title: Modulating effects of rooibos and honeybush herbal teas on the development of esophageal papillomas in rats.
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 mm(3)). 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.
authors.affiliation: PROMEC Unit, Medical Research Council, Tygerberg, South Africa.
authors.forename: Linda
authors.initials: L
authors.lastname: Sissing
authors.forename: Jeanine
authors.initials: J
authors.lastname: Marnewick
authors.forename: Maryna
authors.initials: M
authors.lastname: de Kock
authors.forename: Sonja
authors.initials: S
authors.lastname: Swanevelder
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Joubert
authors.forename: Wentzel
authors.initials: W
authors.lastname: Gelderblom
mesh_terms: D000818:Animals; D016587:Antimutagenic Agents / Q000494:pharmacology; D036903:Aspalathus / Q000737:chemistry*; D001628:Beverages; D028241:Camellia sinensis / Q000737:chemistry; D047188:Chalcones / Q000494:pharmacology; D053998:Cyclopia Plant / Q000737:chemistry*; D004128:Dimethylnitrosamine / Q000031:analogs & derivatives / Q000633:toxicity; D004935:Esophageal Diseases / Q000139:chemically induced / Q000188:drug therapy*; D005285:Fermentation; D047309:Flavones / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D008297:Male; D009374:Neoplasms, Experimental / Q000139:chemically induced / Q000188:drug therapy; D010212:Papilloma / Q000139:chemically induced / Q000188:drug therapy*; D010636:Phenols / Q000494:pharmacology; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology; D059808:Polyphenols; D051381:Rats; D011916:Rats, Inbred F344; D044004:Xanthones / Q000494:pharmacology
chemical_list: D016587:Antimutagenic Agents; D047188:Chalcones; D047309:Flavones; D005419:Flavonoids; D010636:Phenols; D010936:Plant Extracts; D059808:Polyphenols; D044004:Xanthones; C517016:aspalathin; C013592:mangiferin; C014707:nitrosobenzylmethylamine; D004128:Dimethylnitrosamine