The role of plant processing for human the cancer prevention preventive potential by of Ethiopian kale (Brassica carinata)
Background: Ethiopian kale (Brassica carinata) is a horticulturally important crop used as leafy
vegetable in large parts of East and Southern Africa. The leaves are reported to contain high
concentrations of health-promoting secondary plant metabolites. However, scientific knowledge
on their health benefits is scarce.
Objective: This study aimed to determine the cancer preventive potential of B. carinata using a
human liver in vitro model focusing on processing effects on the pattern of secondary plant
metabolites and bioactivity.
Design: B. carinata was cultivated under controlled conditions and differentially processed (raw,
fermented, or cooked) after harvesting. Human liver cancer cells (HepG2) were treated with
ethanolic extracts of raw or processed B. carinata leaves and analyzed for their anti-genotoxic,
anti-oxidant, and cytostatic potential. Chemical analyses were carried out on glucosinolates
including breakdown products, phenolic compounds, carotenoids, and chlorophyll content.
Results: Pre-treatment with B. carinata extracts concentration dependently reduced aflatoxininduced
DNA damage in the Comet assay, reduced the production of reactive oxygen species as
determined by electron paramagnetic resonance spectroscopy, and induced Nrf2-mediated gene
expression. Increasing extract concentrations also promoted cytostasis. Processing had a significant
effect on the content of secondary plant metabolites. However, different processing methodologies
did not dramatically decrease bioactivity, but enhanced the protective effect in some
of the endpoints studied.
Conclusion: Our findings highlight the cancer preventive potential of B. carinata as indicated by
the protection of human liver cells against aflatoxin in vitro. In general, consumption of B. carinata
should be encouraged as part of chemopreventive measures to combat prevalence of aflatoxininduced
Odongoa, G.A.; Schlotz, N.; Herz, C.; Hanschen, F.S.; Baldermann, S.; Neugart, S.; Trierweiler, B.; Frommherz, L.; Franz, C.M.A.P.; Ngwene, B.; Luvonga, A.W.; Schreiner, M.; Rohn, S.; Lamy, E. 2017. The role of plant processing for human the cancer prevention preventive potential by of Ethiopian kale (Brassica carinata). Food & Nutrition Research 61, 1-11.