title: Inhibition of Oxidative Stress and Skin Aging-Related Enzymes by Prenylated Chalcones and Other Flavonoids from Helichrysum teretifolium.
abstract: Ten flavonoid-related structures viz. heliteretifolin (1), isoxanthohumol (2), 2',4',6'-trihydroxy-3'-prenylchalcone (3), isoglabranin (4), glabranin (5), 7-methoxy-isoglabranin (6), quercetin (7), 4'-methoxyquercetin (8), 4'-methoxykaempferol (9) and mosloflavone (10) were isolated from a H. teretifolium methanolic extract and identified. One of them (compound 1) is reported for the first time from a natural source, while compounds 6, 8-10 were isolated for the first time from the genus Helichrysum. The total extract of H. teretifolium showed potent antioxidant activity. When tested for total antioxidant capacity compound 3 possesses moderate biological activity compared to 2, which displayed some of the highest TEAC values (4529.01 ± 2.44; 4170.66 ± 6.72) µM TE/g, respectively. Compounds 7 and 8 demonstrated the highest inhibitory activities on Fe2+-induced lipid peroxidation (IC50 = 2.931; 6.449 µg/mL); tyrosinase (8.092; 27.573) and elastase (43.342; 86.548). Additionally, the total antioxidant capacities measured as FRAP (4816.31 ± 7.42; 3584.17 ± 0.54) µM AAE/g, and ORAC for hydroxyl radical (7.265 ± 0.71; 6.779 ± 3.40) × 106 and peroxyl radical (17.836 ± 2.90; 12.545 ± 5.07) × 103 µM TE/g were also observed for compounds 7 and 8, respectively. In conclusion, H. teretifolium total extract represents a rich source of bioactive constituents with potent antioxidant and moderate anti-tyrosinase and anti-elastase activities that can help to avert accumulation of free radicals in the body, and could therefore be good candidates for the prevention and/or treatment of skin-related conditions, such as aging. This is the first scientific report on the chemical and biological profile of H. teretifolium.
authors.affiliation: Chemistry Department, University of Western Cape, Private Bag X17, Bellville 7535, South Africa. 3318925@myuwc.ac.za.
authors.forename: Olugbenga K
authors.initials: OK
authors.lastname: Popoola
authors.affiliation: Oxidative Stress Research Centre, Institute of Biomedical and Microbial Biotechnology, Faculty of Health and Wellness Sciences, Cape Peninsula University of Technology, P O BOX 1906, Bellville 7535, South Africa. MarnewickJ@cput.ac.za.
authors.forename: Jeanine L
authors.initials: JL
authors.lastname: Marnewick
authors.affiliation: Oxidative Stress Research Centre, Institute of Biomedical and Microbial Biotechnology, Faculty of Health and Wellness Sciences, Cape Peninsula University of Technology, P O BOX 1906, Bellville 7535, South Africa. rautenbachf@cput.ac.za.
authors.forename: Fanie
authors.initials: F
authors.lastname: Rautenbach
authors.affiliation: Chemistry Department, University of Western Cape, Private Bag X17, Bellville 7535, South Africa. Fameer@uwc.ac.za.
authors.forename: Farouk
authors.initials: F
authors.lastname: Ameer
authors.affiliation: Chemistry Department, University of Western Cape, Private Bag X17, Bellville 7535, South Africa. eiwuoha@uwc.ac.za.
authors.forename: Emmanuel I
authors.initials: EI
authors.lastname: Iwuoha
authors.affiliation: Chemistry Department, University of Western Cape, Private Bag X17, Bellville 7535, South Africa. ahmohammed@uwc.ac.za.
authors.forename: Ahmed A
authors.initials: AA
authors.lastname: Hussein
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000737:chemistry* / Q000494:pharmacology; D047188:Chalcones / Q000737:chemistry / Q000494:pharmacology*; D005419:Flavonoids / Q000737:chemistry / Q000494:pharmacology*; D036562:Helichrysum / Q000737:chemistry*; D015227:Lipid Peroxidation / Q000187:drug effects; D015394:Molecular Structure; D014442:Monophenol Monooxygenase / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D010196:Pancreatic Elastase / Q000378:metabolism; D010936:Plant Extracts / Q000737:chemistry; D054876:Prenylation; D051381:Rats; D015595:Skin Aging / Q000187:drug effects
chemical_list: D000975:Antioxidants; D047188:Chalcones; D005419:Flavonoids; D010936:Plant Extracts; D014442:Monophenol Monooxygenase; D010196:Pancreatic Elastase