title: Modulation of hepatic drug metabolizing enzymes and oxidative status by rooibos (Aspalathus linearis) and Honeybush (Cyclopia intermedia), green and black (Camellia sinensis) teas in rats.
abstract: Rooibos and honeybush teas significantly (P < 0.05) enhanced the activity of cytosolic glutathione S-transferase alpha. A significant (P < 0.05) to marginal (P < 0.1) increase in the activity of the microsomal UDP-glucuronosyl transferase was obtained with unprocessed rooibos and honeybush teas, respectively. Oxidized glutathione (GSSG) levels were significantly (P < 0.05) reduced in the liver of all tea treated rats while reduced glutathione (GSH) was markedly increased in the liver of the herbal tea treated rats. These changes resulted in a significant (P < 0.05) increase in the GSH/GSSG ratio by the unprocessed, processed rooibos and unprocessed honeybush teas. Green and black teas markedly to significantly decreased the oxygen radical absorbance capacity in liver homogenates, respectively. Modulation of phase II drug metabolizing enzymes and oxidative status in the liver may be important events in the protection against adverse effects related to mutagenesis and oxidative damage.
authors.affiliation: PROMEC Unit, Medical Research Council, P.O. Box 19070, Tygerberg, 7505 South Africa. jeanine.marnewick@mrc.ac.za
authors.forename: Jeanine L
authors.initials: JL
authors.lastname: Marnewick
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Joubert
authors.forename: Pieter
authors.initials: P
authors.lastname: Swart
authors.forename: Francois
authors.initials: F
authors.lastname: Van Der Westhuizen
authors.forename: Wentzel C
authors.initials: WC
authors.lastname: Gelderblom
mesh_terms: D000818:Animals; D036903:Aspalathus / Q000737:chemistry*; D001628:Beverages / Q000032:analysis*; D028241:Camellia sinensis / Q000737:chemistry*; D007887:Fabaceae / Q000737:chemistry*; D005419:Flavonoids / Q000032:analysis; D014453:Glucuronosyltransferase / Q000378:metabolism; D005978:Glutathione / Q000032:analysis / Q000737:chemistry; D005982:Glutathione Transferase / Q000378:metabolism; D008099:Liver / Q000737:chemistry / Q000201:enzymology*; D008297:Male; D010084:Oxidation-Reduction; D010636:Phenols / Q000008:administration & dosage / Q000032:analysis; D051381:Rats; D011916:Rats, Inbred F344; D017382:Reactive Oxygen Species / Q000737:chemistry; D013662:Tea / Q000737:chemistry*
chemical_list: D005419:Flavonoids; D010636:Phenols; D017382:Reactive Oxygen Species; D013662:Tea; D014453:Glucuronosyltransferase; D005982:Glutathione Transferase; D005978:Glutathione