title: Anti-Inflammatory Effects of Aspalathus linearis and Cyclopia spp. Extracts in a UVB/Keratinocyte (HaCaT) Model Utilising Interleukin-1α Accumulation as Biomarker.
abstract: Ultraviolet B (UVB) radiation is one of the major predisposing risk factors of skin cancer. The anticancer and photoprotective effects of unoxidized rooibos (Aspalathus linearis) and honeybush (Cyclopia) herbal teas, containing high levels of dihydrochalones and xanthones, respectively, have been demonstrated in skin cancer models in vivo. In the current study, the anti-inflammatory effects of methanol and aqueous extracts of these herbal teas were investigated in a UVB/HaCaT keratinocyte model with intracellular interleukin-1α (icIL-1α) accumulation as a biomarker. Extracts of green tea (Camellia sinensis) served as benchmark. Both extracts of green tea and rooibos, as well as the aqueous extract ofC. intermedia, enhanced UVB-induced inhibition of cell viability, proliferation and induction of apoptosis, facilitating the removal of icIL-1α. The underlying mechanisms may involve mitochondrial dysfunction exhibiting pro-oxidant responses via polyphenol-iron interactions. The methanol extracts of honeybush, however, protected against UVB-induced reduction of cell growth parameters, presumably via antioxidant mechanisms that prevented the removal of highly inflamed icIL-1α-containing keratinocytes via apoptosis. The dual antioxidant and/or pro-oxidant role of the polyphenolic herbal tea constituents should be considered in developing preventive strategies against UVB-induced skin carcinogenesis. The indirect removal of UVB damaged keratinocytes by herbal tea extracts via apoptosis may find application in the prevention of photo-induced inflammation.
authors.affiliation: Department of Biochemistry, Stellenbosch University, Private Bag X1, Matieland (Stellenbosch) 7602, South Africa. tmagcwebeba@sun.ac.za.
authors.forename: Tandeka
authors.initials: T
authors.lastname: Magcwebeba
authors.affiliation: Department of Biochemistry, Stellenbosch University, Private Bag X1, Matieland (Stellenbosch) 7602, South Africa. pswart@sun.ac.za.
authors.forename: Pieter
authors.initials: P
authors.lastname: Swart
authors.affiliation: Biostatistics Unit, South African Medical Research Council, P.O. Box 19070, Tygerberg 7505, South Africa. sonja.swanevelder@mrc.ac.za.
authors.forename: Sonja
authors.initials: S
authors.lastname: Swanevelder
authors.affiliation: Post-Harvest and Wine Technology Division, Agricultural Research Council (Infruitec-Nietvoorbij), Private Bag X5026, Stellenbosch 7599, South Africa. joubertL@arc.agric.za.|Department of Food Science, Stellenbosch University, Private Bag X1, Matieland (Stellenbosch) 7602, South Africa. joubertL@arc.agric.za.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Joubert
authors.affiliation: Department of Biochemistry, Stellenbosch University, Private Bag X1, Matieland (Stellenbosch) 7602, South Africa. gelderblomw@cput.ac.za.|Institute of Biomedical and Microbial Biotechnology, Cape Peninsula University of Technology, P.O. Box 1906, Bellville 7535, South Africa. gelderblomw@cput.ac.za.
authors.forename: Wentzel
authors.initials: W
authors.lastname: Gelderblom
mesh_terms: D000893:Anti-Inflammatory Agents / Q000737:chemistry / Q000494:pharmacology*; D036903:Aspalathus / Q000737:chemistry; D015415:Biomarkers / Q000378:metabolism; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D053998:Cyclopia Plant / Q000737:chemistry; D007887:Fabaceae / Q000737:chemistry*; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D053582:Interleukin-1alpha / Q000378:metabolism*; D015603:Keratinocytes / Q000187:drug effects* / Q000528:radiation effects*; D008954:Models, Biological; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D013662:Tea / Q000737:chemistry; D000069459:Teas, Herbal / Q000032:analysis
chemical_list: D000893:Anti-Inflammatory Agents; D015415:Biomarkers; C508584:IL1A protein, human; D053582:Interleukin-1alpha; D010936:Plant Extracts; D013662:Tea; D000069459:Teas, Herbal
keywords: UVB irradiation; anti-inflammatory effects; antioxidants; dihydrochalcones; flavanones; herbal tea polyphenols; xanthones