Anti-inflammatory effects of Aspalathus linearis and Cyclopia spp. extracts in a UVB/keratinocyte (HaCaT) model utilising interleukin-1α accumulation as biomarker
Date
2016-10-02
Journal Title
Journal ISSN
Volume Title
Publisher
MDPI
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 of C. 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.
Description
CITATION: Magcwebeba, T. et al. 2016. Anti-inflammatory effects of Aspalathus linearis and Cyclopia spp. extracts in a UVB/keratinocyte (HaCaT) model utilising interleukin-1α accumulation as biomarker. Molecules, 21(10):1323, doi:10.3390/molecules21101323.
The original publication is available at http://www.mdpi.com/journal/molecules
The original publication is available at http://www.mdpi.com/journal/molecules
Keywords
Herbal tea, Aspalathus linearis, Rooibos tea -- Therapeutic use, Ultraviolet radiation, Honeybush tea -- Therapeutic use, Interleukins, Skin -- Cancer
Citation
Magcwebeba, T. et al. 2016. Anti-inflammatory effects of Aspalathus linearis and Cyclopia spp. extracts in a UVB/keratinocyte (HaCaT) model utilising interleukin-1α accumulation as biomarker. Molecules, 21(10):1323, doi:10.3390/molecules21101323.