were analysed using gas chromatography-mass spectrometry (GC-MS). The results obtained showed variations in the fatty acid composition of the plant extracts, with H. petiolare having the highest saturated fatty acid (SFA) content (7184 µg/g) and polyunsaturated fatty acid (PUFA) content (7005.5 µg/g). In addition, H. foetidum had the highest monounsaturated fatty acid (MUFA) content (1150.3 µg/g), while H. cymocum had the highest PUFA:SFA ratio of 1.202. In conclusion, the findings from this study revealed that H. pandurifolium Schrank, H. foetidum, H. petiolare, and H. cymocum are repositories of natural bioactive compounds with potential health-promoting benefits that need to be investigated, for both their antioxidant activity in a number of disease conditions and for further exploration in drug discovery and development projects.

Keywords: DPPH radical scavenging; antioxidant; drug discovery and development; fatty acids; helichrysum; total phenolics.