[Inhibitory effects of tea polyphenols and vitamin C on lipid peroxidation induced by FeSO4- cysteine in isolated human plasma and carbon tetrachloride-induced liver free radical injury in mice].
OBJECTIVE
To investigate the inhibitory effects of tea polyphenols (TP) and Vitamin C (Vit C) on FeSO4-cysteine induced lipid peroxidation in isolated human plasma and carbon tetrachloride (CCl4) induced liver free radical injury in mice.


METHODS
The experiment included two parts: (1) In FeSO4-cysteine induced lipid peroxidation system of isolated human plasma, malondialdehyde (MDA) content was detected after administration of different concentrations of TP (0.3 ~ 8.1 mg/L, as C ~ F group) and Vit C (3 ~ 81 mg/L, as G ~ J group) respectively; (2) Thirty-six male Kunming mice were randomly divided into four groups: control group (A), CCl4 damage group (B), TP protection group (C) and Vit C protection group (D). TP or Vit C (100 mg/kg) was given orally to group C and D respectively, while the same volume of distilled water was given to the other two groups one time every day, continued for three days. Twelve hours after the final treatment, CCl4 (230 mg/kg) was given orally to group B ~ D. Thirty six hours later, all the mice were decapitated and liver homogenate were prepared for measuring MDA content.


RESULTS
In FeSO4-cysteine induced lipid peroxidation in isolated human plasma, the inhibitory rate of TP (0.3 ~ 8.1 mg/L) was 30.7%, 32.0%, 46.9% and 59.7 %, and the inhibitory rate of Vit C (3 ~ 8.1 mg/L) was 8.3%, 41.4%, 47.7% and 52.7% for various dosages. In the CCl4 induced liver free radical injury system, the inhibitory rate of the same dosage of TP and Vit C was 45.2%, 42.8% respectively.


CONCLUSIONS
TP (0.3 ~ 8.1 mg/L) and Vit C (9 ~ 81 mg/L) had inhibited lipid peroxidation induced by FeSO4-cysteine in isolated human plasma significantly, and the inhibitory effects of TP was superior to that of Vit C at the same dosages. The same dosage of TP and Vit C had remarkable inhibitory effects on the CCl4 induced liver free radical injury, but there was no significant difference between the two groups.
Zhang
Q J
QJ
Institute of Aviation Medicine, Beijing, China.
Li
T
T
Zhan
H
H
Xin
Y M
YM
D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology*; D002251:Carbon Tetrachloride / Q000633:toxicity; D003545:Cysteine / Q000633:toxicity; D004305:Dose-Response Relationship, Drug; D005296:Ferrous Compounds / Q000633:toxicity; D005419:Flavonoids; D005609:Free Radicals / Q000009:adverse effects; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects*; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D051379:Mice; D010636:Phenols / Q000032:analysis / Q000494:pharmacology*; D010949:Plasma / Q000187:drug effects* / Q000378:metabolism; D011108:Polymers / Q000032:analysis / Q000494:pharmacology*; D059808:Polyphenols; D013662:Tea / Q000737:chemistry*
D005296:Ferrous Compounds; D005419:Flavonoids; D005609:Free Radicals; D010636:Phenols; D011108:Polymers; D059808:Polyphenols; D013662:Tea; C020748:ferrous sulfate; D008315:Malondialdehyde; D002251:Carbon Tetrachloride; D003545:Cysteine; D001205:Ascorbic Acid