Modulating effects of rooibos and honeybush herbal teas on the development of esophageal papillomas in rats
Date
2011
Authors
Sissing L.
Marnewick J.
De Kock M.
Swanevelder S.
Joubert E.
Gelderblom W.
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Widespread consumption of herbal teas has stimulated interest in their role as cancer preventive agents. The present investigation monitored the modulation of methylbenzylnitrosamine (MBN)-induced esophageal squamous cell carcinogenesis by rooibos (Aspalathus linearis) and honeybush (Cyclopia intermedia) herbal and Camellia sinensis teas in male F344 rats. The tumor multiplicity was significantly (P < 0.05) inhibited by unfermented honeybush (45.5%), green (50%), and black (36%) teas, while the other teas exhibited weaker effects (<30% inhibition). The mean total papilloma size was reduced by unfermented rooibos (87%), unfermented honeybush (94%), and fermented honeybush (74%) due to the absence of large papillomas (>10 mm3). Reduction of the mean total papilloma number correlated with the total polyphenol (TPP) (r = 0.79; P < 0.02) and flavanol/proanthocyanidin (FLAVA) (r = 0.89; P < 0.008) intake (mg/100 g body weight) of the teas and the FLAVA (r = 0.89; P < 0.04) and flavonol/flavones/xanthones (r = 0.99; P < 0.002) intake when considering only the herbal teas. A daily TPP intake threshold of 7 mg/100 g body weight existed below where no inhibition of papilloma development was observed. Fermentation of herbal teas reduced the inhibitory effects on papilloma development associated with a reduction in the polyphenolic constituents. The inhibitory effect of herbal teas on papilloma development is associated with different flavonoid subgroups and/or combination thereof. Copyright © 2011, Taylor & Francis Group, LLC.
Description
Keywords
Citation
Nutrition and Cancer
63
4
http://www.scopus.com/inward/record.url?eid=2-s2.0-79957594215&partnerID=40&md5=c5a06fd94886aff74b07a729e6402a22
63
4
http://www.scopus.com/inward/record.url?eid=2-s2.0-79957594215&partnerID=40&md5=c5a06fd94886aff74b07a729e6402a22